WorldWideScience

Sample records for ca3 dendritic retraction

  1. Centella asiatica (L. Leaf Extract Treatment During the Growth Spurt Period Enhances Hippocampal CA3 Neuronal Dendritic Arborization in Rats

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    K. G. Mohandas Rao

    2006-01-01

    Full Text Available Centella asiatica (CeA is a creeping plant growing in damp places in India and other Asian countries. The leaves of CeA are used for memory enhancement in the Ayurvedic system of medicine, an alternative system of medicine in India. In this study, we have investigated the effect during the rat growth spurt period of CeA fresh leaf extract treatment on the dendritic morphology of hippocampal CA3 neurons, one of the regions of the brain concerned with learning and memory. Neonatal rat pups (7 days old were fed with 2, 4 or 6 ml kg−1 body weight of fresh leaf extract of CeA for 2, 4 or 6 weeks. After the treatment period the rats were killed, their brains were removed and the hippocampal neurons were impregnated with silver nitrate (Golgi staining. Hippocampal CA3 neurons were traced using a camera lucida, and dendritic branching points (a measure of dendritic arborization and intersections (a measure of dendritic length were quantified. These data were compared with data for age-matched control rats. The results showed a significant increase in the dendritic length (intersections and dendritic branching points along the length of both apical and basal dendrites in rats treated with 4 and 6 ml kg−1 body weight per day of CeA for longer periods of time (i.e. 4 and 6 weeks. We conclude that the constituents/active principles present in CeA fresh leaf extract have a neuronal dendritic growth stimulating property; hence, the extract can be used for enhancing neuronal dendrites in stress and neurodegenerative and memory disorders.

  2. Brain-derived neurotrophic factor prevents dendritic retraction of adult mouse retinal ganglion cells.

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    Binley, Kate E; Ng, Wai S; Barde, Yves-Alain; Song, Bing; Morgan, James E

    2016-08-01

    We used cultured adult mouse retinae as a model system to follow and quantify the retraction of dendrites using diolistic labelling of retinal ganglion cells (RGCs) following explantation. Cell death was monitored in parallel by nuclear staining as 'labelling' with RGC and apoptotic markers was inconsistent and exceedingly difficult to quantify reliably. Nuclear staining allowed us to delineate a lengthy time window during which dendrite retraction can be monitored in the absence of RGC death. The addition of brain-derived neurotrophic factor (BDNF) produced a marked reduction in dendritic degeneration, even when application was delayed for 3 days after retinal explantation. These results suggest that the delayed addition of trophic factors may be functionally beneficial before the loss of cell bodies in the course of conditions such as glaucoma. © 2016 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  3. Toxoplasma gondii infection induces dendritic retraction in basolateral amygdala accompanied by reduced corticosterone secretion

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    Rupshi Mitra

    2013-03-01

    Pathological anxiety is thought to reflect a maladaptive state characterized by exaggerated fear. Naturally occurring perturbations that reduce fear can be crucial in the search for new treatments. The protozoan parasite Toxoplasma gondii invades rat brain and removes the fear that rats have of cat odors, a change believed to be parasitic manipulation of host behavior aimed at increasing parasite transmission. It is likely that mechanisms employed by T. gondii can be used as a heuristic tool to understand possible means of fear reduction in clinical settings. Male Long-Evans rats were infected with T. gondii and compared with sham-infected animals 8 weeks after infection. The amount of circulating plasma corticosterone and dendritic arborization of basolateral amygdala principal neurons were quantified. Previous studies have shown that corticosterone, acting within the basolateral amygdala, enhances the fear response to environmental stimuli. Here we show that T. gondii infection causes a dendritic retraction in basolateral amygdala neurons. Such dendritic retraction is accompanied by lower amounts of circulating corticosterone, both at baseline and when induced by an aversive cat odor. The concerted effects of parasitism on two pivotal physiological nodes of the fear response provide an animal model relevant to interactions between stress hormones and amygdalar plasticity.

  4. Retracted

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    Zhu, Yongjian; Luan, Zhu; Yang, Qingguo; Li, Dashan; Lu, Wei; Liu, Liren

    2007-04-01

    This article has been retracted at the request of the Editor-in-Chief and Author. Please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). Reason: A significant error in calculation was discovered after repeating the VC programming presented in the paperE In the previous programming, the authors neglected to include a term in the reliability function formula due to a spelling mistake, which will lead to a completely different result.

  5. Retraction.

    Science.gov (United States)

    2016-12-01

    This article corrects: Retracted: Three BUB1 and BUBR1/MAD3-related spindle assembly checkpoint proteins are required for accurate mitosis in Arabidopsis. New Phytologist 205: 202-215. Article first published online: 29 September 2014. This article has been retracted at the request of: Editor-in-Chief and Author 'Three BUB1 and BUBR1/MAD3-related spindle assembly checkpoint proteins are required for accurate mitosis in Arabidopsis', by Paganelli L, Caillaud M-C, Quentin M, Damiani I, Govetto B, Lecomte P, Karpov, PA, Abad P, Chabouté M-E and Favery B. The above article, first published online on Wiley Online Library (wileyonlinelibrary.com), and in New Phytologist 205: 202-215, has been retracted by agreement between the authors, the journal Editor-in-Chief, Alistair Hetherington, and John Wiley & Sons Ltd. Since publication of the above article, it has been brought to our attention that errors occurred in the construction of Figs 1 and 2(a); some components were inappropriately edited and duplicated, including the duplication and editing of images that first appeared in Caillaud et al. (2009), which were used by the authors as a basic template. Consequently, the integrity of the yeast two-hybrid experiments reported in the article is undermined, and, with agreement of all parties, the decision has been made to retract this article. We apologize for any inconvenience the publication of this work may have caused our readers. References Caillaud MC, Paganelli L, Lecomte P, Deslandes L, Quentin M, Pecrix Y, Le Bris M, Marfaing N, Abad P, Favery B. 2009. Spindle assembly checkpoint protein dynamics reveal conserved and unsuspected roles in plant cell division. PLoS One 4: e6757. Paganelli L, Caillaud M-C, Quentin M, Damiani I, Govetto B, Lecomte P, Karpov PA, Abad P, Chabouté M-E, Favery B. 2015. Three BUB1 and BUBR1/MAD3-related spindle assembly checkpoint proteins are required for accurate mitosis in Arabidopsis. New Phytologist 205: 202-215. © 2016 The Authors

  6. Retraction

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    Li JZ

    2016-02-01

    Full Text Available Li J-Z, Zhang Y, Wen B, Li M, Wang Y-J. Ability of PITX2 methylation to predict survival in patients with prostate cancer. OncoTargets Ther. 2015;8:3507–3512.Large sections of text in this paper have been reused, albeit with minimal re-wording, without citation back to the source:Li J-Z, Zhang Y, Wen B, Li M, and Wang Y-J have failed to provide any explanation for the unauthorised re-use of figures and tables from the 2014 publication, Vasiljevic N, Ahmad AS, Carter PD, Fisher G, Berney DM, Foster CS, Cuzick J, Lorincz AT. DNA methylation of PITX2 predicts poor survival in men with prostate cancer. Biomark Med. 2014;8(9:1143–1150. This retraction relates to this paper 

  7. Retraction

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    Gu J

    2016-02-01

    Full Text Available Gu J, Sun R, Shen S, Yu Z. The influence of TLR4 agonist lipopolysaccharides on hepatocellular carcinoma cells and the feasibility of its application in treating liver cancer. Onco Targets Ther. 2015;8:2215–2225.The first author (Junsheng Gu created an email address for Dr Yu without permission and used figures from a previously published paper: Lin A, Wang G, Zhao H, et al. TLR4 signaling promotes a COX-2/PGE2/STAT3 positive feedback loop in hepatocellular carcinoma (HCC cells. OncoImmunology. 2015: DOI:10.1080/2162402X.This was done without the knowledge, involvement, or permission of Dr Yu. This retraction relates to this paper

  8. Dendritic morphology and its effects on the amplitude and rise-time of synaptic signals in hippocampal CA3 pyramidal cells.

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    Henze, D A; Cameron, W E; Barrionuevo, G

    1996-06-03

    Detailed anatomical analysis and compartmental modeling techniques were used to study the impact of CA3b pyramidal cell dendritic morphology and hippocampal anatomy on the amplitude and time course of dendritic synaptic signals. We have used computer-aided tracing methods to obtain accurate three-dimensional representations of 8 CA3b pyramidal cells. The average total dendritic length was 6,332 +/- 1,029 microns and 5,062 +/- 1,397 microns for the apical and basilar arbors, respectively. These cells also exhibited a rough symmetry in their maximal transverse and septotemporal extents (311 +/- 84 microns and 269 +/- 106 microns). From the calculated volume of influence (the volume of the neuropil from which the dendritic structures can receive input), it was found that these cells show a limited symmetry between their proximal apical and basilar dendrites (2.1 +/- 1.2 x 10(6) microns 3 and 3.5 +/- 1.1 x 10(6) microns 3, respectively). Based upon these data, we propose that the geometry of these cells can be approximated by a combination of two cones for the apical arbor and a single cone for the basilar arbor. The reconstructed cells were used to build compartmental models and investigate the extent to which the cellular anatomy determines the efficiency with which dendritic synaptic signals are transferred to the soma. We found that slow, long lasting signals show only approximately a 50% attenuation when they occur in the most distal apical dendrites. However, synaptic transients similar to those seen in fast glutamatergic transmission are transferred much less efficiently, showing up to a 95% attenuation. The relationship between the distance along the dendrites and the observed attenuation for a transient is described simply by single exponential functions with parameters of 195 and 147 microns for the apical and basilar arbors respectively. In contrast, there is no simple relation that describes how a transient is attenuated with respect to these cells

  9. Erythropoietin prevents the effect of chronic restraint stress on the number of hippocampal CA3c dendritic terminals-relation to expression of genes involved in synaptic plasticity, angiogenesis, inflammation, and oxidative stress in male rats

    DEFF Research Database (Denmark)

    Aalling, Nadia; Hageman, Ida; Miskowiak, Kamilla

    2018-01-01

    Stress-induced allostatic load affects a variety of biological processes including synaptic plasticity, angiogenesis, oxidative stress, and inflammation in the brain, especially in the hippocampus. Erythropoietin (EPO) is a pleiotropic cytokine that has shown promising neuroprotective effects....... Recombinant human EPO is currently highlighted as a new candidate treatment for cognitive impairment in neuropsychiatric disorders. Because EPO enhances synaptic plasticity, attenuates oxidative stress, and inhibits generation of proinflammatory cytokines, EPO may be able to modulate the effects of stress...... in synaptic plasticity, angiogenesis, oxidative stress, and inflammation; and (iii) remodeling of the dendritic structure of the CA3c area of the hippocampus in male rats. As expected, chronic restraint stress lowered the number of CA3c apical dendritic terminals, and EPO treatment reversed this effect...

  10. RETRACTION NOTE

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    Biryukova NA.

    2017-03-01

    Full Text Available Retracted article: Biryukova NA. Otsenka lichnostnogo razvitiya vzroslogo kak indikator kachestva dopolnitelnogo obrazovaniya [Assessment of the adult’s personal development as an indicator of the quality of further education]. Integratsiya obrazovaniya = Integration of Education. 2016; 2(20:238-244. DOI: 10.15507/1991-9468.083.020.201602.238-244 (In Russian This article by Natalia A. Biryukova (Email: pedagog-108@marsu.ru has been retracted (i.e. withdrawn from the press by the editor with permission of the publisher. The reason for the article retraction is redundant publication: the author has published substantially the same article under the same title in the journal “Obrazovanie i nauka [Education and Science]” (2016; 6(135:141-151. The Editorial Board would like to extend its sincere apologies for any inconvenience this retraction may have caused.

  11. RETRACTED: Hydrological

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    S.S. Panhalkar

    2014-12-01

    This paper has been retracted upon the request of the author and the editor as the paper requires major revision. The author did not have the permission to publish part of the discharge information presented in Figures 10–13. The Publisher apologizes for any inconvenience this may cause.

  12. Retraction notice.

    Science.gov (United States)

    2017-02-01

    At the request of the Journal Editor and the Publisher, the following article has been retracted: Khani Jeihooni A, Hidarnia A, Hossein Kaveh M, Hajizadeh E and Askari A (2015) The effect of an education program based on health belief model and social cognitive theory in prevention of osteoporosis in women. Journal of Health Psychology. Epub ahead of print 8 September. DOI: 10.1177/1359105315603696.

  13. Airbag retraction

    Science.gov (United States)

    1997-01-01

    This image shows that the Mars Pathfinder airbags have been successfully retracted, allowing safe deployment of the rover ramps. The Sojourner rover, still in its deployed position, is at center image, and rocks are visible in the background. Mars Pathfinder landed successfully on the surface of Mars today at 10:07 a.m. PDT.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  14. Stress suppresses and learning induces plasticity in CA3 of rat hippocampus: a three-dimensional ultrastructural study of thorny excrescences and their postsynaptic densities.

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    Stewart, M G; Davies, H A; Sandi, C; Kraev, I V; Rogachevsky, V V; Peddie, C J; Rodriguez, J J; Cordero, M I; Donohue, H S; Gabbott, P L A; Popov, V I

    2005-01-01

    Chronic stress and spatial training have been proposed to affect hippocampal structure and function in opposite ways. Previous morphological studies that addressed structural changes after chronic restraint stress and spatial training were based on two-dimensional morphometry which does not allow a complete morphometric characterisation of synaptic features. Here, for the first time in such studies, we examined these issues by using three-dimensional (3-D) reconstructions of electron microscope images taken from thorny excrescences of hippocampal CA3 pyramidal cells. Ultrastructural alterations in postsynaptic densities (PSDs) of thorny excrescences receiving input from mossy fibre boutons were also determined, as were changes in numbers of multivesicular bodies (endosome-like structures) within thorny excrescences and dendrites. Quantitative 3-D data demonstrated retraction of thorny excrescences after chronic restraint stress which was reversed after water maze training, whilst water maze training alone increased thorny excrescence volume and number of thorns per thorny excrescence. PSD surface area was unaffected by restraint stress but water maze training increased both number and area of PSDs per thorny excrescence. In restrained rats that were water maze trained PSD volume and surface area increased significantly. The proportion of perforated PSDs almost doubled after water maze training and restraint stress. Numbers of endosome-like structures in thorny excrescences decreased after restraint stress and increased after water maze training. These findings demonstrate that circuits involving contacts between mossy fibre terminals and CA3 pyramidal cells at stratum lucidum level are affected conversely by water maze training and chronic stress, confirming the remarkable plasticity of CA3 dendrites. They provide a clear illustration of the structural modifications that occur after life experiences noted for their different impact on hippocampal function.

  15. Experimental diabetes in rats causes hippocampal dendritic and synaptic reorganization and increased glucocorticoid reactivity to stress

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    María Magariños, Ana; McEwen, Bruce S.

    2000-09-01

    We report that 9 d of uncontrolled experimental diabetes induced by streptozotocin (STZ) in rats is an endogenous chronic stressor that produces retraction and simplification of apical dendrites of hippocampal CA3 pyramidal neurons, an effect also observed in nondiabetic rats after 21 d of repeated restraint stress or chronic corticosterone (Cort) treatment. Diabetes also induces morphological changes in the presynaptic mossy fiber terminals (MFT) that form excitatory synaptic contacts with the proximal CA3 apical dendrites. One effect, synaptic vesicle depletion, occurs in diabetes as well as after repeated stress and Cort treatment. However, diabetes produced other MFT structural changes that differ qualitatively and quantitatively from other treatments. Furthermore, whereas 7 d of repeated stress was insufficient to produce dendritic or synaptic remodeling in nondiabetic rats, it potentiated both dendritic atrophy and MFT synaptic vesicle depletion in STZ rats. These changes occurred in concert with adrenal hypertrophy and elevated basal Cort release as well as hypersensitivity and defective shutoff of Cort secretion after stress. Thus, as an endogenous stressor, STZ diabetes not only accelerates the effects of exogenous stress to alter hippocampal morphology; it also produces structural changes that overlap only partially with those produced by stress and Cort in the nondiabetic state.

  16. Homeostatic maintenance in excitability of tree shrew hippocampal CA3 pyramidal neurons after chronic stress

    NARCIS (Netherlands)

    Kole, Maarten H. P.; Czéh, Boldizsár; Fuchs, Eberhard

    2004-01-01

    The experience of chronic stress induces a reversible regression of hippocampal CA3 apical neuron dendrites. Although such postsynaptic membrane reduction will obviously diminish the possibility of synaptic input, the consequences for the functional membrane properties of these cells are not well

  17. Preputial retraction in children

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    Agarwal Abhinav

    2005-01-01

    Full Text Available OBJECTIVE: The aim of the study was to assess preputial retractability in children at various ages. MATERIALS AND METHODS: Nine hundred and sixty boys attending the hospital were included in the study. Children with hypospadias or history of preputial manipulation were excluded. Preputial anatomy was studied and subjects were classified into five groups as described by Kayaba et al . RESULTS: The prepuce could not be retracted at all so as to make even the external urethral meatus visible in 61.4% children aged 0-6 months while this decreased to only 0.9% in children aged 10-12 years. At the other end of the spectrum, while prepuce could not be fully retracted in any child below 6 months, it could be done in about 60% in the age group of 10-12 years. CONCLUSION Preputial nonseparation is the major cause of preputial nonretraction in the pediatric age group. Prepuce spontaneously separates from the glans as age increases and true phimosis is rare in children. Surgical intervention should be avoided for nonseparation of prepuce.

  18. The Tie retraction syndrome.

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    Geerling, Gerd; Neppert, Birte; Hemmant, Bridget

    2012-12-01

    Tissue retraction is implicated in the pathogenesis of various ophthalmic disorders. Here we describe the clinical characteristics, epidemiology and pathophysiology of a form of retraction syndrome which - to the best of our knowledge - has not been reported in the ophthalmic literature so far. We have termed this condition - consisting of a slowly progressive pseudovertical shortening of tie length due to a horizontal extension of girth length - the "Tie retraction syndrome" (TRS). Other pathognomonic features include an increased tie tip to belt buckle distance and a prolapse of the subumbilical fat pad (SUFP). The syndrome has a clear male to female preponderance and shows an increasing incidence with age and income before tax. Based on a newly proposed grading scheme we discuss and illustrate the diagnosis as well as the medical and surgical management options of this abundant, but often undiagnosed condition. The authors have no explanation for the apparent lack of awareness for this widely preponderant syndrome and its severe cosmetically disfiguring potential. We thus would like to invite all fellow colleagues with expertise in the field to comment or present their views.

  19. Cell-intrinsic drivers of dendrite morphogenesis.

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    Puram, Sidharth V; Bonni, Azad

    2013-12-01

    The proper formation and morphogenesis of dendrites is fundamental to the establishment of neural circuits in the brain. Following cell cycle exit and migration, neurons undergo organized stages of dendrite morphogenesis, which include dendritic arbor growth and elaboration followed by retraction and pruning. Although these developmental stages were characterized over a century ago, molecular regulators of dendrite morphogenesis have only recently been defined. In particular, studies in Drosophila and mammalian neurons have identified numerous cell-intrinsic drivers of dendrite morphogenesis that include transcriptional regulators, cytoskeletal and motor proteins, secretory and endocytic pathways, cell cycle-regulated ubiquitin ligases, and components of other signaling cascades. Here, we review cell-intrinsic drivers of dendrite patterning and discuss how the characterization of such crucial regulators advances our understanding of normal brain development and pathogenesis of diverse cognitive disorders.

  20. Corrigendum / Erratum / Retraction

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    Istadi Istadi

    2017-05-01

    Full Text Available RETRACTION TO: Dhal, G.C., Dey, S., Prasad, R., Mohan, D. (2017. Simultaneous Elimination of Soot and NOX through Silver-Barium Based Catalytic Materials. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (1: 71-80 (doi:10.9767/bcrec.12.1.647.71-80 This article has been retracted by Publisher based on the following reason: Letter to Editor from Prof. James J. Spivey (Department of Chemical Engineering, Louisiana State University who reported that a comparison of this paper with a previously paper published in Catalysis Today (258 (2015 405-415, doi:10.1016/j.cattod.2015.02.024 shows significant duplication according to analysis by iThenticate shows 73% similarity, which is far more than acceptable. The authors have plagiarized part of the paper that had already published in [Catalysis Today (258 (2015 405-415, doi:10.1016/j.cattod.2015.02.024]. Based on clarification via email, Authors of the above paper have admitted their plagiarism to the previously published paper by Catalysis Today. Editor of Bulletin of Chemical Reaction Engineering & Catalysis acknowledged Prof. James J. Spivey due to the valuable Letter to Editor. One of the conditions of submission of a paper for publication in this journal is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

  1. Notice of retraction

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    Tunali S

    2010-08-01

    Full Text Available Dear Colleagues,It has recently been brought to my attention that the following case report by Padeyappanavar et al., which was published online in the International Journal of Anatomical Variations (IJAV on February 23rd, 2010 (Padeyappanavar KV, Kazi AK, Nagaleekar A, Kulkarni D, Kulkarni U, Hukkeri V. Elongated styloid process – report of three cases. International Journal of Anatomical Variations. 2010; 3: 30–32. [1], has already been published in the Journal of the Anatomical Society of India in June 2008 [2], and in the Al Ameen Journal of Medical Sciences in January 2010 [3]. The manuscript has been submitted to IJAV in July 30th, 2009, and accepted for publication in January 22nd, 2010. It is obvious that the manuscript has been submitted to IJAV one year later to its initial publication in the Journal of the Anatomical Society of India. The editorial office of IJAV has confirmed that this case report by Padeyappanavar et al. was a duplicate publication, violating the publication agreement of IJAV. The most important condition of submission of a manuscript for publication is explicit declaration of the authors that the paper has not been published or is not under consideration for publication in any other journal. As such this manuscript represents a severe abuse of the scientific publishing system.We immediately contacted the corresponding author (Dr. Kiran V. Padeyappanavar, Department of Anatomy, Belgaum Institute of Medical Sciences, India. E-mail: dr.kiranvp@gmail.com. Unfortunately, we could not get a satisfactory or logical explanation. Therefore, we hereby notice our readers that the paper by Padeyappanavar et al. [1] has been retracted.The institutions of the authors will also be advised via this notice of retraction.We deeply apologize to our readers and the international scientific community for this inconvenience that was totally occurred out of IJAV, and respectfully announce to the scientific world

  2. Age-Induced Loss of Mossy Fibre Synapses on CA3 Thorns in the CA3 Stratum Lucidum

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    Bunmi Ojo

    2013-01-01

    Full Text Available Advanced ageing is associated with hippocampal deterioration and mild cognitive decline. The hippocampal subregion CA3 stratum lucidum (CA3-SL receives neuronal inputs from the giant mossy fibre boutons of the dentate gyrus, but relatively little is known about the integrity of this synaptic connection with ageing. Using serial electron microscopy and unbiased stereology, we examined age-related changes in mossy fibre synapses on CA3 thorny excrescences within the CA3-SL of young adults (4-month-old, middle-aged (12-month-old, and old-aged (28-month-old Wistar rats. Our data show that while there is an increase in CA3 volume with ageing, there is a significant (40–45% reduction in synaptic density within the CA3-SL of 12- and 28-month-old animals compared with 4-month-old animals. We also present preliminary data showing that the CA3 neuropil in advanced ageing was conspicuously full of lipofuscin and phagolysosome positive, activated microglial cellular processes, and altered perivascular pathology. These data suggest that synaptic density in the CA3-SL is significantly impaired in ageing, accompanied by underlying prominent ultrastructural glial and microvascular changes.

  3. Topological organization of CA3-to-CA1 excitation.

    Science.gov (United States)

    Hongo, Yoshie; Ogawa, Koichi; Takahara, Yuji; Takasu, Keiko; Royer, Sebastien; Hasegawa, Minoru; Sakaguchi, Gaku; Ikegaya, Yuji

    2015-09-01

    The CA1-projecting axons of CA3 pyramidal cells, called Schaffer collaterals, constitute one of the major information flow routes in the hippocampal formation. Recent anatomical studies have revealed the non-random structural connectivity between CA3 and CA1, but little is known regarding the functional connectivity (i.e. how CA3 network activity is functionally transmitted downstream to the CA1 network). Using functional multi-neuron calcium imaging of rat hippocampal slices, we monitored the spatiotemporal patterns of spontaneous CA3 and CA1 burst activity under pharmacological GABAergic blockade. We found that spatially clustered CA3 activity patterns were transformed into layered CA1 activity sequences. Specifically, synchronized bursts initiated from multiple hot spots in CA3 ensembles, and CA1 neurons located deeper in the pyramidal cell layer were recruited during earlier phases of the burst events. The order of these sequential activations was maintained across the bursts, but the sequence velocity varied depending on the inter-burst intervals. Thus, CA3 axons innervate CA1 neurons in a highly topographical fashion. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  4. Thermoelectric properties of antiperovskite calcium oxides Ca3PbO and Ca3SnO

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    Okamoto, Y.; Sakamaki, A.; Takenaka, K.

    2016-05-01

    We report the thermoelectric properties of polycrystalline samples of Ca3Pb1-xBixO (x = 0, 0.1, 0.2) and Ca3SnO, both crystallizing in a cubic antiperovskite-type structure. The Ca3SnO sample shows metallic resistivity and its thermoelectric power approaches 100 μV K-1 at room temperature, resulting in the thermoelectric power factor of Ca3SnO being larger than that of Ca3Pb1-xBixO. On the basis of Hall and Sommerfeld coefficients, the Ca3SnO sample is found to be a p-type metal with a carrier density of ˜1019 cm-3, a mobility of ˜80 cm2 V-1 s-1, both comparable to those in degenerated semiconductors, and a moderately large hole carrier effective mass. The coexistence of moderately high mobility and large effective mass observed in Ca3SnO, as well as possible emergence of a multivalley electronic structure with a small band gap at low-symmetry points in k-space, suggests that the antiperovskite Ca oxides have strong potential as a thermoelectric material.

  5. Neuronal migration and its disorders affecting the CA3 region

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    Richard eBelvindrah

    2014-03-01

    Full Text Available In this review, we focus on CA3 neuronal migration disorders in the rodent. We begin by introducing the main steps of hippocampal development, and we summarize characteristic hippocampal malformations in human. We then describe various mouse mutants showing structural hippocampal defects. Notably, genes identified in human cortical neuronal migration disorders consistently give rise to a CA3 phenotype when mutated in the mouse. We successively describe their molecular, physiological and behavioral phenotypes that together contribute to a better understanding of CA3-dependent functions. We finally discuss potential factors underlying the CA3 vulnerability revealed by these mouse mutants and that may also contribute to other human neurological and psychiatric disorders.

  6. Corticotomy-assisted retraction: An outcome assessment

    National Research Council Canada - National Science Library

    Krishnaswamy, NR; Sakthi, SVijayashri; Vikraman, B; Shobana, VR; Iyer, SKavitha

    2014-01-01

      Background: To assess the efficiency and treatment outcome of patients treated with corticotomy-assisted en-masse orthodontic retraction as compared with the en-masse retraction without corticotomy...

  7. JPL Testbed Image of Airbag Retraction

    Science.gov (United States)

    2004-01-01

    This image shows the deflated airbags retracted underneath the lander petal at the JPL In-Situ Instrument Laboratory. Retracting the airbags helps clear the path for the rover to roll off the lander and onto the martian surface.

  8. Retracted publications in the drug literature.

    Science.gov (United States)

    Samp, Jennifer C; Schumock, Glen T; Pickard, A Simon

    2012-07-01

    Recent studies have suggested an increase in the number of retracted scientific publications. It is unclear how broadly the issue of misleading and fraudulent publications pertains to retractions of drug therapy studies. Therefore, we sought to determine the trends and factors associated with retracted publications in drug therapy literature. A PubMed search was conducted to identify retracted drug therapy articles published from 2000-2011. Articles were grouped according to reason for retraction, which was classified as scientific misconduct or error. Scientific misconduct was further divided into data fabrication, data falsification, questions of data veracity, unethical author conduct, and plagiarism. Error was defined as duplicate publication, scientific mistake, journal error, or unstated reasons. Additional data were extracted from the retracted articles, including type of article, funding source, author information, therapeutic area, and retraction issue. A total of 742 retractions were identified from 2000-2011 in the general biomedical literature, and 102 drug studies met our inclusion criteria. Of these, 73 articles (72%) were retracted for a reason classified as scientific misconduct, whereas 29 articles (28%) were retracted for error. Among the 73 articles classified as scientific misconduct, those classified as unethical author conduct (32 articles [44%]) and data fabrication (24 articles [33%]) constituted the majority. The median time from publication of the original article to retraction was 31 months (range 1-130). Fifty percent of retracted articles did not state a funding source, whereas pharmaceutical manufacturer funding accounted for only 13 articles (13%) analyzed. Many retractions were due to repeat offenses by a small number of authors, with nearly 40% of the retracted studies associated with two individuals. We found that a greater proportion of drug therapy articles were retracted for reasons of misconduct and fraud compared with other

  9. Retractions in cancer research: a systematic survey.

    Science.gov (United States)

    Bozzo, Anthony; Bali, Kamal; Evaniew, Nathan; Ghert, Michelle

    2017-01-01

    The annual number of retracted publications in the scientific literature is rapidly increasing. The objective of this study was to determine the frequency and reason for retraction of cancer publications and to determine how journals in the cancer field handle retracted articles. We searched three online databases (MEDLINE, Embase, The Cochrane Library) from database inception until 2015 for retracted journal publications related to cancer research. For each article, the reason for retraction was categorized as plagiarism, duplicate publication, fraud, error, authorship issues, or ethical issues. Accessibility of the retracted article was defined as intact, removed, or available but with a watermark over each page. Descriptive data was collected on each retracted article including number of citations, journal name and impact factor, study design, and time between publication and retraction. The publications were screened in duplicated and two reviewers extracted and categorized data. Following database search and article screening, we identified 571 retracted cancer publications. The majority (76.4%) of cancer retractions were issued in the most recent decade, with 16.6 and 6.7% of the retractions in the prior two decades respectively. Retractions were issued by journals with impact factors ranging from 0 (discontinued) to 55.8. The average impact factor was 5.4 (median 3.54, IQR 1.8-5.5). On average, a retracted article was cited 45 times (median 18, IQR 6-51), with a range of 0-742. Reasons for retraction include plagiarism (14.4%), fraud (28.4%), duplicate publication (18.2%), error (24.2%), authorship issues (3.9%), and ethical issues (2.1%). The reason for retraction was not stated in 9.8% of cases. Twenty-nine percent of retracted articles remain available online in their original form. Retractions in cancer research are increasing in frequency at a similar rate to all biomedical research retractions. Cancer retractions are largely due to academic misconduct

  10. Pharmacotherapy with Fluoxetine Restores Functional Connectivity from the Dentate Gyrus to Field CA3 in the Ts65Dn Mouse Model of Down Syndrome

    Science.gov (United States)

    Guidi, Sandra; Ciani, Elisabetta; Mangano, Chiara; Calzà, Laura; Bartesaghi, Renata

    2013-01-01

    Down syndrome (DS) is a high-incidence genetic pathology characterized by severe impairment of cognitive functions, including declarative memory. Impairment of hippocampus-dependent long-term memory in DS appears to be related to anatomo-functional alterations of the hippocampal trisynaptic circuit formed by the dentate gyrus (DG) granule cells - CA3 pyramidal neurons - CA1 pyramidal neurons. No therapies exist to improve cognitive disability in individuals with DS. In previous studies we demonstrated that pharmacotherapy with fluoxetine restores neurogenesis, granule cell number and dendritic morphology in the DG of the Ts65Dn mouse model of DS. The goal of the current study was to establish whether treatment rescues the impairment of synaptic connectivity between the DG and CA3 that characterizes the trisomic condition. Euploid and Ts65Dn mice were treated with fluoxetine during the first two postnatal weeks and examined 45–60 days after treatment cessation. Untreated Ts65Dn mice had a hypotrophyc mossy fiber bundle, fewer synaptic contacts, fewer glutamatergic contacts, and fewer dendritic spines in the stratum lucidum of CA3, the terminal field of the granule cell projections. Electrophysiological recordings from CA3 pyramidal neurons showed that in Ts65Dn mice the frequency of both mEPSCs and mIPSCs was reduced, indicating an overall impairment of excitatory and inhibitory inputs to CA3 pyramidal neurons. In treated Ts65Dn mice all these aberrant features were fully normalized, indicating that fluoxetine can rescue functional connectivity between the DG and CA3. The positive effects of fluoxetine on the DG-CA3 system suggest that early treatment with this drug could be a suitable therapy, possibly usable in humans, to restore the physiology of the hippocampal networks and, hence, memory functions. PMID:23620781

  11. A survey of retracted articles in dentistry.

    Science.gov (United States)

    Nogueira, Túlio Eduardo; Gonçalves, Andréia Souza; Leles, Cláudio Rodrigues; Batista, Aline Carvalho; Costa, Luciane Rezende

    2017-07-06

    Publication retraction is a mechanism to preserve the scientific literature against publications that contain seriously flawed or erroneous data, redundant publication, plagiarism, unethical research, and other features that compromise the integrity of science. An increase in the occurrence of retractions in recent years has been reported. Nevertheless, there is scarce information on this topic concerning publications in dentistry and related specialties. Thus, this study aimed to investigate retracted papers published in dental journals. Data collection included an exploratory search in PubMed and a specific search in SCImago Journal Rank indexed journals, complemented by the cases reported on the Retraction Watch website and in PubMed. All 167 dental journals included in SCImago were searched for identification of retracted articles up to March 2016. The selected retracted articles and their corresponding retraction notices were recorded and assessed for classification according to the reason for retraction and other additional information. Forty of the 167 journals scrutinised at SCImago (23.9%) had at least one retracted article, and four additional journals were identified from the Retraction Watch website. A total of 72 retracted found were retracted for the reasons: redundant publication (20.8%), plagiarism (18.1%), misconduct (13.8%), overlap (13.6%) and honest error (9.7%). Higher number of retractions were reported in those journals with cites/doc <2.0-n = 49 (74.2%). The types of studies were mainly laboratory studies (34.7%), case reports (22.2%) and review articles (13.9%). The approach to ethical problems in papers published in dental scientific journals is still incipient; retractions were mostly due to the authors' malpractice and were more frequently related to journals with less impact.

  12. Differential protection of injured retinal ganglion cell dendrites by brimonidine.

    Science.gov (United States)

    Lindsey, James D; Duong-Polk, Karen X; Hammond, Dustin; Chindasub, Panida; Leung, Christopher Kai-Shun; Weinreb, Robert N

    2015-01-29

    To determine whether brimonidine protects against the retraction and loss of retinal ganglion cell (RGC) dendrites after optic nerve crush (ONC). Fluorescent RGCs of mice expressing yellow fluorescent protein (YFP) under the control of the Thy-1 promoter (Thy1-YFP mice) were imaged in vivo and assigned to one of six groups according to dendrite structure. The mice then received brimonidine every other day starting 2 days before, or 2 or 6 days after, unilateral ONC. Control animals received vehicle every other day starting 2 days before ONC. Control animals received vehicle every other day starting 2 days before ONC. Total dendrite length, dendrite branching complexity, and the time until complete loss of dendrites were assessed weekly for 4 weeks. Overall, brimonidine treatment significantly slowed the complete loss of RGC dendrites and significantly slowed the reduction of total dendrite length and branching complexity. Separate analysis of each RGC group showed brimonidine significantly delayed the time until complete loss of dendrites in four of the RGC groups. These delays generally were similar when treatment started either 2 days before or 2 days after ONC, but were smaller or absent when treatment started 6 days after ONC Protection against loss of total dendrite length and loss of branching complexity was observed in three of the RGC groups. In two of these RGC groups, protective effects persisted until the end of the study. Brimonidine protects many RGC types against dendrite retraction, loss of branching complexity, and complete loss of dendrites following ONC. However, the pattern and magnitude of this protection differs substantially among different RGC types. These results indicate that requirements for RGC-protective therapies following optic nerve injury may differ among RGC types. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

  13. Clinical characteristics of the eardrum retraction pocket

    Directory of Open Access Journals (Sweden)

    Ješić Snežana

    2003-01-01

    Full Text Available Development of the eardrum retraction pocket, as pathologic finding, depends on Eustachian tube dysfunction, onset of the middle ear infection and site of development of retraction on the eardrum. The study is aimed at: 1. Determining the incidence of eardrum retraction pocket and cholesteatoma within it, as well as at the degree of eardrum retraction; 2. Determining of association between eardrum retraction pocket and changes of the eardrum mucosaand parstensa of the tympanic membrane; 3. Determining of onset and intensity of the bone destruction in eardrum retraction pocket; 4. Examining of Eustachian tube function based on time of mucocilliary transport according to the type of the eardrum retraction pocket. The study is based on the retrospective analysis of the results obtained from the patients treated at the Institute of Oto-Rhino-Laryngology and Maxillofacial Surgery Clinical Centre of Serbia in Belgrade for the diagnosis of the chronic suppurative otitis who underwent otosurgical procedures during the six-year period, from 1996-2001. In our series of 540 patients subjected to otosurgical treatment, the incidence of the retraction pocket of the eardrum was 11.23%. Onset of more severe degree of eardrum retraction was most frequent in the attic. Cholesteatoma was detected in 82.2% of patients of the group with the attic-retraction pocket of the eardrum, as well as in 25% of patients of the group of tensa-sinus retraction pocket of the eardrum. Atrophic changes of the tympanic membrane pars tensa were detected in almost all tensa-sinus retraction pockets of the eardrum. Approximately one half of the attic-retraction pockets of the eardrum were accompanied by eardrum atrophy. Bone destruction of the auditory ossicles was limited to the long process of incus and superior structures of stapes. Time of the mucocilliary transport was significantly longer (p<0.01 in attic-retraction pocket of the eardrum than in tensa-sinus retraction pocket of

  14. Topological stability through extremely tame retractions

    DEFF Research Database (Denmark)

    Feragen, Aasa

    2012-01-01

    not know whether f will be topologically stable if we can find a pair of continuous retractions r and s. The class of extremely tame (E-tame) retractions, introduced by du Plessis and Wall, are defined by their nice geometric properties, which are sufficient to ensure that f is topologically stable....... In this article, we present the E-tame retractions and their relation with topological stability, survey recent results by the author concerning their construction, and illustrate the use of our techniques by constructing E-tame retractions for certain germs belonging to the E- and Z-series of singularities....

  15. Laser Gingival Retraction: A Quantitative Assessment

    Science.gov (United States)

    Krishna Ch, Vamsi; Gupta, Nidhi; Reddy, K. Mahendranadh; Sekhar, N. Chandra; Aditya, Venkata; Reddy, G.V.K. Mohan

    2013-01-01

    Background: Proper gingival retraction improves the prognosis of crowns and bridges with sub gingival finishlines.Use of lasers assists the operator to achieve proper retraction with good clinical results. Aims: The present study was intended to assess the amount of lateral gingival retraction achieved quantitatively by using diode lasers. Settings and Design: Study was carried on 20 patients attended to a dental institution that underwent root canal treatment and indicated for fabrication of crowns. Material and Methods: Gingival retraction was carried out on 20 teeth and elastomeric impressions were obtained. Models retrieved from the impressions were sectioned and the lateral distance between finish line and the marginal gingival was measured using tool makers microscope. Retraction was measured in mid buccal, mesio buccal and disto buccal regions. Statistical Analysis: The values obtained were used to calculate the mean lateral retraction in microns. Results: Mean retraction values of 399.5 μm, 445.5 μm and 422.5μm were obtained in mid buccal, mesio buccal and disto buccal regions respectively. Conclusions: Gingival Retraction achieved was closer to the thickness of sulcular epithelium and greater than the minimum required retraction of 200um. PMID:24086914

  16. [ISOMETRIC RETRACTION AND THE INVISIBLE PROCESSES OF NERVE CELLS].

    Science.gov (United States)

    Sotnikov, O S; Vasyagina, N Yu; Krasnova, T V

    2015-01-01

    Recently, a large number of physiological studies on stress and hibernation had described an unusual morphological phenomenon of the rapid disappearance and reapperance of apical dendrites of pyramidal neurons of the hippocampus, prefrontal cortex and other parts of the brain. In this article an attempt is maid to explain this phenomenon on the basis of morphological analysis of natural elastic properties of neuroplasm and structural kinetics of partially preserved processes of the living isolated neurons. The neuroplasm displacement with its bidirectional flow was identified in the processes. A new physiological phenomenon is described--the isometric retraction of nerve cell processes, during which the neuroplasm fluxes were directed to the opposite sides, leading to abrupt thinning of middle parts of the processes and to a thickening of both ends. It is suggested that the extremely attenuated processes can reach the submicroscopic sizes, becoming invisible in the light microscope. The repeated reversible "disappearance" and "appearance" of the processes was demonstrated supravitally in the culture of neurons and of C-1300 neuroblastoma cells. Reduction of the diameter of the processes to a limit of their visibility was demonstrated by the example of their natural stretching. The same effect was observed in the areas between the reversible varicosities of the processes. These areas became extremely thin, and then invisible. Becoming thinner, the processes were capable of sharp extension. A review of the available literature and our own data allow to conclude that the phenomenon of the disappearance of the apical dendrites was due to their isometric retraction, which lead to the emergence of "invisible processes".

  17. Retraction

    Directory of Open Access Journals (Sweden)

    Singhai R

    2012-03-01

    Full Text Available The Editor-in-Chief and Publisher of Breast Cancer: Targets and Therapy have been alerted to unacceptable levels of duplication with previously published papers. All four papers were submitted by Dr Rajeev Singhai.It is worth noting that all papers were peer-reviewed by a minimum of two peer-reviewers and the Editor-in-Chief of Breast Cancer: Targets and Therapy before publication. The papers concerned are:Patil VW, Tayade MB, Pingale SA, et al. The p53 breast cancer tissue biomarker in Indian women. Breast Cancer: Targets and Therapy. 2011;3:71–78.Singhai R, Patil AV, Patil VW. Cancer biomarker HER-2/neu in breast cancer in Indian women. Breast Cancer: Targets and Therapy. 2011;3:21–26.Patil AV, Bhamre RS, Singhai R, Tayade MB, Patil VW. Estrogen receptor (ER and progesterone receptor (PgR in breast cancer of Indian women. Breast Cancer: Targets and Therapy. 2011;3:27–33.Patil VW, Singhai R, Patil AV, Gurav PD. Triple-negative (ER, PgR, HER-2/neu breast cancer in Indian women. Breast Cancer: Targets and Therapy. 2011;3:9–19.

  18. The Problem of Retraction in Critical Discussion

    NARCIS (Netherlands)

    Krabbe, Erik C. W.

    2001-01-01

    In many contexts a retraction of commitment is frowned upon. For instance, it is not appreciated, generally, if one withdraws a promise or denies an earlier statement. Critical discussion, too, can easily be disrupted by retractions, if these occur too frequently and at critical points. But on the

  19. Gingival Retraction Methods: A Systematic Review.

    Science.gov (United States)

    Tabassum, Sadia; Adnan, Samira; Khan, Farhan Raza

    2017-12-01

    The aim of this systematic review was to assess the gingival retraction methods in terms of the amount of gingival retraction achieved and changes observed in various clinical parameters: gingival index (GI), plaque index (PI), probing depth (PD), and attachment loss (AL). Data sources included three major databases, PubMed, CINAHL plus (Ebsco), and Cochrane, along with hand search. Search was made using the key terms in different permutations of gingival retraction* AND displacement method* OR technique* OR agents OR material* OR medicament*. The initial search results yielded 145 articles which were narrowed down to 10 articles using a strict eligibility criteria of including clinical trials or experimental studies on gingival retraction methods with the amount of tooth structure gained and assessment of clinical parameters as the outcomes conducted on human permanent teeth only. Gingival retraction was measured in 6/10 studies whereas the clinical parameters were assessed in 5/10 studies. The total number of teeth assessed in the 10 included studies was 400. The most common method used for gingival retraction was chemomechanical. The results were heterogeneous with regards to the outcome variables. No method seemed to be significantly superior to the other in terms of gingival retraction achieved. Clinical parameters were not significantly affected by the gingival retraction method. © 2016 by the American College of Prosthodontists.

  20. Retraction of Hard, Lozano, and Tversky (2006)

    Science.gov (United States)

    Hard, B. M.; Lozano, S. C.; Tversky, B.

    2008-01-01

    Reports a retraction of "Hierarchical encoding of behavior: Translating perception into action" by Bridgette Martin Hard, Sandra C. Lozano and Barbara Tversky (Journal of Experimental Psychology: General, 2006[Nov], Vol 135[4], 588-608). All authors retract this article. Co-author Tversky and co-author Hard believe that the research results cannot…

  1. Retracted: FLT3: beyond good and evil.

    Science.gov (United States)

    Lagunas-Rangel, Francisco Alejandro; Cortes-Penagos, Carlos; Viveros-Sandoval, Martha Eva

    2016-07-29

    The above article, published online on 29 July 2016 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the Journal Editor in Chief, Journal Production Manager, and John Wiley & Sons, Ltd. The retraction has been agreed due to 48% similar significant between this article and an article published in Nature Reviews Cancer journal. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Retracted: Inhibition of Corneal Neovascularization by ...

    African Journals Online (AJOL)

    This article previously published in Volume 15 Issue 2 of this journal in February 2016 has been retracted in line with the guidelines from the Committee on Publication Ethics (COPE, http://publicationethics.org/resources/guidelines). Retracted: Zhan W, Zhu J, Zhang Y. Inhibition of corneal neovascularization by ...

  3. 14 CFR 27.729 - Retracting mechanism.

    Science.gov (United States)

    2010-01-01

    ... at any airspeed up to the design maximum landing gear extended speed. (b) Landing gear lock. A... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear § 27.729 Retracting mechanism..., retracting mechansim, wheel-well doors, and supporting structure must be designed for— (1) The loads...

  4. 14 CFR 29.729 - Retracting mechanism.

    Science.gov (United States)

    2010-01-01

    ... at any airspeed up to the design maximum landing gear extended speed. (b) Landing gear lock. A... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear § 29.729 Retracting mechanism..., retracting mechanism, wheel well doors, and supporting structure must be designed for— (1) The loads...

  5. Optical spectroscopy of Ca3Sc2Si3O12, Ca3Y2Si3O12 and Ca3Lu2Si3O12 doped with Pr3+

    NARCIS (Netherlands)

    Ivanovskikh, K.|info:eu-repo/dai/nl/311489605; Meijerink, A.|info:eu-repo/dai/nl/075044986; Piccinelli, F.; Speghini, A.; Zenin, E.I.; Ronda, R.C.; Bettinelli, M.

    2010-01-01

    The silicates Ca3Sc2Si3O12, Ca3Y2Si3O12 and Ca3Lu2Si3O12, both undoped and doped with Pr3+ ions, have been synthesized by solid-state reaction at high temperature. The luminescence spectroscopy and the excited state dynamics of the materials have been studied upon VUV and X-ray excitation using

  6. Anatomically heterogeneous populations of CB1 cannabinoid receptor-expressing interneurons in the CA3 region of the hippocampus show homogeneous input-output characteristics.

    Science.gov (United States)

    Szabó, Gergely G; Papp, Orsolya I; Máté, Zoltán; Szabó, Gábor; Hájos, Norbert

    2014-12-01

    A subpopulation of GABAergic cells in cortical structures expresses CB1 cannabinoid receptors (CB1 ) on their axon terminals. To understand the function of these interneurons in information processing, it is necessary to uncover how they are embedded into neuronal circuits. Therefore, the proportion of GABAergic terminals expressing CB1 and the morphological and electrophysiological properties of CB1 -immunoreactive interneurons should be revealed. We investigated the ratio and the origin of CB1 -expressing inhibitory boutons in the CA3 region of the hippocampus. Using immunocytochemical techniques, we estimated that ∼40% of GABAergic axon terminals in different layers of CA3 also expressed CB1 . To identify the inhibitory cell types expressing CB1 in this region, we recorded and intracellularly labeled interneurons in hippocampal slices. CB1 -expressing interneurons showed distinct axonal arborization, and were classified as basket cells, mossy-fiber-associated cells, dendritic-layer-innervating cells or perforant-path-associated cells. In each morphological category, a substantial variability in axonal projection was observed. In contrast to the diverse morphology, the active and passive membrane properties were found to be rather similar. Using paired recordings, we found that pyramidal cells displayed large and fast unitary postsynaptic currents in response to activating basket and mossy-fiber-associated cells, while they showed slower and smaller synaptic events in pairs originating from interneurons that innervate the dendritic layer, which may be due to dendritic filtering. In addition, CB1 activation significantly reduced the amplitude of the postsynaptic currents in each cell pair tested. Our data suggest that CB1 -expressing interneurons with different axonal projections have comparable physiological characteristics, contributing to a similar proportion of GABAergic inputs along the somato-dendritic axis of CA3 pyramidal cells. © 2014 Wiley Periodicals

  7. Retraction of Neurosurgical Publications: A Systematic Review.

    Science.gov (United States)

    Wang, Justin; Ku, Jerry C; Alotaibi, Naif M; Rutka, James T

    2017-07-01

    Despite the increasing awareness of scientific fraud, no attempt has been made to assess its prevalence in neurosurgery. The aim of our review was to assess the chronologic trend, reasons, research type/design, and country of origin of retracted neurosurgical publications. Three independent reviewers searched the EMBASE and MEDLINE databases using neurosurgical keywords for retracted articles from 1995 to 2016. Archives of retracted articles (retractionwatch.com) and the independent Web sites of neurosurgical journals were also searched. Data including the journal, impact factor, reason for retraction, country of origin, and citations were extracted. A total of 97 studies were included for data extraction. Journal impact factor ranged from 0.57 to 35.03. Most studies (61) were retracted within the last 5 years. The most common reason for retraction was because of a duplicated publication found elsewhere (26), followed closely by plagiarism (22), or presenting fraudulent data (14). Other reasons included scientific errors/mistakes, author misattribution, and compromised peer review. Articles originated from several countries and some were widely cited. Retractions of neurosurgical publications are increasing significantly, mostly because of issues of academic integrity, including duplicate publishing and plagiarism. Implementation of more transparent data-sharing repositories and thorough screening of data before manuscript submission, as well as additional educational programs for new researchers, may help mitigate these issues in the future. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Retracted: Exploring resident reflections to understand burnout.

    Science.gov (United States)

    Winkel, Abigail Ford; Jakalow, Holli; Benton, Laura; Moss, Haley; Mitchell, Lauren; Feldman, Nathalie

    2016-04-05

    Retraction: Winkel, A. F., Jakalow, H., Benton, L., Moss, H., Mitchell, L. and Feldman, N. (2016), Exploring resident reflections to understand burnout. The Clinical Teacher. doi: 10.1111/tct.12513 The above article, published online on 5th April 2016 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Co-Editors, and John Wiley & Sons Ltd. The retraction has been agreed due to a change in the status of the research project's Institutional Review Board approval, leading to permission to use some of the data in this article being revoked. © 2016 John Wiley & Sons Ltd.

  9. Study on Aeroacoustic Noise Characteristic of Retractable Aerial Refueling Assembly

    Science.gov (United States)

    2015-11-27

    Undergraduate Student Paper Postgraduate Student Paper Study on Aeroacoustic Noise Characteristic of Retractable Aerial Refueling Assembly ...The aeroacoustic noise influence of retractable assembly on aircraft surface is researched. Based on a smooth surface airplane without retractable... assembly , aeroacoustic noise is calculated and compared with the airplane contains a retractable assembly . The change of noise and the distribution of

  10. Conditional Deletion of Hippocampal CA2/CA3a Oxytocin Receptors Impairs the Persistence of Long-Term Social Recognition Memory in Mice.

    Science.gov (United States)

    Lin, Yu-Ting; Hsieh, Tsan-Yu; Tsai, Tsung-Chih; Chen, Chien-Chung; Huang, Chiung-Chun; Hsu, Kuei-Sen

    2018-01-31

    Oxytocin (OXT) receptors (OXTRs) are prominently expressed in hippocampal CA2 and CA3 pyramidal neurons, but little is known about its physiological function. As the functional necessity of hippocampal CA2 for social memory processing, we tested whether CA2 OXTRs may contribute to long-term social recognition memory (SRM) formation. Here, we found that conditional deletion of Oxtr from forebrain (Oxtr-/-) or CA2/CA3a-restricted excitatory neurons in adult male mice impaired the persistence of long-term SRM but had no effect on sociability and preference for social novelty. Conditional deletion of CA2/CA3a Oxtr showed no changes in anxiety-like behavior assessed using the open-field, elevated plus maze and novelty-suppressed feeding tests. Application of a highly selective OXTR agonist [Thr4,Gly7]-OXT to hippocampal slices resulted in an acute and lasting potentiation of excitatory synaptic responses in CA2 pyramidal neurons that relied on N-methyl-d-aspartate receptor activation and calcium/calmodulin-dependent protein kinase II activity. In addition, Oxtr-/- mice displayed a defect in the induction of long-term potentiation, but not long-term depression, at the synapses between the entorhinal cortex and CA2 pyramidal neurons. Furthermore, Oxtr deletion led to a reduced complexity of basal dendritic arbors of CA2 pyramidal neurons, but caused no alteration in the density of apical dendritic spines. Considering that the methodologies we have used to delete Oxtr do not rule out targeting the neighboring CA3a region, these findings suggest that OXTR signaling in the CA2/CA3a is crucial for the persistence of long-term SRM.SIGNIFICANCE STATEMENT Oxytocin receptors (OXTRs) are abundantly expressed in hippocampal CA2 and CA3 regions, but there are little known about their physiological function. Taking advantage of the conditional Oxtr knock-out mice, the present study highlights the importance of OXTR signaling in the induction of long-term potentiation at the synapses

  11. A retractable barb needle for drug darts

    Directory of Open Access Journals (Sweden)

    G.L. van Rooyen

    1973-07-01

    Full Text Available The mechanism and action of a new retractable barbneedle for drug darts are described. This dart needle is particularly successful in obviating unnecessary flight reactions andtrauma in darted animals, and facilitates the complete injection of the drug dose before the barb is retracted and the dart is dislogded from the animal. The whole process is completed within a few seconds and the expended dart can usually be retrieved in the immediate vicinity where the animal was darted.

  12. Ablation of NMDA receptors enhances the excitability of hippocampal CA3 neurons.

    Directory of Open Access Journals (Sweden)

    Fumiaki Fukushima

    Full Text Available Synchronized discharges in the hippocampal CA3 recurrent network are supposed to underlie network oscillations, memory formation and seizure generation. In the hippocampal CA3 network, NMDA receptors are abundant at the recurrent synapses but scarce at the mossy fiber synapses. We generated mutant mice in which NMDA receptors were abolished in hippocampal CA3 pyramidal neurons by postnatal day 14. The histological and cytological organizations of the hippocampal CA3 region were indistinguishable between control and mutant mice. We found that mutant mice lacking NMDA receptors selectively in CA3 pyramidal neurons became more susceptible to kainate-induced seizures. Consistently, mutant mice showed characteristic large EEG spikes associated with multiple unit activities (MUA, suggesting enhanced synchronous firing of CA3 neurons. The electrophysiological balance between fast excitatory and inhibitory synaptic transmission was comparable between control and mutant pyramidal neurons in the hippocampal CA3 region, while the NMDA receptor-slow AHP coupling was diminished in the mutant neurons. In the adult brain, inducible ablation of NMDA receptors in the hippocampal CA3 region by the viral expression vector for Cre recombinase also induced similar large EEG spikes. Furthermore, pharmacological blockade of CA3 NMDA receptors enhanced the susceptibility to kainate-induced seizures. These results raise an intriguing possibility that hippocampal CA3 NMDA receptors may suppress the excitability of the recurrent network as a whole in vivo by restricting synchronous firing of CA3 neurons.

  13. A new method for rapid Canine retraction

    Directory of Open Access Journals (Sweden)

    "Khavari A

    2001-06-01

    Full Text Available Distraction osteogenesis method (Do in bone lengthening and rapid midpalatal expansion have shown the great ability of osteognic tissues for rapid bone formation under distraction force and special protocol with optimum rate of one millimeter per day. Periodontal membrane of teeth (PDM is the extension of periostium in the alveolar socked. Orthodontic force distracts PDM fibers in the tension side and then bone formation will begin.Objects: Rapid retraction of canine tooth into extraction space of first premolar by DO protocol in order to show the ability of the PDM in rapid bone formation. The other objective was reducing total orthodontic treatment time of extraction cases.Patients and Methods: Tweleve maxillary canines in six patients were retracted rapidly in three weeks by a custom-made tooth-born appliance. Radiographic records were taken to evaluate the effects of heavy applied force on canine and anchorage teeth.Results: Average retraction was 7.05 mm in three weeks (2.35 mm/week. Canines rotated distal- in by mean 3.5 degrees.Anchorage loss was from 0 to 0.8 mm with average of 0.3 mm.Root resorption of canines was negligible, and was not significant clinically. Periodontium was normal after rapid retraction. No hazard for pulp vitality was observed.Discussion: PDM responded well to heavy distraction force by Do protocol. Rapid canine retraction seems to be a safe method and can considerabely reduce orthodontic time.

  14. MSP dynamics and retraction in nematode sperm

    Science.gov (United States)

    Wolgemuth, Charles; Miao, Long; Vanderlinde, Orion; Roberts, Tom; Oster, George

    2005-03-01

    Most eukaryotic cells can crawl over surfaces. In general, this motility requires three distinct actions: polymerization at the leading edge, adhesion to the substrate, and retraction at the rear. Recent in vitro experiments with extracts from spermatozoa from the nematode Ascaris suum suggest that retraction forces are generated by depolymerization of the Major Sperm Protein (MSP) cytoskeleton. Combining polymer entropy with a simple kinetic model for disassembly I propose a model for disassembly-induced retraction that fit the in vitro experimental data. This model explains the mechanism by which deconstruction of the cytoskeleton produces the force necessary to pull the cell body forward and suggest further experiments that can test the validity of the model.

  15. Retracted: Modern Concepts for Caries Tissue Removal.

    Science.gov (United States)

    Schwendicke, Falk

    2016-02-15

    "Modern Concepts for Caries Tissue Removal", by Falk Schwendicke The above article, published online on 15 February 2016 in Wiley Online Library (http://onlinelibrary.wiley.com/doi/10.llll/jerd.12201), has been retracted by agreement between the author, Dr. Falk Schwendicke, the journal Editor-in-Chief, Dr. Harald O. Heymann, Associate Editor, Dr. Edward Swift and Wiley Periodicals, Inc. The retraction has been agreed as the article was published in advance of other companion work which should have had precedence. The article pages have been replaced by the Retraction Statement and the article condensed accordingly. Schwendicke, F. Swift, EJ. Modern concepts for caries tissue removal. Dent J Esthet Rest 2016; 28:1; DOI: 10.1111/jerd.12201. © 2016 Wiley Periodicals, Inc.

  16. Atypical protein kinase C regulates primary dendrite specification of cerebellar Purkinje cells by localizing Golgi apparatus.

    Science.gov (United States)

    Tanabe, Koji; Kani, Shuichi; Shimizu, Takashi; Bae, Young-Ki; Abe, Takaya; Hibi, Masahiko

    2010-12-15

    Neurons have highly polarized structures that determine what parts of the soma elaborate the axon and dendrites. However, little is known about the mechanisms that establish neuronal polarity in vivo. Cerebellar Purkinje cells extend a single primary dendrite from the soma that ramifies into a highly branched dendritic arbor. We used the zebrafish cerebellum to investigate the mechanisms by which Purkinje cells acquire these characteristics. To examine dendritic morphogenesis in individual Purkinje cells, we marked the cell membrane using a Purkinje cell-specific promoter to drive membrane-targeted fluorescent proteins. We found that zebrafish Purkinje cells initially extend multiple neurites from the soma and subsequently retract all but one, which becomes the primary dendrite. In addition, the Golgi apparatus specifically locates to the root of the primary dendrite, and its localization is already established in immature Purkinje cells that have multiple neurites. Inhibiting secretory trafficking through the Golgi apparatus reduces dendritic growth, suggesting that the Golgi apparatus is involved in the dendritic morphogenesis. We also demonstrated that in a mutant of an atypical protein kinase C (aPKC), Prkci, Purkinje cells retain multiple primary dendrites and show disrupted localization of the Golgi apparatus. Furthermore, a mosaic inhibition of Prkci in Purkinje cells recapitulates the aPKC mutant phenotype. These results suggest that the aPKC cell autonomously controls the Golgi localization and thereby regulates the specification of the primary dendrite of Purkinje cells.

  17. The mechanism of melanocyte dendrite formation: the impact of differentiating keratinocytes.

    Science.gov (United States)

    Kippenberger, S; Bernd, A; Bereiter-Hahn, J; Ramirez-Bosca, A; Kaufmann, R

    1998-02-01

    In human epidermis one dendritic melanocyte interacts with about 36 keratinocytes and supplies them with melanin. In contrast to the vivo situation melanocytes in culture are far less dendritic. In the present study different culture systems were tested in order to observe the mechanism of melanocyte dendrite formation. In particular, we focused on the role of keratinocytes in this process. Time lapse studies revealed that only differentiated keratinocytes enhance melanocyte dendricity. Differentiated keratinocytes form connected cell sheets, which attach to part of the melanocyte plasma membrane. By contraction and retraction of keratinocyte units, new dendrites were drawn out from the melanocytes. Melanocytes remain passive during this process, which is indicated by the observation that sometimes extended dendrites could not withstand the tension and shear.

  18. Effect of retraction materials on gingival health: A histopathological study

    Directory of Open Access Journals (Sweden)

    Phatale Sushma

    2010-01-01

    Full Text Available Background: Gingival retraction methods are used in dentistry for impressions of subgingival crown margins, such as, mechanical, chemical, chemicomechanical, and surgical. These methods may injure the gingival sulcular epithelium. Hence, the present study is carried out to evaluate the effect of different retraction materials, such as, Expasyl, Magic Foam Cord, and impregnated retraction cord on the gingival sulcular epithelium. Materials and Methods: This study included 30 cases of bilateral premolar extraction patients with Loe and Silness gingival index zero. Retraction materials were kept in the dry, isolated labial gingival sulcus for the required time. The retraction materials were removed by rinsing with water. Retracted gingiva of 2 - 3 mm from the gingival margin along with the tooth was extracted and the decalcified sections were microscopically studied. Data analysis: Data were analyzed by applying the chi-square test. Results: This study showed better results with retraction paste as compared to the retraction cord, and there was a significant association between retraction materials and the relative degree of injury to the sulcular epithelium. Conclusion: There is a significant association between retraction materials and gingival sulcular epithelium. It can be stated that impregnated retraction cord, may be used commonly but it needs proper tissue manipulation and is technique sensitive. Newly advanced material in the form of retraction paste like Expasyl or Magic Foam Cord was found to be better than cord as assessed histologically, it respects periodontium.

  19. Article retracted, but the message lives on.

    Science.gov (United States)

    Greitemeyer, Tobias

    2014-04-01

    The retraction of an original article aims to ensure that readers are alerted to the fact that the findings are not trustworthy. However, the present research suggests that individuals still believe in the findings of an article even though they were later told that the data were fabricated and that the article was retracted. Participants in a debriefing condition and a no-debriefing condition learned about the scientific finding of an empirical article, whereas participants in a control condition did not. Afterward, participants in the debriefing condition were told that the article had been retracted because of fabricated data. Results showed that participants in the debriefing condition were less likely to believe in the findings than participants in the no-debriefing condition but were more likely to believe in the findings than participants in the control condition, suggesting that individuals do adjust their beliefs in the perceived truth of a scientific finding after debriefing-but insufficiently. Mediational analyses revealed that the availability of generated causal arguments underlies belief perseverance. These results suggest that a retraction note of an empirical article in a scientific journal is not sufficient to ensure that readers of the original article no longer believe in the article's conclusions.

  20. RETRACTED ARTICLE: Gradually varied flow computation in ...

    Indian Academy of Sciences (India)

    Mohammad Jahandar Malekabadi

    The article ''Gradually varied flow computation in channel networks by adaptive algorithm'' (DOI 10.1007/s12046- · 017-0640-x) which has been published online has been retracted by Chief Editor of the journal Sadhana as per the. Committee on Publication Ethics (COPE) guidelines on redundant publication.

  1. The CA3 Network as a Memory Store for Spatial Representations

    Science.gov (United States)

    Papp, Gergely; Witter, Menno P.; Treves, Alessandro

    2007-01-01

    Comparative neuroanatomy suggests that the CA3 region of the mammalian hippocampus is directly homologous with the medio-dorsal pallium in birds and reptiles, with which it largely shares the basic organization of primitive cortex. Autoassociative memory models, which are generically applicable to cortical networks, then help assess how well CA3

  2. Photolysis of Postsynaptic Caged Ca2+ Can Potentiate and Depress Mossy Fiber Synaptic Responses in Rat Hippocampal CA3 Pyramidal Neurons

    Science.gov (United States)

    Wang, Jun; Yeckel, Mark F.; Johnston, Daniel; Zucker, Robert S.

    2010-01-01

    The induction of mossy fiber-CA3 long-term potentiation (LTP) and depression (LTD) has been variously described as being dependent on either pre- or postsynaptic factors. Some of the postsynaptic factors for LTP induction include ephrin-B receptor tyrosine kinases and a rise in postsynaptic Ca2+ ([Ca2+]i). Ca2+ is also believed to be involved in the induction of the various forms of LTD at this synapse. We used photolysis of caged Ca2+ compounds to test whether a postsynaptic rise in [Ca2+]i is sufficient to induce changes in synaptic transmission at mossy fiber synapses onto rat hippocampal CA3 pyramidal neurons. We were able to elevate postsynaptic [Ca2+]i to approximately 1 μm for a few seconds in pyramidal cell somata and dendrites. We estimate that CA3 pyramidal neurons have approximately fivefold greater endogenous Ca2+ buffer capacity than CA1 neurons, limiting the rise in [Ca2+]i achievable by photolysis. This [Ca2+]i rise induced either a potentiation or a depression at mossy fiber synapses in different preparations. Neither the potentiation nor the depression was accompanied by consistent changes in paired-pulse facilitation, suggesting that these forms of plasticity may be distinct from synaptically induced LTP and LTD at this synapse. Our results are consistent with a postsynaptic locus for the induction of at least some forms of synaptic plasticity at mossy fiber synapses. PMID:14645386

  3. Characteristics of retractions related to faked peer reviews: an overview.

    Science.gov (United States)

    Qi, Xingshun; Deng, Han; Guo, Xiaozhong

    2017-08-01

    A faked peer review is a novel cause for retraction. We reviewed the characteristics of papers retracted due to a faked peer review. All papers retracted due to faked peer reviews were identified by searching the Retraction Watch website and by conducting a manual search. All identified papers were confirmed in published journals. The information of retracted papers was collected, which primarily included publisher, journal, journal impact factor, country, as well as publication and retraction year. Overall, 250 retracted papers were identified. They were published in 48 journals by six publishers. The top 5 journals included the Journal of Vibration and Control (24.8%), Molecular Biology Reports (11.6%), Immunopharmacology and Immunotoxicology (8.0%), Tumour Biology (6.8%) and European Journal of Medical Research (6.4%). The publishers included SAGE (31%), Springer (26%), BioMed Central (18%), Elsevier (13%), Informa (11%) and LWW (1%). A minority (4%) of retracted papers were published in Science Citation Index (SCI) journals with an impact factor of >5. A majority (74.8%) of retracted papers were written by Chinese researchers. In terms of the publication year, the retracted papers were published since 2010, and the number of retracted papers peaked in 2014 (40.8%). In terms of the retraction year, the retractions started in 2012, and the number of retractions peaked in 2015 (59.6%). The number of papers retracted due to faked peer reviews differs largely among journals and countries. With the improvement of the peer review mechanism and increased education about publishing ethics, such academic misconduct may gradually disappear in future. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  4. The race to learn: spike timing and STDP can coordinate learning and recall in CA3.

    Science.gov (United States)

    Nolan, Christopher R; Wyeth, Gordon; Milford, Michael; Wiles, Janet

    2011-06-01

    The CA3 region of the hippocampus has long been proposed as an autoassociative network performing pattern completion on known inputs. The dentate gyrus (DG) region is often proposed as a network performing the complementary function of pattern separation. Neural models of pattern completion and separation generally designate explicit learning phases to encode new information and assume an ideal fixed threshold at which to stop learning new patterns and begin recalling known patterns. Memory systems are significantly more complex in practice, with the degree of memory recall depending on context-specific goals. Here, we present our spike-timing separation and completion (STSC) model of the entorhinal cortex (EC), DG, and CA3 network, ascribing to each region a role similar to that in existing models but adding a temporal dimension by using a spiking neural network. Simulation results demonstrate that (a) spike-timing dependent plasticity in the EC-CA3 synapses provides a pattern completion ability without recurrent CA3 connections, (b) the race between activation of CA3 cells via EC-CA3 synapses and activation of the same cells via DG-CA3 synapses distinguishes novel from known inputs, and (c) modulation of the EC-CA3 synapses adjusts the learned versus test input similarity required to evoke a direct CA3 response prior to any DG activity, thereby adjusting the pattern completion threshold. These mechanisms suggest that spike timing can arbitrate between learning and recall based on the novelty of each individual input, ensuring control of the learn-recall decision resides in the same subsystem as the learned memories themselves. The proposed modulatory signal does not override this decision but biases the system toward either learning or recall. The model provides an explanation for empirical observations that a reduction in novelty produces a corresponding reduction in the latency of responses in CA3 and CA1. Copyright © 2010 Wiley-Liss, Inc.

  5. Pars tensa retractions without cholesteatoma in children: predictors for ossicular chain destruction, air conduction thresholds, and postoperative retractions.

    Science.gov (United States)

    Jesic, Snezana Dragoljub; Rovcanin, Lejla Hilmo; Jovicevic, Ognjen Djordjije; Jotic, Ana Dragan; Slijepcevic, Nikola Aleksandar; Ljubic, Vladimir Radoslav

    2014-07-01

    Determine predictive values of preoperative stages of pars tensa retractions, coexisting attic retraction and preoperative air conduction for ossicular destruction in isolated and combined pars tensa retraction, and predictors for successful tympanic grafts after surgery. Prospective case series study. Tertiary referral center. Forty-eight children ears without cholesteatoma were included in the study: 23 with isolated pars tensa retraction (median age, 11), 25 with combined pars tensa and attic retractions (median age, 13). Otomicroscopy, pure tone audiometry, and impedancmetry were carried out preoperatively. Three surgical procedures for isolated retractions were used: ventilation tube insertion alone or together with fascia graft or cartilage graft. Two surgical procedures for combined retractions were used: ventilation tube insertion alone and with cartilage graft. Incidence of ossicular destruction, postoperative retraction of the grafts. Stage of pars tensa retraction and preoperative air conduction thresholds do not predict long incus process defect in isolated group. Coexistence of an attic retraction predicts combined, long incus process and stapes superstructure defect (Chi = 3.943, p = 0.047, OR = 12.00). Retractions of grafts are predicted by mode of surgery, favoring cartilage graft (isolated group: Chi = 4.306, p = 0.0372,OR = 4.69; combined group Chi = 4.7836, p = 0.0287, OR = 0.1364). Stage of pars tensa retraction predicts poor outcome of fascia graft (Chi = 4.5347, p = 0.0332, OR = 12.00). Absence of correlation between stage of pars tensa retraction and air conduction thresholds with ossicular defects justifies surgical exploration of the auditory ossicles, even in lower stages of retraction. Combined ossicular defect is expected in combined retractions. The usage of cartilage graft proved to be more appropriate.

  6. Dendritic spikes are enhanced by cooperative network activity in the intact hippocampus.

    Science.gov (United States)

    Kamondi, A; Acsády, L; Buzsáki, G

    1998-05-15

    In vitro experiments suggest that dendritic fast action potentials may influence the efficacy of concurrently active synapses by enhancing Ca2+ influx into the dendrites. However, the exact circumstances leading to these effects in the intact brain are not known. We have addressed these issues by performing intracellular sharp electrode recordings from morphologically identified sites in the apical dendrites of CA1 pyramidal neurons in vivo while simultaneously monitoring extracellular population activity. The amplitude of spontaneous fast action potentials in dendrites decreased as a function of distance from the soma, suggesting that dendritic propagation of fast action potentials is strongly attenuated in vivo. Whereas the amplitude variability of somatic action potentials was very small, the amplitude of fast spikes varied substantially in distal dendrites. Large-amplitude fast spikes in dendrites occurred during population discharges of CA3-CA1 neurons concurrent with field sharp waves. The large-amplitude fast spikes were associated with bursts of smaller-amplitude action potentials and putative Ca2+ spikes. Both current pulse-evoked and spontaneously occurring Ca2+ spikes were always preceded by large-amplitude fast spikes. More spikes were observed in the dendrites during sharp waves than in the soma, suggesting that local dendritic spikes may be generated during this behaviorally relevant population pattern. Because not all dendritic spikes produce somatic action potentials, they may be functionally distinct from action potentials that signal via the axon.

  7. Noradrenergic mechanism involved in the nociceptive modulation of hippocampal CA3 region of normal rats.

    Science.gov (United States)

    Jin, Hua; Teng, Yueqiu; Zhang, Xuexin; Yang, Chunxiao; Xu, Manying; Yang, Lizhuang

    2014-06-27

    Norepinephrine (NE) is an important neurotransmitter in the brain, and regulates antinociception. However, the mechanism of action of NE on pain-related neurons in the hippocampal CA3 region is not clear. This study examines the effects of NE, phentolamine on the electrical activities of pain-excited neurons (PENs) and pain-inhibited neurons (PINs) in the hippocampal CA3 region of rats. Trains of electric impulses applied to the right sciatic nerve were used as noxious stimulation. The electrical activities of PENs or PINs in the hippocampal CA3 region were recorded by using a glass microelectrode. Our results revealed that, in the hippocampal CA3 region, the intra-CA3 region microinjection of NE decreased the pain-evoked discharged frequency and prolonged the discharged latency of PEN, and increased the pain-evoked discharged frequency and shortened discharged inhibitory duration (ID) of PIN, exhibiting the specific analgesic effect of NE. While intra-CA3 region microinjection of phentolamine produced the opposite response. It implies that phentolamine can block the effect of endogenous NE to cause the enhanced response of PEN and PIN to noxious stimulation. On the basis of above findings we can deduce that NE, phentolamine and alpha-adrenoceptor are involved in the modulation of nociceptive information transmission in the hippocampal CA3 region. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  8. A quantitative theory of the functions of the hippocampal CA3 network in memory.

    Science.gov (United States)

    Rolls, Edmund T

    2013-01-01

    A quantitative computational theory of the operation of the hippocampal CA3 system as an autoassociation or attractor network used in episodic memory system is described. In this theory, the CA3 system operates as a single attractor or autoassociation network to enable rapid, one-trial, associations between any spatial location (place in rodents, or spatial view in primates) and an object or reward, and to provide for completion of the whole memory during recall from any part. The theory is extended to associations between time and object or reward to implement temporal order memory, also important in episodic memory. The dentate gyrus (DG) performs pattern separation by competitive learning to produce sparse representations suitable for setting up new representations in CA3 during learning, producing for example neurons with place-like fields from entorhinal cortex grid cells. The dentate granule cells produce by the very small number of mossy fiber (MF) connections to CA3 a randomizing pattern separation effect important during learning but not recall that separates out the patterns represented by CA3 firing to be very different from each other, which is optimal for an unstructured episodic memory system in which each memory must be kept distinct from other memories. The direct perforant path (pp) input to CA3 is quantitatively appropriate to provide the cue for recall in CA3, but not for learning. Tests of the theory including hippocampal subregion analyses and hippocampal NMDA receptor knockouts are described, and support the theory.

  9. RETRACTED: Menselijke vrijheid en het Christelijk geloof

    Directory of Open Access Journals (Sweden)

    Jasper Doomen

    2012-05-01

    *This article has been retracted at the request of the Editor-in-Chief. Reason: ‘The article has been retracted to straighten the academic record. It has come to light that this article has significant overlap with an article that had already appeared in Informción Filosófica, Volume 1 (2004, num. 2, pp. 251–265, entitled ‘De onverenigbaarheid van menselijke vrijheid met het christelijk geloof’. Apologies are offered to readers of the journal that this was not detected during the submission process’. The full-text of the original article (2004 is here: https://openaccess.leidenuniv.nl/handle/1887/17816

  10. Growth of Antiperovskite Oxide Ca3SnO Films by Pulsed Laser Deposition

    OpenAIRE

    Minohara, Makoto; Yukawa, Ryu; Kitamura, Miho; Kumai, Reiji; Murakami, Youichi; Kumigashira, Hiroshi

    2017-01-01

    We report the epitaxial growth of Ca3SnO antiperovskite oxide films on (001)-oriented cubic yttria-stabilized zirconia (YSZ) substrates by using a conventional pulsed laser deposition (PLD) technique. In this work, a sintered Ca3SnO pellet is used as the ablation target. X-ray diffraction measurements demonstrate the (001) growth of Ca3SnO films with the antiperovskite structure and a cube-on-cube orientation relationship to the YSZ substrate. The successful synthesis of the antiperovskite ph...

  11. Dentate granule cells form hilar basal dendrites in a rat model of hypoxia-ischemia.

    Science.gov (United States)

    Díaz-Cintra, Sofia; Xue, Baogang; Spigelman, Igor; Van, K; Wong, Alan M; Obenaus, Andre; Ribak, Charles E

    2009-08-18

    Hilar basal dendrites form on dentate granule cells following seizures. To determine whether other brain insults cause the formation of hilar basal dendrites, a model of global cerebral hypoxia/ischemia was used. Rats underwent a transient induction of ischemia by occlusion of both common carotid arteries followed by reperfusion. Hippocampal slices were prepared from these animals 1 month after the ischemic insult, and granule cells were labeled with a retrograde tracing technique after biocytin injections into stratum lucidum of CA3b. Ischemic rats had numerous biocytin-labeled granule cells with hilar basal dendrites located at the hilar border of the granule cell layer. Quantitative analysis of ischemic rats compared to controls showed a significant increase in the percentage of biocytin-labeled granule cells with hilar basal dendrites. These data demonstrate that other brain insults in addition to epilepsy may result in the formation of hilar basal dendrites on granule cells.

  12. [Gingival retraction paste versus gingival retraction cord for fixed prosthodontics: a systematic review].

    Science.gov (United States)

    Hong, Le-guan; Guo, Li-ping; Xue, Li-li

    2013-08-01

    To assess the efficacy of gingival retraction paste versus gingival retraction cord in fixed prosthodontics on gingiva protection, tooth preparation, clarity of the impression and plaster model, and aptness of the prosthesis. Chinese BioMedical Literature Database, VIP, China National Knowledge Infrastructure (CNKI) and Wangfang database were searched on November 15th 2012 for eligible studies. Hand-searching included references of the included studies and Chinese dental journals. Risk of bias of the included studies was assessed by 2 reviewers independently using Cochrane Collaboration's tool, and data extraction was done by the 2 reviewers. Meta analysis was performed with Revman 5.1 software. Nine randomized controlled trials, involving 1153 participants, were included. All of them had moderate risk of bias. Meta analysis revealed that gingival retraction paste had better effect on gingival health [RR=1.05, 95%CI (1.00, 1.11), P=0.04], tooth preparation [RR=1.17, 95%CI (1.07, 1.28), P=0.0008] and clarity of the impression and plaster model [RR=1.08, 95%CI (1.03, 1.13), P=0.0009] than gingival retraction cord, and the aptness of the prosthesis was as good as the cord [RR=1.07, 95%CI (0.96, 1.19), P=0.21]. The gingival retraction paste has better effect on gingival health, tooth preparation and clarity of the impression and plaster model, while the aptness of the prosthesis is as good as the cord and can be considered as a good candidate of the gingival retraction cord, but more randomized controlled trials are needed.

  13. A signature of attractor dynamics in the CA3 region of the hippocampus.

    Directory of Open Access Journals (Sweden)

    César Rennó-Costa

    2014-05-01

    Full Text Available The notion of attractor networks is the leading hypothesis for how associative memories are stored and recalled. A defining anatomical feature of such networks is excitatory recurrent connections. These "attract" the firing pattern of the network to a stored pattern, even when the external input is incomplete (pattern completion. The CA3 region of the hippocampus has been postulated to be such an attractor network; however, the experimental evidence has been ambiguous, leading to the suggestion that CA3 is not an attractor network. In order to resolve this controversy and to better understand how CA3 functions, we simulated CA3 and its input structures. In our simulation, we could reproduce critical experimental results and establish the criteria for identifying attractor properties. Notably, under conditions in which there is continuous input, the output should be "attracted" to a stored pattern. However, contrary to previous expectations, as a pattern is gradually "morphed" from one stored pattern to another, a sharp transition between output patterns is not expected. The observed firing patterns of CA3 meet these criteria and can be quantitatively accounted for by our model. Notably, as morphing proceeds, the activity pattern in the dentate gyrus changes; in contrast, the activity pattern in the downstream CA3 network is attracted to a stored pattern and thus undergoes little change. We furthermore show that other aspects of the observed firing patterns can be explained by learning that occurs during behavioral testing. The CA3 thus displays both the learning and recall signatures of an attractor network. These observations, taken together with existing anatomical and behavioral evidence, make the strong case that CA3 constructs associative memories based on attractor dynamics.

  14. Frequency dependence of CA3 spike phase response arising from h-current properties

    Directory of Open Access Journals (Sweden)

    Melodie eBorel

    2013-12-01

    Full Text Available The phase of firing of hippocampal neurons during theta oscillations encodes spatial information. Moreover, the spike phase response to synaptic inputs in individual cells depends on the expression of the hyperpolarisation-activated mixed cation current (Ih, which differs between CA3 and CA1 pyramidal neurons. Here, we compared the phase response of these two cell types, as well as their intrinsic membrane properties. We found that both CA3 and CA1 pyramidal neurons show a voltage sag in response to negative current steps but that this voltage sag is significantly smaller in CA3 cells. Moreover, CA3 pyramidal neurons have less prominent resonance properties compared to CA1 pyramidal neurons. This is consistent with differential expression of Ih by the two cell types. Despite their distinct intrinsic membrane properties, both CA3 and CA1 pyramidal neurons displayed bidirectional spike phase control by excitatory conductance inputs during theta oscillations. In particular, excitatory inputs delivered at the descending phase of a dynamic clamp-induced membrane potential oscillation delayed the subsequent spike by nearly 50 mrad. The effect was shown to be mediated by Ih and was counteracted by increasing inhibitory conductance driving the membrane potential oscillation. Using our experimental data to feed a computational model, we showed that differences in Ih between CA3 and CA1 pyramidal neurons could predict frequency-dependent differences in phase response properties between these cell types. We confirmed experimentally such frequency-dependent spike phase control in CA3 neurons. Therefore, a decrease in theta frequency, which is observed in intact animals during novelty, might switch the CA3 spike phase response from unidirectional to bidirectional and thereby promote encoding of the new context.

  15. Synthesis & photoluminescence study of UV emitting borate phosphor Ca3B2O6:Pb2+

    Science.gov (United States)

    Gawande, A. B.; Sonekar, R. P.; Omanwar, S. K.

    2013-06-01

    The powder sample of Ca3B2O6:Pb2+ has been prepared by a novel method which is slight variation of solution Combustion Synthesis. The synthesis is based on the exothermic reaction between the fuel (Urea) and Oxidizer (Ammonium nitrate). The structure of Ca3B2O6:Pb2+ has been confirmed by comparing the powder XRD pattern of the samples with the standard ICDD data files. The photoluminescent properties of Ca3B2O6:Pb2+ materials were investigated using F-7000 FL spectrophotometer at room temperature. The emission and excitation bands of Ca3B2O6:Pb2+ were observed at 335 and 270 nm, respectively. The Stoke shifts of phosphors Ca3B2O6:Pb2+ were calculated to be 7186 cm-1. The dependence of the emission intensity on the Pb2+ concentration was studied in detail. It has observed that, the phosphor Ca3B2O6:Pb2+ exhibits optimum emission intensity for 0.5 % concentration of Pb2+.

  16. Recurrent synapses and circuits in the CA3 region of the hippocampus: an associative network.

    Directory of Open Access Journals (Sweden)

    Richard eMiles

    2014-01-01

    Full Text Available In the CA3 region of the hippocampus, pyramidal cells excite other pyramidal cells and interneurons. The axons of CA3 pyramidal cells spread throughout most of the region to form an associative network. These connections were first drawn by Cajal and Lorente de No. Their physiological properties were explored to understand epileptiform discharges generated in the region. Synapses between pairs of pyramidal cells involve one or few release sites and are weaker than connections made by mossy fibres on CA3 pyramidal cells. Synapses with interneurons are rather effective, as needed to control unchecked excitation. We examine contributions of recurrent synapses to epileptiform synchrony, to the genesis of sharp waves in the CA3 region and to population oscillations at theta and gamma frequencies. Recurrent connections in CA3, as other associative cortices, have a lower connectivity spread over a larger area than in primary sensory cortices. This sparse, but wide-ranging connectivity serves the functions of an associative network, including acquisition of neuronal representations as activity in groups of CA3 cells and completion involving the recall from partial cues of these ensemble firing patterns.

  17. Why articles are retracted: a retrospective cross-sectional study of retraction notices at BioMed Central.

    Science.gov (United States)

    Moylan, Elizabeth C; Kowalczuk, Maria K

    2016-11-23

    To assess why articles are retracted from BioMed Central journals, whether retraction notices adhered to the Committee on Publication Ethics (COPE) guidelines, and are becoming more frequent as a proportion of published articles. Retrospective cross-sectional analysis of 134 retractions from January 2000 to December 2015. 134 retraction notices were published during this timeframe. Although they account for 0.07% of all articles published (190 514 excluding supplements, corrections, retractions and commissioned content), the rate of retraction is rising. COPE guidelines on retraction were adhered to in that an explicit reason for each retraction was given. However, some notices did not document who retracted the article (eight articles, 6%) and others were unclear whether the underlying cause was honest error or misconduct (15 articles, 11%). The largest proportion of notices was issued by the authors (47 articles, 35%). The majority of retractions were due to some form of misconduct (102 articles, 76%), that is, compromised peer review (44 articles, 33%), plagiarism (22 articles, 16%) and data falsification/fabrication (10 articles, 7%). Honest error accounted for 17 retractions (13%) of which 10 articles (7%) were published in error. The median number of days from publication to retraction was 337.5 days. The most common reason to retract was compromised peer review. However, the majority of these cases date to March 2015 and appear to be the result of a systematic attempt to manipulate peer review across several publishers. Retractions due to plagiarism account for the second largest category and may be reduced by screening manuscripts before publication although this is not guaranteed. Retractions due to problems with the data may be reduced by appropriate data sharing and deposition before publication. Adopting a checklist (linked to COPE guidelines) and templates for various classes of retraction notices would increase transparency of retraction notices

  18. Dendritic solidification in binary alloys

    Science.gov (United States)

    Chopra, M. A.; Glicksman, M. E.; Singh, N. B.

    1988-01-01

    Alloys generally solidify dendritically, and associated with that is the microsegregation of impurities. Pure metals also solidify in dendritic form as 'thermal' dendrites, which actually segregate the system's enthalpy. In this investigation, small additions of solute to succinonitrile have been studied and dendritic growth observed in a supercooled melt. This free dendritic growth-mode is similar to that experienced by equiaxed dendrites found in alloy castings. Observations of these free dendrites include measurement of velocity and tip radius of the dendrites at different supercoolings and solute concentrations.

  19. Twigs into branches: how a filopodium becomes a dendrite.

    Science.gov (United States)

    Heiman, Maxwell G; Shaham, Shai

    2010-02-01

    A dendrite grows by sprouting filopodia, some of which mature into stable dendrite branches that bear synapses and sprout filopodia of their own. Recent work has shown that a filopodium begins deciding to become a stable branch within 1min of contacting a presynaptic partner, but what triggers this decision remains unknown. We consider the evidence for three possible triggers: activity of neurotransmitter receptors, signaling through adhesion proteins, and heightened membrane tension as the filopodium attempts to retract but is held in place by adhesive contacts with the target. Of these, membrane tension-induced signaling is especially appealing, as it would serve as a general reporter of attachment, independent of which specific adhesion molecules are used. 2009 Elsevier Ltd. All rights reserved.

  20. Retraction: Statement of Retraction: Khaki-khatibi F, Yaghoubi A.R ...

    African Journals Online (AJOL)

    The article has been retracted upon the request of the corresponding author, Khaki-khatibi F, due to admitted plagiarism. However, this constitutes a violation of publication ethics. It is a breach of warranties made by the author with respect to originality upon which we received, peer-reviewed, accepted and published the ...

  1. Auditory function in Duane's retraction syndrome.

    Science.gov (United States)

    Ro, A; Chernoff, G; MacRae, D; Orton, R B; Cadera, W

    1990-01-15

    We obtained audiograms and auditory brainstem responses from 44 patients with Duane's retraction syndrome to assess the incidence and nature of hearing deficit. Of 44 patients, seven (15.9%) had evidence of hearing impairment. Three (6.8%) subjects had a temporary conductive hearing loss because of middle ear fluid, and another patient had hearing loss from Crouzon's disease. The remaining three (6.8%) patients demonstrated sensorineural hearing deficit. This hearing impairment was attributed to a cochlear lesion and not to a pontine lesion. We believe that the frequency of sensorineural hearing loss in these patients warrants hearing screening programs similar to those used for infants in neonatal intensive care units.

  2. Oxytocin stimulates hippocampal neurogenesis via oxytocin receptor expressed in CA3 pyramidal neurons.

    Science.gov (United States)

    Lin, Yu-Ting; Chen, Chien-Chung; Huang, Chiung-Chun; Nishimori, Katsuhiko; Hsu, Kuei-Sen

    2017-09-14

    In addition to the regulation of social and emotional behaviors, the hypothalamic neuropeptide oxytocin has been shown to stimulate neurogenesis in adult dentate gyrus; however, the mechanisms underlying the action of oxytocin are still unclear. Taking advantage of the conditional knockout mouse model, we show here that endogenous oxytocin signaling functions in a non-cell autonomous manner to regulate survival and maturation of newly generated dentate granule cells in adult mouse hippocampus via oxytocin receptors expressed in CA3 pyramidal neurons. Through bidirectional chemogenetic manipulations, we also uncover a significant role for CA3 pyramidal neuron activity in regulating adult neurogenesis in the dentate gyrus. Retrograde neuronal tracing combined with immunocytochemistry revealed that the oxytocin neurons in the paraventricular nucleus project directly to the CA3 region of the hippocampus. Our findings reveal a critical role for oxytocin signaling in adult neurogenesis.Oxytocin (OXT) has been implicated in adult neurogenesis. Here the authors show that CA3 pyramidal cells in the adult mouse hippocampus express OXT receptors and receive inputs from hypothalamic OXT neurons; activation of OXT signaling in CA3 pyramidal cells promotes the survival and maturation of newborn neurons in the dentate gyrus in a non-cell autonomous manner.

  3. Network bursting using experimentally constrained single compartment CA3 hippocampal neuron models with adaptation.

    Science.gov (United States)

    Dur-e-Ahmad, Muhammad; Nicola, Wilten; Campbell, Sue Ann; Skinner, Frances K

    2012-08-01

    The hippocampus is a brain structure critical for memory functioning. Its network dynamics include several patterns such as sharp waves that are generated in the CA3 region. To understand how population outputs are generated, models need to consider aspects of network size, cellular and synaptic characteristics and context, which are necessarily 'balanced' in appropriate ways to produce particular outputs. Thick slice hippocampal preparations spontaneously produce sharp waves that are initiated in CA3 regions and depend on the right balance of glutamatergic activities. As a step toward developing network models that can explain important balances in the generation of hippocampal output, we develop models of CA3 pyramidal cells. Our models are single compartment in nature, use an Izhikevich-type structure and involve parameter values that are specifically designed to encompass CA3 intrinsic properties. Importantly, they incorporate spike frequency adaptation characteristics that are directly comparable to those measured experimentally. Excitatory networks using these model cells are able to produce bursting suggesting that the amount of spike frequency adaptation expressed in the biological cells is an essential contributor to network bursting, and as such, may be important for sharp wave generation. The network bursting mechanism is numerically dissected showing the critical balance between adaptation and excitatory drive. The compact nature of our models allows large network simulations to be efficiently computed. This, together with the linkage of our models to cellular characteristics, will allow us to develop an understanding of population output of CA3 hippocampus with direct biological comparisons.

  4. Toward a self-wired active reconstruction of the hippocampal trisynaptic loop: DG-CA3

    Directory of Open Access Journals (Sweden)

    Gregory J. Brewer

    2013-10-01

    Full Text Available The mammalian hippocampus functions to encode and retrieve memories by transiently changing synaptic strengths, yet encoding in individual subregions for transmission between regions remains poorly understood. Toward the goal of better understanding the coding in the trisynaptic pathway from the dentate gyrus (DG to the CA3 and CA1, we report a novel microfabricated device that divides a micro-electrode array into two compartments of separate hippocampal network subregions connected by axons that grow through 3x10x400 μm tunnels. Gene expression by qPCR demonstrated selective enrichment of separate DG, CA3 and CA1 subregions. Reconnection of DG to CA3 altered burst dynamics associated with marked enrichment of GAD67 in DG and GFAP in CA3. Surprisingly, DG axon spike propagation was preferentially unidirectional to the CA3 region at 0.5 m/s with little reverse transmission. Therefore, select hippocampal subregions intrinsically self-wire in anatomically appropriate patterns and maintain their distinct subregion phenotype without external inputs

  5. Is Duane retraction syndrome part of the VACTERL association?

    Science.gov (United States)

    Akar, Serpil; Gokyigit, Birsen; Kavadarli, Isilay; Demirok, Ahmet

    2013-01-01

    We report here a patient with type 1 Duane’s retraction syndrome and multiple congenital abnormalities as a result of the VACTERL association. The presented combination of Duane’s retraction syndrome and the VACTERL association has not been reported in the literature. The present case was instructive for reviewing the continuous spectrum of ocular anomalies that accompany the VACTERL association. PMID:23658476

  6. Jumlah Sel Piramidal CA3 Hipokampus Tikus Putih Jantan pada Berbagai Model Stres Kerja Kronik

    Directory of Open Access Journals (Sweden)

    Fitranto Arjadi

    2014-12-01

    Full Text Available Prolonged and chronic exposure to stress leads to the loss of neurons at the CA3 (cornu ammonis hippocampus region and spatial memory deficits. The aim of this study was to study the number of CA3 pyramidal cells in albino rats that were exposed to chronic stress of works model consisting of paradoxical sleep deprivation (PSD, immobilization, and foot shock stresses. The method applied was the post-test only method with control group experimental design using completed randomized design (CRD on 24 3–4 month old male Wistar rats. The rats were divided into 4 groups: group I (control, group II (PSD stress, group III (immobilization stress, and group IV (footshock stress. The CA3 pyramidal cell hippocampus was stained with toluidine-blue. The number of CA3 pyramidal cell of hippocampus was counted using Image raster v2.1 software at 400x magnification in 10 duplicates for each sample. The study was conducted in six months (April–September 2012 at the Animal Laboratory, Faculty of Medical and Health Sciences, Jenderal Soedirman University. Analysis for the differences in the number of CA3 pyramidal cells was conducted using analysis of variance (ANOVA with Post-Hoc LSD. The results of the ANOVA showed a p value=0.037, meaning that there was significant difference in at least two groups of treatment. Further statistical test using Post-Hoc LSD showed a significant difference between the control group (12.9±2.47 and the chronic immobillization group (9,00±1,53 (p<0.05. In conclusion, the chronic immobillization stress group has the lowest average number of hippocampus CA3 pyramidal cells compared to other groups.

  7. Genetic Characterization of Accumulation of Polyhydroxyalkanoate from Styrene in Pseudomonas putida CA-3

    Science.gov (United States)

    O'Leary, Niall D.; O'Connor, Kevin E.; Ward, Patrick; Goff, Miriam; Dobson, Alan D. W.

    2005-01-01

    Pseudomonas putida CA-3 is capable of accumulating medium-chain-length polyhydroxyalkanoates (MCL-PHAs) when growing on the toxic pollutant styrene as the sole source of carbon and energy. In this study, we report on the molecular characterization of the metabolic pathways involved in this novel bioconversion. With a mini-Tn5 random mutagenesis approach, acetyl-coenzyme A (CoA) was identified as the end product of styrene metabolism in P. putida CA-3. Amplified flanking-region PCR was used to clone functionally expressed phenylacetyl-CoA catabolon genes upstream from the sty operon in P. putida CA-3, previously reported to generate acetyl-CoA moieties from the styrene catabolic intermediate, phenylacetyl-CoA. However, the essential involvement of a (non-phenylacetyl-CoA) catabolon-encoded 3-hydroxyacyl-CoA dehydrogenase is also reported. The link between de novo fatty acid synthesis and PHA monomer accumulation was investigated, and a functionally expressed 3-hydroxyacyl-acyl carrier protein-CoA transacylase (phaG) gene in P. putida CA-3 was identified. The deduced PhaG amino acid sequence shared >99% identity with a transacylase from P. putida KT2440, involved in 3-hydroxyacyl-CoA MCL-PHA monomer sequestration from de novo fatty acid synthesis under inorganic nutrient-limited conditions. Similarly, with P. putida CA-3, maximal phaG expression was observed only under nitrogen limitation, with concomitant PHA accumulation. Thus, β-oxidation and fatty acid de novo synthesis appear to converge in the generation of MCL-PHA monomers from styrene in P. putida CA-3. Cloning and functional characterization of the pha locus, responsible for PHA polymerization/depolymerization is also reported and the significance and future prospects of this novel bioconversion are discussed. PMID:16085828

  8. From atoms to dendrites

    Science.gov (United States)

    Hoyt, J. J.; Karma, Alain; Asta, M. A.; Sun, D. Y.

    2004-04-01

    Dendritic microstructures control the properties of a wide range of advanced materials ranging from nickel-based superalloys used in turbine blades to lightweight aluminum-based alloys for the automotive industry. This article reviews recent progress in quantitative modeling dendritic growth through the combination of state-of-the-art atomistic and phase field simulations. Also shown is how the combination of these two distinct length-scale modeling approaches can yield a parameter-free prediction of the dendrite growth velocity as a function of undercooling for deeply undercooled nickel melts.

  9. Publication misconduct and plagiarism retractions: a systematic, retrospective study.

    Science.gov (United States)

    Stretton, Serina; Bramich, Narelle J; Keys, Janelle R; Monk, Julie A; Ely, Julie A; Haley, Cassandra; Woolley, Mark J; Woolley, Karen L

    2012-10-01

    To investigate whether plagiarism is more prevalent in publications retracted from the medical literature when first authors are affiliated with lower-income countries versus higher-income countries. Secondary objectives included investigating other factors associated with plagiarism (e.g., national language of the first author's country affiliation, publication type, journal ranking). Systematic, controlled, retrospective, bibliometric study. Retracted publications dataset in MEDLINE (search filters: English, human, January 1966-February 2008). Retracted misconduct publications were classified according to the first author's country affiliation, country income level, and country national language, publication type, and ranking of the publishing journal. Standardised definitions and data collection tools were used; data were analysed (odds ratio [OR], 95% confidence limits [CL], chi-squared tests) by an independent academic statistician. Of the 213 retracted misconduct publications, 41.8% (89/213) were retracted for plagiarism, 52.1% (111/213) for falsification/fabrication, 2.3% (5/213) for author disputes, 2.3% (5/213) for ethical issues, and 1.4% (3/213) for unknown reasons. The OR (95% CL) of plagiarism retractions (other misconduct retractions as reference) were higher (P 1 retraction) with publications retracted for plagiarism (11.5%, 9/78) than other types of misconduct (28.9%, 24/83). This is the first study to demonstrate that publications retracted for plagiarism are significantly associated with first authors affiliated with lower-income countries. These findings have implications for developing appropriate evidence-based strategies and allocation of resources to help mitigate plagiarism misconduct.

  10. Dust and Debris Tolerant Retractable Cover Connector

    Science.gov (United States)

    Lewis, Mark E. (Inventor); Dokos, Adam G. (Inventor); Townsend, III, Ivan I. (Inventor); Carlson, Jeffrey W. (Inventor); Bastin, Gary L. (Inventor); Murtland, Kevin A. (Inventor)

    2017-01-01

    A debris exclusion and removal apparatus for connectors which have retractable cover configurations which include internal wafers that clean the connectors prior to mating. XXXX connectors. More particularly, embodiments relate to dust tolerant connectors. Some embodiments also relate to an intelligent connector system capable of detecting damage to or faults within a conductor and then rerouting the energy to a non-damaged spare conductor. Discussion Connectors of the present invention may be used to transfer electrical current, fluid, and gas in a wide variety of environments containing dust and other debris, wherein that debris may present substantial challenges. For example, lunar/Martian dust intrusion and/or accumulation in connectors used to transfer oxygen, hydrogen, nitrogen, etc., may lead to larger system failures as well as loss of life in extraterrestrial human exploration endeavors. Additionally, embodiments of the present invention may also be suitable for use where connectors must resist water intrusion, such as terrestrial deep water operations.

  11. Opening and retraction of particulate soap films

    Science.gov (United States)

    Timounay, Yousra; Lorenceau, Elise; Rouyer, Florence

    2015-07-01

    We study for the first time the bursting dynamics of thin liquid films laden with hydrophobic micronic particles either with free or constrained edges. We highlight that the particles can arrange in bilayer or monolayer configurations and explore a range of particles coverage from zero to random close packing. When the particles bridge the two interfaces (monolayer configuration) of free-edge films, the hole opens intermittently. For the other cases, we observe constant retraction velocities, modeled by balancing liquid and particles inertia against surface tension as in Taylor-Culick theory. But, this approach is only valid up to a critical value of particles coverage due to the interplay between the interfaces and the friction between particles.

  12. Visibility of retractions: a cross-sectional one-year study.

    Science.gov (United States)

    Decullier, Evelyne; Huot, Laure; Samson, Géraldine; Maisonneuve, Hervé

    2013-06-19

    Retraction in Medline medical literature experienced a tenfold increase between 1999 and 2009, however retraction remains a rare event since it represents 0.02% of publications. Retractions used to be handled following informal practices until they were formalized in 2009 by the Committee on Publication Ethics (COPE). The objective of our study was to describe the compliance to these guidelines. All retractions published in 2008 were identified using the Medline publication type "retraction of publication". The notices of retraction and the original articles were retrieved. For each retraction, we identified the reason for retraction, the country of affiliation of the first author, the time to retraction, the impact factor of the journal and the mention of retraction on the original article. Overall, 244 retractions were considered for analysis. Formal retraction notices could not be retrieved for 9. Of the 235 retractions available (96%), the reason was not detailed for 21 articles (9%). The most cited reasons were mistakes (28%), plagiarism (20%), fraud (14%) and overlap (11%). The original paper or its location was found for 233 retractions (95%). Of these, 22% were available with no mention of the retraction. A standard retraction form could be helpful, with a check list of major reason, leaving the editor free to provide the reader with any further information. Original articles should remain available with a clear mention of the retraction.

  13. Data of evolutionary structure change: 1E1CA-3BICA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1E1CA-3BICA 1E1C 3BIC A A STLPRFDSVDLGNAPVPADAARRFEELAAKAGTGE----...yChain> 3BIC A 3BICA...ryChain> 3BIC A 3BICA LIEKMFQPKNS...D> 2 3BIC A 3BICAA 3BICA DNIKQ--QGLSV

  14. Doublecortin knockout mice show normal hippocampal-dependent memory despite CA3 lamination defects.

    Directory of Open Access Journals (Sweden)

    Johanne Germain

    Full Text Available Mutations in the human X-linked doublecortin gene (DCX cause major neocortical disorganization associated with severe intellectual disability and intractable epilepsy. Although Dcx knockout (KO mice exhibit normal isocortical development and architecture, they show lamination defects of the hippocampal pyramidal cell layer largely restricted to the CA3 region. Dcx-KO mice also exhibit interneuron abnormalities. As well as the interest of testing their general neurocognitive profile, Dcx-KO mice also provide a relatively unique model to assess the effects of a disorganized CA3 region on learning and memory. Based on its prominent anatomical and physiological features, the CA3 region is believed to contribute to rapid encoding of novel information, formation and storage of arbitrary associations, novelty detection, and short-term memory. We report here that Dcx-KO adult males exhibit remarkably preserved hippocampal- and CA3-dependant cognitive processes using a large battery of classical hippocampus related tests such as the Barnes maze, contextual fear conditioning, paired associate learning and object recognition. In addition, we show that hippocampal adult neurogenesis, in terms of proliferation, survival and differentiation of granule cells, is also remarkably preserved in Dcx-KO mice. In contrast, following social deprivation, Dcx-KO mice exhibit impaired social interaction and reduced aggressive behaviors. In addition, Dcx-KO mice show reduced behavioral lateralization. The Dcx-KO model thus reinforces the association of neuropsychiatric behavioral impairments with mouse models of intellectual disability.

  15. In vitro evolution of styrene monooxygenase from Pseudomonas putida CA-3 for improved epoxide synthesis

    NARCIS (Netherlands)

    Gursky, Lucas J.; Nikodinovic-Runic, Jasmina; Feenstra, K Anton; O'Connor, Kevin E.

    2010-01-01

    The styAB genes from Pseudomonas putida CA-3, which encode styrene monooxygenase, were subjected to three rounds of in vitro evolution using error-prone polymerase chain reaction with a view to improving the rate of styrene oxide and indene oxide formation. Improvements in styrene monooxygenase

  16. Optimization principles of dendritic structure

    Directory of Open Access Journals (Sweden)

    Borst Alexander

    2007-06-01

    Full Text Available Abstract Background Dendrites are the most conspicuous feature of neurons. However, the principles determining their structure are poorly understood. By employing cable theory and, for the first time, graph theory, we describe dendritic anatomy solely on the basis of optimizing synaptic efficacy with minimal resources. Results We show that dendritic branching topology can be well described by minimizing the path length from the neuron's dendritic root to each of its synaptic inputs while constraining the total length of wiring. Tapering of diameter toward the dendrite tip – a feature of many neurons – optimizes charge transfer from all dendritic synapses to the dendritic root while housekeeping the amount of dendrite volume. As an example, we show how dendrites of fly neurons can be closely reconstructed based on these two principles alone.

  17. Electronic and Optical Properties of Ca3MN (M = Ge, Sn, Pb, P, As, Sb and Bi) Antiperovskite Compounds

    Science.gov (United States)

    Iqbal, Samad; Murtaza, G.; Khenata, R.; Mahmood, Asif; Yar, Abdullah; Muzammil, M.; Khan, Matiullah

    2016-08-01

    The electronic and optical properties of cubic antiperovskites Ca3MN (M = Ge, Sn, Pb, P, As, Sb and Bi) were investigated by applying the full potential linearized augmented plane wave plus local orbitals (FP-LAPW + lo) scheme based on density functional theory. Different exchange correlation potentials were adopted for the calculations. The results of band structure and density of states show that, by changing the central anion of Ca3MN, the nature of the materials change from metallic (Ca3GeN, Ca3SnN, Ca3PbN) to semiconducting with small band gaps (Ca3SbN and Ca3BiN) to insulating (Ca3PN and Ca3AsN). The optical properties such as dielectric function, absorption coefficient, optical conductivity, reflectivity and refractive indices have also been calculated. The results reveal that all the studied compounds are optically active in the visible and ultraviolet energy regions, and therefore can be effectively utilized for optoelectronic devices.

  18. Retraction: Plagiarism in the article Emphysematous cystitis and ...

    African Journals Online (AJOL)

    Retraction: Plagiarism in the article Emphysematous cystitis and emphysematous pyelitis: a clinically misleading association. Mustapha Ahsaini et al. The Pan African Medical Journal. 2013;16:18. (doi:10.11604/pamj.2013.16.18.2505)

  19. Longitudinal Effects of Ketamine on Dendritic Architecture In Vivo in the Mouse Medial Frontal Cortex123

    Science.gov (United States)

    Phoumthipphavong, Victoria; Barthas, Florent; Hassett, Samantha

    2016-01-01

    Abstract A single subanesthetic dose of ketamine, an NMDA receptor antagonist, leads to fast-acting antidepressant effects. In rodent models, systemic ketamine is associated with higher dendritic spine density in the prefrontal cortex, reflecting structural remodeling that may underlie the behavioral changes. However, turnover of dendritic spines is a dynamic process in vivo, and the longitudinal effects of ketamine on structural plasticity remain unclear. The purpose of the current study is to use subcellular resolution optical imaging to determine the time course of dendritic alterations in vivo following systemic ketamine administration in mice. We used two-photon microscopy to visualize repeatedly the same set of dendritic branches in the mouse medial frontal cortex (MFC) before and after a single injection of ketamine or saline. Compared to controls, ketamine-injected mice had higher dendritic spine density in MFC for up to 2 weeks. This prolonged increase in spine density was driven by an elevated spine formation rate, and not by changes in the spine elimination rate. A fraction of the new spines following ketamine injection was persistent, which is indicative of functional synapses. In a few cases, we also observed retraction of distal apical tuft branches on the day immediately after ketamine administration. These results indicate that following systemic ketamine administration, certain dendritic inputs in MFC are removed immediately, while others are added gradually. These dynamic structural modifications are consistent with a model of ketamine action in which the net effect is a rebalancing of synaptic inputs received by frontal cortical neurons. PMID:27066532

  20. Potential role of lampalizumab for treatment of geographic atrophy [Retraction

    Directory of Open Access Journals (Sweden)

    Rhoades W

    2015-06-01

    Full Text Available Rhoades W, Dickson D, Do DV. Clinical Ophthalmology. 2015;9:1049–1056.The authors respectfully retract this review article. We realize that some of the results referenced in this manuscript are preliminary analyses and may not reflect the final data and conclusions of the clinical trials cited.Sincerely,Diana V Do, MDWilliam Rhoades, MDDrew Dickson, BAThis retraction relates to this paper.

  1. Retracted: Post-stroke epilepsy in Polish paediatric patients.

    Science.gov (United States)

    Kopyta, Ilona; Sarecka-Hujar, Beata

    2015-08-01

    The above article, published online on 5 October 2013 in Wiley Online Library Early View (http://onlinelibrary.wiley.com/), has been retracted by agreement between the authors, the journal Editor in Chief, Dr Peter Baxter, and John Wiley & Sons Ltd. The retraction has been agreed due to several errors in the statistics. These errors make interpretation of the data difficult and the validity of the conclusions questionable. © 2013 Mac Keith Press.

  2. Retractions in general and internal medicine in a high-profile scientific indexing database

    OpenAIRE

    Almeida,Renan Moritz Varnier Rodrigues de; Catelani,Fernanda; Fontes-Pereira,Aldo José; Gave,Nárrima de Souza

    2016-01-01

    CONTEXT AND OBJECTIVE: Increased frequency of retractions has recently been observed, and retractions are important events that deserve scientific investigation. This study aimed to characterize cases of retraction within general and internal medicine in a high-profile database, with interest in the country of origin of the article and the impact factor (IF) of the journal in which the retraction was made. DESIGN AND SETTING: This study consisted of reviewing retraction notes in the Thomso...

  3. Influence of Ca substitution by Mg on the Ca3Co4O9 performances

    Directory of Open Access Journals (Sweden)

    Constantinescu, G.

    2014-02-01

    Full Text Available Ca3-xMgxCo4O9 polycrystalline thermoelectric ceramics with small amounts of Mg have been synthesized by the classical solid state method. Microstructural characterizations have shown that all the Mg has been incorporated into the Ca3Co4O9 structure and no Mg-based secondary phases have been identified. Apparent density measurements have shown that samples do not modify their density until 0.05 Mg content, decreasing for higher contents. Electrical resistivity decreases and Seebeck coefficient slightly raises when Mg content increases until 0.05 Mg addition. The improvement in both parameters leads to higher power factor values than the usually obtained in samples prepared by the conventional solid state routes and close to those obtained in textured materials.Se han preparado cerámicas termoeléctricas policristalinas de Ca3-xMgxCo4O9, con pequeñas cantidades de Mg, utilizando el método clásico de estado sólido. La caracterización microestructural ha mostrado que el Mg se ha incorporado en la estructura del Ca3Co4O9 y que no se han formado fases secundarias con el Mg. Las medidas de densidad aparente han mostrado que las muestras prácticamente poseen la misma densidad hasta un contenido de 0.05 Mg, disminuyendo para contenidos mayores. La resistividad eléctrica disminuye y el coeficiente Seebeck aumenta cuando el contenido de Mg se incrementa hasta valores de 0.05. La mejora de ambos parámetros conduce a valores del factor de potencia mayores que los obtenidos en muestras preparadas por la vía convencional de estado sólido, alcanzando valores próximos a los que se encuentran en materiales texturados.

  4. NMDA-dependent phase synchronization between septal and temporal CA3 hippocampal networks.

    Science.gov (United States)

    Gu, Ning; Jackson, Jesse; Goutagny, Romain; Lowe, Germaine; Manseau, Frédéric; Williams, Sylvain

    2013-05-08

    Increasing evidence suggests that synchronization between brain regions is essential for information exchange and memory processes. However, it remains incompletely known which synaptic mechanisms contribute to the process of synchronization. Here, we investigated whether NMDA receptor-mediated synaptic plasticity was an important player in synchronization between septal and temporal CA3 areas of the rat hippocampus. We found that both the septal and temporal CA3 regions intrinsically generate weakly synchronized δ frequency oscillations in the complete hippocampus in vitro. Septal and temporal oscillators differed in frequency, power, and rhythmicity, but both required GABAA and AMPA receptors. NMDA receptor activation, and most particularly the NR2B subunit, contributed considerably more to rhythm generation at the temporal than the septal region. Brief activation of NMDA receptors by application of extracellular calcium dramatically potentiated the septal-temporal coherence for long durations (>40 min), an effect blocked by the NMDA antagonist AP-5. This long-lasting NMDA-receptor-dependent increase in coherence was also associated with an elevated phase locking of spikes locally and across regions. Changes in coherence between oscillators were associated with increases in phase locking between oscillators independent of oscillator amplitude. Finally, although the septal CA3 rhythm preceded the oscillations in temporal regions in control conditions, this was reversed during the NMDA-dependent enhancement in coherence, suggesting that NMDA receptor activation can change the direction of information flow along the septotemporal CA3 axis. These data demonstrate that plastic changes in communication between septal and temporal hippocampal regions can arise from the NMDA-dependent phase locking of neural oscillators.

  5. Synaptic plasticity of the CA3 commissural projection in epileptic rats: an in vivo electrophysiological study.

    Science.gov (United States)

    Queiroz, Claudio M T; Mello, Luiz Eugênio

    2007-05-01

    The hippocampal commissural system has recently been found to participate in the generation of mirror foci after kainate-induced epileptiform discharges. In the present study we have evaluated the electrophysiological alterations in the ventral commissural hippocampal system that originates in the pyramidal CA3 cells and connects to the contralateral CA3 pyramidal cells. The recordings were performed in epileptic rats 24 h after an early behavioural spontaneous seizure between 5 and 21 days after pilocarpine-induced status epilepticus. Epileptic animals presented a marked increase in neuronal excitability after contralateral CA3 stimulation, characterized by a shift to the left in the input-output curve and the clear appearance of a population spike. Input-output curves showed that maximum population excitatory postsynaptic potential (pEPSP) amplitude was decreased by 30%, which could be related to cell death in these regions. Using paired-pulse protocols to evaluate a fast form of synaptic plasticity (i.e. paired-pulse facilitation) we observed that, despite the similar pEPSP amplitude between control and experimental groups, only epileptic animals showed strong paired-pulse population spike facilitation up to 500 ms interstimulus intervals. Despite increased excitability and pyramidal cell death, epileptic animals presented a more robust potentiation after high-frequency stimulation than controls, a protocol used to evaluate a slow form of synaptic plasticity (i.e. long-term potentiation). The increased excitability in CA3 pyramidal neurons enhanced the probability of burst activity in these neurons; this could lead to greater CA1 synchronization. The present results might have relevance for the understanding of epileptogenesis and of learning and memory deficits seen in temporal lobe epilepsy.

  6. Dendritic Polymers for Theranostics.

    Science.gov (United States)

    Ma, Yuan; Mou, Quanbing; Wang, Dali; Zhu, Xinyuan; Yan, Deyue

    2016-01-01

    Dendritic polymers are highly branched polymers with controllable structures, which possess a large population of terminal functional groups, low solution or melt viscosity, and good solubility. Their size, degree of branching and functionality can be adjusted and controlled through the synthetic procedures. These tunable structures correspond to application-related properties, such as biodegradability, biocompatibility, stimuli-responsiveness and self-assembly ability, which are the key points for theranostic applications, including chemotherapeutic theranostics, biotherapeutic theranostics, phototherapeutic theranostics, radiotherapeutic theranostics and combined therapeutic theranostics. Up to now, significant progress has been made for the dendritic polymers in solving some of the fundamental and technical questions toward their theranostic applications. In this review, we briefly summarize how to control the structures of dendritic polymers, the theranostics-related properties derived from their structures and their theranostics-related applications.

  7. Quasi-Two-Dimensional Metallic Ground State of Ca3Ru2O7

    Science.gov (United States)

    Yoshida, Yoshiyuki

    2005-03-01

    Ca3Ru2O7 is a three-dimensional antiferromagnetic metal between a first-order metal to nonmetal transition at 48 K and the antiferromagnetic ordering temperature, TN=56 K[1]. The crystal structure is the double layered Ruddlesden-Popper type with the Bb21m space group, which has both the rotation and tiling of RuO6 octahedra. We have succeeded in growing single crystals of Ca3Ru2O7 using a floating-zone method for the first time. The temperature dependence of the electrical resistivity establishes that Ca3Ru2O7 develops a quasi-two-dimensional metallic ground state below 30 K, from which the observed quantum oscillation derives. The specific heat measurement reveals the electronic specific-heat coefficient γ to be as small as 1.7 mJ/Ru mol K^2[2]. From the results of powder neutron diffractions, we proposed the most possible magnetic structure with an antiferromagnetic ordering. The field dependence of the resistivity at the metamagnetic transition around 6 T can be explained by the tunneling magnetoresistance. This work was done in collaboration with S. I. Ikeda, N. Shirakawa, C. H. Lee, M. Kosaka, and S. Katano. [1] G. Cao et al., Phys. Rev. Lett. 78 (1997) 1751. [2] Y. Yoshida et al., Phys. Rev. B 69 (2004) R220411.

  8. Transport and NMR characteristics of the skutterudite-related compound Ca3Rh4Sn13

    Science.gov (United States)

    Tseng, C. W.; Kuo, C. N.; Li, B. S.; Wang, L. M.; Gippius, A. A.; Kuo, Y. K.; Lue, C. S.

    2018-02-01

    We report the electronic properties of the Yb3Rh4Sn13-type single crystalline Ca3Rh4Sn13 by means of the electrical resistivity, Hall coefficient, Seebeck coefficient, thermal conductivity, as well as 119Sn nuclear magnetic resonance (NMR) measurements. The negative sign of the Hall coefficient and Seebeck coefficient at low temperatures suggests that the n-type carriers dominate the electrical transport in Ca3Rh4Sn13, in contrast to the observations in Sr3Rh4Sn13 which has a p-type conduction. Such a finding indicates a significant difference in the electronic features between these two stannides. Furthermore, we analyzed the temperature-dependent 119Sn NMR spin-lattice relaxation rate for Ca3Rh4Sn13, (Sr0.7Ca0.3)3Rh4Sn13, and Sr3Rh4Sn13 to examine the change of the electronic Fermi-level density of states (DOS) in (Sr1-xCax)3Rh4Sn13. It indicates that the Sn 5s partial Fermi-level DOS enhances with increasing the Ca content, being consistent with the trend of the superconducting temperature. Since the total Fermi-level DOS usually obeys the same trend of the partial Fermi-level DOS, the NMR analysis provides microscopic evidence for the correlation between the electronic DOS and superconductivity of the (Sr1-xCax)3Rh4Sn13 system.

  9. Permanent reduction of seizure threshold in post-ischemic CA3 pyramidal neurons.

    Science.gov (United States)

    Congar, P; Gaïarsa, J L; Popovici, T; Ben-Ari, Y; Crépel, V

    2000-04-01

    The effects of ischemia were examined on CA3 pyramidal neurons recorded in hippocampal slices 2-4 mo after a global forebrain insult. With intracellular recordings, CA3 post-ischemic neurons had a more depolarized resting membrane potential but no change of the input resistance, spike threshold and amplitude, fast and slow afterhyperpolarization (AHP) or ADP, and firing properties in response to depolarizing pulses. With both field and whole-cell recordings, synaptic responses were similar in control and post-ischemic neurons. Although there were no spontaneous network-driven discharges, the post-ischemic synaptic network had a smaller threshold to generate evoked and spontaneous synchronized burst discharges. Thus lower concentrations of convulsive agents (kainate, high K(+)) triggered all-or-none network-driven synaptic events in post-ischemic neurons more readily than in control ones. Also, paired-pulse protocol generates, in post-ischemics but not controls, synchronized field burst discharges when interpulse intervals ranged from 60 to 100 ms. In conclusion, 2-4 mo after the insult, the post-ischemic CA3 pyramidal cells are permanently depolarized and have a reduced threshold to generate synchronized bursts. This may explain some neuropathological and behavioral consequences of ischemia as epileptic syndromes observed several months to several years after the ischemic insult.

  10. Partial Aminoglycoside Lesions in Vestibular Epithelia Reveal Broad Sensory Dysfunction Associated with Modest Hair Cell Loss and Afferent Calyx Retraction.

    Science.gov (United States)

    Sultemeier, David R; Hoffman, Larry F

    2017-01-01

    Although the effects of aminoglycoside antibiotics on hair cells have been investigated for decades, their influences on the dendrites of primary afferent neurons have not been widely studied. This is undoubtedly due to the difficulty in disassociating pathology to dendritic processes from that resulting from loss of the presynaptic hair cell. This was overcome in the present investigation through development of a preparation using Chinchilla laniger that enabled direct perilymphatic infusion. Through this strategy we unmasked gentamicin's potential effects on afferent calyces. The pathophysiology of the vestibular neuroepithelia after post-administration durations of 0.5 through 6 months was assessed using single-neuron electrophysiology, immunohistochemistry, and confocal microscopy. Hair cell densities within cristae central zones (0.5-, 1-, 2-, and 6-months) and utricle peri- and extrastriola (6-months) regions were determined, and damage to calretinin-immunoreactive calyces was quantified. Gentamicin-induced hair cell loss exhibited a profile that reflected elimination of a most-sensitive group by 0.5-months post-administration (18.2%), followed by loss of a second group (20.6%) over the subsequent 5.5 months. The total hair cell loss with this gentamicin dose (approximately 38.8%) was less than the estimated fraction of type I hair cells in the chinchilla's crista central zone (approximately 60%), indicating that viable type I hair cells remained. Extensive lesions to afferent calyces were observed at 0.5-months, though stimulus-evoked modulation was intact at this post-administration time. Widespread compromise to calyx morphology and severe attenuation of stimulus-evoked afferent discharge modulation was found at 1 month post-administration, a condition that persisted in preparations examined through the 6-month post-administration interval. Spontaneous discharge was robust at all post-administration intervals. All calretinin-positive calyces had retracted

  11. Partial Aminoglycoside Lesions in Vestibular Epithelia Reveal Broad Sensory Dysfunction Associated with Modest Hair Cell Loss and Afferent Calyx Retraction

    Science.gov (United States)

    Sultemeier, David R.; Hoffman, Larry F.

    2017-01-01

    retracted at 2 and 6 months post-administration. We found no evidence of morphologic or physiologic recovery. These results indicate that gentamicin-induced partial lesions to vestibular epithelia include hair cell loss (ostensibly reflecting an apoptotic effect) that is far less extensive than the compromise to stimulus-evoked afferent discharge modulation and retraction of afferent calyces (reflecting non-apoptotic effects). Additionally, calyx retraction cannot be completely accounted for by loss of type I hair cells, supporting the possibility for direct action of gentamicin on the afferent dendrite. PMID:29163044

  12. Ischemic damage in hippocampal CA1 is dependent on glutamate release and intact innervation from CA3

    DEFF Research Database (Denmark)

    Benveniste, H; Jørgensen, M B; Sandberg, M

    1989-01-01

    The removal of glutamatergic afferents to CA1 by destruction of the CA3 region is known to protect CA1 pyramidal cells against 10 min of transient global ischemia. To investigate further the pathogenetic significance of glutamate, we measured the release of glutamate in intact and CA3-lesioned CA1...... hippocampal tissue. In intact CA1 hippocampal tissue, glutamate increased sixfold during ischemia; in the CA3-lesioned CA1 region, however, glutamate only increased 1.4-fold during ischemia. To assess the neurotoxic potential of the ischemia-induced release of glutamate, we injected the same concentration...... of glutamate into the CA1 region as is released during ischemia in normal, CA3-lesioned, and ischemic CA1 tissue. We found that this particular concentration of glutamate was sufficient to destroy CA1 pyramids in the vicinity of the injection site in intact and CA3-lesioned CA1 tissue when administered during...

  13. Cryotherapy in Dendritic Keratitis.

    African Journals Online (AJOL)

    This study evaluates the effectiveness of cryotherapy in the treatment of dendritic Keratitis where antiviral agents are not available. The results show some improvement in visual acuity while one patient has a drop in vision. The extent of corneal scarring appears to depend on the duration of the disease and extent of stroma.

  14. Modification of dendritic development.

    Science.gov (United States)

    Feria-Velasco, Alfredo; del Angel, Alma Rosa; Gonzalez-Burgos, Ignacio

    2002-01-01

    Since 1890 Ramón y Cajal strongly defended the theory that dendrites and their processes and spines had a function of not just nutrient transport to the cell body, but they had an important conductive role in neural impulse transmission. He extensively discussed and supported this theory in the Volume 1 of his extraordinary book Textura del Sistema Nervioso del Hombre y de los Vertebrados. Also, Don Santiago significantly contributed to a detailed description of the various neural components of the hippocampus and cerebral cortex during development. Extensive investigation has been done in the last Century related to the functional role of these complex brain regions, and their association with learning, memory and some limbic functions. Likewise, the organization and expression of neuropsychological qualities such as memory, exploratory behavior and spatial orientation, among others, depend on the integrity and adequate functional activity of the cerebral cortex and hippocampus. It is known that brain serotonin synthesis and release depend directly and proportionally on the availability of its precursor, tryptophan (TRY). By using a chronic TRY restriction model in rats, we studied their place learning ability in correlation with the dendritic spine density of pyramidal neurons in field CA1 of the hippocampus during postnatal development. We have also reported alterations in the maturation pattern of the ability for spontaneous alternation and task performance evaluating short-term memory, as well as adverse effects on the density of dendritic spines of hippocampal CA1 field pyramidal neurons and on the dendritic arborization and the number of dendritic spines of pyramidal neurons from the third layer of the prefrontal cortex using the same model of TRY restriction. The findings obtained in these studies employing a modified Golgi method, can be interpreted as a trans-synaptic plastic response due to understimulation of serotoninergic receptors located in the

  15. Pattern separation of emotional information in hippocampal dentate and CA3.

    Science.gov (United States)

    Leal, Stephanie L; Tighe, Sarah K; Jones, Craig K; Yassa, Michael A

    2014-09-01

    Emotional arousal, mediated by the amygdala, is known to modulate episodic memories stored by the hippocampus, a region involved in pattern separation (the process by which similar representations are independently stored). While emotional modulation and pattern separation have been examined independently, this study attempts to link the two areas of research to propose an alternative account for how emotion modulates episodic memory. We used an emotional discrimination task designed to tax pattern separation of emotional information by concurrently varying emotional valence and similarity of stimuli. To examine emotional modulation of memory at the level of hippocampal subfields, we used high-resolution fMRI (1.5 mm isotropic) of the medial temporal lobe. Consistent with prior reports, we observed engagement of the hippocampal dentate gyrus (DG) and CA3 during accurate discrimination of highly similar items (behavioral correlate of pattern separation). Furthermore, we observed an emotional modulation of this signal (negative > neutral) specific to trials on which participants accurately discriminated similar emotional items. The amygdala was also modulated by emotion, regardless of the accuracy of discrimination. Additionally, we found aberrant amygdala-hippocampal network activity in a sample of adults with depressive symptoms. In this sample, amygdala activation was enhanced and DG/CA3 activation was diminished during emotional discrimination compared to those without depressive symptoms. Depressive symptom severity was also negatively correlated with DG/CA3 activity. This study suggests a novel mechanistic account for how emotional information is processed by hippocampal subfields as well as how this network may be altered in mood disorders. © 2014 Wiley Periodicals, Inc.

  16. High-temperature stability of thermoelectric Ca3Co4O9 thin films

    DEFF Research Database (Denmark)

    Brinks, P.; Van Nong, Ngo; Pryds, Nini

    2015-01-01

    An enhanced thermal stability in thermoelectric Ca3Co4O9 thin films up to 550 °C in an oxygen rich environment was demonstrated by high-temperature electrical and X-ray diffraction measurements. In contrast to generally performed heating in helium gas, it is shown that an oxygen/helium mixture...... provides sufficient thermal contact, while preventing the previously disregarded formation of oxygen vacancies. Combining thermal cycling with electrical measurements proves to be a powerful tool to study the real intrinsic thermoelectric behaviour of oxide thin films at elevated temperatures. © 2015 AIP...

  17. Regulation of phenylacetic acid uptake is sigma54 dependent in Pseudomonas putida CA-3.

    LENUS (Irish Health Repository)

    O' Leary, Niall D

    2011-10-13

    Abstract Background Styrene is a toxic and potentially carcinogenic alkenylbenzene used extensively in the polymer processing industry. Significant quantities of contaminated liquid waste are generated annually as a consequence. However, styrene is not a true xenobiotic and microbial pathways for its aerobic assimilation, via an intermediate, phenylacetic acid, have been identified in a diverse range of environmental isolates. The potential for microbial bioremediation of styrene waste has received considerable research attention over the last number of years. As a result the structure, organisation and encoded function of the genes responsible for styrene and phenylacetic acid sensing, uptake and catabolism have been elucidated. However, a limited understanding persists in relation to host specific regulatory molecules which may impart additional control over these pathways. In this study the styrene degrader Pseudomonas putida CA-3 was subjected to random mini-Tn5 mutagenesis and mutants screened for altered styrene\\/phenylacetic acid utilisation profiles potentially linked to non-catabolon encoded regulatory influences. Results One mutant, D7, capable of growth on styrene, but not on phenylacetic acid, harboured a Tn5 insertion in the rpoN gene encoding σ54. Complementation of the D7 mutant with the wild type rpoN gene restored the ability of this strain to utilise phenylacetic acid as a sole carbon source. Subsequent RT-PCR analyses revealed that a phenylacetate permease, PaaL, was expressed in wild type P. putida CA-3 cells utilising styrene or phenylacetic acid, but could not be detected in the disrupted D7 mutant. Expression of plasmid borne paaL in mutant D7 was found to fully restore the phenylacetic acid utilisation capacity of the strain to wild type levels. Bioinformatic analysis of the paaL promoter from P. putida CA-3 revealed two σ54 consensus binding sites in a non-archetypal configuration, with the transcriptional start site being resolved by

  18. Typology of Retractable Roof Structures in Stadiums and Sports Halls

    Directory of Open Access Journals (Sweden)

    Andrej Mahovič

    2015-10-01

    Full Text Available Retractable roof structures are one of the four fundamental systems (in addition to the playing area, stands and facade in a stadium and sports hall. The roof protects users against various weather conditions and creates optimum circumstances for carrying out different activities. Stadiums and sports halls with retractable roof structures can host a greater variety of activities, improve the quality of their implementation and the quality of visitors’ experience, and affect the perception and experience of people using or observing such buildings. A retractable roof structure allows for natural lighting and ventilation of the venue, gives optimal conditions for grass growth on the playing field, and reduces costs of use and maintenance of the building. Different typologies of movement of roof structures (frequency of opening and closing, design of the structure, and methods of movement are categorised in terms of their architectural and structural design. Application of different retractable roof systems worldwide is indicator of their effectiveness and efficiency, and is basis for use of movement also in other fundamental systems of stadiums and sports halls. Research and identification of characteristics of retractable roof structures lead to the design of new moving systems that can with the application of the moving principle change the purpose of movable elements or assume the characteristics of other fundamental systems.

  19. Exploring the characteristics, global distribution and reasons for retraction of published articles involving human research participants: a literature survey.

    Science.gov (United States)

    Li, Guowei; Kamel, Mariam; Jin, Yanling; Xu, Michael Kuan; Mbuagbaw, Lawrence; Samaan, Zainab; Levine, Mitchell Ah; Thabane, Lehana

    2018-01-01

    Article retraction is a measure taken by journals or authors where there is evidence of research misconduct or error, redundancy, plagiarism or unethical research. Recently, the retraction of scientific publications has been on the rise. In this survey, we aimed to describe the characteristics and distribution of retracted articles and the reasons for retractions. We searched retracted articles on the PubMed database and Retraction Watch website from 1980 to February 2016. The primary outcomes were the characteristics and distribution of retracted articles and the reasons for retractions. The secondary outcomes included how article retractions were handled by journals and how to improve the journal practices toward article retractions. We included 1,339 retracted articles. Most retracted articles had six authors or fewer. Article retraction was most common in the USA (26%), Japan (11%) and Germany (10%). The main reasons for article retraction were misconduct (51%, n = 685) and error (14%, n = 193). There were 66% (n = 889) of retracted articles having male senior or corresponding authors. Of the articles retracted after August 2010, 63% (n = 567) retractions were reported on Retraction Watch. Large discrepancies were observed in the ways that different journals handled article retractions. For instance, articles were completely withdrawn from some journals, while in others, articles were still available with no indication of retraction. Likewise, some retraction notices included a detailed account of the events that led to article retraction, while others only consisted of a statement indicating the article retraction. The characteristics, geographic distribution and reasons for retraction of published articles involving human research participants were examined in this survey. More efforts are needed to improve the consistency and transparency of journal practices toward article retractions.

  20. Nanomedicine to improve drug delivery outcomes [Retracted

    Directory of Open Access Journals (Sweden)

    Meenakshi Joshi

    2012-01-01

    Full Text Available The early genesis of the concept of nanomedicine sprang from the visionary idea that tiny nanorobots and related machines could be designed, manufactured, and introduced into the human body to perform cellular repairs at the molecular level. Nanomedicine today has branched out in hundreds of different directions, each of them embodying the key insight that the ability to structure materials and devices at the molecular scale can bring enormous immediate benefits in the research and practice of medicine. The integration of nanotechnology with biology and medicine has given birth to a new field of science called "Nanomedicine". Research into the rational delivery and targeting of pharmaceutical, therapeutic, and diagnostic agents is at the forefront of projects in nanomedicine. These involve the identification of precise targets (cells and receptors related to specific clinical conditions and choice of the appropriate nanocarriers to achieve the required responses while minimizing the side effects. Mononuclear phagocytes, dendritic cells, endothelial cells, and cancers (tumor cells as well as tumor neovasculature are key targets. The ultimate goal of nanomedicine is to develop well-engineered nanotools for the prevention, diagnosis, and treatment of many diseases. Nanomedicine today has branched out in hundreds of different directions, each of them embodying the key insight that the ability to structure materials and devices at the molecular scale can bring enormous immediate benefits in the research and practice of medicine.

  1. Antiepileptic effects of GABAb receptor activation in area CA3 of rat hippocampus.

    Science.gov (United States)

    Morrisett, R A; Lewis, D V; Swartzwelder, H S; Wilson, W A

    1993-01-15

    The role of GABAb receptor activation in the expression of both interictal and ictal phenomena was investigated in slices of area CA3 of the rat hippocampal formation. Interictal-like bursts occurred following application of high frequency trains to the Schaffer collaterals. When two bursts were triggered using paired stimuli, profound depression of the second burst was seen 150-600 ms following the first burst. GABAb receptor antagonists potently reversed the paired pulse depression of the interictal-like bursts. Reversal of the paired depression was also accomplished by increasing the extracellular concentration of K+ by 2-3 mM. Additional experiments were performed in area CA3 to determine the role of GABAb receptor activation on the expression of ictal phenomena. Electrographic seizures (EGSs) were induced by application of high frequency trains. 2-Hydroxy-saclofen (200 microM) significantly decreased the duration of trains required to elicit EGSs. Taken together, these data suggest that GABAb receptor activation has potent inhibitory effects on both ictal and interictal-like events.

  2. Pycnogenol protects CA3-CA1 synaptic function in a rat model of traumatic brain injury.

    Science.gov (United States)

    Norris, Christopher M; Sompol, Pradoldej; Roberts, Kelly N; Ansari, Mubeen; Scheff, Stephen W

    2016-02-01

    Pycnogenol (PYC) is a patented mix of bioflavonoids with potent anti-oxidant and anti-inflammatory properties. Previously, we showed that PYC administration to rats within hours after a controlled cortical impact (CCI) injury significantly protects against the loss of several synaptic proteins in the hippocampus. Here, we investigated the effects of PYC on CA3-CA1 synaptic function following CCI. Adult Sprague-Dawley rats received an ipsilateral CCI injury followed 15 min later by intravenous injection of saline vehicle or PYC (10 mg/kg). Hippocampal slices from the injured (ipsilateral) and uninjured (contralateral) hemispheres were prepared at seven and fourteen days post-CCI for electrophysiological analyses of CA3-CA1 synaptic function and induction of long-term depression (LTD). Basal synaptic strength was impaired in slices from the ipsilateral, relative to the contralateral, hemisphere at seven days post-CCI and susceptibility to LTD was enhanced in the ipsilateral hemisphere at both post-injury timepoints. No interhemispheric differences in basal synaptic strength or LTD induction were observed in rats treated with PYC. The results show that PYC preserves synaptic function after CCI and provides further rationale for investigating the use of PYC as a therapeutic in humans suffering from neurotrauma. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Dopamine D3 receptors inhibit hippocampal gamma oscillations by disturbing CA3 pyramidal cell firing synchrony

    Directory of Open Access Journals (Sweden)

    Clément E. Lemercier

    2016-01-01

    Full Text Available Cortical gamma oscillations are associated with cognitive processes and are altered in several neuropsychiatric conditions such as schizophrenia and Alzheimer’s disease. Since dopamine D3 receptors are possible targets in treatment of these conditions, it is of great importance to understand their role in modulation of gamma oscillations. The effect of D3 receptors on gamma oscillations and the underlying cellular mechanisms were investigated by extracellular local field potential and simultaneous intracellular sharp micro-electrode recordings in the CA3 region of the hippocampus in vitro. D3 receptors decreased the power and broadened the bandwidth of gamma oscillations induced by acetylcholine or kainate. Blockade of the D3 receptors resulted in faster synchronization of the oscillations, suggesting that endogenous dopamine in the hippocampus slows down the dynamics of gamma oscillations by activation of D3 receptors. Investigating the underlying cellular mechanisms for these effects showed that D3 receptor activation decreased the rate of action potentials during gamma oscillations and reduced the precision of the action potential phase coupling to the gamma cycle in CA3 pyramidal cells. The results may offer an explanation how selective activation of D3 receptors may impair cognition and how, in converse, D3 antagonists may exert pro-cognitive and antipsychotic effects.

  4. Cannabinoids disrupt memory encoding by functionally isolating hippocampal CA1 from CA3.

    Directory of Open Access Journals (Sweden)

    Roman A Sandler

    2017-07-01

    Full Text Available Much of the research on cannabinoids (CBs has focused on their effects at the molecular and synaptic level. However, the effects of CBs on the dynamics of neural circuits remains poorly understood. This study aims to disentangle the effects of CBs on the functional dynamics of the hippocampal Schaffer collateral synapse by using data-driven nonparametric modeling. Multi-unit activity was recorded from rats doing an working memory task in control sessions and under the influence of exogenously administered tetrahydrocannabinol (THC, the primary CB found in marijuana. It was found that THC left firing rate unaltered and only slightly reduced theta oscillations. Multivariate autoregressive models, estimated from spontaneous spiking activity, were then used to describe the dynamical transformation from CA3 to CA1. They revealed that THC served to functionally isolate CA1 from CA3 by reducing feedforward excitation and theta information flow. The functional isolation was compensated by increased feedback excitation within CA1, thus leading to unaltered firing rates. Finally, both of these effects were shown to be correlated with memory impairments in the working memory task. By elucidating the circuit mechanisms of CBs, these results help close the gap in knowledge between the cellular and behavioral effects of CBs.

  5. Characteristics of Retractions from Korean Medical Journals in the KoreaMed Database: A Bibliometric Analysis.

    Directory of Open Access Journals (Sweden)

    Sun Huh

    Full Text Available Flawed or misleading articles may be retracted because of either honest scientific errors or scientific misconduct. This study explored the characteristics of retractions in medical journals published in Korea through the KoreaMed database.We retrieved retraction articles indexed in the KoreaMed database from January 1990 to January 2016. Three authors each reviewed the details of the retractions including the reason for retraction, adherence to retraction guidelines, and appropriateness of retraction. Points of disagreement were reconciled by discussion among the three.Out of 217,839 articles in KoreaMed published from 1990 to January 2016, the publication type of 111 articles was retraction (0.051%. Of the 111 articles (addressing the retraction of 114 papers, 58.8% were issued by the authors, 17.5% were jointly issued (author, editor, and publisher, 15.8% came from editors, and 4.4% were dispatched by institutions; in 5.3% of the instances, the issuer was unstated. The reasons for retraction included duplicate publication (57.0%, plagiarism (8.8%, scientific error (4.4%, author dispute (3.5%, and other (5.3%; the reasons were unstated or unclear in 20.2%. The degree of adherence to COPE's retraction guidelines varied (79.8%-100%, and some retractions were inappropriate by COPE standards. These were categorized as follows: retraction of the first published article in the case of duplicate publication (69.2%, authorship dispute (15.4%, errata (7.7%, and other (7.7%.The major reason for retraction in Korean medical journals is duplicate publication. Some retractions resulted from overreaction by the editors. Therefore, editors of Korean medical journals should take careful note of the COPE retraction guidelines and should undergo training on appropriate retraction practices.

  6. Is Duane retraction syndrome part of the VACTERL association?

    Directory of Open Access Journals (Sweden)

    Akar S

    2013-03-01

    Full Text Available Serpil Akar,1 Birsen Gokyigit,1 Isilay Kavadarli,2 Ahmet Demirok11Pediatric Ophthalmology and Strabismus Department, Prof Dr N Resat Belger Beyoglu Education and Research Eye Hospital, Istanbul, 2Department of Ophthalmology, Gaziantep, Kilis State Hospital, Kilis, TurkeyAbstract: We report here a patient with type 1 Duane’s retraction syndrome and multiple congenital abnormalities as a result of the VACTERL association. The presented combination of Duane’s retraction syndrome and the VACTERL association has not been reported in the literature. The present case was instructive for reviewing the continuous spectrum of ocular anomalies that accompany the VACTERL association.Keywords: Duane’s retraction syndrome, VACTERL association, combination

  7. Retraction statement: Modern Concepts for Caries Tissue Removal.

    Science.gov (United States)

    2016-01-01

    "Modern Concepts for Caries Tissue Removal", by Falk Schwendicke The above article, published online on 15 February 2016 in Wiley Online Library (http://onlinelibrary.wiley.com/doi/10.llll/jerd.12201), has been retracted by agreement between the author, Dr. Falk Schwendicke, the journal Editor-in-Chief, Dr. Harald O. Heymann, Associate Editor, Dr. Edward Swift and Wiley Periodicals, Inc. The retraction has been agreed as the article was published in advance of other companion work which should have had precedence. The article pages have been replaced by the Retraction Statement and the article condensed accordingly. Schwendicke, F. Swift, EJ. Modern concepts for caries tissue removal. Dent J Esthet Rest 2016; 28:1; DOI: 10.1111/jerd.12201. © 2016 Wiley Periodicals, Inc.

  8. Dendritic Polymers for Theranostics

    OpenAIRE

    Ma, Yuan; Mou, Quanbing; Wang, Dali; Zhu, Xinyuan; Yan, Deyue

    2016-01-01

    Dendritic polymers are highly branched polymers with controllable structures, which possess a large population of terminal functional groups, low solution or melt viscosity, and good solubility. Their size, degree of branching and functionality can be adjusted and controlled through the synthetic procedures. These tunable structures correspond to application-related properties, such as biodegradability, biocompatibility, stimuli-responsiveness and self-assembly ability, which are the key poin...

  9. Orientation selection in dendritic evolution

    Science.gov (United States)

    Haxhimali, Tomorr; Karma, Alain; Gonzales, Frédéric; Rappaz, Michel

    2006-08-01

    Dendritic crystal growth patterns have fascinated scientists for several centuries. Much of the aesthetic appeal of these patterns stems from the hierarchical structure of primary-, secondary-, and higher-order branches, which typically grow along principal crystallographic axes. Atypical growth directions have also been observed. Here, we demonstrate both computationally and experimentally that the range of possible dendrite growth directions, and hence the morphological diversity of the resulting dendritic structures, is much richer than previously anticipated. In particular, we show that primary dendrite growth directions can vary continuously between different crystallographic directions as a function of the composition-dependent anisotropy parameters. The study combines phase-field simulations of equiaxed dendritic growth and directional freezing of Al-Zn alloys. Both simulations and experiments exhibit continuous changes of direction from to for an underlying cubic symmetry. These results have important implications for controlling the microstructure of a wide range of cast alloys that solidify dendritically.

  10. Attic cholesteatoma with tiny retraction of pars flaccida.

    Science.gov (United States)

    Lee, Jun Ho; Hong, Seok Min; Kim, Chang Woo; Park, Yeo Hoon; Baek, So-Hye

    2015-04-01

    This clinical study was performed to analyze the characteristics of attic cholesteatoma occurring behind a tiny retraction of the pars flaccida, which was classified as Tos type I or II and had an intact pars tensa of the tympanic membrane. The clinical records of patients who underwent tympanomastoidectomy for attic cholesteatoma at a tertiary care referral center (Kangdong Sacred Heart Hospital of Seoul, Korea) between March 2004 and December 2012 were retrospectively reviewed. Eleven patients (five men and six women) who underwent tympanomastoidectomy between March 2004 and December 2012 for attic cholesteatoma occurring behind a tiny attic retraction were included. The mean age of patients was 41.1 years (range 20-58 years) and the mean duration of follow-up was 29.5 months (range 13-52 months). Every patient had a unilateral cholesteatoma, and the opposite side was normal except in one patient. Hearing loss was the most common symptom, followed by earfullness and otalgia. Five patients had type I attic retraction, and six patients had type II attic retraction. No patient had definite scutum erosion. Interestingly, during regular postoperative checkup, one patient was found incidentally for the opposite ear. Six patients had a cholesteatoma sac that was separated from the pars flaccida, whereas in five patients it was in contact with the pars flaccida but was easily separated. Six patients had a limited cholesteatoma within the epitympanum, and five patients had extension beyond the epitympanum. The average air-bone gap was 24.3±10.1dB before the operation and 14.2±6.6dB after the operation. Every patient had an intact tympanic membrane without retraction pocket postoperatively. There was no recurrence of cholesteatoma during follow-up. The rate of attic cholesteatomas occurring behind a tiny retraction of the pars flaccida was 7.7% (11 of 142 patients with attic cholesteatoma). Attic retractions must be followed closely using endoscopy, microscopy, and

  11. Stomaplasty with pannicuectomy in an obese patient with stomal retraction: A case report

    Directory of Open Access Journals (Sweden)

    Eisaku Ito

    2016-01-01

    Conclusion: We report a case of an obese patient who underwent stomaplasty with pannicuectomy for stomal retraction. We believe that stomaplasty with pannicuectomy is a feasible option in obese patients with stomal retraction.

  12. Disappearance of Ising nature in Ca3ZnMnO6 studied by high-field ESR.

    Science.gov (United States)

    Ruan, M Y; Ouyang, Z W; Guo, Y M; Cheng, J J; Sun, Y C; Xia, Z C; Rao, G H; Okubo, S; Ohta, H

    2014-06-11

    High-field electron spin resonance measurements of an antiferromagnet Ca3ZnMnO6 isostructure, with the Ising-chain multiferroic Ca3CoMnO6, have been carried out. Two distinct resonance modes were observed below TN = 25 K, which is well explained by conventional antiferromagnetic resonance theory with easy-plane anisotropy. The zero-field spin gap is derived to be about 166 GHz, originating from the easy-plane anisotropy and exchange interaction. Our result suggests that the Dzyaloshinsky-Moriya interaction, which may induce spin canting, is absent. Disappearance of Ising anisotropy in Ca3ZnMnO6 suggests that the Co(4+) ion, as well as the Co-Mn superexchange, plays an important role for the Ising nature in Ca3CoMnO6.

  13. Modulation of K(Ca3.1 channels by eicosanoids, omega-3 fatty acids, and molecular determinants.

    Directory of Open Access Journals (Sweden)

    Michael Kacik

    Full Text Available Cytochrome P450- and ω-hydrolase products (epoxyeicosatrienoic acids (EETs, hydroxyeicosatetraeonic acid (20-HETE, natural omega-3 fatty acids (ω3, and pentacyclic triterpenes have been proposed to contribute to a wide range of vaso-protective and anti-fibrotic/anti-cancer signaling pathways including the modulation of membrane ion channels. Here we studied the modulation of intermediate-conductance Ca(2+/calmodulin-regulated K(+ channels (K(Ca3.1 by EETs, 20-HETE, ω3, and pentacyclic triterpenes and the structural requirements of these fatty acids to exert channel blockade.We studied modulation of cloned human hK(Ca3.1 and the mutant hK(Ca3.1(V275A in HEK-293 cells, of rK(Ca3.1 in aortic endothelial cells, and of mK(Ca3.1 in 3T3-fibroblasts by inside-out and whole-cell patch-clamp experiments, respectively. In inside-out patches, Ca(2+-activated hK(Ca3.1 were inhibited by the ω3, DHA and α-LA, and the ω6, AA, in the lower µmolar range and with similar potencies. 5,6-EET, 8,9-EET, 5,6-DiHETE, and saturated arachidic acid, had no appreciable effects. In contrast, 14,15-EET, its stable derivative, 14,15-EEZE, and 20-HETE produced channel inhibition. 11,12-EET displayed less inhibitory activity. The K(Ca3.1(V275A mutant channel was insensitive to any of the blocking EETs. Non-blocking 5,6-EET antagonized the inhibition caused by AA and augmented cloned hK(Ca3.1 and rK(Ca3.1 whole-cell currents. Pentacyclic triterpenes did not modulate K(Ca3.1 currents.Inhibition of K(Ca3.1 by EETs (14,15-EET, 20-HETE, and ω3 critically depended on the presence of electron double bonds and hydrophobicity within the 10 carbons preceding the carboxyl-head of the molecules. From the physiological perspective, metabolism of AA to non-blocking 5,6,- and 8,9-EET may cause AA-de-blockade and contribute to cellular signal transduction processes influenced by these fatty acids.

  14. Functional differences in the backward shifts of CA1 and CA3 place fields in novel and familiar environments.

    Directory of Open Access Journals (Sweden)

    Eric D Roth

    Full Text Available Insight into the processing dynamics and other neurophysiological properties of different hippocampal subfields is critically important for understanding hippocampal function. In this study, we compared shifts in the center of mass (COM of CA3 and CA1 place fields in a familiar and completely novel environment. Place fields in CA1 and CA3 were simultaneously recorded as rats ran along a closed loop track in a familiar room followed by a session in a completely novel room. This process was repeated each day over a 4-day period. CA3 place fields shifted backward (opposite to the direction of motion of the rat only in novel environments. This backward shift gradually diminished across days, as the novel environment became more familiar with repeated exposures. Conversely, CA1 place fields shifted backward across all days in both familiar and novel environments. Prior studies demonstrated that CA1 place fields on average do not exhibit a backward shift during the first exposure to an environment in which the familiar cues are rearranged into a novel configuration, although CA3 place fields showed a strong backward shift. Under the completely novel conditions of the present study, no dissociation was observed between CA3 and CA1 during the first novel session (although a strong dissociation was observed in the familiar sessions and the later novel sessions. In summary, this is the first study to use simultaneous recordings in CA1 and CA3 to compare place field COM shift and other associated properties in truly novel and familiar environments. This study further demonstrates functional differentiation between CA1 and CA3 as the plasticity of CA1 place fields is affected differently by exposure to a completely novel environment in comparison to an altered, familiar environment, whereas the plasticity of CA3 place fields is affected similarly during both types of environmental novelty.

  15. Functional Differences in the Backward Shifts of CA1 and CA3 Place Fields in Novel and Familiar Environments

    OpenAIRE

    Roth, Eric D.; Yu, Xintian; Rao, Geeta; Knierim, James J.

    2012-01-01

    Insight into the processing dynamics and other neurophysiological properties of different hippocampal subfields is critically important for understanding hippocampal function. In this study, we compared shifts in the center of mass (COM) of CA3 and CA1 place fields in a familiar and completely novel environment. Place fields in CA1 and CA3 were simultaneously recorded as rats ran along a closed loop track in a familiar room followed by a session in a completely novel room. This process was re...

  16. Dentate gyrus-CA3 glutamate release/NMDA transmission mediates behavioral despair and antidepressant-like responses to leptin.

    Science.gov (United States)

    Wang, X; Zhang, D; Lu, X-Y

    2015-04-01

    Compelling evidence supports the important role of the glutamatergic system in the pathophysiology of major depression and also as a target for rapid-acting antidepressants. However, the functional role of glutamate release/transmission in behavioral processes related to depression and antidepressant efficacy remains to be elucidated. In this study, glutamate release and behavioral responses to tail suspension, a procedure commonly used for inducing behavioral despair, were simultaneously monitored in real time. The onset of tail suspension stress evoked a rapid increase in glutamate release in hippocampal field CA3, which declined gradually after its offset. Blockade of N-methyl-D-aspartic acid (NMDA) receptors by intra-CA3 infusion of MK-801, a non-competitive NMDA receptor antagonist, reversed behavioral despair. A subpopulation of granule neurons that innervated the CA3 region expressed leptin receptors and these cells were not activated by stress. Leptin treatment dampened tail suspension-evoked glutamate release in CA3. On the other hand, intra-CA3 infusion of NMDA blocked the antidepressant-like effect of leptin in reversing behavioral despair in both the tail suspension and forced swim tests, which involved activation of Akt signaling in DG. Taken together, these results suggest that the DG-CA3 glutamatergic pathway is critical for mediating behavioral despair and antidepressant-like responses to leptin.

  17. Dentate gyrus–CA3 glutamate release/NMDA transmission mediates behavioral despair and antidepressant-like responses to leptin

    Science.gov (United States)

    Wang, Xuezhen; Zhang, Di; Lu, Xin-Yun

    2014-01-01

    Compelling evidence supports the important role of the glutamatergic system in the pathophysiology of major depression and also as a target for rapid-acting antidepressants. However, the functional role of glutamate release/transmission in behavioral processes related to depression and antidepressant efficacy remains to be elucidated. In this study, glutamate release and behavioral responses to tail suspension, a procedure commonly used for inducing behavioral despair, were simultaneously monitored in real time. The onset of tail suspension stress evoked a rapid increase in glutamate release in hippocampal field CA3, which declined gradually after its offset. Blockade of NMDA receptors by intra-CA3 infusion of MK-801, a non-competitive NMDA receptor antagonist, reversed behavioral despair. The CA3 was innervated by granule neurons expressing the leptin receptor (LepRb) in the dentate gyrus (DG), representing a subpopulation of granule neurons that were devoid of stress-induced activation. Leptin treatment dampened tail suspension-evoked glutamate release in CA3. On the other hand, intra-CA3 infusion of NMDA blocked the antidepressant-like effect of leptin in reversing behavioral despair in both the tail suspension and forced swim tests, which involved activation of Akt signaling in DG. Together, these results suggest that the DG-CA3 glutamatergic pathway is critical for mediating behavioral despair and antidepressant-like responses to leptin. PMID:25092243

  18. Electromagnetic properties of LaCa3Fe5Oi2 in the microwave range

    Science.gov (United States)

    Golenkina, V. V.; Ghyngazov, S. A.; Suslyaev, V. I.; Korovin, E. Yu; Kuleshov, G. E.; Kaykenov, D. A.; Mustafin, E. S.; Mylnikova, T. S.

    2016-02-01

    The X-ray diffraction analysis of the LaCa3Fe5O12 ferrite (lanthanum ferrite) prepared through high-temperature synthesis via ceramic technology was performed. It was found that ferrites belong to tetragonal system. The electromagnetic response from a flat layer of the composite based on this material under electromagnetic radiation in the frequency range of 0.01-18 GHz was investigated. It is shown that the developed material effectively interacts with electromagnetic radiation. The interaction effectiveness is directly proportional to ferrite concentration. Increased concentration of ferrite leads to growth of the reflection coefficient due to high conductivity of the material and visible decrease in the transmission coefficient in the frequency range of 4-14 GHz.

  19. Earliest signs of life on land preserved in ca. 3.5 Ga hot spring deposits

    Science.gov (United States)

    Djokic, Tara; van Kranendonk, Martin J.; Campbell, Kathleen A.; Walter, Malcolm R.; Ward, Colin R.

    2017-05-01

    The ca. 3.48 Ga Dresser Formation, Pilbara Craton, Western Australia, is well known for hosting some of Earth's earliest convincing evidence of life (stromatolites, fractionated sulfur/carbon isotopes, microfossils) within a dynamic, low-eruptive volcanic caldera affected by voluminous hydrothermal fluid circulation. However, missing from the caldera model were surface manifestations of the volcanic-hydrothermal system (hot springs, geysers) and their unequivocal link with life. Here we present new discoveries of hot spring deposits including geyserite, sinter terracettes and mineralized remnants of hot spring pools/vents, all of which preserve a suite of microbial biosignatures indicative of the earliest life on land. These include stromatolites, newly observed microbial palisade fabric and gas bubbles preserved in inferred mineralized, exopolymeric substance. These findings extend the known geological record of inhabited terrestrial hot springs on Earth by ~3 billion years and offer an analogue in the search for potential fossil life in ancient Martian hot springs.

  20. Electronic structure of the Ca3Co4O9 compound from ab initio local interactions

    Science.gov (United States)

    Soret, Julien; Lepetit, Marie-Bernadette

    2012-04-01

    We used fully correlated ab initio calculations to determine the effective parameters of Hubbard and t-J models for the thermoelectric misfit compound Ca3Co4O9. As for the NaxCoO2 family, the Fermi level orbitals are the a1g orbitals of the cobalt atoms; the eg' being always lower in energy by more than 240 meV. The electron correlation is found very large U/t˜26 as well as the parameters fluctuations as a function of the structural modulation. The main consequences are a partial a1g electrons localization and a fluctuation of the in-plane magnetic exchange from antiferromagnetic to ferromagnetic. The behavior of the Seebeck coefficient and the figure of merit are discussed in view of the ab initio results, as well as the 496 K phase transition.

  1. Rosiglitazone attenuates inflammation and CA3 neuronal loss following traumatic brain injury in rats

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hao; Rose, Marie E. [Geriatric Research Educational and Clinical Center, V.A. Pittsburgh Healthcare System, PA (United States); Department of Neurology, University of Pittsburgh School of Medicine, PA (United States); Culver, Sherman; Ma, Xiecheng; Dixon, C. Edward [Geriatric Research Educational and Clinical Center, V.A. Pittsburgh Healthcare System, PA (United States); Department of Neurosurgery, University of Pittsburgh, PA 15216 (United States); Department of Critical Care Medicine, University of Pittsburgh, PA 15216 (United States); Graham, Steven H., E-mail: Steven.Graham@va.gov [Geriatric Research Educational and Clinical Center, V.A. Pittsburgh Healthcare System, PA (United States); Department of Neurology, University of Pittsburgh School of Medicine, PA (United States)

    2016-04-15

    Rosiglitazone, a potent peroxisome proliferator-activated receptor (PPAR)-γ agonist, has been shown to confer neuroprotective effects in stroke and spinal cord injury, but its role in the traumatic brain injury (TBI) is still controversial. Using a controlled cortical impact model in rats, the current study was designed to determine the effects of rosiglitazone treatment (6 mg/kg at 5 min, 6 h and 24 h post injury) upon inflammation and histological outcome at 21 d after TBI. In addition, the effects of rosiglitazone upon inflammatory cytokine transcription, vestibulomotor behavior and spatial memory function were determined at earlier time points (24 h, 1–5 d, 14–20 d post injury, respectively). Compared with the vehicle-treated group, rosiglitazone treatment suppressed production of TNFα at 24 h after TBI, attenuated activation of microglia/macrophages and increased survival of CA3 neurons but had no effect on lesion volume at 21 d after TBI. Rosiglitazone-treated animals had improved performance on beam balance testing, but there was no difference in spatial memory function as determined by Morris water maze. In summary, this study indicates that rosiglitazone treatment in the first 24 h after TBI has limited anti-inflammatory and neuroprotective effects in rat traumatic injury. Further study using an alternative dosage paradigm and more sensitive behavioral testing may be warranted. - Highlights: • Effects of rosiglitazone after CCI were evaluated using a rat TBI model. • Rosiglitazone suppressed production of TNFα at 24 h after CCI. • Rosiglitazone inhibited microglial activation at 21 d after CCI. • Rosiglitazone increased survival of CA3 neurons at 21 d after CCI. • Rosiglitazone-treated animals had improved performance in beam balance testing.

  2. Duane retraction syndrome type 1 with Usher syndrome type 2: an unreported association.

    Science.gov (United States)

    Khurana, Bhawna Piplani; Khurana, Aruj Kumar; Grover, Sumit

    2015-05-07

    Duane retraction syndrome is characterized by globe retraction and palpebral fissure narrowing on adduction, with restriction of abduction, adduction, or both. Usher syndrome type 2 consists of congenital bilateral sensorineural hearing loss and retinitis pigmentosa. The authors present a case with a yet unreported association between Duane retraction syndrome type 1 and Usher syndrome type 2. Copyright 2015, SLACK Incorporated.

  3. Plagiarism Allegations Account for Most Retractions in Major Latin American/Caribbean Databases.

    Science.gov (United States)

    Almeida, Renan Moritz V R; de Albuquerque Rocha, Karina; Catelani, Fernanda; Fontes-Pereira, Aldo José; Vasconcelos, Sonia M R

    2016-10-01

    This study focuses on retraction notices from two major Latin American/Caribbean indexing databases: SciELO and LILACS. SciELO includes open scientific journals published mostly in Latin America/the Caribbean, from which 10 % are also indexed by Thomson Reuters Web of Knowledge Journal of Citation Reports (JCR). LILACS has a similar geographical coverage and includes dissertations and conference/symposia proceedings, but it is limited to publications in the health sciences. A search for retraction notices was performed in these two databases using the keywords "retracted", "retraction" "withdrawal", "withdrawn", "removed" and "redress". Documents were manually checked to identify those that actually referred to retractions, which were then analyzed and categorized according to the reasons alleged in the notices. Dates of publication/retraction and time to retraction were also recorded. Searching procedures were performed between June and December 2014. Thirty-one retraction notices were identified, fifteen of which were in JCR-indexed journals. "Plagiarism" was alleged in six retractions of this group. Among the non-JCR journals, retraction reasons were alleged in fourteen cases, twelve of which were attributed to "plagiarism". The proportion of retracted articles for the SciELO database was approximately 0.005 %. The reasons alleged in retraction notices may be used as signposts to inform discussions in Latin America on plagiarism and research integrity. At the international level, these results suggest that the correction of the literature is becoming global and is not limited to mainstream international publications.

  4. Dendritic Alloy Solidification Experiment (DASE)

    Science.gov (United States)

    Beckermann, C.; Karma, A.; Steinbach, I.; deGroh, H. C., III

    2001-01-01

    A space experiment, and supporting ground-based research, is proposed to study the microstructural evolution in free dendritic growth from a supercooled melt of the transparent model alloy succinonitrile-acetone (SCN-ACE). The research is relevant to equiaxed solidification of metal alloy castings. The microgravity experiment will establish a benchmark for testing of equiaxed dendritic growth theories, scaling laws, and models in the presence of purely diffusive, coupled heat and solute transport, without the complicating influences of melt convection. The specific objectives are to: determine the selection of the dendrite tip operating state, i.e. the growth velocity and tip radius, for free dendritic growth of succinonitrile-acetone alloys; determine the growth morphology and sidebranching behavior for freely grown alloy dendrites; determine the effects of the thermal/solutal interactions in the growth of an assemblage of equiaxed alloy crystals; determine the effects of melt convection on the free growth of alloy dendrites; measure the surface tension anisotropy strength of succinon itrile -acetone alloys establish a theoretical and modeling framework for the experiments. Microgravity experiments on equiaxed dendritic growth of alloy dendrites have not been performed in the past. The proposed experiment builds on the Isothermal Dendritic Growth Experiment (IDGE) of Glicksman and coworkers, which focused on the steady growth of a single crystal from pure supercooled melts (succinonitrile and pivalic acid). It also extends the Equiaxed Dendritic Solidification Experiment (EDSE) of the present investigators, which is concerned with the interactions and transients arising in the growth of an assemblage of equiaxed crystals (succinonitrile). However, these experiments with pure substances are not able to address the issues related to coupled heat and solute transport in growth of alloy dendrites.

  5. Probing the Forces of Germband Retraction with Laser-Microsurgery

    Science.gov (United States)

    Lynch, Holley; Rosenthal, Brett; Kim, Elliott; Gish, Robert; Hutson, M. Shane

    2010-03-01

    Germband retraction is a stage of fruit fly embryogenesis that involves the coordinated movement of two tissues: the germband (GB), which uncurls while its cells elongate, and the amnioserosa (AS), whose cells shorten their long axis. To determine the mechanical causes of GB retraction, we conducted three series of laser ablations. First, we made linear incisions in the GB. We find an anisotropy in the maximum wound expansion consistent with a tensile force generated by the AS and applied to segments located around the curve of the GB. Second, we separated a patch of cells from the rest of the GB. These isolated cells do not continue to elongate, but instead round up. Even so, they often continue moving in the same direction. Third, we ablated part of one side of the saddle-shaped AS. Cuts destroying the AS cells closest to the curve of the GB halt GB retraction. Other AS cuts slow it. Our results indicate that the AS plays a mechanical role in GB retraction by applying tensile force to the curve of the GB.

  6. Alkaline phosphatase activity in gingival crevicular fluid during canine retraction.

    Science.gov (United States)

    Batra, P; Kharbanda, Op; Duggal, R; Singh, N; Parkash, H

    2006-02-01

    The aim of the study was to investigate alkaline phosphatase activity in the gingival crevicular fluid (GCF) during orthodontic tooth movement in humans. Postgraduate orthodontic clinic. Ten female patients requiring all first premolar extractions were selected and treated with standard edgewise mechanotherapy. Canine retraction was done using 100 g sentalloy springs. Maxillary canine on one side acted as experimental site while the contralateral canine acted as control. Gingival crevicular fluid was collected from mesial and distal of canines before initiation of canine retraction (baseline), immediately after initiation of retraction, and on 1st, 7th, 14th and 21st day and the alkaline phosphatase activity was estimated. The results show significant (p alkaline phosphatase activity on the 7th, 14th and 21st day on both mesial and distal aspects of the compared experimental and control sides. The peak in enzyme activity occurred on the 14th day of initiation of retraction followed by a significant fall in activity especially on the mesial aspect. The study showed that alkaline phosphatase activity could be successfully estimated in the GCF using calorimetric estimation assay kits. The enzyme activity showed variation according to the amount of tooth movement.

  7. Composition, Enzymes Analysis and Retraction Time of Columellar ...

    African Journals Online (AJOL)

    Composition, Enzymes Analysis and Retraction Time of Columellar Muscles of Giant African Land Snail ( Archachatina marginata ) in Response to External ... The columellar muscle of A. achatina had the highest concentration of glucose and lipids(8.3mg/dl and 46.9mg/dl respectively) while A. marginata had the least.

  8. Ergodic Retractions for Families of Asymptotically Nonexpansive Mappings

    Directory of Open Access Journals (Sweden)

    Saeidi Shahram

    2010-01-01

    Full Text Available We prove some theorems for the existence of ergodic retractions onto the set of common fixed points of a family of asymptotically nonexpansive mappings. Our results extend corresponding results of Benavides and Ramírez (2001, and Li and Sims (2002.

  9. Promoting Ethics and Integrity in Management Academic Research: Retraction Initiative.

    Science.gov (United States)

    Ayodele, Freida Ozavize; Yao, Liu; Haron, Hasnah

    2018-02-13

    In the management academic research, academic advancement, job security, and the securing of research funds at one's university are judged mainly by one's output of publications in high impact journals. With bogus resumes filled with published journal articles, universities and other allied institutions are keen to recruit or sustain the appointment of such academics. This often places undue pressure on aspiring academics and on those already recruited to engage in research misconduct which often leads to research integrity. This structured review focuses on the ethics and integrity of management research through an analysis of retracted articles published from 2005 to 2016. The study employs a structured literature review methodology whereby retracted articles published between 2005 and 2016 in the field of management science were found using Crossref and Google Scholar. The searched articles were then streamlined by selecting articles based on their relevance and content in accordance with the inclusion criteria. Based on the analysed retracted articles, the study shows evidence of ethical misconduct among researchers of management science. Such misconduct includes data falsification, the duplication of submitted articles, plagiarism, data irregularity and incomplete citation practices. Interestingly, the analysed results indicate that the field of knowledge management includes the highest number of retracted articles, with plagiarism constituting the most significant ethical issue. Furthermore, the findings of this study show that ethical misconduct is not restricted to a particular geographic location; it occurs in numerous countries. In turn, avenues of further study on research misconduct in management research are proposed.

  10. Age-related Changes in Lateral Entorhinal and CA3 Neuron Allocation Predict Poor Performance on Object Discrimination

    Directory of Open Access Journals (Sweden)

    Andrew P. Maurer

    2017-06-01

    Full Text Available Age-related memory deficits correlate with dysfunction in the CA3 subregion of the hippocampus, which includes both hyperactivity and overly rigid activity patterns. While changes in intrinsic membrane currents and interneuron alterations are involved in this process, it is not known whether alterations in afferent input to CA3 also contribute. Neurons in layer II of the lateral entorhinal cortex (LEC project directly to CA3 through the perforant path, but no data are available regarding the effects of advanced age on LEC activity and whether these activity patterns update in response to environmental change. Furthermore, it is not known the extent to which age-related deficits in sensory discrimination relate to the inability of aged CA3 neurons to update in response to new environments. Young and aged rats were pre-characterized on a LEGO© object discrimination task, comparable to behavioral tests in humans in which CA3 hyperactivity has been linked to impairments. The cellular compartment analysis of temporal activity with fluorescence in situ hybridization for the immediate-early gene Arc was then used to identify the principal cell populations that were active during two distinct epochs of random foraging in different environments. This approach enabled the extent to which rats could discriminate two similar objects to be related to the ability of CA3 neurons to update across different environments. In both young and aged rats, there were animals that performed poorly on the LEGO object discrimination task. In the aged rats only, however, the poor performers had a higher percent of CA3 neurons that were active during random foraging in a novel environment, but this is not related to the ability of CA3 neurons to remap when the environment changed. Afferent neurons to CA3 in LEC, as identified with the retrograde tracer choleratoxin B (CTB, also showed a higher percentage of cells that were positive for Arc mRNA in aged poor performing rats

  11. Retractable Pin Tools for the Friction Stir Welding Process

    Science.gov (United States)

    1998-01-01

    Two companies have successfully commercialized a specialized welding tool developed at the Marshall Space Flight Center (MSFC). Friction stir welding uses the high rotational speed of a tool and the resulting frictional heat created from contact to crush, 'stir' together, and forge a bond between two metal alloys. It has had a major drawback, reliance on a single-piece pin tool. The pin is slowly plunged into the joint between two materials to be welded and rotated as high speed. At the end of the weld, the single-piece pin tool is retracted and leaves a 'keyhole,' something which is unacceptable when welding cylindrical objects such as drums, pipes and storage tanks. Another drawback is the requirement for different-length pin tools when welding materials of varying thickness. An engineer at the MSFC helped design an automatic retractable pin tool that uses a computer-controlled motor to automatically retract the pin into the shoulder of the tool at the end of the weld, preventing keyholes. This design allows the pin angle and length to be adjusted for changes in material thickness and results in a smooth hole closure at the end of the weld. Benefits of friction stir welding, using the MSFC retractable pin tool technology, include the following: The ability to weld a wide range of alloys, including previously unweldable and composite materials; provision of twice the fatigue resistance of fusion welds and no keyholes; minimization of material distortion; no creation of hazards such as welding fumes, radiation, high voltage, liquid metals, or arcing; automatic retraction of the pin at the end of the weld; and maintaining full penetration of the pin.

  12. Impurity effects in dendritic solidification

    Science.gov (United States)

    Karma, A.; Langer, J. S.

    1984-01-01

    A quantitative calculation of growth rates and tip radii is presented for dendrites growing in undercooled dilute solutions. Included in the calculations are the capillary corrections to the steady-state Ivantsov needle-crystal solutions. The results show good agreement with available experimental data and support the validity of the marginal-stability theory of dendritic growth.

  13. Involvement of the serotonergic system of the ventral hippocampus (CA3) on amnesia induced by ACPA in mice.

    Science.gov (United States)

    Nasehi, Mohammad; Kafi, Faezeh; Khakpai, Fatemeh; Zarrindast, Mohammad-Reza

    2015-06-01

    Interactions between the cannabinoid and serotonin systems have been reported in many studies. In the present study, we investigated the influence of the serotonergic receptor agents on amnesia induced by the cannabinoid CB1 receptor agonist, arachydonilcyclopropylamide (ACPA). Bilateral guide-cannulae were implanted to allow intra-CA3 microinjection of the drugs. The results showed that the intra-peritoneal (i.p.) injection of ACPA induce amnesia but did not alter head dip latency, head dip counts, and locomotion. Moreover, intra-CA3 injection of M-Chlorophenylbiguanide (M-CHL, a 5-HT3 serotonin receptor agonist), Y-25130 (a 5-HT3 serotonin receptor antagonist), RS67333 (a 5-HT4 serotonin receptor agonist), and RS23597-190 (a 5-HT4 serotonin receptor antagonist) impaired memory but have no effect on head dip latency and locomotor activity. In addition, intra-CA3 injection of Y-25130, RS67333, and RS23597-190 heighten the ACPA-induced amnesia and head dip counts while did not alter head dip latency and locomotor activity. On the other hand, intra-CA3 microinjection of M-CHL could not modify the ACPA-induced amnesia, head dip latency and locomotor activity whereas increased head dip counts. It can be concluded that the amnesia induced by i.p. administration of ACPA is at least partly mediated through the serotonergic receptor mechanism in the CA3 area. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Development of dendrite polarity in Drosophila neurons

    Directory of Open Access Journals (Sweden)

    Hill Sarah E

    2012-10-01

    Full Text Available Abstract Background Drosophila neurons have dendrites that contain minus-end-out microtubules. This microtubule arrangement is different from that of cultured mammalian neurons, which have mixed polarity microtubules in dendrites. Results To determine whether Drosophila and mammalian dendrites have a common microtubule organization during development, we analyzed microtubule polarity in Drosophila dendritic arborization neuron dendrites at different stages of outgrowth from the cell body in vivo. As dendrites initially extended, they contained mixed polarity microtubules, like mammalian neurons developing in culture. Over a period of several days this mixed microtubule array gradually matured to a minus-end-out array. To determine whether features characteristic of dendrites were localized before uniform polarity was attained, we analyzed dendritic markers as dendrites developed. In all cases the markers took on their characteristic distribution while dendrites had mixed polarity. An axonal marker was also quite well excluded from dendrites throughout development, although this was perhaps more efficient in mature neurons. To confirm that dendrite character could be acquired in Drosophila while microtubules were mixed, we genetically disrupted uniform dendritic microtubule organization. Dendritic markers also localized correctly in this case. Conclusions We conclude that developing Drosophila dendrites initially have mixed microtubule polarity. Over time they mature to uniform microtubule polarity. Dendrite identity is established before the mature microtubule arrangement is attained, during the period of mixed microtubule polarity.

  15. Equiaxed Dendritic Solidification Experiment (EDSE)

    Science.gov (United States)

    Beckermann, C.; Karma, A.; Steinbach, I.; deGroh, H. C., III

    2001-01-01

    The objective of the research is to quantitatively determine and understand the fundamental mechanisms that control the microstructural evolution during equiaxed dendritic solidification. A microgravity experiment will be conducted to obtain benchmark data on the transient growth and interaction of up to four equiaxed crystals of a pure and transparent metal analog (succinonitrile, SCN) under strictly diffusion-dominated conditions. Of interest in the experiment are the transient evolution of the primary and secondary dendrite tip speeds, the dendrite morphology and solid fraction, the tip selection criterion, and the temperature field in the melt for a range of interaction "strengths" between the crystals. The experiment extends the microgravity measurements of Glicksman and co-workers isothermal dendritic growth experiment (IDGE) for steady growth of a single dendrite to a case where growth transients are introduced due to thermal interactions between neighboring dendrites - a situation closer to actual casting conditions. Corresponding Earth-based experiments will be conducted to ascertain the influence of melt convection. The experiments are supported by a variety of analytical models and numerical simulations. The data will be used to develop and test theories of transient dendritic growth and the solidification of multiple interacting equiaxed crystals in a supercooled melt.

  16. Dendrite Injury Triggers DLK-Independent Regeneration

    Directory of Open Access Journals (Sweden)

    Michelle C. Stone

    2014-01-01

    Full Text Available Axon injury triggers regeneration through activation of a conserved kinase cascade, which includes the dual leucine zipper kinase (DLK. Although dendrites are damaged during stroke, traumatic brain injury, and seizure, it is not known whether mature neurons monitor dendrite injury and initiate regeneration. We probed the response to dendrite damage using model Drosophila neurons. Two larval neuron types regrew dendrites in distinct ways after all dendrites were removed. Dendrite regeneration was also triggered by injury in adults. Next, we tested whether dendrite injury was initiated with the same machinery as axon injury. Surprisingly, DLK, JNK, and fos were dispensable for dendrite regeneration. Moreover, this MAP kinase pathway was not activated by injury to dendrites. Thus, neurons respond to dendrite damage and initiate regeneration without using the conserved DLK cascade that triggers axon regeneration.

  17. TCDQ-TCT retraction and losses during asynchronous beam dump

    CERN Document Server

    Bracco, Chiara; Quaranta, Elena; CERN. Geneva. ATS Department

    2016-01-01

    The protection provided by the TCDQs in case of asynchronous beam dump depends strongly on their correct setup. They have to respect the strict hierarchy of the full collimation system and shield the tertiary collimators in the experimental regions. This MD aimed at performing asynchronous beam dump tests with different configurations, in order to assess the minimum allowed retraction between TCTs and TCDQs and, as a consequence, on the The protection provided by the TCDQs in case of asynchronous beam dump depends strongly on their correct setup. They have to respect the strict hierarchy of the full collimation system and shield the tertiary collimators in the experimental regions. This MD aimed at performing asynchronous beam dump tests with different configurations, in order to assess the minimum allowed retraction between TCTs and TCDQs and, as a consequence, on the β* reach.

  18. Pyrotechnic Actuator for Retracting Tubes Between MSL Subsystems

    Science.gov (United States)

    Gallon, John C.; Webster, Richard G.; Patterson, Keith D.; Orzewalla, Matthew A.; Roberts, Eric T.; Tuszynski, Andrew J.

    2010-01-01

    An apparatus, denoted the "retractuator" (a contraction of "retracting actuator"), was designed to help ensure clean separation between the cruise stage and the entry-vehicle subsystem of the Mars Science Laboratory (MSL) mission. The retractuator or an equivalent mechanism is needed because of tubes that (1) transport a heat-transfer fluid between the stages during flight and (2) are cut immediately prior to separation of the stages retractuator. The role of the retractuator is to retract the tubes, after they are cut and before separation of the subsystem, so that cut ends of the tubes do not damage thermal-protection coats on the entry vehicle and do not contribute to uncertainty of drag and consequent uncertainty in separation velocity.

  19. RETRACTED ARTICLE: Typhoon disasters and adaptive governance in Guangdong, China.

    Science.gov (United States)

    2014-03-01

    The peer-review process for the above article was found to have been compromised and inappropriately influenced by the first author, Yongdeng Lei. As a result the findings and conclusions of these articles cannot be relied upon. The Editor-in-Chief was misled in believing that she had accepted the article based upon a favorable review. The article is retracted based upon violation of the integrity of the peer review process.The first author and the publisher wish to retract this paper to preserve the integrity of material published in the journal. The publisher acknowledges that the integrity of the peer review process should have been subject to more rigorous verification to ensure the reviews provided were genuine and impartial. The publisher apologizes for any inconvenience rendered to the readers of the journal and wishes to assure the reader that measures have been taken to ensure that the peer review process is comprehensively checked to avoid a similar error occurring.

  20. Retracted: Spontaneous rectus sheath haematoma associated with rivaroxaban treatment.

    Science.gov (United States)

    Tas Tuna, A; Palabiyik, O; Beyaz, S G

    2015-08-01

    http://onlinelibrary.wiley.com/doi/10.1111/jcpt.12228/pdf The above article, published online on 10 November 2014 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor in Chief, A. Li Wan Po, and John Wiley & Sons Ltd. The retraction has been agreed because, unknown to the authors, another group published a similar study based on the same material in the Indian Journal of Pharmacology: Kocayigit I, Can Y, Sahinkus S, et al. Spontaneous rectus sheath haematoma during rivaroxaban therapy. Indian Journal of Pharmacology. 2014;46(3):339-340. doi:10.4103/0253-7613.132193. © 2014 John Wiley & Sons Ltd.

  1. Retracted Article : Corruption And Economic Growth: A Survey Of ...

    African Journals Online (AJOL)

    This article was retracted by the journal Editor-in-Chief at the request of the authors (as of February 2013). http://dx.doi.org/10.4314/jorind.v6i1.42402 · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use ...

  2. Modified Dento - Alveolar Distraction Osteogenesis Technique for Rapid Canine Retraction

    Directory of Open Access Journals (Sweden)

    Sameer Patil

    2012-01-01

    Full Text Available Distraction Osteogenesis claims to reduce the duration of treatment as well aid in conservation of anchorage. With the introduction of Dento- alveolar distraction retraction of canine can now be done in about 2-3 weeks with minimal loss of anchorage and little/no root resorption. However, surgical procedure required for dento-alveolar distraction can cause significant swelling and post operative discomfort. Our small modification in the surgical procedure drastically reduces the discomfort and improves patient compliance.

  3. Duane retraction syndrome: causes, effects and management strategies

    Directory of Open Access Journals (Sweden)

    Kekunnaya R

    2017-10-01

    Full Text Available Ramesh Kekunnaya, Mithila Negalur Pediatric Ophthalmology and Strabismus Services, Child Sight Institute, Jasti V Ramannama Children’s Eye Care Center, KAR Campus, Hyderabad, India Abstract: Duane retraction syndrome (DRS is a congenital eye movement anomaly characterized by variable horizontal duction deficits, with narrowing of the palpebral fissure and globe retraction on attempted adduction, occasionally accompanied by upshoot or downshoot. The etiopathogenesis of this condition can be explained by a spectrum of mechanical, innervational, neurologic and genetic abnormalities occurring independently or which influence each other giving rise to patterns of clinical presentations along with a complex set of ocular and systemic anomalies. Huber type I DRS is the most common form of DRS with an earlier presentation, while Huber type II is the least common presentation. Usually, patients with unilateral type I Duane syndrome have esotropia more frequently than exotropia, those with type II have exotropia and those with type III have esotropia and exotropia occurring equally common. Cases of bilateral DRS may have variable presentation depending upon the type of presentation in each eye. As regards its management, DRS classification based on primary position deviation as esotropic, exotropic or orthotropic is more relevant than Huber’s classification before planning surgery. Surgical approach to these patients is challenging and must be individualized based on the amount of ocular deviation, abnormal head position, associated globe retraction and overshoots. Keywords: Duane syndrome, strabismus surgery, esotropia, overshoots

  4. Optimizing Anterior En Masse Retraction with Miniscrew Anchorage

    Directory of Open Access Journals (Sweden)

    Pavankumar Janardan Vibhute

    2011-01-01

    Full Text Available In severely protrusive patients, skeletal anchorage from miniscrew is often used to avoid anchorage loss with preferred miniscrew location near centre of resistance (Cres of posterior teeth. Biomechanical requirement for directing retraction force towards Cres of posterior teeth demands the insertion of miniscrew in loose mucosa, where risk of infection and failure increases. In addition, undesirable biomechanical side effects on anterior and posterior segments may be possible in all three planes, when continuous arch sliding mechanics are installed with miniscrew anchorage. This paper describes technique of molar-stabilizing power arm (MSPA for simultaneous intrusion and retraction of anteriors with miniscrew placement at attached gingiva between 1st molar and 2nd premolar. Advantages of this technique include (i the need of miniscrews placement in loose mucosa apically near the Cres of the posterior teeth is eliminated, (ii the risk of infection and miniscrew failure is lowered since the miniscrew is placed in attached gingiva rather than the loose mucosa, and (iii by adjusting vertical length or replacing MSPA, alteration of the retraction force vector is possible in all three planes; thus, need of removal and repositioning of the miniscrew (e.g., in correction of occlusal cant can be eliminated.

  5. Retractions of the gingival margins evaluated by holographic methods

    Science.gov (United States)

    Sinescu, Cosmin; Negrutiu, Meda Lavinia; Manole, Marius; de Sabata, Aldo; Rusu, Laura-Cristina; Stratul, Stefan; Dudea, Diana; Dughir, Ciprian; Duma, Virgil-Florin

    2015-05-01

    The periodontal disease is one of the most common pathological states of the teeth and gums system. The issue is that its evaluation is a subjective one, i.e. it is based on the skills of the dental medical doctor. As for any clinical condition, a quantitative evaluation and monitoring in time of the retraction of the gingival margins is desired. This phenomenon was evaluated in this study with a holographic method by using a He-Ne laser with a power of 13 mW. The holographic system we have utilized - adapted for dentistry applications - is described. Several patients were considered in a comparative study of their state of health - regarding their oral cavity. The impressions of the maxillary dental arch were taken from a patient during his/her first visit and after a period of six months. The hologram of the first model was superposed on the model cast after the second visit. The retractions of the gingival margins could be thus evaluated three-dimensionally in every point of interest. An evaluation of the retraction has thus been made. Conclusions can thus be drawn for the clinical evaluation of the health of the teeth and gums system of each patient.

  6. Glutamate excitotoxicity inflicts paranodal myelin splitting and retraction.

    Science.gov (United States)

    Fu, Yan; Sun, Wenjing; Shi, Yunzhou; Shi, Riyi; Cheng, Ji-Xin

    2009-08-20

    Paranodal myelin damage is observed in white matter injury. However the culprit for such damage remains unknown. By coherent anti-Stokes Raman scattering imaging of myelin sheath in fresh tissues with sub-micron resolution, we observed significant paranodal myelin splitting and retraction following glutamate application both ex vivo and in vivo. Multimodal multiphoton imaging further showed that glutamate application broke axo-glial junctions and exposed juxtaparanodal K+ channels, resulting in axonal conduction deficit that was demonstrated by compound action potential measurements. The use of 4-aminopyridine, a broad-spectrum K+ channel blocker, effectively recovered both the amplitude and width of compound action potentials. Using CARS imaging as a quantitative readout of nodal length to diameter ratio, the same kind of paranodal myelin retraction was observed with applications of Ca2+ ionophore A23187. Moreover, exclusion of Ca2+ from the medium or application of calpain inhibitor abolished paranodal myelin retraction during glutamate exposure. Examinations of glutamate receptor agonists and antagonists further showed that the paranodal myelin damage was mediated by NMDA and kainate receptors. These results suggest that an increased level of glutamate in diseased white matter could impair paranodal myelin through receptor-mediated Ca2+ overloading and subsequent calpain activation.

  7. Glutamate excitotoxicity inflicts paranodal myelin splitting and retraction.

    Directory of Open Access Journals (Sweden)

    Yan Fu

    2009-08-01

    Full Text Available Paranodal myelin damage is observed in white matter injury. However the culprit for such damage remains unknown. By coherent anti-Stokes Raman scattering imaging of myelin sheath in fresh tissues with sub-micron resolution, we observed significant paranodal myelin splitting and retraction following glutamate application both ex vivo and in vivo. Multimodal multiphoton imaging further showed that glutamate application broke axo-glial junctions and exposed juxtaparanodal K+ channels, resulting in axonal conduction deficit that was demonstrated by compound action potential measurements. The use of 4-aminopyridine, a broad-spectrum K+ channel blocker, effectively recovered both the amplitude and width of compound action potentials. Using CARS imaging as a quantitative readout of nodal length to diameter ratio, the same kind of paranodal myelin retraction was observed with applications of Ca2+ ionophore A23187. Moreover, exclusion of Ca2+ from the medium or application of calpain inhibitor abolished paranodal myelin retraction during glutamate exposure. Examinations of glutamate receptor agonists and antagonists further showed that the paranodal myelin damage was mediated by NMDA and kainate receptors. These results suggest that an increased level of glutamate in diseased white matter could impair paranodal myelin through receptor-mediated Ca2+ overloading and subsequent calpain activation.

  8. The GABAergic projection of the dentate gyrus to hippocampal area CA3 of the rat: pre- and postsynaptic actions after seizures.

    Science.gov (United States)

    Treviño, Mario; Gutiérrez, Rafael

    2005-09-15

    The glutamatergic granule cells of the dentate gyrus transiently express GABAergic markers after seizures. Here we show that when this occurs, their activation produces (i) GABA(A) receptor-mediated synaptic field responses in CA3, with the physiological and pharmacological characteristics of mossy fibre transmission, and (ii) GABA(A) receptor-mediated collateral inhibition. Control hippocampal slices present, on stimulation of the dentate gyrus, population responses in stratum lucidum, which are blocked by ionotropic glutamate receptor antagonists. By contrast, in slices from rats subjected to seizures in vivo, dentate activation additionally produces GABA(A) receptor-mediated field synaptic responses in the presence of glutamate receptor antagonists. One-dimensional current source density analysis confirmed the spatial coincidence of the glutamatergic and GABAergic dendritic currents. The GABA(A) receptor-mediated field responses show frequency-dependent facilitation and strong inhibition during activation of metabotropic glutamate receptors. In the presence of glutamate receptor blockers, a conditioning pulse delivered to one site of the dentate gyrus inhibits the population synaptic response and the afferent volley provoked by the activation of a second site, in a bicuculline-sensitive manner. In accordance with this, antidromic responses evoked by mossy fibre activation were enhanced by perfusion of bicuculline. Our results suggest that, for GABA receptor-dependent field potentials to be detected, a considerable number of boutons of a well-defined GABAergic pathway should simultaneously release GABA to act on a large number of receptors. Therefore, putative GABA release from the mossy fibres acts on pre- and postsynaptic sites to affect hippocampal activity at the network level after seizures.

  9. The AMPA receptor positive allosteric modulator S 47445 rescues in vivo CA3-CA1 long-term potentiation and structural synaptic changes in old mice.

    Science.gov (United States)

    Giralt, Albert; Gómez-Climent, María Ángeles; Alcalá, Rafael; Bretin, Sylvie; Bertrand, Daniel; María Delgado-García, José; Pérez-Navarro, Esther; Alberch, Jordi; Gruart, Agnès

    2017-09-01

    Positive allosteric modulators of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) are small molecules that decrease deactivation of AMPARs via an allosteric site. These molecules keep the receptor in an active state. Interestingly, this type of modulator has been proposed for treating cognitive decline in ageing, dementias, and Alzheimer's disease (AD). S 47445 (8-cyclopropyl-3-[2-(3-fluorophenyl)ethyl]-7,8-dihydro-3H-[1,3]oxazino[6,5-g][1,2,3]benzotriazine-4,9-dione) is a novel AMPAR positive allosteric modulator (AMPA-PAM). Here, the mechanisms by which S 47445 could improve synaptic strength and connectivity were studied and compared between young and old mice. A single oral administration of S 47445 at 10 mg/kg significantly increased long-term potentiation (LTP) in CA3-CA1 hippocampal synapses in alert young mice in comparison to control mice. Moreover, chronic treatment with S 47445 at 10 mg/kg in old alert animals significantly counteracted the deficit of LTP due to age. Accordingly, chronic treatment with S 47445 at 10 mg/kg seems to preserve synaptic cytoarchitecture in old mice as compared with young control mice. It was shown that the significant decreases in number and size of pre-synaptic buttons stained for VGlut1, and post-synaptic dendritic spines stained for spinophilin, observed in old mice were significantly prevented after chronic treatment with 10 mg/kg of S 47445. Altogether, by its different effects on LTP, VGlut1-positive particles, and spinophilin, S 47445 is able to modulate both the structure and function of hippocampal excitatory synapses known to be involved in learning and memory processes. These results open a new window for the treatment of specific age-dependent cognitive decline and dementias such as AD. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Retractions in the medical literature: how many patients are put at risk by flawed research?

    Science.gov (United States)

    Steen, R Grant

    2011-11-01

    Clinical papers so flawed that they are eventually retracted may put patients at risk. Patient risk could arise in a retracted primary study or in any secondary study that draws ideas or inspiration from a primary study. To determine how many patients were put at risk, we evaluated 788 retracted English-language papers published from 2000 to 2010, describing new research with humans or freshly derived human material. These primary papers-together with all secondary studies citing them-were evaluated using ISI Web of Knowledge. Excluded from study were 468 basic science papers not studying fresh human material; 88 reviews presenting older data; 22 case reports; 7 papers retracted for journal error and 23 papers unavailable on Web of Knowledge. Overall, 180 retracted primary papers (22.8%) met the inclusion criteria. Subjects enrolled and patients treated in 180 primary studies and 851 secondary studies were combined. Retracted papers were cited over 5000 times, with 93% of citations being research related, suggesting that ideas promulgated in retracted papers can influence subsequent research. Over 28 000 subjects were enrolled-and 9189 patients were treated-in 180 retracted primary studies. Over 400 000 subjects were enrolled-and 70 501 patients were treated-in 851 secondary studies which cited a retracted paper. Papers retracted for fraud (n=70) treated more patients per study (pclinical studies were tallied.

  11. Cooperative retraction of bundled type IV pili enables nanonewton force generation.

    Directory of Open Access Journals (Sweden)

    Nicolas Biais

    2008-04-01

    Full Text Available The causative agent of gonorrhea, Neisseria gonorrhoeae, bears retractable filamentous appendages called type IV pili (Tfp. Tfp are used by many pathogenic and nonpathogenic bacteria to carry out a number of vital functions, including DNA uptake, twitching motility (crawling over surfaces, and attachment to host cells. In N. gonorrhoeae, Tfp binding to epithelial cells and the mechanical forces associated with this binding stimulate signaling cascades and gene expression that enhance infection. Retraction of a single Tfp filament generates forces of 50-100 piconewtons, but nothing is known, thus far, on the retraction force ability of multiple Tfp filaments, even though each bacterium expresses multiple Tfp and multiple bacteria interact during infection. We designed a micropillar assay system to measure Tfp retraction forces. This system consists of an array of force sensors made of elastic pillars that allow quantification of retraction forces from adherent N. gonorrhoeae bacteria. Electron microscopy and fluorescence microscopy were used in combination with this novel assay to assess the structures of Tfp. We show that Tfp can form bundles, which contain up to 8-10 Tfp filaments, that act as coordinated retractable units with forces up to 10 times greater than single filament retraction forces. Furthermore, single filament retraction forces are transient, whereas bundled filaments produce retraction forces that can be sustained. Alterations of noncovalent protein-protein interactions between Tfp can inhibit both bundle formation and high-amplitude retraction forces. Retraction forces build over time through the recruitment and bundling of multiple Tfp that pull cooperatively to generate forces in the nanonewton range. We propose that Tfp retraction can be synchronized through bundling, that Tfp bundle retraction can generate forces in the nanonewton range in vivo, and that such high forces could affect infection.

  12. Ionic mechanisms of endogenous bursting in CA3 hippocampal pyramidal neurons: a model study.

    Directory of Open Access Journals (Sweden)

    Jun Xu

    2008-04-01

    Full Text Available A critical property of some neurons is burst firing, which in the hippocampus plays a primary role in reliable transmission of electrical signals. However, bursting may also contribute to synchronization of electrical activity in networks of neurons, a hallmark of epilepsy. Understanding the ionic mechanisms of bursting in a single neuron, and how mutations associated with epilepsy modify these mechanisms, is an important building block for understanding the emergent network behaviors. We present a single-compartment model of a CA3 hippocampal pyramidal neuron based on recent experimental data. We then use the model to determine the roles of primary depolarizing currents in burst generation. The single compartment model incorporates accurate representations of sodium (Na(+ channels (Na(V1.1 and T-type calcium (Ca(2+ channel subtypes (Ca(V3.1, Ca(V3.2, and Ca(V3.3. Our simulations predict the importance of Na(+ and T-type Ca(2+ channels in hippocampal pyramidal cell bursting and reveal the distinct contribution of each subtype to burst morphology. We also performed fast-slow analysis in a reduced comparable model, which shows that our model burst is generated as a result of the interaction of two slow variables, the T-type Ca(2+ channel activation gate and the Ca(2+-dependent potassium (K(+ channel activation gate. The model reproduces a range of experimentally observed phenomena including afterdepolarizing potentials, spike widening at the end of the burst, and rebound. Finally, we use the model to simulate the effects of two epilepsy-linked mutations: R1648H in Na(V1.1 and C456S in Ca(V3.2, both of which result in increased cellular excitability.

  13. Ca3(P x V1 - x O4)2: Eu3+ nanophosphor synthesis, controlled microstructure, and photoluminescence

    Science.gov (United States)

    Zhou, Xiaochun; Wang, Xiaojun

    2013-11-01

    In this paper, Eu3+-doped Ca3(P x V1 - x O4)2 ( x = 0.1, 0.4, 0.7) nanophosphors were synthesized in the presence of sodium dodecyl benzene sulfonate (SDBS). The products present interesting and regular morphologies under the mild conditions. For Ca3(P x V1 - x O4)2: Eu3+, they have the similar phase and their morphologies vary with the content ratio of P to V. Furthermore, the luminescence behavior of Eu3+ has been investigated in this one kinds of matrices. In Ca3(P x V1 - x O4)2: Eu3+, the 5 D 0-7 F 2 emissions of Eu3+ were the strongest, indicating that the Eu3+ site is without inversion symmetry, the host compositions with different molar ratio of P to V have; great influence on the luminescent performance. Among those products, The value of I 615/ I 593 for Eu3+ in Ca3(P0.7V0.3O4)2 host lattice is the biggest. The substitution of PO{4/3-} for VO{4/3-} increase the ratio of surface Eu cations as well as the value of I 615/ I 593 of Eu3+.

  14. Observations on hippocampal mossy cells in mink (Neovison vison) with special reference to dendrites ascending to the granular and molecular layers.

    Science.gov (United States)

    Blackstad, Jan Sigurd; Osen, Kirsten K; Scharfman, Helen E; Storm-Mathisen, Jon; Blackstad, Theodor W; Leergaard, Trygve B

    2016-02-01

    Detailed knowledge about the neural circuitry connecting the hippocampus and entorhinal cortex is necessary to understand how this system contributes to spatial navigation and episodic memory. The two principal cell types of the dentate gyrus, mossy cells and granule cells, are interconnected in a positive feedback loop, by which mossy cells can influence information passing from the entorhinal cortex via granule cells to hippocampal pyramidal cells. Mossy cells, like CA3 pyramidal cells, are characterized by thorny excrescences on their proximal dendrites, postsynaptic to giant terminals of granule cell axons. In addition to disynaptic input from the entorhinal cortex and perforant path via granule cells, mossy cells may also receive monosynaptic input from the perforant path via special dendrites ascending to the molecular layer. We here report qualitative and quantitative descriptions of Golgi-stained hippocampal mossy cells in mink, based on light microscopic observations and three-dimensional reconstructions. The main focus is on the location, branching pattern, and length of dendrites, particularly those ascending to the granular and molecular layers. In mink, the latter dendrites are more numerous than in rat, but fewer than in primates. They form on average 12% (and up to 29%) of the total dendritic length, and appear to cover the terminal fields of both the lateral and medial perforant paths. In further contrast to rat, the main mossy cell dendrites in mink branch more extensively with distal dendrites encroaching upon the CA3 field. The dendritic arbors extend both along and across the septotemporal axis of the dentate gyrus, not conforming to the lamellar pattern of the hippocampus. The findings suggest that the afferent input to the mossy cells becomes more complex in species closer to primates. © 2015 Wiley Periodicals, Inc.

  15. The visibility of scientific misconduct: A review of the literature on retracted journal articles

    Science.gov (United States)

    Hesselmann, Felicitas; Graf, Verena; Schmidt, Marion; Reinhart, Martin

    2016-01-01

    Retractions of scientific articles are becoming the most relevant institution for making sense of scientific misconduct. An increasing number of retracted articles, mainly attributed to misconduct, is currently providing a new empirical basis for research about scientific misconduct. This article reviews the relevant research literature from an interdisciplinary context. Furthermore, the results from these studies are contextualized sociologically by asking how scientific misconduct is made visible through retractions. This study treats retractions as an emerging institution that renders scientific misconduct visible, thus, following up on the sociology of deviance and its focus on visibility. The article shows that retractions, by highlighting individual cases of misconduct and general policies for preventing misconduct while obscuring the actors and processes through which retractions are effected, produce highly fragmented patterns of visibility. These patterns resemble the bifurcation in current justice systems. PMID:28943647

  16. Npas4 Is a Critical Regulator of Learning-Induced Plasticity at Mossy Fiber-CA3 Synapses during Contextual Memory Formation

    DEFF Research Database (Denmark)

    Weng, Feng-Ju; Garcia, Rodrigo I; Lutzu, Stefano

    2018-01-01

    Synaptic connections between hippocampal mossy fibers (MFs) and CA3 pyramidal neurons are essential for contextual memory encoding, but the molecular mechanisms regulating MF-CA3 synapses during memory formation and the exact nature of this regulation are poorly understood. Here we report...... that the activity-dependent transcription factor Npas4 selectively regulates the structure and strength of MF-CA3 synapses by restricting the number of their functional synaptic contacts without affecting the other synaptic inputs onto CA3 pyramidal neurons. Using an activity-dependent reporter, we identified CA3...... pyramidal cells that were activated by contextual learning and found that MF inputs on these cells were selectively strengthened. Deletion of Npas4 prevented both contextual memory formation and this learning-induced synaptic modification. We further show that Npas4 regulates MF-CA3 synapses by controlling...

  17. Stress-induced alterations in prefrontal cortical dendritic morphology predict selective impairments in perceptual attentional set-shifting.

    Science.gov (United States)

    Liston, Conor; Miller, Melinda M; Goldwater, Deena S; Radley, Jason J; Rocher, Anne B; Hof, Patrick R; Morrison, John H; McEwen, Bruce S

    2006-07-26

    Stressful life events have been implicated clinically in the pathogenesis of mental illness, but the neural substrates that may account for this observation remain poorly understood. Attentional impairments symptomatic of these psychiatric conditions are associated with structural and functional abnormalities in a network of prefrontal cortical structures. Here, we examine whether chronic stress-induced dendritic alterations in the medial prefrontal cortex (mPFC) and orbital frontal cortex (OFC) underlie impairments in the behaviors that they subserve. After 21 d of repeated restraint stress, rats were tested on a perceptual attentional set-shifting task, which yields dissociable measures of reversal learning and attentional set-shifting, functions that are mediated by the OFC and mPFC, respectively. Intracellular iontophoretic injections of Lucifer yellow were performed in a subset of these rats to examine dendritic morphology in layer II/III pyramidal cells of the mPFC and lateral OFC. Chronic stress induced a selective impairment in attentional set-shifting and a corresponding retraction (20%) of apical dendritic arbors in the mPFC. In stressed rats, but not in controls, decreased dendritic arborization in the mPFC predicted impaired attentional set-shifting performance. In contrast, stress was not found to adversely affect reversal learning or dendritic morphology in the lateral OFC. Instead, apical dendritic arborization in the OFC was increased by 43%. This study provides the first direct evidence that dendritic remodeling in the prefrontal cortex may underlie the functional deficits in attentional control that are symptomatic of stress-related mental illnesses.

  18. Biologic targeting in the treatment of inflammatory bowel diseases [Retraction

    Directory of Open Access Journals (Sweden)

    Bosani M

    2014-01-01

    Full Text Available Bosani M, Ardizzone S, Porro GB. Biologics: Targets and Therapy. 2009;3:77–97.This paper has been retracted after we were made aware that it contains a large amount of reused, and uncited material that was not placed within quotation marks.The following statement has been supplied by Dr Sandro Ardizzone:The review entitled "Biologic targeting in the treatment of inflammatory bowel disease" has been commissioned by this journal and published in 2009 (Matteo Bosani, Sandro Ardizzone, Gabriele Bianchi Porro. Biologics: Targets & Therapy 2009;3:77–97. The paper was written by our young coworker (Dr M Bosani. He has consulted many papers, including our previous reviews published years before. The not perfect knowledge of English language has greatly influenced the writing of the paper itself. So he saved in word file several parts of our previous papers (Ardizzone S, Bianchi Porro G. Inflammatory bowel disease: new insights into pathogenesis and treatment. J Intern Med 2002;252:475–496 – Ardizzone S, Bianchi Porro G. Biologic therapy for inflammatory bowel disease. Drugs 2005:2253–2286, and then transferred to the final paper. He was unaware as we are, of the fact that he could not reuse previously published material in other journals. The reuse of this material was made in good faith.Taking our responsibility for what happened, we intend to apologize for this inconvenience to the Editor (Dr Doris Benbrook and Publisher (Dr Tim Hill. Moreover, for the reasons mentioned above, I consider appropriate to retract the paper itself.This retraction relates to this paper.

  19. Simultaneous Occurrence of Duane Retraction Syndrome with Marfan Syndrome

    Directory of Open Access Journals (Sweden)

    Mihir Kothari

    2011-01-01

    Full Text Available Marfan syndrome (MFS is an autosomal dominant disorder of connective tissue, while Duane retraction syndrome (DRS is a congenital cranial dysinnervation disorder (CCDD which can be transmitted as autosomal dominant disorder in 5–10% of patients. In this paper, we present an 8-year-old girl who presented with left eye DRS and bilateral subluxation of the lens associated with MFS in absence of familial involvement. To our knowledge this is the first case report of DRS with MFS. The occurrence of these syndromes together is very rare and appears to be coincidental.

  20. On permanent retraction of the fingers, according to Dupuytren.

    Science.gov (United States)

    Dohlem, R

    1996-06-01

    During a lecture on clinical surgery that he gave at the Hôtel-Dieu Hospital in Paris in 1831, Guillaume Dupuytren established the nature of "Permanent retraction of the fingers", that has been designated Dupuytren's contracture since the end of the XIXth century. The nosological individualization of this soft tissue rheumatism is analyzed based on a review of Dupuytren's lectures and of writings by XIXth century practitioners; the other two conditions included in Dupuytren's diathesis, namely Ledderhose's contracture and Peyronie's disease, are also discussed.

  1. Short- and long-term effects of LRRK2 on axon and dendrite growth.

    Directory of Open Access Journals (Sweden)

    Bryan Sepulveda

    Full Text Available Mutations in leucine-rich repeat kinase 2 (LRRK2 underlie an autosomal-dominant form of Parkinson's disease (PD that is clinically indistinguishable from idiopathic PD. The function of LRRK2 is not well understood, but it has become widely accepted that LRRK2 levels or its kinase activity, which is increased by the most commonly observed mutation (G2019S, regulate neurite growth. However, growth has not been measured; it is not known whether mean differences in length correspond to altered rates of growth or retraction, whether axons or dendrites are impacted differentially or whether effects observed are transient or sustained. To address these questions, we compared several developmental milestones in neurons cultured from mice expressing bacterial artificial chromosome transgenes encoding mouse wildtype-LRRK2 or mutant LRRK2-G2019S, Lrrk2 knockout mice and non-transgenic mice. Over the course of three weeks of development on laminin, the data show a sustained, negative effect of LRRK2-G2019S on dendritic growth and arborization, but counter to expectation, dendrites from Lrrk2 knockout mice do not elaborate more rapidly. In contrast, young neurons cultured on a slower growth substrate, poly-L-lysine, show significantly reduced axonal and dendritic motility in Lrrk2 transgenic neurons and significantly increased motility in Lrrk2 knockout neurons with no significant changes in length. Our findings support that LRRK2 can regulate patterns of axonal and dendritic growth, but they also show that effects vary depending on growth substrate and stage of development. Such predictable changes in motility can be exploited in LRRK2 bioassays and guide exploration of LRRK2 function in vivo.

  2. Gravitational effects in dendritic growth

    Science.gov (United States)

    Glicksman, M. E.; Singh, N. B.; Chopra, M.

    1983-01-01

    The theories of diffusion-controlled dendritic crystallization will be reviewed briefly, along with recently published critical experiments on the kinetics and morphology of dendritic growth in pure substances. The influence of the gravitational body force on dendrite growth kinetics will be shown to be highly dependent on the growth orientation with respect to the gravity vector and on the level of the thermal supercooling. In fact, an abrupt transition occurs at a critical supercooling, above which diffusional transport dominates the growth process and below which convective transport dominates. Our most recent work on binary mixtures shows that dilute solute additions influence the crystallization process indirectly, by altering the interfacial stability, rather than by directly affecting the transport mode. Directions for future studies in this field will also be discussed.

  3. Mechanisms and Function of Dendritic Exocytosis

    OpenAIRE

    Kennedy, Matthew J.; Ehlers, Michael D.

    2011-01-01

    Dendritic exocytosis is required for a broad array of neuronal functions including retrograde signaling, neurotransmitter release, synaptic plasticity, and establishment of neuronal morphology. While the details of synaptic vesicle exocytosis from presynaptic terminals have been intensely studied for decades, the mechanisms of dendritic exocytosis are only now emerging. Here we review the molecules and mechanisms of dendritic exocytosis, and discuss how exocytosis from dendrites influences ne...

  4. Coloration and thermoluminescence of translucent AlN ceramics sintered with Ca3Al2O6 as sintering additive

    Science.gov (United States)

    Honma, T.; Kuroki, Y.; Okamoto, T.; Takata, M.; Kanechika, Y.; Azuma, M.; Taniguchi, H.

    2011-03-01

    Coloration of translucent AlN ceramics sintered with Ca3Al2O6 as a sintering additive occurs by exposure to ultraviolet light. The trap related to this coloration was investigated by thermoluminescence (TL) measurements. With increasing oxygen content, the TL intensity increased, reflecting an increase in the trap concentration in the samples. The thermal activation energy of the trap also decreased with decreasing defect density. The trap is considered to be an oxygen-induced defect.

  5. Postsynaptic GABA(B Receptors Contribute to the Termination of Giant Depolarizing Potentials in CA3 Neonatal Rat Hippocampus

    Directory of Open Access Journals (Sweden)

    Ilgam Khalilov

    2017-06-01

    Full Text Available During development, hippocampal CA3 network generates recurrent population bursts, so-called Giant Depolarizing Potentials (GDPs. GDPs are characterized by synchronous depolarization and firing of CA3 pyramidal cells followed by afterhyperpolarization (GDP-AHP. Here, we explored the properties of GDP-AHP in CA3 pyramidal cells using gramicidin perforated patch clamp recordings from neonatal rat hippocampal slices. We found that GDP-AHP occurs independently of whether CA3 pyramidal cells fire action potentials (APs or remain silent during GDPs. However, the amplitude of GDP-AHP increased with the number of APs the cells fired during GDPs. The reversal potential of the GDP-AHP was close to the potassium equilibrium potential. During voltage-clamp recordings, current-voltage relationships of the postsynaptic currents activated during GDP-AHP were characterized by reversal near the potassium equilibrium potential and inward rectification, similar to the responses evoked by the GABA(B receptor agonists. Finally, the GABA(B receptor antagonist CGP55845 strongly reduced GDP-AHP and prolonged GDPs, eventually transforming them to the interictal and ictal-like discharges. Together, our findings suggest that the GDP-AHP involves two mechanisms: (i postsynaptic GABA(B receptor activated potassium currents, which are activated independently on whether the cell fires or not during GDPs; and (ii activity-dependent, likely calcium activated potassium currents, whose contribution to the GDP-AHP is dependent on the amount of firing during GDPs. We propose that these two complementary inhibitory postsynaptic mechanisms cooperate in the termination of GDP.

  6. Eu2+-activated Ba3Ca3(PO4)4 phosphor with doping-concentration dependent luminescence

    Science.gov (United States)

    Tang, Huidong; Yang, Rong; Li, Rongzhu

    2017-10-01

    A color tunable phosphor of Eu2+-activated monophosphate Ba3Ca3(PO4)4 was developed via facile solid-state reaction synthesis. The samples were tested by X-ray powder diffraction (XRD) patterns, morphological properties, luminescence and decay lifetime measurements. The structural characteristics were discussed. The excitation bands of the phosphors cover the UV-, near-UV and blue-wavelength bands extending from 300 to 440 nm. The luminescence spectra of the phosphors show a great dependence on the Eu2+-concentration in Ba3Ca3(PO4)4, which can give blue to yellow emission colors. There are two kinds of Eu2+ centers in Ba3Ca3(PO4)4 lattices, which give yellow (EuI) and blue (EuII) luminescence with the maximum wavelength at 565 nm and 450 nm, respectively. The structural occupations and luminescence properties of EuI and EuII centers were discussed. EuI (yellow center) has a dominant contribution to the total luminescence with the increase of the Eu2+-doping level. The luminescence internal quantum efficiency and thermal stability (activation energy) were reported. The reported results could be helpful for the further potential application of the phosphor.

  7. Age-related changes in glutamate release in the CA3 and dentate gyrus of the rat hippocampus

    Science.gov (United States)

    Stephens, Michelle L.; Quintero, Jorge E.; Pomerleau, Francois; Huettl, Peter; Gerhardt, Greg A.

    2012-01-01

    The present studies employed a novel microelectrode array recording technology to study glutamate release and uptake in the dentate gyrus, CA3 and CA1 hippocampal subregions in anesthetized young, late-middle aged and aged male Fischer 344 rats. The mossy fiber terminals in CA3 showed a significantly decreased amount of KCl-evoked glutamate release in aged rats compared to both young and late-middle-aged rats. Significantly more KCl-evoked glutamate release was seen from perforant path terminals in the DG of late-middle-aged rats compared young and aged rats. The DG of aged rats developed an increased glutamate uptake rate compared to the DG of young animals, indicating a possible age-related change in glutamate regulation to deal with increased glutamate release that occurred in late-middle age. No age-related changes in resting levels of glutamate were observed in the DG, CA3 and CA1. Taken together, these data support dynamic changes to glutamate regulation during aging in subregions of the mammalian hippocampus that are critical for learning and memory. PMID:19535175

  8. A cellular Potts model of germband retraction and dorsal closure

    Science.gov (United States)

    Hutson, M. Shane; Rohner, Jason; Crews, Sarah; McCleery, W. Tyler; Robinson, W. Bradley

    2011-03-01

    Germband retraction and dorsal closure are critical morphogenetic events in fruit fly embryogenesis. Both involve the coordinated reshaping of two epitheloid tissues -- germband (GB) and amnioserosa (AS). The GB is initially curled into a U-shape with the AS between the arms of the U. Retraction leaves the embryo's dorsal surface covered by AS cells which then contract to pull lateral parts of the GB up to cover the dorsal surface. We have simulated these events using a cellular Potts model. The model is 3D with several generalized cell types: a central yolk; a surrounding monolayer of AS and GB cells with epithelial polarization; and an outer vitelline membrane enclosing the cells and a perivitelline fluid. The model also incorporates several critical cell behaviors: polarized apical constriction of AS cells; controlled relaxation of stretched GB cells; and differentiation of GB cells at the GB-AS interface so that these cells then contract a supracellular purse-string and extend filopodia that reach across the AS and zip together the GB's approaching lateral flanks. We will discuss how all of these components are necessary to reproduce normal tissue motions and those observed during laser microsurgery experiments. Supported by NSF Grant IOB-0545679.

  9. Surgical effects in patients with Duane retraction syndrome

    Directory of Open Access Journals (Sweden)

    Shui-Lian Zhou

    2017-03-01

    Full Text Available AIM: To investigate the clinical characteristics and surgical effects in patients with Duane retraction syndrome(DRS.METHODS: Totally 13 patients with DRS during June 2011 to December 2015 were analyzed retrospectively. The data including clinical types and manifestations, surgical methods and outcomes were reviewed and analyzed. RESULTS: There were 11 male cases and 2 female cases who all had no ocular and systemic anomalies. The left eye was involved in 9 cases, the right eye was involved in 3 cases and 1 case involved in both eyes. Six cases were type Ⅰ,1 case was typeⅡand 6 cases were type Ⅲ. Eleven cases had abnormal head posture(AHP, 9 cases had the up- or down-shoot phenomenon. The surgical treatment was designed according to subtypes and clinical features which included medial rectus recession, lateral rectus recession, recession of both horizontal rectus muscles and lateral rectus recession combined with Y splitting. After surgery, horizontal deviation was less than ±10△ in all patients, and AHP disappeared in 4 cases and improved in 7 cases. The up- or down-shoot and global retraction disappeared in 5 cases and improved in 4 cases. Simultaneously, the restriction of ocular motility was improved in all patients. CONCLUSION: The clinical features of DRS are variant in different types. Detailed examination before surgery and reasonable surgical design are important in treatment of patients with DRS.

  10. Migratory dermal dendritic cells act as rapid sensors of protozoan parasites.

    Directory of Open Access Journals (Sweden)

    Lai Guan Ng

    2008-11-01

    Full Text Available Dendritic cells (DC, including those of the skin, act as sentinels for intruding microorganisms. In the epidermis, DC (termed Langerhans cells, LC are sessile and screen their microenvironment through occasional movements of their dendrites. The spatio-temporal orchestration of antigen encounter by dermal DC (DDC is not known. Since these cells are thought to be instrumental in the initiation of immune responses during infection, we investigated their behavior directly within their natural microenvironment using intravital two-photon microscopy. Surprisingly, we found that, under homeostatic conditions, DDC were highly motile, continuously crawling through the interstitial space in a Galpha(i protein-coupled receptor-dependent manner. However, within minutes after intradermal delivery of the protozoan parasite Leishmania major, DDC became immobile and incorporated multiple parasites into cytosolic vacuoles. Parasite uptake occurred through the extension of long, highly dynamic pseudopods capable of tracking and engulfing parasites. This was then followed by rapid dendrite retraction towards the cell body. DDC were proficient at discriminating between parasites and inert particles, and parasite uptake was independent of the presence of neutrophils. Together, our study has visualized the dynamics and microenvironmental context of parasite encounter by an innate immune cell subset during the initiation of the immune response. Our results uncover a unique migratory tissue surveillance program of DDC that ensures the rapid detection of pathogens.

  11. 14 CFR 23.729 - Landing gear extension and retraction system.

    Science.gov (United States)

    2010-01-01

    ... use of hydraulic pressure) to keep the landing gear extended. (c) Emergency operation. For a landplane... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing gear extension and retraction... Design and Construction Landing Gear § 23.729 Landing gear extension and retraction system. (a) General...

  12. When Scholarly Publishing Goes Awry: Educating Ourselves and Our Patrons about Retracted Articles

    Science.gov (United States)

    Thielen, Joanna

    2018-01-01

    Retracted articles, articles that violate professional ethics, are an unsettling, yet integral, part of the scholarly publishing process seldom discussed in the academy. Unfortunately, article retractions continue to rise across all disciplines. Although academic librarians consistently provide instruction on scholarly publishing, little has been…

  13. Retracted: The clinical anatomy of the insertion of the rotator cuff ...

    African Journals Online (AJOL)

    2nd March 2017 - Article Retracted. The Article THE CLINICAL ANATOMY OF THE INSERTION OF THE ROTATOR CUFF TENDON has been retracted from the Anatomy Journal of Africa on author request, and on the understanding that it was concurrently submitted and published in another journal. Managing Editor.

  14. 76 FR 472 - Harmonization of Airworthiness Standards for Transport Category Airplanes-Landing Gear Retracting...

    Science.gov (United States)

    2011-01-05

    ... Airworthiness Standards for Transport Category Airplanes--Landing Gear Retracting Mechanisms and Pilot... transport category airplanes on landing gear retracting mechanisms and the pilot compartment view. This... in a stalling maneuver, and would add an additional requirement to keep the landing gear and doors in...

  15. Effects of inhaled anesthetic isoflurane on long-term potentiation of CA3 pyramidal cell afferents in vivo

    Directory of Open Access Journals (Sweden)

    Ballesteros KA

    2012-11-01

    Full Text Available Kristen A Ballesteros,1 Angela Sikorski,2 James E Orfila,3 Joe L Martinez Jr41Department of Biology, The University of Texas at San Antonio, San Antonio, TX, USA; 2Texas A&M University Texarkana, Texarkana, TX, USA; 3University of Colorado in Denver, Denver, CO, USA; 4University of Illinois in Chicago, Chicago, IL, USAAbstract: Isoflurane is a preferred anesthetic, due to its properties that allow a precise concentration to be delivered continually during in vivo experimentation. The major mechanism of action of isoflurane is modulation of the γ-amino butyric acid (GABAA receptor-chloride channel, mediating inhibitory synaptic transmission. Animal studies have shown that isoflurane does not cause cell death, but it does inhibit cell growth and causes long-term hippocampal learning deficits. As there are no studies characterizing the effects of isoflurane on electrophysiological aspects of long-term potentiation (LTP in the hippocampus, it is important to determine whether isoflurane alters the characteristic responses of hippocampal afferents to cornu ammonis region 3 (CA3. We investigated the effects of isoflurane on adult male rats during in vivo induction of LTP, using the mossy fiber pathway, the lateral perforant pathway, the medial perforant pathway, and the commissural CA3 (cCA3 to CA3, with intracranial administration of Ringer’s solution, naloxone, RS-aminoindan-1, 5-dicarboxylic acid (AIDA, or 3-[(R-2-carboxypiperazin-4-yl]-propo-2-enyl-1-phosphonic acid (CPP. Then, we compared these responses to published electrophysiological data, using sodium pentobarbital as an anesthetic, under similar experimental conditions. Our results showed that LTP was exhibited in animals anesthetized with isoflurane under vehicle conditions. With the exception of AIDA in the lateral perforant pathway, the defining characteristics of the four pathways appeared to remain intact, except for the observation that LTP was markedly reduced in animals

  16. K(Ca3.1 channel-blockade attenuates airway pathophysiology in a sheep model of chronic asthma.

    Directory of Open Access Journals (Sweden)

    Joanne Van Der Velden

    Full Text Available The Ca(2+-activated K(+ channel K(Ca3.1 is expressed in several structural and inflammatory airway cell types and is proposed to play an important role in the pathophysiology of asthma. The aim of the current study was to determine whether inhibition of K(Ca3.1 modifies experimental asthma in sheep.Atopic sheep were administered either 30 mg/kg Senicapoc (ICA-17073, a selective inhibitor of the K(Ca3.1-channel, or vehicle alone (0.5% methylcellulose twice daily (orally. Both groups received fortnightly aerosol challenges with house dust mite allergen for fourteen weeks. A separate sheep group received no allergen challenges or drug treatment. In the vehicle-control group, twelve weeks of allergen challenges resulted in a 60±19% increase in resting airway resistance, and this was completely attenuated by treatment with Senicapoc (0.25±12%; n = 10, P = 0.0147. The vehicle-control group had a peak-early phase increase in lung resistance of 82±21%, and this was reduced by 58% with Senicapoc treatment (24±14%; n = 10, P = 0.0288. Senicapoc-treated sheep also demonstrated reduced airway hyperresponsiveness, requiring a significantly higher dose of carbachol to increase resistance by 100% compared to allergen-challenged vehicle-control sheep (20±5 vs. 52±18 breath-units of carbachol; n = 10, P = 0.0340. Senicapoc also significantly reduced eosinophil numbers in bronchoalveolar lavage taken 48 hours post-allergen challenge, and reduced vascular remodelling.These findings suggest that K(Ca3.1-activity contributes to allergen-induced airway responses, inflammation and vascular remodelling in a sheep model of asthma, and that inhibition of K(Ca3.1 may be an effective strategy for blocking allergen-induced airway inflammation and hyperresponsiveness in humans.

  17. Transient changes in excitability of rabbit CA3 neurons with a time course appropriate to support memory consolidation.

    Science.gov (United States)

    Thompson, L T; Moyer, J R; Disterhoft, J F

    1996-09-01

    1. The excitability of CA3 pyramidal neurons was assessed with intracellular recordings in hippocampal slices from behaviorally naive rabbits. CA3 pyramidal neurons had large (-13.1 +/- 0.3 mV; mean +/- SE) postburst afterhyperpolarization (AHPs) and exhibited robust spike-frequency adaptation (accommodation) to prolonged (800-ms) depolarizing current injection at resting potentials of -68 mV. AHP and accommodation measures differed in scale but not in kind from those obtained in stable recordings from CA1 pyramidal neurons in the same slices or from the same rabbits, with CA3 neurons having larger longer AHPs but fewer spikes during accommodation. 2. Groups of rabbits were trained in a simple, associative-learning task, trace eye-blink conditioning, which required an intact hippocampus for successful acquisition. Memory consolidation in this task also involves the hippocampus, whereas long-term retention of the learned response does not. The time course and magnitude of learning-specific changes in excitability were assessed in 201 CA3 pyramidal neurons. 3. Learning increased the excitability of CA3 pyramidal neurons soon after acquisition (within 1-24 h). The mean postburst AHP was reduced to approximately half (-6.4 +/- 0.3 mV) the basal amplitude of the AHP observed in naive controls. The area and duration of the postburst AHP similarly were reduced. Approximately half of all pyramidal neurons tested soon after learning exhibited significantly reduced AHPs, whereas none exhibited enhanced AHPs. 4. Trace conditioning also reduced accommodation of CA3 pyramidal neurons 1-24 h after learning. Neurons from successfully trained rabbits fired significantly more action potentials (5.6 +/- 1.5) in response to prolonged depolarization than did neurons from naive controls (4.1 +/- 0.2). The magnitude of the learning-specific change in accommodation was less than that for the AHP. Approximately 45% of neurons tested exhibited significantly reduced accommodation soon after

  18. Correlation Between Cerebellar Retraction and Hearing Loss After Microvascular Decompression for Hemifacial Spasm: A Prospective Study.

    Science.gov (United States)

    Li, Ning; Zhao, Wei-Guo; Pu, Chun-Hua; Yang, Wen-Lei

    2017-06-01

    This study prospectively investigated the relationship between cerebellar retraction factors measured on preoperative magnetic resonance and the development of postoperative hearing loss and evaluated their potential role in predicting the possibility of hearing loss after microvascular decompression (MVD) for hemifacial spasm (HFS). The study included 110 patients clinically diagnosed with primary HFS who underwent MVD in our department. The cerebellar retraction factors were quantitatively measured on preoperative magnetic resonance. Associations of cerebellar retraction and other risk factors with postoperative hearing loss were analyzed. Eleven patients (10%) developed nonserviceable hearing loss after MVD. Compared with the group without hearing loss, the cerebellar retraction distance and depth of the group with hearing loss were significantly greater (P hearing loss (P hearing loss after MVD for HFS. In addition, cerebellar retraction depth could be considered as a useful tool to predict the risk of post-MVD hearing loss. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Assisted morphogenesis: glial control of dendrite shapes.

    Science.gov (United States)

    Procko, Carl; Shaham, Shai

    2010-10-01

    Neurons display a myriad of dendritic architectures, reflecting their diverse roles in information processing and transduction in the nervous system. Recent findings suggest that neuronal signals may not account for all aspects of dendrite morphogenesis. Observations from C. elegans and other organisms suggest that glial cells can affect dendrite length and guidance, as well as localization and shapes of dendritic receptive structures, such as dendritic spines and sensory cilia. Thus, besides direct roles in controlling neuronal activity, glia contribute to neuron function by ensuring that neurons attain their proper shapes. Copyright © 2010 Elsevier Ltd. All rights reserved.

  20. Advanced dendritic web growth development

    Science.gov (United States)

    Hopkins, R. H.

    1985-01-01

    A program to develop the technology of the silicon dendritic web ribbon growth process is examined. The effort is being concentrated on the area rate and quality requirements necessary to meet the JPL/DOE goals for terrestrial PV applications. Closed loop web growth system development and stress reduction for high area rate growth is considered.

  1. Retractions in general and internal medicine in a high-profile scientific indexing database

    Directory of Open Access Journals (Sweden)

    Renan Moritz Varnier Rodrigues de Almeida

    Full Text Available CONTEXT AND OBJECTIVE: Increased frequency of retractions has recently been observed, and retractions are important events that deserve scientific investigation. This study aimed to characterize cases of retraction within general and internal medicine in a high-profile database, with interest in the country of origin of the article and the impact factor (IF of the journal in which the retraction was made. DESIGN AND SETTING: This study consisted of reviewing retraction notes in the Thomson-Reuters Web of Knowledge (WoK indexing database, within general and internal medicine. METHODS: The retractions were classified as plagiarism/duplication, error, fraud and authorship problems and then aggregated into two categories: "plagiarism/duplication" and "others." The countries of origin of the articles were dichotomized according to the median of the indicator "citations per paper" (CPP, and the IF was dichotomized according to its median within general and internal medicine, also obtained from the WoK database. These variables were analyzed using contingency tables according to CPP (high versus low, IF (high versus low and period (1992-2002 versus 2003-2014. The relative risk (RR and 95% confidence interval (CI were estimated for plagiarism/duplication. RESULTS: A total of 86 retraction notes were identified, and retraction reasons were found for 80 of them. The probability that plagiarism/duplication was the reason for retraction was more than three times higher for the low CPP group (RR: 3.4; 95% CI: [1.9-6.2], and similar results were seen for the IF analysis. CONCLUSION: The study identified greater incidence of plagiarism/duplication among retractions from countries with lower scientific impact.

  2. Retractions in general and internal medicine in a high-profile scientific indexing database.

    Science.gov (United States)

    de Almeida, Renan Moritz Varnier Rodrigues; Catelani, Fernanda; Fontes-Pereira, Aldo José; Gave, Nárrima de Souza

    2016-01-01

    Increased frequency of retractions has recently been observed, and retractions are important events that deserve scientific investigation. This study aimed to characterize cases of retraction within general and internal medicine in a high-profile database, with interest in the country of origin of the article and the impact factor (IF) of the journal in which the retraction was made. This study consisted of reviewing retraction notes in the Thomson-Reuters Web of Knowledge (WoK) indexing database, within general and internal medicine. The retractions were classified as plagiarism/duplication, error, fraud and authorship problems and then aggregated into two categories: "plagiarism/duplication" and "others." The countries of origin of the articles were dichotomized according to the median of the indicator "citations per paper" (CPP), and the IF was dichotomized according to its median within general and internal medicine, also obtained from the WoK database. These variables were analyzed using contingency tables according to CPP (high versus low), IF (high versus low) and period (1992-2002 versus 2003-2014). The relative risk (RR) and 95% confidence interval (CI) were estimated for plagiarism/duplication. A total of 86 retraction notes were identified, and retraction reasons were found for 80 of them. The probability that plagiarism/duplication was the reason for retraction was more than three times higher for the low CPP group (RR: 3.4; 95% CI: [1.9-6.2]), and similar results were seen for the IF analysis. The study identified greater incidence of plagiarism/duplication among retractions from countries with lower scientific impact.

  3. Activity of the principal cells of the olfactory bulb promotes a structural dynamic on the distal dendrites of immature adult-born granule cells via activation of NMDA receptors.

    Science.gov (United States)

    Breton-Provencher, Vincent; Coté, Daniel; Saghatelyan, Armen

    2014-01-29

    The adult olfactory bulb is continuously supplied with neuronal precursors that differentiate into granule and periglomerular cells. Little is known about the structural dynamic of adult-born granule cells (GCs) at their different maturational stages, the mechanisms controlling the integration of new neurons into the pre-existing neuronal circuitry, or the role of principal cell activity in these processes. We used two-photon time-lapse imaging to reveal a high level of filopodia formation and retraction on the distal dendrites of adult-born GCs at their early maturational stages. This dynamic decreased as the adult-born interneurons matured. Filopodia formation/retraction on the dendrites of adult-born GCs at the early maturational stages depended on the activation of NMDA receptors (NMDARs). The stimulation of mitral cells using a pattern that mimics activity of these principal neurons to odor presentation promotes the NMDAR-dependent filopodia dynamic of adult-born GCs during their early but not late maturational stages. Moreover, NMDA iontophoresis was sufficient to induce the formation of new filopodia on the distal dendrites of immature adult-born GCs. The maturation of adult-born interneurons was accompanied by a progressive hyperpolarization of the membrane potential and an increased Mg(2+) block of NMDARs. Decreasing the extracellular Mg(2+) concentration led to filopodia formation on the dendrites of mature adult-born GCs following NMDA iontophoresis. Our findings reveal an increased structural dynamic of adult-born GCs during the early stages of their integration into the mouse bulbar circuitry and highlight a critical period during which the principal cells' activity influences filopodia formation/retraction on the dendrites of interneurons.

  4. Atypical association of Duane retraction syndrome and Bardet Biedl syndrome

    Directory of Open Access Journals (Sweden)

    Jethani Jitendra

    2007-01-01

    Full Text Available Duane′s retraction syndrome (DRS includes changes in palpebral fissure width along with restriction of ocular motility. Bardet Biedl syndrome (BBS includes presence of retinitis pigmentosa (RP with obesity, mental retardation, polydactyly and renal abnormalities. We report a case of rare association of DRS with BBS in a seven-year-old child. The ocular motility examination revealed left DRS with esotropia. Fundus examination revealed findings characteristic of an atypical retinitis pigmentosa. The electro-retinogram waveforms were extinguished both for rods and cones. He was diagnosed as a case of BBS on the basis of the ophthalmological findings plus association with the systemic features of obesity, polydactyly, hypogonadism, mental retardation and renal abnormalities. This case gives further evidence of the fact that BBS may be associated with abnormalities of eye movements.

  5. Prenatal hypoxia-ischemia induces abnormalities in CA3 microstructure, potassium chloride cotransporter 2 expression and inhibitory tone

    Directory of Open Access Journals (Sweden)

    Lauren L Jantzie

    2015-09-01

    Full Text Available Infants who suffer perinatal brain injury, including those with encephalopathy of prematurity, are prone to chronic neurological deficits including epilepsy, cognitive impairment, and behavioral problems such as anxiety, inattention and poor social interaction. These deficits, especially in combination, pose the greatest hindrance to these children becoming independent adults. Cerebral function depends on adequate development of essential inhibitory neural circuits and the appropriate amount of excitation and inhibition at specific stages of maturation. Early neuronal synaptic responses to γ-amino butyric acid (GABA are initially excitatory. During the early postnatal period, GABAAR responses switch to inhibitory with the upregulation of potassium-chloride co-transporter KCC2. With extrusion of chloride by KCC2, the Cl- reversal potential shifts and GABA and glycine responses become inhibitory. We hypothesized that prenatal hypoxic-ischemic brain injury chronically impairs the developmental upregulation of KCC2 that is essential for cerebral circuit formation. Following late gestation hypoxia-ischemia, diffusion tensor imaging in juvenile rats shows poor microstructural integrity in the hippocampal CA3 subfield, with reduced fractional anisotropy and elevated radial diffusivity. The loss of microstructure correlates with early reduced KCC2 expression on NeuN-positive pyramidal neurons, and decreased monomeric and oligomeric KCC2 protein expression in the CA3 subfield. Together with decreased IPSCs during a critical window of development, we document for the first time that prenatal transient systemic hypoxia-ischemia in rats impairs hippocampal CA3 inhibitory tone. Failure of timely development of inhibitory tone likely contributes to a lower seizure threshold and impaired cognitive function in children who suffer perinatal brain injury.

  6. Excitable actin dynamics in lamellipodial protrusion and retraction.

    Science.gov (United States)

    Ryan, Gillian L; Petroccia, Heather M; Watanabe, Naoki; Vavylonis, Dimitrios

    2012-04-04

    Many animal cells initiate crawling by protruding lamellipodia, consisting of a dense network of actin filaments, at their leading edge. We imaged XTC cells that exhibit flat lamellipodia on poly-L-lysine-coated coverslips. Using active contours, we tracked the leading edge and measured the total amount of F-actin by summing the pixel intensities within a 5-μm band. We observed protrusion and retraction with period 130-200 s and local wavelike features. Positive (negative) velocities correlated with minimum (maximum) integrated actin concentration. Approximately constant retrograde flow indicated that protrusions and retractions were driven by fluctuations of the actin polymerization rate. We present a model of these actin dynamics as an excitable system in which a diffusive, autocatalytic activator causes actin polymerization; F-actin accumulation in turn inhibits further activator accumulation. Simulations of the model reproduced the pattern of actin polymerization seen in experiments. To explore the model's assumption of an autocatalytic activation mechanism, we imaged cells expressing markers for both F-actin and the p21 subunit of the Arp2/3 complex. We found that integrated Arp2/3-complex concentrations spike several seconds before spikes of F-actin concentration. This suggests that the Arp2/3 complex participates in an activation mechanism that includes additional diffuse components. Response of cells to stimulation by fetal calf serum could be reproduced by the model, further supporting the proposed dynamical picture. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  7. The functional genome of CA1 and CA3 neurons under native conditions and in response to ischemia

    Directory of Open Access Journals (Sweden)

    Rossner Moritz

    2007-10-01

    Full Text Available Abstract Background The different physiological repertoire of CA3 and CA1 neurons in the hippocampus, as well as their differing behaviour after noxious stimuli are ultimately based upon differences in the expressed genome. We have compared CA3 and CA1 gene expression in the uninjured brain, and after cerebral ischemia using laser microdissection (LMD, RNA amplification, and array hybridization. Results Profiling in CA1 vs. CA3 under normoxic conditions detected more than 1000 differentially expressed genes that belong to different, physiologically relevant gene ontology groups in both cell types. The comparison of each region under normoxic and ischemic conditions revealed more than 5000 ischemia-regulated genes for each individual cell type. Surprisingly, there was a high co-regulation in both regions. In the ischemic state, only about 100 genes were found to be differentially expressed in CA3 and CA1. The majority of these genes were also different in the native state. A minority of interesting genes (e.g. inhibinbetaA displayed divergent expression preference under native and ischemic conditions with partially opposing directions of regulation in both cell types. Conclusion The differences found in two morphologically very similar cell types situated next to each other in the CNS are large providing a rational basis for physiological differences. Unexpectedly, the genomic response to ischemia is highly similar in these two neuron types, leading to a substantial attenuation of functional genomic differences in these two cell types. Also, the majority of changes that exist in the ischemic state are not generated de novo by the ischemic stimulus, but are preexistant from the genomic repertoire in the native situation. This unexpected influence of a strong noxious stimulus on cell-specific gene expression differences can be explained by the activation of a cell-type independent conserved gene-expression program. Our data generate both novel

  8. Phase field modeling of dendritic coarsening during isothermal

    Directory of Open Access Journals (Sweden)

    Zhang Yutuo

    2011-08-01

    Full Text Available Dendritic coarsening in Al-2mol%Si alloy during isothermal solidification at 880K was investigated by phase field modeling. Three coarsening mechanisms operate in the alloy: (a melting of small dendrite arms; (b coalescence of dendrites near the tips leading to the entrapment of liquid droplets; (c smoothing of dendrites. Dendrite melting is found to be dominant in the stage of dendritic growth, whereas coalescence of dendrites and smoothing of dendrites are dominant during isothermal holding. The simulated results provide a better understanding of dendrite coarsening during isothermal solidification.

  9. Effectiveness of en masse versus two-step retraction: a systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Mumen Z. Rizk

    2018-01-01

    Full Text Available Abstract Background This review aims to compare the effectiveness of en masse and two-step retraction methods during orthodontic space closure regarding anchorage preservation and anterior segment retraction and to assess their effect on the duration of treatment and root resorption. Methods An electronic search for potentially eligible randomized controlled trials and prospective controlled trials was performed in five electronic databases up to July 2017. The process of study selection, data extraction, and quality assessment was performed by two reviewers independently. A narrative review is presented in addition to a quantitative synthesis of the pooled results where possible. The Cochrane risk of bias tool and the Newcastle-Ottawa Scale were used for the methodological quality assessment of the included studies. Results Eight studies were included in the qualitative synthesis in this review. Four studies were included in the quantitative synthesis. En masse/miniscrew combination showed a statistically significant standard mean difference regarding anchorage preservation − 2.55 mm (95% CI − 2.99 to − 2.11 and the amount of upper incisor retraction − 0.38 mm (95% CI − 0.70 to − 0.06 when compared to a two-step/conventional anchorage combination. Qualitative synthesis suggested that en masse retraction requires less time than two-step retraction with no difference in the amount of root resorption. Conclusions Both en masse and two-step retraction methods are effective during the space closure phase. The en masse/miniscrew combination is superior to the two-step/conventional anchorage combination with regard to anchorage preservation and amount of retraction. Limited evidence suggests that anchorage reinforcement with a headgear produces similar results with both retraction methods. Limited evidence also suggests that en masse retraction may require less time and that no significant differences exist in the amount of root

  10. Effectiveness of en masse versus two-step retraction: a systematic review and meta-analysis.

    Science.gov (United States)

    Rizk, Mumen Z; Mohammed, Hisham; Ismael, Omar; Bearn, David R

    2018-01-05

    This review aims to compare the effectiveness of en masse and two-step retraction methods during orthodontic space closure regarding anchorage preservation and anterior segment retraction and to assess their effect on the duration of treatment and root resorption. An electronic search for potentially eligible randomized controlled trials and prospective controlled trials was performed in five electronic databases up to July 2017. The process of study selection, data extraction, and quality assessment was performed by two reviewers independently. A narrative review is presented in addition to a quantitative synthesis of the pooled results where possible. The Cochrane risk of bias tool and the Newcastle-Ottawa Scale were used for the methodological quality assessment of the included studies. Eight studies were included in the qualitative synthesis in this review. Four studies were included in the quantitative synthesis. En masse/miniscrew combination showed a statistically significant standard mean difference regarding anchorage preservation - 2.55 mm (95% CI - 2.99 to - 2.11) and the amount of upper incisor retraction - 0.38 mm (95% CI - 0.70 to - 0.06) when compared to a two-step/conventional anchorage combination. Qualitative synthesis suggested that en masse retraction requires less time than two-step retraction with no difference in the amount of root resorption. Both en masse and two-step retraction methods are effective during the space closure phase. The en masse/miniscrew combination is superior to the two-step/conventional anchorage combination with regard to anchorage preservation and amount of retraction. Limited evidence suggests that anchorage reinforcement with a headgear produces similar results with both retraction methods. Limited evidence also suggests that en masse retraction may require less time and that no significant differences exist in the amount of root resorption between the two methods.

  11. Effects of Synthesis and Processing on the Thermoelectric Properties of Ca3Co4O9+δ

    DEFF Research Database (Denmark)

    Wu, NingYu; Holgate, Tim; Van Nong, Ngo

    In the present study, Ca3Co4O9+δ was synthesized by solid-state and sol-gel reactions followed by spark plasma sintering (SPS) under different conditions such as sintering temperatures, applied pressures and ramping rates. The materials were then characterized with respect to their microstructure......, phase purity and thermoelectric properties. With the identical optimal SPS process, the power factor of about 400 µW/m•K2 and 465 µW/m•K2 (at 800 °C) is measured from samples produced by solid-state and sol-gel reactions respectively, both of these values are higher than the value reported so far....... The thermoelectric performance improvement observed for the solid-state and sol-gel reactions suggests that the particle sizes may be a predominant key parameter of the Ca3Co4O9+δ thermoelectric properties. Smaller particle size (500 nm) as produced in this study by sol-gel synthesis method with optimal SPS process...

  12. ARPES studies of the inverse perovskite Ca3PbO : Experimental confirmation of a candidate 3D Dirac fermion system

    Science.gov (United States)

    Obata, Yukiko; Yukawa, Ryu; Horiba, Koji; Kumigashira, Hiroshi; Toda, Yoshitake; Matsuishi, Satoru; Hosono, Hideo

    2017-10-01

    We investigate the band structure of the inverse perovskite Ca3PbO , a candidate three-dimensional (3D) Dirac fermion material, through soft x-ray angle-resolved photoemission spectroscopy. Conelike band dispersions are observed for Ca3PbO , in close agreement with the predictions of electronic structure calculations. We further demonstrate that chemical substitution of Bi for Pb is effective in tuning the Fermi level of Ca3PbO while leaving its electronic structure intact. Our study confirms that the inverse perovskite family provides a promising platform for the exploration of 3D Dirac fermion systems.

  13. Quantification of intrusive/retraction force and moment generated during en-masse retraction of maxillary anterior teeth using mini-implants: A conceptual approach

    Directory of Open Access Journals (Sweden)

    A. Sumathi Felicita

    Full Text Available ABSTRACT Objective: The aim of the present study was to clarify the biomechanics of en-masse retraction of the upper anterior teeth and attempt to quantify the different forces and moments generated using mini-implants and to calculate the amount of applied force optimal for en-masse intrusion and retraction using mini-implants. Methods: The optimum force required for en-masse intrusion and retraction can be calculated by using simple mathematical formulae. Depending on the position of the mini-implant and the relationship of the attachment to the center of resistance of the anterior segment, different clinical outcomes are encountered. Using certain mathematical formulae, accurate measurements of the magnitude of force and moment generated on the teeth can be calculated for each clinical outcome. Results: Optimum force for en-masse intrusion and retraction of maxillary anterior teeth is 212 grams per side. Force applied at an angle of 5o to 16o from the occlusal plane produce intrusive and retraction force components that are within the physiologic limit. Conclusion: Different clinical outcomes are encountered depending on the position of the mini-implant and the length of the attachment. It is possible to calculate the forces and moments generated for any given magnitude of applied force. The orthodontist can apply the basic biomechanical principles mentioned in this study to calculate the forces and moments for different hypothetical clinical scenarios.

  14. Analyzing Dendritic Morphology in Columns and Layers.

    Science.gov (United States)

    Ting, Chun-Yuan; McQueen, Philip G; Pandya, Nishith; McCreedy, Evan S; McAuliffe, Matthew; Lee, Chi-Hon

    2017-03-23

    In many regions of the central nervous systems, such as the fly optic lobes and the vertebrate cortex, synaptic circuits are organized in layers and columns to facilitate brain wiring during development and information processing in developed animals. Postsynaptic neurons elaborate dendrites in type-specific patterns in specific layers to synapse with appropriate presynaptic terminals. The fly medulla neuropil is composed of 10 layers and about 750 columns; each column is innervated by dendrites of over 38 types of medulla neurons, which match with the axonal terminals of some 7 types of afferents in a type-specific fashion. This report details the procedures to image and analyze dendrites of medulla neurons. The workflow includes three sections: (i) the dual-view imaging section combines two confocal image stacks collected at orthogonal orientations into a high-resolution 3D image of dendrites; (ii) the dendrite tracing and registration section traces dendritic arbors in 3D and registers dendritic traces to the reference column array; (iii) the dendritic analysis section analyzes dendritic patterns with respect to columns and layers, including layer-specific termination and planar projection direction of dendritic arbors, and derives estimates of dendritic branching and termination frequencies. The protocols utilize custom plugins built on the open-source MIPAV (Medical Imaging Processing, Analysis, and Visualization) platform and custom toolboxes in the matrix laboratory language. Together, these protocols provide a complete workflow to analyze the dendritic routing of Drosophila medulla neurons in layers and columns, to identify cell types, and to determine defects in mutants.

  15. Low Power Dendritic Computation for Wordspotting

    Directory of Open Access Journals (Sweden)

    Stephen Nease

    2013-05-01

    Full Text Available In this paper, we demonstrate how a network of dendrites can be used to build the state decoding block of a wordspotter similar to a Hidden Markov Model (HMM classifier structure. We present simulation and experimental data for a single line dendrite and also experimental results for a dendrite-based classifier structure. This work builds on previously demonstrated building blocks of a neural network: the channel, synapses and dendrites using CMOS circuits. These structures can be used for speech and pattern recognition. The computational efficiency of such a system is >10 MMACs/μW as compared to Digital Systems which perform 10 MMACs/mW.

  16. Bilateral inverse Duane′s retraction syndrome-A case report

    Directory of Open Access Journals (Sweden)

    Chatterjee Pranab

    1991-01-01

    Full Text Available Duane′s retraction syndrome is a well known congenital musculo-facial anomaly. Various explanations have been given for the aetiology of this syndrome. Inverse Duane′s retraction syndrome is a condition with reverse clinical features. Abduction of the affected eye is possible to some extent and is accompanied by retraction of the eyeball, narrowing of the palpebral fissure and pseudoptosis. There may be some restriction of movement on adduction. The primary lesion is suspected to be in the medial rectus muscle. Frequently the muscle is found to be entrapped following trauma to the medial wall of the orbit. A case of bilateral inverse Duane′s retraction syndrome and convergent squint along with left-sided perceptive deafness is reported. As is usually the case there was no structural abnormality or entrapment of the muscle from trauma.

  17. Retraction and expansion of flock mobility in central asia: costs and ...

    African Journals Online (AJOL)

    Retraction and expansion of flock mobility in central asia: costs and consequences. Carol Kerven, Ilya Ilych Alimaev, Roy Behnke, Grant Davidson, Leen Franchois, Nurlan Malmakov, Erik Mathijs, Aidos Smailov, Sayat Temirbekov, Iain Wright ...

  18. Effectiveness of mini implants in three-dimensional control during retraction - a clinical study

    National Research Council Canada - National Science Library

    Victor, Deepak; Prabhakar, Ramchandra; Karthikeyan, M K; Saravanan, R; Vanathi, P; Vikram, N Raj; Reddy, P Adarsh; Sudeepthi, M

    2014-01-01

    .... The purpose of this study was to compare and measure the vertical control and torque control of incisors and molar during enmass retraction with titanium microimplants and conventional molar anchorage...

  19. Rapid maxillary anterior teeth retraction en masse by bone compression: a canine model

    National Research Council Canada - National Science Library

    Liu, Chufeng; Cao, Yang; Liu, Conghua; Zhang, Jincai; Xu, Pingping

    2011-01-01

    The present study sought to establish an animal model to study the feasibility and safety of rapid retraction of maxillary anterior teeth en masse aided by alveolar surgery in order to reduce orthodontic treatment time...

  20. Retraction Note: Radiation Sialadenitis Induced by High-dose Radioactive Iodine Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Shin Young; Lee, Jaetae [Kyungpook National Univ. Hospital, Daegu (Korea, Republic of)

    2014-06-15

    The senior author (J. Lee) and the first author (S. Y. Jeong) have retracted this review article due to misconduct. They have discovered multiple instances of misreferencing and misquotation in the text which raise the concern of potential plagiarism.

  1. [Two cases of koro syndrome or anxiety disorder associated with genital retraction fear].

    Science.gov (United States)

    Atalay, Hakan

    2007-01-01

    As a cultural-bound syndrome, koro is described in the DSM-IV as "an episode of sudden and intense anxiety that the penis (or, in females, the vulva and the nipples) will recede into the body and possibly cause death." Sometimes the syndrome may occur as an epidemic involving several hundreds to thousands of subjects within a short period of time. While the syndrome individually involves an anxiety reaction and fear of mortal genital retraction, it collectively takes the form of epidemics and mass panic. Recently a consensus has been reached about the fact that genital retraction is intimately related not only with ethno-cultural beliefs but also with the dramatic expression of acute anxiety and fear of impending catastrophe or death. We present two cases of koro syndrome who experienced severe anxiety due to the feeling of genital retraction and thus we question the cultural specifity of fears of genital retraction.

  2. RETRACTED: Facies analysis and depositional environments of the Oligocene–Miocene Asmari Formation, Zagros Basin, Iran

    OpenAIRE

    Sahraeyan, Mohammad; Bahrami, Mohammad; Arzaghi, Solmaz

    2014-01-01

    This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. The article duplicates significant parts of three other articles without proper citations (Allahkarampour Dill, M., Seyrafian, A., Vaziri-Moghaddam, H., 2010. The Asmari Formation, north of the Gascharan (Dill anticline), southwest Iran: facies analysis, depositional environments and se...

  3. Intramuscular fat accumulation and muscle atrophy in the absence of muscle retraction

    OpenAIRE

    Uhthoff, H K; Coletta, E.; Trudel, G.

    2014-01-01

    Objectives Although many clinical and experimental investigations have shed light on muscle atrophy and intramuscular accumulation of fat after rotator cuff disruption, none have reported on their onset in the absence of muscle retraction. Methods In 30 rabbits, we detached one supraspinatus (SSP) tendon and repaired it immediately, thus preventing muscle retraction. The animals were killed in groups of 10 at one, two and six weeks. Both shoulders of 15 non-operated rabbits served as controls...

  4. Retraction: Two novel duck antibacterial peptides, avian β-defensins 9 and 10, with antimicrobial activity.

    Science.gov (United States)

    2013-01-01

    The article by Ma et al. that published in the Journal of Microbiology and Biotechnology (2009, 19: 1447-1455) was used the same data in two journal articles (Acta Veterinaria et Zootechnica Sinica, 2009, 40(9): 1320-1326, Scientia Agricultura Sinica, 2009, 42(4): 1406-1412). Therefore, the article is retracted from JMB as a misconduct of the authors. JMB as the publisher regrets for any inconvenience may have caused by the retraction to readers.

  5. RETRACTED: A novel technique of multi-track percutaneous balloon mitral commissurotomy (PBMC

    Directory of Open Access Journals (Sweden)

    Sherif A. Sakr

    2012-07-01

    This paper has been retracted upon mutual agreement between the publisher and the Editor-in-Chief of EJCDT when it was discovered that this article had also been submitted and published in the International Heart Journal http://dx.doi.org/10.1536/ihj.54.196. The authors did not give clarification for the action, therefore the paper was retracted following international publishing practices.

  6. [Retraction of: Diagnostics and treatment of early stages of oral cancer].

    Science.gov (United States)

    Warloe, Trond; Aamdal, Steinar; Reith, Albrecht; Bryne, Magne

    2006-09-07

    The undersigned, who are co-authors of the article Diagnostics and treatment of early stages of oral cancer, wish to retract it. The reason is that the basis for the review article has been shown to be false. A review committee, that has assessed the research activity of the main author, has concluded that the data in this article are fabricated. We can no longer stand behind the article and hereby retract it.

  7. Separation increases passive stress-coping behaviors during forced swim and alters hippocampal dendritic morphology in California mice.

    Directory of Open Access Journals (Sweden)

    Molly M Hyer

    Full Text Available Individuals within monogamous species form bonds that may buffer against the negative effects of stress on physiology and behavior. In some species, involuntary termination of the mother-offspring bond results in increased symptoms of negative affect in the mother, suggesting that the parent-offspring bond may be equally as important as the pair bond. To our knowledge, the extent to which affect in paternal rodents is altered by involuntary termination of the father-offspring bond is currently unknown. Here, we investigated to what extent separation and paternal experience alters passive stress-coping behaviors and dendritic morphology in hippocampal subfields of California mice (Peromyscus californicus. Irrespective of paternal experience, separated mice displayed shorter latencies to the first bout of immobility, longer durations of immobility, and more bouts of immobility than control (non-separated mice. This effect of separation was exacerbated by paternal experience in some measures of behavioral despair-separation from offspring further decreased the latency to immobility and increased bouts of immobility. In the dentate gyrus, separation reduced dendritic spine density regardless of paternal experience. Increased spine density was observed on CA1 basal, but not apical, dendrites following paternal experience. Regardless of offspring presence, fatherhood was associated with reduced apical dendritic spine density in area CA3 of the hippocampus. Separation enhanced complexity of both basal and apical dendrites in CA1, while fatherhood reduced dendritic complexity in this region. Our data suggest that forced dissolution of the pair bond induces passive stress-coping behaviors and contributes to region-specific alterations in hippocampal structure in California mouse males.

  8. Piezoelectric Ca3NbGa3Si2O14 crystal: crystal growth, piezoelectric and acoustic properties

    Science.gov (United States)

    Roshchupkin, Dmitry; Ortega, Luc; Plotitcyna, Olga; Erko, Alexei; Zizak, Ivo; Vadilonga, Simone; Irzhak, Dmitry; Emelin, Evgenii; Buzanov, Oleg; Leitenberger, Wolfram

    2016-08-01

    Ca3NbGa3Si2O14 (CNGS), a five-component crystal of lanthanum-gallium silicate group, was grown by the Czochralski method. The parameters of the elementary unit cell of the crystal were measured by powder diffraction. The independent piezoelectric strain coefficients d{}_{11} and d_{14} were determined by the triple-axis X-ray diffraction in the Bragg and Laue geometries. Excitation and propagation of surface acoustic waves (SAW) were studied by high-resolution X-ray diffraction at BESSY II synchrotron radiation source. The velocity of SAW propagation and power flow angles in the Y-, X- and yxl/{+}36°-cuts of the CNGS crystal were determined from the analysis of the diffraction spectra. The CNGS crystal was found practically isotropic by its acoustic properties.

  9. Size and receptor density of glutamatergic synapses: a viewpoint from left-right asymmetry of CA3-CA1 connections

    Directory of Open Access Journals (Sweden)

    Yoshiaki Shinohara

    2009-07-01

    Full Text Available Synaptic plasticity is considered to be the main mechanism for learning and memory. Excitatory synapses in the cerebral cortex and hippocampus undergo plastic changes during development and in response to electric stimulation. It is widely accepted that this process is mediated by insertion and elimination of various glutamate receptors. In a series of recent investigations on left-right asymmetry of hippocampal CA3-CA1 synapses, glutamate receptor subunits have been found to have distinctive expression patterns that depend on the postsynaptic density (PSD area. Particularly notable are the GluR1 AMPA receptor subunit and NR2B NMDA receptor subunit, where receptor density has either a supra-linear (GluR1 AMPA or inverse (NR2B NMDAR relationship to the PSD area. We review current understanding of structural and physiological synaptic plasticity and propose a scheme to classify receptor subtypes by their expression pattern with respect to PSD area.

  10. Can triggered electromyography monitoring throughout retraction predict postoperative symptomatic neuropraxia after XLIF? Results from a prospective multicenter trial.

    Science.gov (United States)

    Uribe, Juan S; Isaacs, Robert E; Youssef, Jim A; Khajavi, Kaveh; Balzer, Jeffrey R; Kanter, Adam S; Küelling, Fabrice A; Peterson, Mark D

    2015-04-01

    This multicenter study aims to evaluate the utility of triggered electromyography (t-EMG) recorded throughout psoas retraction during lateral transpsoas interbody fusion to predict postoperative changes in motor function. Three hundred and twenty-three patients undergoing L4-5 minimally invasive lateral interbody fusion from 21 sites were enrolled. Intraoperative data collection included initial t-EMG thresholds in response to posterior retractor blade stimulation and subsequent t-EMG threshold values collected every 5 min throughout retraction. Additional data collection included dimensions/duration of retraction as well as pre-and postoperative lower extremity neurologic exams. Prior to expanding the retractor, the lowestt-EMG threshold was identified posterior to the retractor in 94 % of cases. Postoperatively, 13 (4.5 %) patients had a new motor weakness that was consistent with symptomatic neuropraxia (SN) of lumbar plexus nerves on the approach side. There were no significant differences between patients with or without a corresponding postoperative SN with respect to initial posterior blade reading (p = 0.600), or retraction dimensions (p > 0.05). Retraction time was significantly longer in those patients with SN vs. those without (p = 0.031). Stepwise logistic regression showed a significant positive relationship between the presence of new postoperative SN and total retraction time (p neuropraxia may be reduced by limiting retraction time and utilizing t-EMG throughout retraction, while understanding that the specificity of this monitoring technique is low during initial retraction and increases with longer retraction duration.

  11. Retraction With Face Saving: modelling conversational interaction through dynamic hypermedia

    Directory of Open Access Journals (Sweden)

    Roberto Bolognesi

    1994-12-01

    Full Text Available This paper describes RWFS (Retraction With Face Saving, a hypermedia application which models an interview between a lawyer and his client - a lorry driver - facing court charges of reckless driving. At one level RWFS takes the form of a sophisticated game in which different outcomes to the interview are possible according to the learner's degree of skill. At another level, RWFS is designed to encourage the language learner's awareness and understanding of the pragmatic features of conversation. RWFS runs on HyperContext, a hybrid hypertextlexpert system developed in Pavia by two of the authors, Marco Piastra and Roberto Bolognesi, and which supports dynamic hypermedia units. HyperContext's dynamic linking capacity plays a vital role in simulating significant conversational features such as the conditioning of a current move in the conversation by information acquired much earlier in the course of the interview. In this connection, the paper discusses the contribution of RMCI (Re-usable Model of Conversational Interaction, a re-usable application-independent applied model of interaction on which the game is based, and which links a tactical level (the conversation to a metalevel which provides a moveby- move commentary on interactional theory. In its turn, RMCFs metalevel is linked to a strategic level which interprets the structure of the conversation in terms of a pyramid-like hierarchy of increasingly abstract theoretical concepts.

  12. Management of Duane retraction syndrome with prismatic glasses

    Science.gov (United States)

    Aygit, Ebru Demet; Kocamaz, Murat; Inal, Asli; Fazil, Korhan; Ocak, Osman Bulut; Akar, Serpil; Gokyigit, Birsen

    2017-01-01

    Purpose To report the results of using prismatic glasses for Duane retraction syndrome (DRS). Methods Data were obtained from the records of patients who were evaluated during the year 2000 in the Strabismus Unit of the Beyoglu Eye Training and Research Hospital. The average follow-up was 12.2±17.7 months. In all cases, 2 main variables were evaluated: horizontal deviation in the primary position and face turn. Prismatic glasses were provided to patients according to the degree of shift in the primary position. Results The mean age of patients was 11.2 years. An analysis was performed on the data collected from 12 cases; 7 patients were females (58.3%) and 5 were males (41.7%), with 11 (91.7%) cases being of type I DRS. All 12 patients had abnormal head posture (face turn) and an angle of mean deviation equaling 10 PD (prism dioptri). Conclusion Treatment was individualized on a case-by-case basis. Prismatic glasses are useful for eliminating abnormal head posture and ocular misalignment in selected cases. PMID:28442887

  13. Learned navigation in unknown terrains: A retraction method

    Science.gov (United States)

    Rao, Nageswara S. V.; Stoltzfus, N.; Iyengar, S. Sitharama

    1989-01-01

    The problem of learned navigation of a circular robot R, of radius delta (is greater than or equal to 0), through a terrain whose model is not a-priori known is considered. Two-dimensional finite-sized terrains populated by an unknown (but, finite) number of simple polygonal obstacles are also considered. The number and locations of the vertices of each obstacle are unknown to R. R is equipped with a sensor system that detects all vertices and edges that are visible from its present location. In this context two problems are covered. In the visit problem, the robot is required to visit a sequence of destination points, and in the terrain model acquisition problem, the robot is required to acquire the complete model of the terrain. An algorithmic framework is presented for solving these two problems using a retraction of the freespace onto the Voronoi diagram of the terrain. Algorithms are then presented to solve the visit problem and the terrain model acquisition problem.

  14. Effects of Duane's retraction syndrome on sensory visual development.

    Science.gov (United States)

    Sloper, J S; Collins, A D

    1999-03-01

    To study the effects of Duane's retraction syndrome on sensory visual development. Monocular and binocular visual function and ocular motility have been studied and pattern reversal visual evoked potentials recorded from 22 patients with Duane's syndrome aged from 4 to 55 years. Sixteen of the patients maintained binocular single vision using an abnormal head posture. All had normal visual acuities in both eyes. The 12 adults in this group had a mean stereoacuity of 78 seconds of arc with the Titmus stereotest and 101 seconds of arc with the TNO test. Both these values were significantly worse than for normal adults with a similar age range. The binocular VEPs from these patients showed enhancement of the binocular P100 VEP amplitude compared to the mean monocular P100 amplitude when they used their head posture but, unlike in normal subjects, this binocular enhancement was not reduced significantly after the age of 5. Six patients had lost binocular function and had a manifest convergent squint. Of these, 4 were anisometropic. VEPs in this group showed mildly delayed P100 latencies in the affected eye with asymmetric amplitudes even though their amblyopia had been successfully treated by patching and only one patient had a substantially reduced acuity. In neither group was there any relationship between the degree of restriction of ocular motility and the sensory changes. Patients with Duane's syndrome who retain binocular single vision show abnormal binocular visual maturation after the age of 5 years. This results in reduced stereoacuity in the absence of amblyopia.

  15. Fast generation of dendritic cells

    DEFF Research Database (Denmark)

    Kvistborg, P; Bøgh, Marie; Pedersen, A W

    2009-01-01

    Dendritic cells (DC) are potent antigen presenting cells capable of inducing immune responses. DC are widely used as vaccine adjuvant in experimental clinical settings. DC-based vaccines are normally generated using a standard 8day DC protocol (SDDC). In attempts to shorten the vaccine production...... SDDC to the IL-10 inducing stimulus of TLR ligands (R848 and LPS). Thus to determine the clinical relevance of fast DC protocols in cancer settings, small phase I trials should be conducted monitoring regulatory T cells carefully....

  16. XOR at a Single Vertex -- Artificial Dendrites

    OpenAIRE

    Burger, John Robert

    2010-01-01

    New to neuroscience with implications for AI, the exclusive OR, or any other Boolean gate may be biologically accomplished within a single region where active dendrites merge. This is demonstrated below using dynamic circuit analysis. Medical knowledge aside, this observation points to the possibility of specially coated conductors to accomplish artificial dendrites.

  17. Dendrite fragmentation: an experiment-driven simulation.

    Science.gov (United States)

    Cool, T; Voorhees, P W

    2018-02-28

    The processes leading to the fragmentation of secondary dendrite arms are studied using a three-dimensional Sn dendritic structure that was measured experimentally as an initial condition in a phase-field simulation. The phase-field model replicates the kinetics of the coarsening process seen experimentally. Consistent with the experiment, the simulations of the Sn-rich dendrite show that secondary dendrite arm coalescence is prevalent and that fragmentation is not. The lack of fragmentation is due to the non-axisymmetric morphology and comparatively small spacing of the dendrite arms. A model for the coalescence process is proposed, and, consistent with the model, the radius of the contact region following coalescence increases as t1/3 We find that small changes in the width and spacing of the dendrite arms can lead to a very different fragmentation-dominated coarsening process. Thus, the alloy system and growth conditions of the dendrite can have a major impact on the fragmentation process.This article is part of the theme issue 'From atomistic interfaces to dendritic patterns'. © 2018 The Author(s).

  18. Dendrite fragmentation: an experiment-driven simulation

    Science.gov (United States)

    Cool, T.; Voorhees, P. W.

    2018-01-01

    The processes leading to the fragmentation of secondary dendrite arms are studied using a three-dimensional Sn dendritic structure that was measured experimentally as an initial condition in a phase-field simulation. The phase-field model replicates the kinetics of the coarsening process seen experimentally. Consistent with the experiment, the simulations of the Sn-rich dendrite show that secondary dendrite arm coalescence is prevalent and that fragmentation is not. The lack of fragmentation is due to the non-axisymmetric morphology and comparatively small spacing of the dendrite arms. A model for the coalescence process is proposed, and, consistent with the model, the radius of the contact region following coalescence increases as t1/3. We find that small changes in the width and spacing of the dendrite arms can lead to a very different fragmentation-dominated coarsening process. Thus, the alloy system and growth conditions of the dendrite can have a major impact on the fragmentation process. This article is part of the theme issue `From atomistic interfaces to dendritic patterns'.

  19. News from dendritic cells in atopic dermatitis.

    Science.gov (United States)

    Schäkel, Knut; Hänsel, Anja

    2011-10-01

    Dendritic cells are essential for the generation of innate and adaptive immune responses, which makes them stay on center stage when studying the immuno pathogenesis of atopic dermatitis. This review will discuss recent findings on the role of dendritic cells subsets in atopic dermatitis and will report novel findings on how the microenvironment conditions dendritic cells to fuel atopic dermatitis. Several microenvironmental factors characteristic for atopic dermatitis and with direct relevance for the disease have been defined. We now increasingly understand how thymic stromal lymphopoietin and histamine contribute to the disease by modulating the function of dendritic cells. We have learned much about the pathogenesis of atopic dermatitis by the studies on inflammatory dendritic epidermal cells. However, the current analysis on the functional and phenotypic heterogeneity of dendritic cells in eczematous skin lesions may lead to the definition of additional dendritic cell types relevant in the pathogenesis of atopic dermatitis. In this respect, it appears interesting to further discuss the parallels and differences in atopic dermatitis and psoriasis. Understanding the heterogeneity of dendritic cells and their functional alteration by local factors in the inflamed skin will provide essential clues to the immunopathogenesis of atopic dermatitis.

  20. Early events in axon/dendrite polarization.

    Science.gov (United States)

    Cheng, Pei-lin; Poo, Mu-ming

    2012-01-01

    Differentiation of axons and dendrites is a critical step in neuronal development. Here we review the evidence that axon/dendrite formation during neuronal polarization depends on the intrinsic cytoplasmic asymmetry inherited by the postmitotic neuron, the exposure of the neuron to extracellular chemical factors, and the action of anisotropic mechanical forces imposed by the environment. To better delineate the functions of early signals among a myriad of cellular components that were shown to influence axon/dendrite formation, we discuss their functions by distinguishing their roles as determinants, mediators, or modulators and consider selective degradation of these components as a potential mechanism for axon/dendrite polarization. Finally, we examine whether these early events of axon/dendrite formation involve local autocatalytic activation and long-range inhibition, as postulated by Alan Turing for the morphogenesis of patterned biological structure.

  1. Effect of acetylcholine receptors on the pain-related electrical activities in the hippocampal CA3 region of morphine-addicted rats

    Directory of Open Access Journals (Sweden)

    Guan Zeng Li

    2015-07-01

    Full Text Available Objective(s:To determine the effect of acetylcholine (ACh, pilocarpine, and atropine on pain evoked responses of pain excited neurons (PEN and pain inhibited neurons (PIN in hippocampal CA3 region of morphine addicted rats. Materials and Methods:Female Wistar rats, weighing between 230-260 g were used in this study. Morphine addicted rats were generated by subcutaneous injection of increasing concentrations of morphine hydrochloride for six days. Trains of electrical impulses applied to the sciatic nerve were used as noxious stimulation and the evoked electrical activities of PEN or PIN in hippocampal CA3 area were recorded using extracellular electrophysiological recording techniques in hippocampal slices. The effect of acetylcholine receptor stimulation byACh, the muscarinic agonist pilocarpine, and the muscarinic antagonist atropine on the pain evoked responses of pain related electrical activities was analyzed in hippocampal CA3 area of morphine addicted rats. Results:Intra-CA3 microinjection of ACh (2 μg/1 μl or pilocarpine (2 μg/1 μl decreased the discharge frequency and prolonged the firing latency of PEN, but increased the discharge frequency and shortened the firing inhibitory duration (ID of PIN. The intra-CA3 administration of atropine (0.5 μg/1 μl produced opposite effect. The peak activity of cholinergic modulators was 2 to 4 min later in morphine addicted rats compared to peak activity previously observed in normal rats. Conclusion: ACh dependent modulation of noxious stimulation exists in hippocampal CA3 area of morphine addicted rats. Morphine treatment may shift the sensitivity of pain related neurons towards a delayed response to muscarinergic neurotransmission in hippocampal CA3 region.

  2. Stress and trauma: BDNF control of dendritic-spine formation and regression.

    Science.gov (United States)

    Bennett, M R; Lagopoulos, J

    2014-01-01

    Chronic restraint stress leads to increases in brain derived neurotrophic factor (BDNF) mRNA and protein in some regions of the brain, e.g. the basal lateral amygdala (BLA) but decreases in other regions such as the CA3 region of the hippocampus and dendritic spine density increases or decreases in line with these changes in BDNF. Given the powerful influence that BDNF has on dendritic spine growth, these observations suggest that the fundamental reason for the direction and extent of changes in dendritic spine density in a particular region of the brain under stress is due to the changes in BDNF there. The most likely cause of these changes is provided by the stress initiated release of steroids, which readily enter neurons and alter gene expression, for example that of BDNF. Of particular interest is how glucocorticoids and mineralocorticoids tend to have opposite effects on BDNF gene expression offering the possibility that differences in the distribution of their receptors and of their downstream effects might provide a basis for the differential transcription of the BDNF genes. Alternatively, differences in the extent of methylation and acetylation in the epigenetic control of BDNF transcription are possible in different parts of the brain following stress. Although present evidence points to changes in BDNF transcription being the major causal agent for the changes in spine density in different parts of the brain following stress, steroids have significant effects on downstream pathways from the TrkB receptor once it is acted upon by BDNF, including those that modulate the density of dendritic spines. Finally, although glucocorticoids play a canonical role in determining BDNF modulation of dendritic spines, recent studies have shown a role for corticotrophin releasing factor (CRF) in this regard. There is considerable improvement in the extent of changes in spine size and density in rodents with forebrain specific knockout of CRF receptor 1 (CRFR1) even when

  3. Evaluation of Ca3(Co,M2O6 (M=Co, Fe, Mn, Ni as new cathode materials for solid-oxide fuel cells

    Directory of Open Access Journals (Sweden)

    Fushao Li

    2015-10-01

    Full Text Available Series compounds Ca3(Co0.9M0.12O6 (M=Co, Fe, Mn, Ni with hexagonal crystal structure were prepared by sol–gel route as the cathode materials for solid oxide fuel cells (SOFCs. Effects of the varied atomic compositions on the structure, electrical conductivity, thermal expansion and electrochemical performance were systematically evaluated. Experimental results showed that the lattice parameters of Ca3(Co0.9Fe0.12O6 and Ca3(Co0.9Mn0.12O6 were both expanded to certain degree. Electron-doping and hole-doping effects were expected in Ca3(Co0.9Mn0.12O6 and Ca3(Co0.9Ni0.12O6 respectively according to the chemical states of constituent elements and thermal-activated behavior of electrical conductivity. Thermal expansion coefficients (TEC of Ca3(Co0.9M0.12O6 were measured to be distributed around 16×10−6 K−1, and compositional elements of Fe, Mn, and Ni were especially beneficial for alleviation of the thermal expansion problem of cathode materials. By using Ca3(Co0.9M0.12O6 as the cathodes operated at 800 °C, the interfacial area-specific resistance varied in the order of M=CoCa3(Co0.9Fe0.12O6 showed the best electrochemical performance and the power density as high as ca. 500 mW cm−2 at 800 °C achieved in the single cell with La0.8Sr0.2Ga0.83Mg0.17O2.815 as electrolyte and Ni–Ce0.8Sm0.2O1.9 as anode. Ca3(Co0.9M0.12O6 (M=Co, Fe, Mn, Ni can be used as the cost-effective cathode materials for SOFCs.

  4. β1-and β2-adrenoceptors in hippocampal CA3 region are required for long-term memory consolidation in rats.

    Science.gov (United States)

    Zheng, Jian; Luo, Fei; Guo, Nan-nan; Cheng, Zong-yue; Li, Bao-ming

    2015-11-19

    The existence of β-adrenoceptors (ARs) in the hippocampus and the importance of β-ARs in regulating synaptic plasticity and learning/memory function are well documented. As known, β-ARs in area cornu ammonis 1 (CA1) are involved in regulating memory consolidation. However, little is known about the functional roles of the β-ARs subtypes, β1- and β2-ARs, in the hippocampal cornu ammonis 3 (CA3) region. To address this question, we firstly locally infused the β1- or β2-ARs antagonist into the CA3 region and observed that blockage of either β1-AR or β2-AR impaired long-term contextual fear memory and water-maze spatial memory. We also found that, following the contextual fear conditioning, the expression of β1-AR in the CA3 region significantly increased, whereas β2-AR was unchanged. Then intra-CA3 infusion of recombinant lentiviral RNAi vectors for β1 or β2-ARs also produced deficit in contextual memory consolidation. Taken together, the results suggested that the β1- and β2-ARs in the CA3 region were involved in hippocampus dependent memory consolidation. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. A Comprehensive Analysis of Articles Retracted Between 2004 and 2013 from Biomedical Literature – A Call for Reforms

    Directory of Open Access Journals (Sweden)

    Harkanwal Preet Singh

    2014-07-01

    Full Text Available Science is a dynamic subject and it was never free of misconduct or bad research. Indeed, the scientific method itself is intended to overcome mistakes and misdeeds. So, we aimed to assess various factors associated with retraction of scientific articles from 2004 to 2013. Data were retrieved from PubMed and Medline using the keywords retraction of articles, retraction notice, and withdrawal of article in April 2014 to detect articles retracted from 2004 to 2013. Statistical analysis was carried out using t-test and Karl Pearson's correlation coefficient. Results showed that a total of 2343 articles were retracted between 2004 and 2013, and original articles followed by case reports constituted major part of it. Time interval between submission and retraction of article has reduced in recent times. Impact factor and retraction do not have any significant correlation. We conclude that although retraction of articles is a rare event, its constant rise in scientific literature is quite worrisome. It is still unclear whether misconduct/mistakes in articles are increasing hastily or the articles are retracted at a rapid rate in recent times. So, it should be considered as an urgent issue and it is the responsibility of journal editors to track misconduct by following Committee on Publication Ethics (COPE guidelines and making an effective strategy.

  6. Dendritic Actin Cytoskeleton: Structure, Functions, and Regulations

    Directory of Open Access Journals (Sweden)

    Anja Konietzny

    2017-05-01

    Full Text Available Actin is a versatile and ubiquitous cytoskeletal protein that plays a major role in both the establishment and the maintenance of neuronal polarity. For a long time, the most prominent roles that were attributed to actin in neurons were the movement of growth cones, polarized cargo sorting at the axon initial segment, and the dynamic plasticity of dendritic spines, since those compartments contain large accumulations of actin filaments (F-actin that can be readily visualized using electron- and fluorescence microscopy. With the development of super-resolution microscopy in the past few years, previously unknown structures of the actin cytoskeleton have been uncovered: a periodic lattice consisting of actin and spectrin seems to pervade not only the whole axon, but also dendrites and even the necks of dendritic spines. Apart from that striking feature, patches of F-actin and deep actin filament bundles have been described along the lengths of neurites. So far, research has been focused on the specific roles of actin in the axon, while it is becoming more and more apparent that in the dendrite, actin is not only confined to dendritic spines, but serves many additional and important functions. In this review, we focus on recent developments regarding the role of actin in dendrite morphology, the regulation of actin dynamics by internal and external factors, and the role of F-actin in dendritic protein trafficking.

  7. From atomistic interfaces to dendritic patterns

    Science.gov (United States)

    Galenko, P. K.; Alexandrov, D. V.

    2018-01-01

    Transport processes around phase interfaces, together with thermodynamic properties and kinetic phenomena, control the formation of dendritic patterns. Using the thermodynamic and kinetic data of phase interfaces obtained on the atomic scale, one can analyse the formation of a single dendrite and the growth of a dendritic ensemble. This is the result of recent progress in theoretical methods and computational algorithms calculated using powerful computer clusters. Great benefits can be attained from the development of micro-, meso- and macro-levels of analysis when investigating the dynamics of interfaces, interpreting experimental data and designing the macrostructure of samples. The review and research articles in this theme issue cover the spectrum of scales (from nano- to macro-length scales) in order to exhibit recently developing trends in the theoretical analysis and computational modelling of dendrite pattern formation. Atomistic modelling, the flow effect on interface dynamics, the transition from diffusion-limited to thermally controlled growth existing at a considerable driving force, two-phase (mushy) layer formation, the growth of eutectic dendrites, the formation of a secondary dendritic network due to coalescence, computational methods, including boundary integral and phase-field methods, and experimental tests for theoretical models-all these themes are highlighted in the present issue. This article is part of the theme issue `From atomistic interfaces to dendritic patterns'.

  8. The morphological identity of insect dendrites.

    Directory of Open Access Journals (Sweden)

    Hermann Cuntz

    2008-12-01

    Full Text Available Dendrite morphology, a neuron's anatomical fingerprint, is a neuroscientist's asset in unveiling organizational principles in the brain. However, the genetic program encoding the morphological identity of a single dendrite remains a mystery. In order to obtain a formal understanding of dendritic branching, we studied distributions of morphological parameters in a group of four individually identifiable neurons of the fly visual system. We found that parameters relating to the branching topology were similar throughout all cells. Only parameters relating to the area covered by the dendrite were cell type specific. With these areas, artificial dendrites were grown based on optimization principles minimizing the amount of wiring and maximizing synaptic democracy. Although the same branching rule was used for all cells, this yielded dendritic structures virtually indistinguishable from their real counterparts. From these principles we derived a fully-automated model-based neuron reconstruction procedure validating the artificial branching rule. In conclusion, we suggest that the genetic program implementing neuronal branching could be constant in all cells whereas the one responsible for the dendrite spanning field should be cell specific.

  9. Chronic fluoxetine administration enhances synaptic plasticity and increases functional dynamics in hippocampal CA3-CA1 synapses.

    Science.gov (United States)

    Popova, Dina; Castrén, Eero; Taira, Tomi

    2017-11-01

    Recent studies demonstrate that chronic administration of the widely used antidepressant fluoxetine (FLX) promotes neurogenesis, synaptogenesis and synaptic plasticity in the adult hippocampus, cortex and amygdala. However, the mechanisms underlying these effects and how are they related to the clinical antidepressant efficacy are still poorly understood. We show here that chronic FLX administration decreases hippocampus-associated neophobia in naïve mice. In parallel, electrophysiological recordings in hippocampal CA3-CA1 circuitry revealed that the FLX treatment resulted in increased short- and long-term plasticity likely attributed to changes in presynaptic function. These changes were accompanied by enhancement in the expression of proteins related to vesicular trafficking and release, namely synaptophysin, synaptotagmin 1, MUNC 18 and syntaxin 1. Thus, chronic FLX administration is associated with enhanced synaptic dynamics atypical of mature CA1 synapses, elevated hippocampal plasticity, improved hippocampus-dependent behavior as well as altered expression of synaptic proteins regulating neurotransmitter trafficking and release. The results support the idea that antidepressants can promote neuronal plasticity and show that they can increase the functional dynamic range and information processing in synaptic circuitries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Comparison of anchorage capacity between implant and headgear during anterior segment retraction.

    Science.gov (United States)

    Li, F; Hu, H K; Chen, J W; Liu, Z P; Li, G F; He, S S; Zou, S J; Ye, Q S

    2011-09-01

    To compare the anchorage effects of the implants and the headgear for patients with anterior teeth retraction in terms of incisor retraction, anchorage loss, inclination of maxillary incisors, positional change of maxillary basal bone, and treatment duration. An electronic search for relative randomized controlled trials (RCTs) prospective and retrospective controlled trials was done through the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, Medline, and CNKI, regardless of language of study. Study selection, methodological quality assessment, and data extraction were performed by two reviewers independently. Meta-analysis was performed when possible; otherwise descriptive assessment was done. The search yielded 35 articles, of which eight met the inclusion criteria and were categorized into five groups according to types of intervention. For the midpalatal implant, the anchorage loss was much less than for the headgear group, with insignificant differences in terms of anterior teeth retraction, maxillary incisor inclination, positional change of basal bone, and treatment duration. For the mini-implant, greater anterior teeth retraction and less anchorage loss were demonstrated, with inconsistent results for the other measures. For the onplant, less anchorage loss was noted, with insignificant differences for the other measures. The skeletal anchorage of the midpalatal implant, mini-implant, and onplant offer better alternatives to headgear, with less anchorage loss and more anterior teeth retraction. There were inconsistent results from the included studies in terms of maxillary incisor inclination, positional change of maxillary basal bone, and treatment duration. More qualified RCTs are required to provide clear recommendations.

  11. A novel magnetic-driven tissue retraction device for minimally invasive surgery.

    Science.gov (United States)

    Brancadoro, Margherita; Tognarelli, Selene; Ciuti, Gastone; Menciassi, Arianna

    2017-02-01

    The purpose of this work is to design and validate an innovative magnetic-based device for tissue retraction for minimally invasive surgery. An intra-abdominal magnetic module is coupled with an extracorporeal system for establishing a stable attraction, and consequently a reliable tissue retraction. Once the retractor has been inserted into the abdomen, tissue retraction is not constrained by a fixed access port, thus guaranteeing a more flexible, safer and less invasive operation. The intra-abdominal unit is composed of an axial permanent magnet attached to a stainless-steel non-magnetic alligator clip by a traditional suturing thread. A miniaturized mechanism to adjust the length of the suturing thread for lengthening or shortening the distance between the tissue grasper and the internal magnetic unit is included. A multiphysics approach assured a dedicated design that thoroughly fulfills anatomical, physiological and engineering constraints. System functionalities were demonstrated both in in-vitro and ex-vivo conditions, reaching good results and promising outcomes in terms of effectiveness and maneuverability. The retractor was successfully tested in an animal model, carrying out a whole retraction procedure. The proposed retraction system resulted to be intuitive, reliable, robust and easy to use, representing a suitable device for MIS procedures.

  12. Gingival Retraction Methods for Fabrication of Fixed Partial Denture: Literature Review

    Directory of Open Access Journals (Sweden)

    Safari S

    2016-06-01

    Full Text Available Fixed dental prosthesis success requires appropriate impression taking of the prepared finish line. This is critical in either tooth supported fixed prosthesis (crown and bridge or implant supported fixed prosthesis (solid abutment. If the prepared finish line is adjacent to the gingival sulcus, gingival retraction techniques should be used to decrease the marginal discrepancy among the restoration and the prepared abutment. Accurate marginal positioning of the restoration in the prepared finish line of the abutment is required for therapeutic, preventive and aesthetic purposes. In this article, conventional and modern methods of gingival retraction in the fixed tooth supported prosthesis and fixed implant supported prosthesis are expressed. PubMed and Google Scholar databases were searched manually for studies on gingival tissue managements prior to impression making in fixed dental prosthesis since 1975. Conclusions were extracted and summarized. Keywords were impression making, gingival retraction, cordless retraction, and implant. Gingival retraction techniques can be classified as mechanical, chemical or surgical. In this article, different gingival management techniques are discussed.

  13. A Miniature Robot for Retraction Tasks under Vision Assistance in Minimally Invasive Surgery

    Directory of Open Access Journals (Sweden)

    Giuseppe Tortora

    2014-03-01

    Full Text Available Minimally Invasive Surgery (MIS is one of the main aims of modern medicine. It enables surgery to be performed with a lower number and severity of incisions. Medical robots have been developed worldwide to offer a robotic alternative to traditional medical procedures. New approaches aimed at a substantial decrease of visible scars have been explored, such as Natural Orifice Transluminal Endoscopic Surgery (NOTES. Simple surgical tasks such as the retraction of an organ can be a challenge when performed from narrow access ports. For this reason, there is a continuous need to develop new robotic tools for performing dedicated tasks. This article illustrates the design and testing of a new robotic tool for retraction tasks under vision assistance for NOTES. The retraction robots integrate brushless motors to enable additional degrees of freedom to that provided by magnetic anchoring, thus improving the dexterity of the overall platform. The retraction robot can be easily controlled to reach the target organ and apply a retraction force of up to 1.53 N. Additional degrees of freedom can be used for smooth manipulation and grasping of the organ.

  14. Non-linear dendrites can tune neurons

    Directory of Open Access Journals (Sweden)

    Romain Daniel Cazé

    2014-03-01

    Full Text Available A signature of visual, auditory, and motor cortices is the presence of neurons tuned to distinct features of the environment. While neuronal tuning can be observed in most brain areas, its origin remains enigmatic, and new calcium imaging data complicate this problem. Dendritic calcium signals, in a L2/3 neuron from the mouse visual cortex, display a wide range of tunings that could be different from the neuronal tuning (Jia et al 2010. To elucidate this observation we use multi-compartmental models of increasing complexity, from a binary to a realistic biophysical model of L2/3 neuron. These models possess non-linear dendritic subunits inside which the result of multiple excitatory inputs is smaller than their arithmetic sum. While dendritic non-linear subunits are ad-hoc in the binary model, non-linearities in the realistic model come from the passive saturation of synaptic currents. Because of these non-linearities our neuron models are scatter sensitive: the somatic membrane voltage is higher when presynaptic inputs target different dendrites than when they target a single dendrite. This spatial bias in synaptic integration is, in our models, the origin of neuronal tuning. Indeed, assemblies of presynaptic inputs encode the stimulus property through an increase in correlation or activity, and only the assembly that encodes the preferred stimulus targets different dendrites. Assemblies coding for the non-preferred stimuli target single dendrites, explaining the wide range of observed tunings and the possible difference between dendritic and somatic tuning. We thus propose, in accordance with the latest experimental observations, that non-linear integration in dendrites can generate neuronal tuning independently of the coding regime.

  15. Inhibition of the K+ channel K(Ca3.1 reduces TGF-β1-induced premature senescence, myofibroblast phenotype transition and proliferation of mesangial cells.

    Directory of Open Access Journals (Sweden)

    Rong-Guo Fu

    Full Text Available OBJECTIVE: K(Ca3.1 channel participates in many important cellular functions. This study planned to investigate the potential involvement of K(Ca3.1 channel in premature senescence, myofibroblast phenotype transition and proliferation of mesangial cells. METHODS & MATERIALS: Rat mesangial cells were cultured together with TGF-β1 (2 ng/ml and TGF-β1 (2 ng/ml + TRAM-34 (16 nM separately for specified times from 0 min to 60 min. The cells without treatment served as controls. The location of K(Ca3.1 channels in mesangial cells was determined with Confocal laser microscope, the cell cycle of mesangial cells was assessed with flow cytometry, the protein and mRNA expression of K(Ca3.1, α-smooth muscle actin (α-SMA and fibroblast-specific protein-1 (FSP-1 were detected with Western blot and RT-PCR. One-way analysis of variance (ANOVA and Student-Newman-Keuls-q test (SNK-q were used to do statistical analysis. Statistical significance was considered at P<0.05. RESULTS: Kca3.1 channels were located in the cell membranes and/or in the cytoplasm of mesangial cells. The percentage of cells in G0-G1 phase and the expression of K(ca3.1, α-SMA and FSP-1 were elevated under the induction of TGF-β1 when compared to the control and decreased under the induction of TGF-β1+TRAM-34 when compared to the TGF-β1 induced (P<0.05 or P<0.01. CONCLUSION: Targeted disruption of K(Ca3.1 inhibits TGF-β1-induced premature aging, myofibroblast-like phenotype transdifferentiation and proliferation of mesangial cells.

  16. Forest management could counteract distribution retractions forced by climate change.

    Science.gov (United States)

    Mair, Louise; Harrison, Philip J; Räty, Minna; Bärring, Lars; Strandberg, Gustav; Snäll, Tord

    2017-07-01

    Climate change is expected to drive the distribution retraction of northern species. However, particularly in regions with a history of intensive exploitation, changes in habitat management could facilitate distribution expansions counter to expectations under climate change. Here, we test the potential for future forest management to facilitate the southward expansion of an old-forest species from the boreal region into the boreo-nemoral region, contrary to expectations under climate change. We used an ensemble of species distribution models based on citizen science data to project the response of Phellinus ferrugineofuscus, a red-listed old-growth indicator, wood-decaying fungus, to six forest management and climate change scenarios. We projected change in habitat suitability across the boreal and boreo-nemoral regions of Sweden for the period 2020-2100. Scenarios varied in the proportion of forest set aside from production, the level of timber extraction, and the magnitude of climate change. Habitat suitabilities for the study species were projected to show larger relative increases over time in the boreo-nemoral region compared to the boreal region, under all scenarios. By 2100, mean suitabilities in set-aside forest in the boreo-nemoral region were similar to the suitabilities projected for set-aside forest in the boreal region in 2020, suggesting that occurrence in the boreo-nemoral region could be increased. However, across all scenarios, consistently higher projected suitabilities in set-aside forest in the boreal region indicated that the boreal region remained the species stronghold. Furthermore, negative effects of climate change were evident in the boreal region, and projections suggested that climatic changes may eventually counteract the positive effects of forest management in the boreo-nemoral region. Our results suggest that the current rarity of this old-growth indicator species in the boreo-nemoral region may be due to the history of intensive

  17. Activation of rectus capitis posterior major muscles during voluntary retraction of the head in asymptomatic subjects.

    Science.gov (United States)

    Hallgren, Richard C; Rowan, Jacob J; Bai, Peng; Pierce, Steven J; Shafer-Crane, Gail A; Prokop, Lawrence L

    2014-01-01

    The purpose of this study was to assess levels of electromyographic activity measured from rectus capitis posterior major (RCPM) muscles of asymptomatic subjects as their heads moved from a self-defined neutral position to a retracted position. A 2 × 2 within-subjects factorial research design was used. Disposable, intramuscular electrodes were used to collect electromyographic data from asymptomatic subjects between the ages of 20 and 40 years old. Data analysis was performed using mixed effects β regression models. Activation of RCPM muscles was found to significantly increase (P < .0001) as the head moved from a self-defined neutral position to a retracted position. Rectus capitis posterior major muscle activation levels, measured as a function of head position, have not been previously reported. The findings from this study showed that RCPM muscle activation significantly increases during voluntary retraction of the head. Copyright © 2014 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

  18. Retracted: Differential expression of microRNAs in myometrium and leiomyomas and regulation by ovarian steroids.

    Science.gov (United States)

    2015-10-01

    The above article, published online on 20 December 2007 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor in Chief, Professor L Popescu and John Wiley and Sons Ltd. The retraction has been requested by the University of Florida, Office of Research, in response to their investigation which concluded fabrication of data in Figures 2, 3 and 4. Reference Pan Q, Luo X, Chegini N. Retracted: differential expression of microRNAs in myometrium and leiomyomas and regulation by ovarian steroids. J Cell Mol Med 12: 227-240. Doi: 10.1111/j.1582-4934.2007.00207.x. Copyright © 2015 Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  19. Improvement of the mechanical properties and corrosion resistance of biodegradable β-Ca3(PO4)2/Mg-Zn composites prepared by powder metallurgy: the adding β-Ca3(PO4)2,hot extrusion and aging treatment.

    Science.gov (United States)

    Yan, Yang; Kang, Yijun; Li, Ding; Yu, Kun; Xiao, Tao; Deng, Youwen; Dai, Han; Dai, Yilong; Xiong, Hanqing; Fang, Hongjie

    2017-05-01

    In this study, 10%β-Ca 3 (PO 4 ) 2 /Mg-6%Zn (wt.%) composites with Mg-6%Zn alloy as control were prepared by powder metallurgy. After hot extrusion, the as-extruded composites were aged for 72h at 150°C. The effects of the adding β-Ca 3 (PO 4 ) 2 , hot extrusion and aging treatment on their microstructure, mechanical properties and corrosion resistance were investigated. The XRD results identified α-Mg, MgZn phase and β-Ca 3 (PO 4 ) 2 phase in these composites. After hot extrusion, grains were significantly refined, and the larger-sized β-Ca 3 (PO 4 ) 2 particles and coarse MgZn phases were broken into linear-distributed β-Ca 3 (PO 4 ) 2 and MgZn phases along the extrusion direction. After aging treatment, the elements of Zn, Ca, P and O presented a more homogeneous distribution. The compressive strengths of the β-Ca 3 (PO 4 ) 2 /Mg-Zn composites were approximately double those of natural bone, and their densities and elastic moduli matched those of natural bone. The immersion tests and electrochemical tests revealed that the adding β-Ca 3 (PO 4 ) 2 , hot extrusion and aging treatment could promote the formation of protective corrosion product layer on the sample surface in Ringer's solution, which improved corrosion resistance of the β-Ca 3 (PO 4 ) 2 /Mg-Zn composites. The XRD results indicated that the corrosion product layer contained Mg(OH) 2 , β-Ca 3 (PO 4 ) 2 and hydroxyapatite (HA). The cytotoxicity assessments showed the as-extruded β-Ca 3 (PO 4 ) 2 /Mg-Zn composite aged for 72h was harmless to L-929 cells. These results suggested that the β-Ca 3 (PO 4 ) 2 /Mg-Zn composites prepared by powder metallurgy were promising to be used for bone tissue engineering. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. [Study of skin retraction applied to the treatment of skin tumors. Mapping of the human body].

    Science.gov (United States)

    Dumas, P; Benatar, M; Cardot-Leccia, N; Lebreton, E; Chignon-Sicard, B

    2012-04-01

    Skin, the main organ of the human body, is equipped with own biomechanical characteristics, highly variable depending on intra-individual factors (location, weight status, dermatological diseases…) and interindividual (age, sex…). Despite some recent cutometric studies, our review of the literature shows that there is no currently reliable analytical model representing the biomechanical behavior of the skin. Yet, this is a central issue in dermatology surgery, especially in the treatment of skin tumors, for the proper observance of surgical margins. We studied prospectively on 75 resection specimens (about 71 patient(s)), for the treatment of skin lesions tumor suspicious or known malignant or benign. Room dimensions were measured before and 5 minutes after excision, leading us to calculate a ratio of retraction of the skin surface. This retraction was correlated with age, gender, tumor type, and anatomic location of the site of excision. The power of retraction of the skin varies significantly by region of the body. It is maximum in the upper limb (hand excluded) and in the cervical region. At the cephalic region, skin of the ear and periorbital skin have capacities of important early retraction. Unlike the lower limb (foot excluded), the back skin of the nose and face appear to be a minimum of shrinkage. Age also seems to change on that capacity shrinkage, sex would have no influence. Our study confirms the variations in the ability of skin retraction based on a number of factors. In dermato-oncology, that power retraction could cause significant differences between clinical surgical margins and final pathologist margins. We believe it must be taken into account by the couple surgeon-pathologist, especially in the context of invasive and/or recurrent tumors. Copyright © 2012. Published by Elsevier SAS.

  1. Probabilistic Design Methodology and its Application to the Design of an Umbilical Retract Mechanism

    Science.gov (United States)

    Onyebueke, Landon; Ameye, Olusesan

    2002-01-01

    A lot has been learned from past experience with structural and machine element failures. The understanding of failure modes and the application of an appropriate design analysis method can lead to improved structural and machine element safety as well as serviceability. To apply Probabilistic Design Methodology (PDM), all uncertainties are modeled as random variables with selected distribution types, means, and standard deviations. It is quite difficult to achieve a robust design without considering the randomness of the design parameters which is the case in the use of the Deterministic Design Approach. The US Navy has a fleet of submarine-launched ballistic missiles. An umbilical plug joins the missile to the submarine in order to provide electrical and cooling water connections. As the missile leaves the submarine, an umbilical retract mechanism retracts the umbilical plug clear of the advancing missile after disengagement during launch and retrains the plug in the retracted position. The design of the current retract mechanism in use was based on the deterministic approach which puts emphasis on factor of safety. A new umbilical retract mechanism that is simpler in design, lighter in weight, more reliable, easier to adjust, and more cost effective has become desirable since this will increase the performance and efficiency of the system. This paper reports on a recent project performed at Tennessee State University for the US Navy that involved the application of PDM to the design of an umbilical retract mechanism. This paper demonstrates how the use of PDM lead to the minimization of weight and cost, and the maximization of reliability and performance.

  2. Modeling length-tension properties of RCPm muscles during voluntary retraction of the head.

    Science.gov (United States)

    Hallgren, Richard C

    2014-08-01

    Head retraction exercises are one of several commonly used clinical tools that are used to assess and treat patients with head and neck pain and to aid in restoration of a normal neutral head posture. Retraction of the head results in flexion of the occipitoatlantal (OA) joint and stretching of rectus capitis posterior minor (RCPm) muscles. The role that retraction of the head might have in treating head and neck pain patients is currently unknown. RCPm muscles arise from the posterior tubercle of the posterior arch of C1 and insert into the occipital bone inferior to the inferior nuchal line and lateral to the midline. RCPm muscles are the only muscles that attach to the posterior arch of C1. The functional role of RCPm muscles has not been clearly defined. The goal of this project was to develop a three-dimensional, computer-based biomechanical model of the posterior aspect of the OA joint. This model should help clarify why voluntary head retraction exercises seem to contribute to the resolution of head and neck pain and restoration of a normal head posture in some patients. The model documents that length-tension properties of RCPm muscles are significantly affected by variations in the physical properties of the musculotendonous unit. The model suggests that variations in the cross sectional area of RCPm muscles due to pathologies that weaken the muscle, such as muscle atrophy, may reduce the ability of these muscles to generate levels of force that are necessary for the performance of normal, daily activities. The model suggests that the main benefit of the initial phase of head retraction exercises may be to strengthen RCPm muscles through eccentric contractions, and that the main benefit of the final phase of retraction may be to stretch the muscles as the final position is held. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Dendritic ion channelopathy in acquired epilepsy

    Science.gov (United States)

    Poolos, Nicholas P.; Johnston, Daniel

    2012-01-01

    Summary Ion channel dysfunction or “channelopathy” is a proven cause of epilepsy in the relatively uncommon genetic epilepsies with Mendelian inheritance. But numerous examples of acquired channelopathy in experimental animal models of epilepsy following brain injury have also been demonstrated. Our understanding of channelopathy has grown due to advances in electrophysiology techniques that have allowed the study of ion channels in the dendrites of pyramidal neurons in cortex and hippocampus. The apical dendrites of pyramidal neurons comprise the vast majority of neuronal surface membrane area, and thus the majority of the neuronal ion channel population. Investigation of dendritic ion channels has demonstrated remarkable plasticity in ion channel localization and biophysical properties in epilepsy, many of which produce hyperexcitability and may contribute to the development and maintenance of the epileptic state. Here we review recent advances in dendritic physiology and cell biology, and their relevance to epilepsy. PMID:23216577

  4. Dendritic polymers: Universal glue for cells

    Science.gov (United States)

    Frey, Holger

    2012-05-01

    A dendritic polymer consisting of inversely oriented lipid head groups on a polyvalent polyglycerol scaffold makes an effective reversible biomembrane adhesive that may find use as a tissue sealant and a drug-delivery vehicle.

  5. Dendritic cells in autoimmune thyroid disease.

    Science.gov (United States)

    Kabel, P J; Voorbij, H A; van der Gaag, R D; Wiersinga, W M; de Haan, M; Drexhage, H A

    1987-01-01

    Dendritic cells form a morphologically distinct class of cells characterized by shape, reniform nucleus, absent to weak acid-phosphatase activity and strong Class II MHC determinant positivity. Functionally they are the most efficient cells in antigen presentation to T-lymphocytes which indicates their role in the initiation of an immune response. Using immunehistochemical techniques we studied the presence of dendritic cells in normal Wistar rat and human thyroids, in thyroids of BBW rats developing thyroid autoimmunity and in Graves' goitres. Dendritic cells could be identified in all thyroids studied and were positioned underneath the thyrocytes in between the follicles. Skin dendritic cells travel via lymphatics to draining lymph nodes, thus forming an antigen presenting cell system. It is likely that a similar cell system exists on the level of the thyroid for dendritic cells have also been detected in thyroid draining lymph nodes. In normal thyroid tissue of both human and rat dendritic cells were relatively scarce. During the initial phases of the thyroid autoimmune response in the BBW rat (before the appearance of Tg-antibodies in the circulation) numbers of thyroid dendritic cells increased. Intrathyroidal T-helper cells, B-cells or plasma cells could not be found. The thyroid draining lymph node contained large numbers of plasma cells. During the later stages of the thyroid autoimmune response in the BB/W rat (after the appearance of Tg-antibodies in the circulation) and in Graves' goitres dendritic cells were not only present in high number, but 20-30% were seen in contact with now-present intrathyroidal T-helper lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. RETRACTED: A novel membrane-based anti-diabetic action of atorvastatin

    Energy Technology Data Exchange (ETDEWEB)

    Horvath, Emily M.; Tackett, Lixuan [Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Center for Diabetes Research, VanNuys Medical Science, Building Rm 308A, Indianapolis, IN 46202 (United States); Elmendorf, Jeffrey S., E-mail: jelmendo@iupui.edu [Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Center for Diabetes Research, VanNuys Medical Science, Building Rm 308A, Indianapolis, IN 46202 (United States); Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Center for Diabetes Research, Indianapolis, IN 46202 (United States)

    2008-08-08

    This article has been retracted. Please see Elsevier Policy on Article Withdrawal ((http://www.elsevier.com/locate/withdrawalpolicy)). Reason: The editors would like to confirm the retraction of this paper at the request of the authors. One of the authors, Emily M. Horvath, admitted to altering data in two of the figures. Specifically in Figures 2, and 4A, some of the values were incorrectly reported for the radioactive glucose uptake assays. None of the other authors associated with this publication were aware of the data manipulation. The authors sincerely regret if this has caused problems with investigators that have used this information experimentally.

  7. Attenuation of the Type IV Pilus Retraction Motor Influences Neisseria gonorrhoeae Social and Infection Behavior.

    Science.gov (United States)

    Hockenberry, Alyson M; Hutchens, Danielle M; Agellon, Al; So, Magdalene

    2016-12-06

    Retraction of the type IV pilus (Tfp) mediates DNA uptake, motility, and social and infection behavior in a wide variety of prokaryotes. To date, investigations into Tfp retraction-dependent activities have used a mutant deleted of PilT, the ATPase motor protein that causes the pilus fiber to retract. ΔpilT cells are nontransformable, nonmotile, and cannot aggregate into microcolonies. We tested the hypothesis that these retraction-dependent activities are sensitive to the strength of PilT enzymatic activity by using the pathogen Neisseria gonorrhoeae as a model. We constructed an N. gonorrhoeae mutant with an amino acid substitution in the PilT Walker B box (a substitution of cysteine for leucine at position 201, encoded by pilTL201C). Purified PilTL201C forms a native hexamer, but mutant hexamers hydrolyze ATP at half the maximal rate. N. gonorrhoeae pilTL201C cells produce Tfp fibers, crawl at the same speed as the wild-type (wt) parent, and are equally transformable. However, the social behavior of pilTL201C cells is intermediate between the behaviors of wt and ΔpilT cells. The infection behavior of pilTL201C is also defective, due to its failure to activate the epidermal growth factor receptor (EGFR)-heparin-binding EGF-like growth factor (HB-EGF) pathway. Our study indicates that pilus retraction, per se, is not sufficient for N. gonorrhoeae microcolony formation or infectivity; rather, these activities are sensitive to the strength of PilT enzymatic activity. We discuss the implications of these findings for Neisseria pathogenesis in the context of mechanobiology. Type IV pili are fibers expressed on the surface of many bacteria. Neisseria gonorrhoeae cells crawl, take up DNA, and communicate with each other and with human cells by retracting these fibers. Here, we show that an N. gonorrhoeae mutant expressing an enzymatically weakened type IV pilus retraction motor still crawls and takes up DNA normally. However, mutant cells exhibit abnormal social

  8. Retraction statement: Advances in the physiological and pathological implications of cholesterol.

    Science.gov (United States)

    2015-08-01

    The above article, published online on 28 February 2013 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor in Chief, William Foster, and John Wiley and Sons Ltd. The retraction has been agreed due to the publication of a similar paper by the same authors (with the exclusion of P Mardones) in Frontiers in Bioscience in January 2014. The authors believed that they had taken the necessary steps to withdraw their paper from Frontiers in Bioscience before they submitted to Biological Reviews in June 2012. © 2015 Cambridge Philosophical Society.

  9. Retracted: Bacteria diversity overview and endoglucanase assessment from Himalayan Tapovan geothermal spring.

    Science.gov (United States)

    Sahoo, Jitendra Kumar; Navani, Naveen Kumar; Pathania, Ranjana

    2015-08-25

    The above article from the Journal of Basic Microbiology, published online on 25 August 2015 in Wiley Online Library as Early View (http://onlinelibrary.wiley.com/doi/10.1002/jobm.201500135/pdf), has been retracted by agreement between Naveen Kumar Navani and Ranjana Pathania, the Editor-in-Chief and Wiley-VCH GmbH & Co. KGaA. The retraction has been agreed because the article has been submitted and approved for publication by Jitendra Kumar Sahoo without consent in any form by the named co-authors Naveen Kumar Navani and Ranjana Pathania. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. On retracting properties and covering homotopy theorem for S-maps into Sχ-cofibrations and Sχ-fibrations

    Directory of Open Access Journals (Sweden)

    Amin Saif

    2016-10-01

    Full Text Available In this paper we generalize the retracting property in homotopy theory for topological semigroups by introducing the notions of deformation S-retraction with its weaker forms and ES-homotopy extension property. Furthermore, the covering homotopy theorems for S-maps into Sχ-fibrations and Sχ-cofibrations are introduced and pullbacks for Sχ-fibrations behave properly.

  11. 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.

  12. Retracted article: Khasanov I.F. Modern regional investment policy implementation methods. Statistics and Economics. 2016;(6:114-119. (In Russ.

    Directory of Open Access Journals (Sweden)

    article Editorial

    2017-01-01

    Full Text Available This article by Ildar F. Khasanov has been retracted (i.e. withdrawn from the press by the editor with permission of the publisher.Retracted article due to unformed borrowings (plagiarism.

  13. Effects of social housing on hippocampal dendrites and behavior in ovariectomized rats.

    Science.gov (United States)

    Leedy, Gail M; Barrows, Lorraine F; Clark, Suzanne

    2013-03-01

    Social stress is both species and gender specific. For female rats, individual housing and social instability housing conditions are associated with behavioral indicators of stress and depression. The present study directly compared the effects of six weeks of individual housing, social instability and mixed sex, semi-crowded housing in a visible burrow system (VBS) on ovariectomized female rats. Paired, stable housing was used as the control. Behavioral tests were conducted two, four and six weeks into the housing manipulations and included sucrose consumption, social interest, and activity in the open field. Following a series of four behavioral tests, animals were sacrificed and brains were processed for Golgi impregnation. Basal dendrites of CA3 hippocampal neurons were measured. Results indicate that the individual housing and social instability groups were comparable to the control group for all measures. In contrast, the rats housed in the VBS exhibited reduced activity in open field testing, and alterations in social interest. Dendritic lengths were also reduced in those animals living in the VBS in comparison to the animals housed in pairs. To our knowledge, this is the first report of behavioral and neural effects of VBS housing on female rats. Further research is necessary to determine what facets of the VBS housing are responsible for the behavioral and neural changes. This article is part of a Special Issue entitled 'Animal Models'. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Distinct Pattern Separation Related Transfer Functions in Human CA3/Dentate and CA1 Revealed Using High-Resolution fMRI and Variable Mnemonic Similarity

    Science.gov (United States)

    Lacy, Joyce W.; Yassa, Michael A.; Stark, Shauna M.; Muftuler, L. Tugan; Stark, Craig E. L.

    2011-01-01

    Producing and maintaining distinct (orthogonal) neural representations for similar events is critical to avoiding interference in long-term memory. Recently, our laboratory provided the first evidence for separation-like signals in the human CA3/dentate. Here, we extended this by parametrically varying the change in input (similarity) while…

  15. The analysis of hippocampus neuronal density (CA1 and CA3 after Ocimum sanctum ethanolic extract treatment on the young adulthood and middle age rat model

    Directory of Open Access Journals (Sweden)

    Dwi Liliek Kusindarta

    2018-02-01

    Full Text Available Aim: This study aimed to assess the changes in neuronal density in CA1 and CA3 regions in the hippocampus of young adulthood and middle age rat model after feeding by Ocimum sanctum ethanolic extract. Materials and Methods: In this research, 30 male Wistar rats consist of young to middle-aged rats were divided into three groups (3, 6, and 9 months old and treated with a different dosage of O. sanctum ethanolic extract (0, 50, and 100 mg/kg b.w. for 45 days. Furthermore, cresyl violet staining was performed to analyze hippocampus formation mainly in CA1 and CA3 area. The concentrations of acetylcholine (Ach in brain tissues were analyzed by enzyme-linked immunosorbent assay. Results: In our in vivo models using rat model, we found that the administration of O. sanctum ethanolic extract with a dosage of 100 mg/kg b.w. for 45 days induced the density of pyramidal cells significantly in CA1 and CA3 of the hippocampus. These results were supported by an increase of Ach concentrations on the brain tissue. Conclusion: The administration of O. sanctum ethanolic extract may promote the density of the pyramidal cells in the CA1 and CA3 mediated by the up-regulated concentration of Ach.

  16. Characterization of the interface between an Fe–Cr alloy and the p-type thermoelectric oxide Ca3Co4O9

    DEFF Research Database (Denmark)

    Holgate, Tim; Han, Li; Wu, NingYu

    2014-01-01

    A customized Fe–Cr alloy that has been optimized for high temperature applications in oxidizing atmospheres has been interfaced via spark plasma sintering (SPS) with a p-type thermoelectric oxide material: calcium cobaltate (Ca3Co4O9). The properties of the alloy have been analyzed for its...

  17. Anisomycin Injection in Area CA3 of the Hippocampus Impairs Both Short-Term and Long-Term Memories of Contextual Fear

    Science.gov (United States)

    Remaud, Jessica; Ceccom, Johnatan; Carponcy, Julien; Dugué, Laura; Menchon, Gregory; Pech, Stéphane; Halley, Helene; Francés, Bernard; Dahan, Lionel

    2014-01-01

    Protein synthesis is involved in the consolidation of short-term memory into long-term memory. Previous electrophysiological data concerning LTP in CA3 suggest that protein synthesis in that region might also be necessary for short-term memory. We tested this hypothesis by locally injecting the protein synthesis inhibitor anisomycin in hippocampal…

  18. Luminescence enhancement of Ca3Sr3(VO4)4:Eu3+, Sm3+ red-emitting phosphor by charge compensation

    Science.gov (United States)

    Tang, Qinxue; Qiu, Kehui; Zhang, Wentao; Shen, Yuqiao; Wang, Junlan

    2018-01-01

    A series of red-emitting phosphors Ca3Sr3(VO4)4:0.05Eu3+; Ca3Sr3(VO4)4:0.05Eu3+, xSm3+; and Ca3Sr3(VO4)4:0.05Eu3+, 0.05Sm3+, yM+ (M = Li, Na, and K) were fabricated with the combustion method. The microstructure and photoluminescence properties of the phosphors were investigated via X-ray powder diffraction, scanning electron microscopy, and photoluminescence spectroscopy. The obtained results revealed that all samples perfectly matched the rhombohedral structure with R3c space group. The results showed that the luminescence properties of Eu3+ ions could evidently be improved by co-doping with Sm3+ ions. When the doping mole fraction of Sm3+ ions was 5%, the relative luminous intensity at 619 nm was maximal under an excitation of 464 nm. Moreover, incorporation of charge compensators (i.e., Li+, Na+, and K+) could improve both the luminescence intensity and thermal stability of phosphors under an excitation of 464 nm and this paper discusses and interprets the underlying reason. The optimal concentration of the charge compensator M+ (M = Li, Na, and K) was 5%. In particular, the Li+-doped sample exhibited significantly enhanced emission intensity and thermal stability under an excitation wavelength of 464 nm and its emission intensity was approximately 1.9-fold of that of Ca3Sr3(VO4)4:0.05Eu3+, 0.05Sm3+. Furthermore, the CIE chromaticity coordinate of Ca3Sr3(VO4)4:0.05Eu3+, 0.05Sm3+, 0.05Li+ phosphor was found to be closer to the standard red-emitting point (x = 0.67, y = 0.33) compared to Ca3Sr3(VO4)4:0.05Eu3+, 0.05Sm3+. The luminescence performance of Ca3Sr3(VO4)4:Eu3+, Sm3+, Li+ upon excitation with blue light radiation makes this a potential red-emitting phosphor for application in blue-based white light emitting diodes.

  19. Fatigue reversibly reduced cortical and hippocampal dendritic spines concurrent with compromise of motor endurance and spatial memory.

    Science.gov (United States)

    Chen, J-R; Wang, T-J; Huang, H-Y; Chen, L-J; Huang, Y-S; Wang, Y-J; Tseng, G-F

    2009-07-21

    Fatigue could be induced following forced exercise, sickness, heat stroke or sleep disturbance and impaired brain-related functions such as concentration, attention and memory. Here we investigated whether fatigue altered the dendrites of central neurons. Central fatigue was induced by housing rats in cage with 1.5-cm deep water for 1-5 days. Three days of sleep deprivation seriously compromised rats' performance in weight-loaded forced swimming and spatial learning tests, and 5 days of treatment worsened it further. Combinations of intracellular dye injection and three-dimensional analysis revealed that dendritic spines on retrograde tracer-identified corticospinal neurons and Cornu Ammonis (CA)1 and CA3 pyramidal neurons were significantly reduced while the shape or length of the dendritic arbors was not altered. Three days of rest restored the spine loss and the degraded spatial learning and weight-loaded forced swimming performances to control levels. In conclusion, although we could not rule out additional non-hypothalamic-pituitary-adrenal stress, the apparent fatigue induced following a few days of sleep deprivation could change brain structurally and functionally and the effects were reversible with a few days of rest.

  20. Electroconvulsive stimulations prevent stress-induced morphological changes in the hippocampus

    DEFF Research Database (Denmark)

    Hageman, I; Nielsen, M; Wörtwein, Gitta

    2008-01-01

    pathophysiological events contribute to the shrinkage phenomenon. Animal studies have shown that various stress paradigms can induce dendritic retraction in the CA3 pyramidal neurons of the hippocampus. Since electroconvulsive treatment is the most effective treatment in humans with major depression, we investigated...

  1. Prenatal nicotine and maternal deprivation stress de-regulate the development of CA1, CA3, and dentate gyrus neurons in hippocampus of infant rats.

    Directory of Open Access Journals (Sweden)

    Hong Wang

    Full Text Available Adverse experiences by the developing fetus and in early childhood are associated with profound effects on learning, emotional behavior, and cognition as a whole. In this study we investigated the effects of prenatal nicotine exposure (NIC, postnatal maternal deprivation (MD or the combination of the two (NIC+MD to determine if hippocampal neuron development is modulated by exposure to drugs of abuse and/or stress. Growth of rat offspring exposed to MD alone or NIC+MD was repressed until after weaning. In CA1 but not CA3 of postnatal day 14 (P14 pups, MD increased pyramidal neurons, however, in dentate gyrus (DG, decreased granule neurons. NIC had no effect on neuron number in CA1, CA3 or DG. Unexpectedly, NIC plus MD combined caused a synergistic increase in the number of CA1 or CA3 neurons. Neuron density in CA regions was unaffected by treatment, but in the DG, granule neurons had a looser packing density after NIC, MD or NIC+MD exposure. When septotemporal axes were analyzed, the synergism of stress and drug exposure in CA1 and CA3 was associated with rostral, whereas MD effects were predominantly associated with caudal neurons. TUNEL labeling suggests no active apoptosis at P14, and doublecortin positive neurons and mossy fibers were diminished in NIC+MD relative to controls. The laterality of the effect of nicotine and/or maternal deprivation in right versus left hippocampus was also analyzed and found to be insiginificant. We report for the first time that early life stressors such as postnatal MD and prenatal NIC exposure, when combined, may exhibit synergistic consequences for CA1 and CA3 pyramidal neuron development, and a potential antagonistic influence on developing DG neurons. These results suggest that early stressors may modulate neurogenesis, apoptosis, or maturation of glutamatergic neurons in the hippocampus in a region-specific manner during critical periods of neurodevelopment.

  2. Sustained increase of spontaneous input and spike transfer in the CA3-CA1 pathway following long term potentiation in vivo

    Directory of Open Access Journals (Sweden)

    Oscar eHerreras

    2012-10-01

    Full Text Available Long term potentiation (LTP is commonly used to study synaptic plasticity but the associated changes in the spontaneous activity of individual neurons or the computational properties of neural networks in vivo remain largely unclear. The multisynaptic origin of spontaneous spikes makes difficult estimating the impact of a particular potentiated input. Accordingly, we adopted an approach that isolates pathway-specific postsynaptic activity from raw local field potentials (LFPs in the rat hippocampus in order to study the effects of LTP on ongoing spike transfer between cell pairs in the CA3-CA1 pathway. CA1 Schaffer-specific LFPs elicited by spontaneous clustered firing of CA3 pyramidal cells involved a regular succession of elementary micro-field-EPSPs (gamma-frequency that fired spikes in CA1 units. LTP increased the amplitude but not the frequency of these ongoing excitatory quanta. Also, the proportion of Schaffer-driven spikes in both CA1 pyramidal cells and interneurons increased in a cell-specific manner only in previously connected CA3-CA1 cell pairs, i.e., when the CA3 pyramidal cell had shown pre-LTP significant correlation with firing of a CA1 unit and potentiated spike-triggered average of Schaffer LFPs following LTP. Moreover, LTP produced subtle reorganization of presynaptic CA3 cell assemblies. These findings show effective enhancement of pathway specific ongoing activity which leads to increased spike transfer in potentiated segments of a network. These indicate that plastic phenomena induced by external protocols may intensify spontaneous information flow across specific channels as proposed in transsynaptic propagation of plasticity and synfire chain hypotheses that may be the substrate for different types of memory involving multiple brain structures.

  3. Propagation of errors in citation networks: a study involving the entire citation network of a widely cited paper published in, and later retracted from, the journal Nature

    NARCIS (Netherlands)

    van der Vet, P.E.; Nijveen, Harmen

    2016-01-01

    Background In about one in 10,000 cases, a published article is retracted. This very often means that the results it reports are flawed. Several authors have voiced concerns about the presence of retracted research in the memory of science. In particular, a retracted result is propagated by citing

  4. Propagation of errors in citation networks: a study involving the entire citation network of a widely cited paper published in, and later retracted from, the journal Nature

    NARCIS (Netherlands)

    Vet, Van Der Paul E.; Nijveen, Harm

    2016-01-01

    Background
    In about one in 10,000 cases, a published article is retracted. This very often means that the results it reports are flawed. Several authors have voiced concerns about the presence of retracted research in the memory of science. In particular, a retracted result is propagated by

  5. Crossover between activated reptation and arm retraction mechanisms in entangled rod-coil block copolymers

    Science.gov (United States)

    Wang, Muzhou; Likhtman, Alexei E.; Olsen, Bradley D.

    2015-11-01

    Using a coarse-grained slip-spring model, the dynamics of rod-coil block copolymers is explored over a wide parameter space to fully capture the crossover between the short rod (activated reptation) and long rod (arm retraction) limits. An analytical, closed-form expression for curvilinear diffusion by activated reptation was derived by separating the drag into individual components for the rod and coil block. Curvilinear diffusion in the intermediate rod regime, where both mechanisms are important, was then found to be faster than predicted when both mechanisms are independently combined. The discrepancy in the crossover regime arises because the rod-coil copolymer's exploration of space is not accurately described by either a coil homopolymer (assumed by activated reptation) or a rod homopolymer (assumed by arm retraction). This effect is explored by tracking the rod orientation as the polymer reptates, confirming that the polymer reptates along a path that becomes more rodlike as the rod fraction is increased. Thus, activated reptation under-predicts diffusion because the rod can choose reptation paths that are more extended than the coil homopolymer by renewal of the entanglement tube from the ends. Arm retraction under-predicts diffusion because minor rotations of the rod allow some motion before full retractions of the coil block. Finally, more familiar 3-dimensional center-of-mass diffusion measurements are related to the curvilinear diffusion analysis because the ratio of these two quantities varies smoothly between the coil and rod homopolymer limits as the reptation path becomes more extended.

  6. Retraction of "Women's Preference for Attractive Makeup Tracks Changes in Their Salivary Testosterone".

    Science.gov (United States)

    2016-03-01

    At the request of the authors, the following article has been retracted by the Editor and publishers of Psychological Science:Fisher, C. I., Hahn, A. C., DeBruine, L. M., & Jones, B. C. (2015). Women's preference for attractive makeup tracks changes in their salivary testosterone. Psychological Science, 26, 1958-1964. doi:10.1177/0956797615609900. © The Author(s) 2016.

  7. 77 FR 75189 - Certain Electronic Devices Having a Retractable USB Connector; Termination of an Investigation

    Science.gov (United States)

    2012-12-19

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Certain Electronic Devices Having a Retractable USB Connector; Termination of an Investigation... viewed on the Commission's electronic docket (EDIS) at http://edis.usitc.gov . Hearing-impaired persons...

  8. Statement of Retraction: Kumar Ajay, Singh Neetu, Gaurav S.S. ...

    African Journals Online (AJOL)

    McRoy

    The Editors and Publisher of the International Journal of Medicine and Biomedical Research wish to state that the following article has been retracted from the journal: Kumar Ajay, Singh. Neetu, Gaurav S.S. Forensic Bioinformatics: An innovative technological advancement in the field of Forensic Medicine and Diagnosis.

  9. Eugregarine trophozoite detachment from the host epithelium via epimerite retraction: Fiction or fact?

    Czech Academy of Sciences Publication Activity Database

    Valigurová, A.; Michalková, V.; Koudela, Břetislav

    2009-01-01

    Roč. 39, č. 11 (2009), s. 1235-1242 ISSN 0020-7519 R&D Projects: GA MŠk LC522 Institutional research plan: CEZ:AV0Z60220518 Keywords : Apicomplexa * epimerite retraction * trophozoite Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 3.819, year: 2009

  10. RETRACTED: Investigation into the kinetic behavior of molten aluminum pressureless infiltration into SiC preforms

    Directory of Open Access Journals (Sweden)

    Hassan Sharifi

    2016-10-01

    According to the policy of our Journal, this paper has been retracted because of sheer plagiarism. This paper has been published at the same time in the International Journal of Materials Research (IJMR: http://dx.doi.org/10.3139/146.111422.

  11. Electromyographic activity of rectus capitis posterior minor muscles associated with voluntary retraction of the head.

    Science.gov (United States)

    Hallgren, Richard C; Pierce, Steven J; Prokop, Lawrence L; Rowan, Jacob J; Lee, Angela S

    2014-01-01

    The functional role of rectus capitis posterior minor (RCPm) muscles is not well defined. To the best of our knowledge, electromyographic (EMG) data from RCPm muscles in humans have never been collected and analyzed. To test the null hypothesis that there will be no difference in normalized levels of EMG activity measured from RCPm muscles with the head in a neutral position and with the head in a retracted position. A repeated measures design intended to quantify normalized levels of EMG activity measured from RCPm muscles. Disposable 25-gauge, bipolar fine wire hooked electrodes were used to collect EMG data from both right and left RCPm muscles from 17 asymptomatic subjects. Data were collected while subjects performed five trials with the head maintained in a neutral position; performed three maximal voluntary isometric contraction efforts; performed four trials with the head maintained in a retracted position. Mixed effects beta regression models were used to analyze the data. Normalized EMG activity of RCPm muscles collected with the subject's head held in a retracted position was significantly higher (p<.0001) than normalized EMG activity collected with the subject's head held in a self-selected, neutral position. Rectus capitis posterior minor muscles are active when the head is held in a neutral position and show a significant increase in activity when the head is held in a retracted position. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Retracted: Nrf2: a novel therapeutic target in fragile X syndrome is modulated by NNZ2566.

    Science.gov (United States)

    Deacon, R M J; Hurley, M J; Rebolledo, C M; Snape, M; Altimiras, F J; Farías, L; Pino, M; Biekofsky, R; Glass, L; Cogram, P

    2017-09-01

    Retraction: "Nrf2: a novel therapeutic target in fragile X syndrome is modulated by NNZ2566" by R. M. J. Deacon, M. J. Hurley, C. M. Rebolledo, M. Snape, F. J. Altimiras, L. Farías, M. Pino, R. Biekofsky, L. Glass and P. Cogram. The above article, from Genes, Brain and Behavior, published online on 12th May 2017 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor in Chief, Andrew Holmes and John Wiley & Sons Ltd. The retraction has been agreed as all authors cannot agree on a revised author order, and at least one author continues to dispute the original order. In this case, the original article is being retracted on the grounds that the journal does not have permission to publish. Reference: Deacon, R. M. J., Hurley, M. J., Rebolledo, C. M., Snape, M., Altimiras, F. J., Farías, L., Pino, M., Biekofsky, R., Glass, L. and Cogram, P. (2017), Nrf2: a novel therapeutic target in fragile X syndrome is modulated by NNZ2566. Genes, Brain and Behavior. doi:10.1111/gbb.12373. © 2017 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

  13. Molecular dynamics simulation of the self-retracting motion of a graphene flake

    Science.gov (United States)

    Popov, Andrey M.; Lebedeva, Irina V.; Knizhnik, Andrey A.; Lozovik, Yurii E.; Potapkin, Boris V.

    2011-12-01

    The self-retracting motion of a graphene flake on a stack of graphene flakes is studied using molecular dynamics simulations. It is shown that in the case when the extended flake is initially rotated to an incommensurate state, there is no barrier to the self-retracting motion of the flake and the flake retracts as fast as possible. If the extended flake is initially commensurate with the other flakes, the self-retracting motion is hindered by potential energy barriers. However, in this case, rotation of the flake to incommensurate states is often observed. Such a rotation is found to be induced by the torque acting on the flake on hills of the potential relief of interaction energy between the flakes. Contrary to carbon nanotubes, telescopic oscillations of the graphene flake are suppressed because of high dynamic friction related to the excitation of flexural vibrations of the flake. This makes graphene promising for the use in fast-responding electromechanical memory cells.

  14. Magnetic resonance imaging findings of the abducens nerves in type 1 Duane's retraction syndrome.

    Science.gov (United States)

    Tuzcu, Esra Ayhan; Bayarogullari, Hanifi; Atci, Nesrin; Basarslan, Fatmagul; Coskun, Mesut; Yilmaz, Cahide; Ilhan, Nilufer; Daglioglu, Mutlu

    2014-05-01

    To investigate nervus abducens and extraocular mucles in patients with Type 1 Duane's retraction syndrome using high-definition magnetic resonance imaging. The study included 10 patients with Type I Duane's retraction syndrome who underwent magnetic resonance imaging (MRI) of the brain and orbits. Overall, 10 cases were included in the study. There were seven women and three men. The mean age was 5.2 years (1-15 years). MRI of the abducens nerve was performed in all cases. Of the cases, the left eye was involved in eight cases, whereas the right eye was involved in two cases. There was no bilateral eye involvement. Among the 10 patients clinically diagnosed as Type 1 Duane's retraction syndrome, the abducens nerve could not be visualized in eight cases, whereas the nerve was hypoplastic in one case and bilateral abducens nerves were present in one case by MRI. The extraocular muscles were normal in all cases on T2 weighted coronal MRI of the orbits. Absence of abducens nerve and normal extraocular muscles was detected in patients with Type 1 Duane's retraction syndrome at the affected side.

  15. Assessment of Eustachian tube function in patients with tympanic membrane retraction and in normal subjects.

    Science.gov (United States)

    Canali, Inesângela; Petersen Schmidt Rosito, Letícia; Siliprandi, Bruno; Giugno, Cláudia; Selaimen da Costa, Sady

    The diagnosis of Eustachian tube dysfunctions is essential for better understanding of the pathogenesis of chronic otitis media. A series of tests to assess tube function are described in the literature; however, they are methodologically heterogeneous, with differences ranging from application protocols to standardization of tests and their results. To evaluate the variation in middle ear pressure in patients with tympanic membrane retraction and in normal patients during tube function tests, as well as to evaluate intra-individual variation between these tests. An observational, contemporary, cross-sectional study was conducted, in which the factor under study was the variation in middle ear pressure during tube function tests (Valsalva maneuver, sniff test, Toynbee maneuver) in healthy patients and in patients with mild and moderate/severe tympanic retraction. A total of 38 patients (76 ears) were included in the study. Patients underwent tube function tests at two different time points to determine pressure measurements after each maneuver. Statistical analysis was performed using SPSS software, version 18.0, considering p-values <0.05 as statistically significant. Mean (standard deviation) age was 11 (2.72) years; 55.3% of patients were male and 44.7% female. The prevalence of type A tympanogram was higher among participants with healthy ears and those with mild retraction, whereas type C tympanograms were more frequent in the moderate/severe retraction group. An increase in middle ear pressure was observed during the Valsalva maneuver at the first time point evaluated in all three groups of ears (p=0.012). The variation in pressure was not significant either for the sniff test or for the Toynbee maneuver at the two time points evaluated (p≥0.05). Agreement between measurements obtained at the two different time points was weak to moderate for all tests in all three groups of ears, and the variations in discrepancy between measurements were higher in ears

  16. Assessment of Eustachian tube function in patients with tympanic membrane retraction and in normal subjects,

    Directory of Open Access Journals (Sweden)

    Inesângela Canali

    Full Text Available Abstract Introduction The diagnosis of Eustachian tube dysfunctions is essential for better understanding of the pathogenesis of chronic otitis media. A series of tests to assess tube function are described in the literature; however, they are methodologically heterogeneous, with differences ranging from application protocols to standardization of tests and their results. Objective To evaluate the variation in middle ear pressure in patients with tympanic membrane retraction and in normal patients during tube function tests, as well as to evaluate intra-individual variation between these tests. Methods An observational, contemporary, cross-sectional study was conducted, in which the factor under study was the variation in middle ear pressure during tube function tests (Valsalva maneuver, sniff test, Toynbee maneuver in healthy patients and in patients with mild and moderate/severe tympanic retraction. A total of 38 patients (76 ears were included in the study. Patients underwent tube function tests at two different time points to determine pressure measurements after each maneuver. Statistical analysis was performed using SPSS software, version 18.0, considering p-values <0.05 as statistically significant. Results Mean (standard deviation age was 11 (2.72 years; 55.3% of patients were male and 44.7% female. The prevalence of type A tympanogram was higher among participants with healthy ears and those with mild retraction, whereas type C tympanograms were more frequent in the moderate/severe retraction group. An increase in middle ear pressure was observed during the Valsalva maneuver at the first time point evaluated in all three groups of ears (p = 0.012. The variation in pressure was not significant either for the sniff test or for the Toynbee maneuver at the two time points evaluated (p ≥ 0.05. Agreement between measurements obtained at the two different time points was weak to moderate for all tests in all three groups of ears, and the

  17. Evaluation of corticotomy-facilitated orthodontics and piezocision in rapid canine retraction.

    Science.gov (United States)

    Abbas, Noha Hussein; Sabet, Noha Ezzat; Hassan, Islam Tarek

    2016-04-01

    The purpose of this study was to evaluate the efficiency of corticotomy-facilitated orthodontics and piezocision in rapid canine retraction. The sample consisted of 20 patients (15-25 years old) with Class II Division 1 malocclusions. The suggested treatment plan was extraction of the maxillary first premolars with subsequent canine retraction. The sample was divided into 2 equal groups. In the first group, 1 side of the maxillary arch was randomly chosen for treatment with corticotomy, and in the second group, piezocision treatment was used. The contralateral sides of both groups served as the controls. Cuts and perforations were performed with a piezotome, and canine retraction was initiated bilaterally in both groups with closed-coil nickel-titanium springs that applied 150 g of force on each side. The following variables were examined over a 3-month follow-up period: rate of canine crown tip, molar anchorage loss, canine rotation, canine inclination, canine root resorption, plaque index, gingival index, probing depth, attachment level, and gingival recession. The rate of canine crown tip was assessed every 2 weeks after the start of canine retraction at 6 time points. The rates of canine crown tip were greater in the experimental sides than in the control sides in both groups. Corticotomies produced greater rates of canine movement than did piezocision at 4 time points. Canine root resorption was greater in the control sides. The remaining studied variables exhibited no differences between the control and the experimental sides. Corticotomy-facilitated orthodontics and piezocision are efficient treatment modalities for accelerating canine retraction. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  18. Miniscrew implant-supported maxillary canine retraction with and without corticotomy-facilitated orthodontics.

    Science.gov (United States)

    Aboul-Ela, Shadw Mohammed Badr El-Din; El-Beialy, Amr Ragab; El-Sayed, Karim Mohamed Fawzy; Selim, Essam Mohamed Nassef; El-Mangoury, Nagwa Helmy; Mostafa, Yehya Ahmed

    2011-02-01

    The purpose of this study was to clinically evaluate miniscrew implant-supported maxillary canine retraction with corticotomy-facilitated orthodontics. The sample consisted of 13 adult patients (5 men, 8 women; mean age, 19 years) exhibiting Class II Division 1 malocclusion with increased overjet requiring the therapeutic extraction of the maxillary first premolars, with subsequent retraction of the maxillary canines. Corticotomy-facilitated orthodontics was randomly assigned to 1 side of the maxillary arch at the canine-premolar region, and the other side served as the control. By using miniscrews as anchorage, canine retraction was initiated via closed nickel-titanium coil springs applying 150 g of force per side. The following variables were examined over a 4-month follow-up period: rate of tooth movement, molar anchorage loss, plaque index, gingival index, probing depth, attachment loss, and gingival recession. The average daily rate of canine retraction was significantly higher on the corticotomy than the control side by 2 times during the first 2 months after the corticotomy surgery. This rate of tooth movement declined to only 1.6 times higher in the third month and 1.06 times higher by the end of the fourth month. No molar anchorage loss occurred during canine retraction on either the operated or the nonoperated side. There was no statistically significant difference between preoperative and postoperative measurements of plaque index, probing depth, attachment loss, and gingival recession. Corticotomy-facilitated orthodontics can be a feasible treatment modality for adults seeking orthodontic treatment with reduced treatment times. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  19. Cell protrusion and retraction driven by fluctuations in actin polymerization: A two-dimensional model.

    Science.gov (United States)

    Ryan, Gillian L; Holz, Danielle; Yamashiro, Sawako; Taniguchi, Daisuke; Watanabe, Naoki; Vavylonis, Dimitrios

    2017-07-28

    Animal cells that spread onto a surface often rely on actin-rich lamellipodial extensions to execute protrusion. Many cell types recently adhered on a two-dimensional substrate exhibit protrusion and retraction of their lamellipodia, even though the cell is not translating. Travelling waves of protrusion have also been observed, similar to those observed in crawling cells. These regular patterns of protrusion and retraction allow quantitative analysis for comparison to mathematical models. The periodic fluctuations in leading edge position of XTC cells have been linked to excitable actin dynamics using a one-dimensional model of actin dynamics, as a function of arc-length along the cell. In this work we extend this earlier model of actin dynamics into two dimensions (along the arc-length and radial directions of the cell) and include a model membrane that protrudes and retracts in response to the changing number of free barbed ends of actin filaments near the membrane. We show that if the polymerization rate at the barbed ends changes in response to changes in their local concentration at the leading edge and/or the opposing force from the cell membrane, the model can reproduce the patterns of membrane protrusion and retraction seen in experiment. We investigate both Brownian ratchet and switch-like force-velocity relationships between the membrane load forces and actin polymerization rate. The switch-like polymerization dynamics recover the observed patterns of protrusion and retraction as well as the fluctuations in F-actin concentration profiles. The model generates predictions for the behavior of cells after local membrane tension perturbations. © 2017 Wiley Periodicals, Inc.

  20. Finite element analysis of rapid canine retraction through reducing resistance and distraction

    Directory of Open Access Journals (Sweden)

    Junjie XUE

    2014-01-01

    Full Text Available Objective: The aims of this study were to compare different surgical approaches to rapid canine retraction by designing and selecting the most effective method of reducing resistance by a three-dimensional finite element analysis. Material and Methods: Three-dimensional finite element models of different approaches to rapid canine retraction by reducing resistance and distraction were established, including maxillary teeth, periodontal ligament, and alveolar. The models were designed to dissect the periodontal ligament, root, and alveolar separately. A 1.5 N force vector was loaded bilaterally to the center of the crown between first molar and canine, to retract the canine distally. The value of total deformation was used to assess the initial displacement of the canine and molar at the beginning of force loading. Stress intensity and force distribution were analyzed and evaluated by Ansys 13.0 through comparison of equivalent (von Mises stress and maximum shear stress. Results: The maximum value of total deformation with the three kinds of models occurred in the distal part of the canine crown and gradually reduced from the crown to the apex of the canine; compared with the canines in model 3 and model 1, the canine in model 2 had the maximum value of displacement, up to 1.9812 mm. The lowest equivalent (von Mises stress and the lowest maximum shear stress were concentrated mainly on the distal side of the canine root in model 2. The distribution of equivalent (von Mises stress and maximum shear stress on the PDL of the canine in the three models was highly concentrated on the distal edge of the canine cervix. . Conclusions: Removal of the bone in the pathway of canine retraction results in low stress intensity for canine movement. Periodontal distraction aided by surgical undermining of the interseptal bone would reduce resistance and effectively accelerate the speed of canine retraction.

  1. Modulating STDP Balance Impacts the Dendritic Mosaic

    Directory of Open Access Journals (Sweden)

    Nicolangelo Iannella

    2017-06-01

    Full Text Available The ability for cortical neurons to adapt their input/output characteristics and information processing capabilities ultimately relies on the interplay between synaptic plasticity, synapse location, and the nonlinear properties of the dendrite. Collectively, they shape both the strengths and spatial arrangements of convergent afferent inputs to neuronal dendrites. Recent experimental and theoretical studies support a clustered plasticity model, a view that synaptic plasticity promotes the formation of clusters or hotspots of synapses sharing similar properties. We have previously shown that spike timing-dependent plasticity (STDP can lead to synaptic efficacies being arranged into spatially segregated clusters. This effectively partitions the dendritic tree into a tessellated imprint which we have called a dendritic mosaic. Here, using a biophysically detailed neuron model of a reconstructed layer 2/3 pyramidal cell and STDP learning, we investigated the impact of altered STDP balance on forming such a spatial organization. We show that cluster formation and extend depend on several factors, including the balance between potentiation and depression, the afferents' mean firing rate and crucially on the dendritic morphology. We find that STDP balance has an important role to play for this emergent mode of spatial organization since any imbalances lead to severe degradation- and in some case even destruction- of the mosaic. Our model suggests that, over a broad range of of STDP parameters, synaptic plasticity shapes the spatial arrangement of synapses, favoring the formation of clustered efficacy engrams.

  2. Modulating STDP Balance Impacts the Dendritic Mosaic

    Science.gov (United States)

    Iannella, Nicolangelo; Launey, Thomas

    2017-01-01

    The ability for cortical neurons to adapt their input/output characteristics and information processing capabilities ultimately relies on the interplay between synaptic plasticity, synapse location, and the nonlinear properties of the dendrite. Collectively, they shape both the strengths and spatial arrangements of convergent afferent inputs to neuronal dendrites. Recent experimental and theoretical studies support a clustered plasticity model, a view that synaptic plasticity promotes the formation of clusters or hotspots of synapses sharing similar properties. We have previously shown that spike timing-dependent plasticity (STDP) can lead to synaptic efficacies being arranged into spatially segregated clusters. This effectively partitions the dendritic tree into a tessellated imprint which we have called a dendritic mosaic. Here, using a biophysically detailed neuron model of a reconstructed layer 2/3 pyramidal cell and STDP learning, we investigated the impact of altered STDP balance on forming such a spatial organization. We show that cluster formation and extend depend on several factors, including the balance between potentiation and depression, the afferents' mean firing rate and crucially on the dendritic morphology. We find that STDP balance has an important role to play for this emergent mode of spatial organization since any imbalances lead to severe degradation- and in some case even destruction- of the mosaic. Our model suggests that, over a broad range of of STDP parameters, synaptic plasticity shapes the spatial arrangement of synapses, favoring the formation of clustered efficacy engrams. PMID:28649195

  3. Nerve Conduction Through Dendrites via Proton Hopping.

    Science.gov (United States)

    Kier, Lemont B

    2017-01-01

    In our previous studies of nerve conduction conducted by proton hopping, we have considered the axon, soma, synapse and the nodes of Ranvier. The role of proton hopping described the passage of information through each of these units of a typical nerve system. The synapse projects information from the axon to the dendrite and their associated spines. We have invoked the passage of protons via a hopping mechanism to illustrate the continuum of the impulse through the system, via the soma following the dendrites. This is proposed to be a continuum invoked by the proton hopping method. With the proposal of the activity through the dendrites, via proton hopping, a complete model of the nerve function is invoked. At each step to the way, a water pathway is present and is invoked in the proposed model as the carrier of the message via proton hopping. The importance of the dendrites is evident by the presence of a vast number of spines, each possessing the possibility to carry unique messages through the nervous system. With this model of the role of dendrites, functioning with the presence of proton hopping, a complete model of the nerve system is presented. The validity of this model will be available for further studies and models to assess it's validity. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  4. Lack of Improvement in Scientific Integrity: An Analysis of WoS Retractions by Chinese Researchers (1997-2016).

    Science.gov (United States)

    Lei, Lei; Zhang, Ying

    2017-09-09

    This study investigated the status quo of article retractions by Chinese researchers. The bibliometric information of 834 retractions from the Web of Science SCI-expanded database were downloaded and analysed. The results showed that the number of retractions increased in the past two decades, and misconduct such as plagiarism, fraud, and faked peer review explained approximately three quarters of the retractions. Meanwhile, a large proportion of the retractions seemed typical of deliberate fraud, which might be evidenced by retractions authored by repeat offenders of data fraud and those due to faked peer review. In addition, a majority of Chinese fraudulent authors seemed to aim their articles which contained a possible misconduct at low-impact journals, regardless of the types of misconduct. The system of scientific evaluation, the "publish or perish" pressure Chinese researchers are facing, and the relatively low costs of scientific integrity may be responsible for the scientific integrity. We suggested more integrity education and severe sanctions for the policy-makers, as well as change in the peer review system and transparent retraction notices for journal administrators.

  5. A SOFTWARE FOR SIMULATING ELECTRICAL PROPERTIES OF PASSIVE DENDRITES

    Directory of Open Access Journals (Sweden)

    Yalçın İŞLER

    2006-01-01

    Full Text Available In this study, a software is introduced for simulating the electrical properties of passive dendrite based on the cable theory. Dendrites along which the synaptic information is conveyed are the largest component of a neuron in surface area. The Cable theory for dendritic neurons addresses to current-voltage relations in a continuous passive dendritic tree. It is briefly summarized that the cable theory related to passive cables and dendrites, which is a useful approximation and an important reference for excitable cases. The proposed software can be used to construct user-defined dendritic tree model. The user can define the model in detail, display the constructed dendritic tree, and examine the basic electrical properties of the dendritic tree.

  6. Neurotrophin-mediated dendrite-to-nucleus signaling revealed by microfluidic compartmentalization of dendrites.

    Science.gov (United States)

    Cohen, Michael S; Bas Orth, Carlos; Kim, Hyung Joon; Jeon, Noo Li; Jaffrey, Samie R

    2011-07-05

    Signaling from dendritic synapses to the nucleus regulates important aspects of neuronal function, including synaptic plasticity. The neurotrophin brain-derived neurotrophic factor (BDNF) can induce long-lasting strengthening of synapses in vivo and this effect is dependent on transcription. However, the mechanism of signaling to the nucleus is not well understood. Here we describe a microfluidic culture device to investigate dendrite-to-nucleus signaling. Using these microfluidic devices, we demonstrate that BDNF can act directly on dendrites to elicit an anterograde signal that induces transcription of the immediate early genes, Arc and c-Fos. Induction of Arc is dependent on dendrite- and cell body-derived calcium, whereas induction of c-Fos is calcium-independent. In contrast to retrograde neurotrophin-mediated axon-to-nucleus signaling, which is MEK5-dependent, BDNF-mediated anterograde dendrite-to-nucleus signaling is dependent on MEK1/2. Intriguingly, the activity of TrkB, the BDNF receptor, is required in the cell body for the induction of Arc and c-Fos mediated by dendritically applied BDNF. These results are consistent with the involvement of a signaling endosome-like pathway that conveys BDNF signals from the dendrite to the nucleus.

  7. Convection Effects in Three-dimensional Dendritic Growth

    Science.gov (United States)

    Lu, Yili; Beckermann, C.; Karma, A.

    2003-01-01

    A phase-field model is developed to simulate free dendritic growth coupled with fluid flow for a pure material in three dimensions. The preliminary results presented here illustrate the strong influence of convection on the three-dimensional (3D) dendrite growth morphology. The detailed knowledge of the flow and temperature fields in the melt around the dendrite from the simulations allows for a detailed understanding of the convection effects on dendritic growth.

  8. Single dendrite-targeting interneurons generate branch-specific inhibition.

    Directory of Open Access Journals (Sweden)

    Caleb eStokes

    2014-11-01

    Full Text Available Microcircuits composed of dendrite-targeting inhibitory interneurons and pyramidal cells are fundamental elements of cortical networks, however, the impact of individual interneurons on pyramidal dendrites is unclear. Here, we combine paired recordings and calcium imaging to determine the spatial domain over which single dendrite-targeting interneurons influence pyramidal cells in olfactory cortex. We show that a major action of individual interneurons is to inhibit dendrites in a branch-specific fashion.

  9. Energy transfer and thermal stability of Ce3+, Tb3+ co-doped Ca3Si2O4N2 phosphors for white light-emitting diodes

    Science.gov (United States)

    Wang, Baochen; Liu, Yan-gai; Huang, Zhaohui; Fang, Minghao

    2017-12-01

    A series of Ca3Si2O4N2:Ce3+, Tb3+ phosphors were synthesized and their phase composition and luminescence properties were investigated. Results showed that an efficient energy transfer occurred between the Ce3+ and Tb3+ ions. The thermal stability of the Ce3+ emission was dramatically enhanced upon Tb3+ doping. The mechanism was attributed to a shift of the configuration coordinate and an increased energy barrier for thermal quenching, which resulted from the enhanced rigid structure of the host. Finally, a white light emitting diode lamp was fabricated, which exhibited excellent properties. These results indicate that Ca3Si2O4N2:Ce3+, Tb3+ can serve as promising blue-green emitting phosphors for w-LEDs.

  10. K(Ca)3.1 channel downregulation and impaired endothelium-derived hyperpolarization-type relaxation in pulmonary arteries from chronically hypoxic rats

    DEFF Research Database (Denmark)

    Kroigaard, Christel; Kudryavtseva, Olga; Dalsgaard, Thomas

    2013-01-01

    hypoxia-induced pulmonary hypertension in rats. For functional studies, pulmonary arteries were mounted in microvascular myographs for isometric tension recordings. The K(Ca) channel expression was evaluated by immunoblotting and quantitative PCR. Although ACh induced similar relaxations, the ACh......-induced relaxations were abolished by the combined inhibition of nitric oxide synthase (by L-nitro-arginine, L-NOARG), cyclo-oxygenase (by indomethacin) and soluble guanylate cyclase (by ODQ) in pulmonary arteries from hypoxic rats, whereas 20 ± 6% (n = 8) maximal relaxation in response to ACh persisted in arteries......-dependent relaxations, which were markedly reduced in arteries from chronically hypoxic rats compared with arteries from normoxic rats. The mRNA levels of K(Ca)2.3 and K(Ca)3.1 were unaltered, whereas K(Ca)2.3 protein expression was upregulated and K(Ca)3.1 protein expression downregulated in pulmonary arteries from...

  11. Retraction: Genistein protects genioglossus myocyte against hypoxia-induced injury through PI3K-Akt and ERK MAPK pathways.

    Science.gov (United States)

    2012-05-01

    RETRACTION: The following article from Journal of Cellular Biochemistry, Genistein protects genioglossus myocyte against hypoxia-induced injury through PI3K-Akt and ERK MAPK pathways by Wanghui Ding and Yuehua Liu, posted online on May 19, 2011 in Wiley Online Library (onlinelibrary.wiley.com), has been retracted by agreement between the authors, the journal Editor in Chief, Dr. Gary S. Stein and Wiley-Liss, Inc. The retraction has been made as authorization to publish was not granted by one of the funding bodies. Copyright © 2012 Wiley Periodicals, Inc.

  12. [Effect of multiple-micronutrient supplementation on learning and memorizing ability of young rats and the ultra-structure in CA3 region of hippocampus of rat's brain].

    Science.gov (United States)

    Liang, Aihua; Chen, Yikun; Zhang, Wen; Hong, Junrong

    2009-01-01

    To study the effects of multiple-micronutrient on the learning and memory ability of young rats using shuttle-box, as well as to observe the ultra-structure and the synaptophysin (SYN) immunoreactive expression in the region of hippocampal CA3. Forty 5-week-old male Sprague-Dawley rats were randomized divided into control group and 3 test groups by body weight. Rats were injected intraperitoneally with multiple-micronutrient [0 g/(kg x d), 0.74 g/(kg x d), 1.48 g/(kg x d) and 2.22 g/(kg x d)] once per day for 30 days. Active avoidance behayior of learning and memory performance in different groups were measured by shuttle-box. The immune expression of Syn in the region of hippoeampal CA3 were tested with immunohistochemical method. Moreover, ultrastructural pathologic features of the CA3 region of hippocampus were investigated by transmission electron microscope. The shuttle-box test showed that the time of escape reaction of high-dose group (13.15 +/- 8.106, 9.50 +/- 5.063) was longer (P < 0.05) than that of control group. The results revealed a significant increase in the number of synapses, the thickness of postsynaptic density, synaptic curvature and the absorbency of positive product of Syn immunoreaction in the region of hippocampal CA3 in high-dose group compared with control group, which were significant difference (P < 0.05). Our study suggests that synaptic plasticity might be the probable mechanism on improving the learning and memory ability by multiple-micronutrient in young rats.

  13. A novel orange-red phosphor Ca3B2O6:Sm3+, A+(A = Li, Na, K) for white light emitting diodes

    Science.gov (United States)

    Liu, Qingbo; Liu, Yufeng; Yang, Fu; Han, Bing; Feng, Hao; Yu, Quanmao

    2014-03-01

    A novel orange-red phosphor Ca3B2O6:Sm3+, A+(A = Li, Na, K) has been synthesized by solid-state reaction at 950°C. The phase purity and photoluminescence (PL) behavior of the phosphor are studied in detail using the powder X-ray diffraction (XRD) technique and PL measurements. Ca3B2O6:Sm3+ phosphor can be efficiently excited by near ultraviolet (n-UV) and blue light, and the emission spectrum consists of four emission peaks at 563, 599, 646 and 709 nm, generating bright orange-red light. When a cation A+ is introduced into Ca3B2O6:Sm3+ as charge compensator, the emission intensity of Ca3B2O6:Sm3+ is evidently enhanced, but the PL spectral profile is unchanged. The integral intensity of the emission spectrum of Ca2.96Sm0.02Na0.02B2O6 excited at 401 nm is about 1.2 times than that of Y2O2S:Eu3+ commercial red phosphor. The CIE chromaticity coordinates of Ca2.96Sm0.02Na0.02B2O6 phosphor were (0.608, 0.365), which are close to that of the commercial red phosphors Y2O3:Eu3+ (0.655, 0.345), Y2O2S:Eu3+ (0.622, 0.351) and Sr2Si5N8:Eu2+ (0.620, 0.370).

  14. Sequence learning in differentially activated dendrites

    DEFF Research Database (Denmark)

    Nielsen, Bjørn Gilbert

    2003-01-01

    Differentially activated areas of a dendrite permit the existence of zones with distinct rates of synaptic modification, and such areas can be individually accessed using a reference signal which localizes synaptic plasticity and memory trace retrieval to certain subregions of the dendrite...... to participate in multiple sequences, which can be learned without suffering from the 'wash-out' of synaptic efficacy associated with superimposition of training patterns. This is a biologically plausible solution to the stability-plasticity dilemma of learning in neural networks....

  15. The GLP-1 Receptor Agonist Exendin-4 and Diazepam Differentially Regulate GABAA Receptor-Mediated Tonic Currents in Rat Hippocampal CA3 Pyramidal Neurons.

    Directory of Open Access Journals (Sweden)

    Sergiy V Korol

    Full Text Available Glucagon-like peptide-1 (GLP-1 is a metabolic hormone that is secreted in a glucose-dependent manner and enhances insulin secretion. GLP-1 receptors are also found in the brain where their signalling affects neuronal activity. We have previously shown that the GLP-1 receptor agonists, GLP-1 and exendin-4 enhanced GABA-activated synaptic and tonic currents in rat hippocampal CA3 pyramidal neurons. The hippocampus is the centre for memory and learning and is important for cognition. Here we examined if exendin-4 similarly enhanced the GABA-activated currents in the presence of the benzodiazepine diazepam. In whole-cell recordings in rat brain slices, diazepam (1 μM, an allosteric positive modulator of GABAA receptors, alone enhanced the spontaneous inhibitory postsynaptic current (sIPSC amplitude and frequency by a factor of 1.3 and 1.6, respectively, and doubled the tonic GABAA current normally recorded in the CA3 pyramidal cells. Importantly, in the presence of exendin-4 (10 nM plus diazepam (1 μM, only the tonic but not the sIPSC currents transiently increased as compared to currents recorded in the presence of diazepam alone. The results suggest that exendin-4 potentiates a subpopulation of extrasynaptic GABAA receptors in the CA3 pyramidal neurons.

  16. Revising the Subsystem Nurse’s A-Phase-Silicocarnotite within the System Ca3(PO4)2–Ca2SiO4

    Science.gov (United States)

    Ros-Tárraga, Patricia; Mazón, Patricia; Meseguer-Olmo, Luis; De Aza, Piedad N.

    2016-01-01

    The subsystem Nurse’s A-phase-silicocarnotite within the system Ca3(PO4)2–Ca2SiO4 was conducted as a preliminary step toward obtaining new biomaterials with controlled microstructures. Phase composition of the resulting ceramics was studied by X-ray diffraction, differential thermal analysis, and scanning electron microscopy with attached wavelength dispersive spectroscopy. The results showed that the sub-system presents an invariant eutectoid point at 1366 ± 4 °C with a composition of 59.5 wt % Ca3(PO4)2 and 40.5 wt % Ca2SiO4, and typical eutectoid microstructure of lamellae morphology. These results are in disagreement with the previous reported data, which locate the invariant eutectoid point at 1250 ± 20 °C with a composition of 55 wt % Ca3(PO4)2 and 45 wt % Ca2SiO4. In addition, cell attachment testing showed that the new eutectoid material supported the mesenchymal stem cell adhesion and spreading, and the cells established close contact with the ceramic after 28 days of culture. These findings indicate that the new ceramic material with eutectoid microstructure of lamellae morphology possesses good bioactivity and biocompatibility and might be a promising bone implant material. PMID:28773447

  17. Imaging a memory trace over half a life-time in the medial temporal lobe reveals a time-limited role of CA3 neurons in retrieval

    Science.gov (United States)

    Lux, Vanessa; Atucha, Erika; Kitsukawa, Takashi; Sauvage, Magdalena M

    2016-01-01

    Whether retrieval still depends on the hippocampus as memories age or relies then on cortical areas remains a major controversy. Despite evidence for a functional segregation between CA1, CA3 and parahippocampal areas, their specific role within this frame is unclear. Especially, the contribution of CA3 is questionable as very remote memories might be too degraded to be used for pattern completion. To identify the specific role of these areas, we imaged brain activity in mice during retrieval of recent, early remote and very remote fear memories by detecting the immediate-early gene Arc. Investigating correlates of the memory trace over an extended period allowed us to report that, in contrast to CA1, CA3 is no longer recruited in very remote retrieval. Conversely, we showed that parahippocampal areas are then maximally engaged. These results suggest a shift from a greater contribution of the trisynaptic loop to the temporoammonic pathway for retrieval. DOI: http://dx.doi.org/10.7554/eLife.11862.001 PMID:26880561

  18. The GLP-1 Receptor Agonist Exendin-4 and Diazepam Differentially Regulate GABAA Receptor-Mediated Tonic Currents in Rat Hippocampal CA3 Pyramidal Neurons

    Science.gov (United States)

    Korol, Sergiy V.; Jin, Zhe; Birnir, Bryndis

    2015-01-01

    Glucagon-like peptide-1 (GLP-1) is a metabolic hormone that is secreted in a glucose-dependent manner and enhances insulin secretion. GLP-1 receptors are also found in the brain where their signalling affects neuronal activity. We have previously shown that the GLP-1 receptor agonists, GLP-1 and exendin-4 enhanced GABA-activated synaptic and tonic currents in rat hippocampal CA3 pyramidal neurons. The hippocampus is the centre for memory and learning and is important for cognition. Here we examined if exendin-4 similarly enhanced the GABA-activated currents in the presence of the benzodiazepine diazepam. In whole-cell recordings in rat brain slices, diazepam (1 μM), an allosteric positive modulator of GABAA receptors, alone enhanced the spontaneous inhibitory postsynaptic current (sIPSC) amplitude and frequency by a factor of 1.3 and 1.6, respectively, and doubled the tonic GABAA current normally recorded in the CA3 pyramidal cells. Importantly, in the presence of exendin-4 (10 nM) plus diazepam (1 μM), only the tonic but not the sIPSC currents transiently increased as compared to currents recorded in the presence of diazepam alone. The results suggest that exendin-4 potentiates a subpopulation of extrasynaptic GABAA receptors in the CA3 pyramidal neurons. PMID:25927918

  19. Revising the Subsystem Nurse’s A-Phase-Silicocarnotite within the System Ca3(PO42–Ca2SiO4

    Directory of Open Access Journals (Sweden)

    Patricia Ros-Tárraga

    2016-04-01

    Full Text Available The subsystem Nurse’s A-phase-silicocarnotite within the system Ca3(PO42–Ca2SiO4 was conducted as a preliminary step toward obtaining new biomaterials with controlled microstructures. Phase composition of the resulting ceramics was studied by X-ray diffraction, differential thermal analysis, and scanning electron microscopy with attached wavelength dispersive spectroscopy. The results showed that the sub-system presents an invariant eutectoid point at 1366 ± 4 °C with a composition of 59.5 wt % Ca3(PO42 and 40.5 wt % Ca2SiO4, and typical eutectoid microstructure of lamellae morphology. These results are in disagreement with the previous reported data, which locate the invariant eutectoid point at 1250 ± 20 °C with a composition of 55 wt % Ca3(PO42 and 45 wt % Ca2SiO4. In addition, cell attachment testing showed that the new eutectoid material supported the mesenchymal stem cell adhesion and spreading, and the cells established close contact with the ceramic after 28 days of culture. These findings indicate that the new ceramic material with eutectoid microstructure of lamellae morphology possesses good bioactivity and biocompatibility and might be a promising bone implant material.

  20. The impact of local structure variation on thermal quenching of luminescence in Ca3MoxW1-xO6:Eu3+ solid solution phosphors

    Science.gov (United States)

    Wang, Chunhao; Ye, Shi; Li, Ye; Zhang, Qinyuan

    2017-03-01

    Near-ultraviolet (NUV, 365-410 nm) excitable white light emitting diodes require intense absorption in the NUV region for the tri-color phosphors (red, green, and blue). Optional red phosphor Ca3MoO6:Eu3+ meets the requirement of NUV absorption but suffers from severe quenching, while Ca3WO6:Eu3+ has good resistance to thermal quenching but could not absorb NUV light efficiently. It is requisite to investigate the candidate Ca3MoxW1-xO6:Eu3+ to balance the both effects. Results indicate that thermal quenching turns to be worse with an increase in Mo contents in the solid solutions with inevitable distortions or defects, especially when exciting the charge transfer band of WO6 and MoO6 groups. Temperature-dependent Raman spectroscopy is utilized to reveal the impact of structural variation in the quenching process since the variations influence the energy transfer between WO6/MoO6 groups and Eu3+ ions or among Eu3+ ions. Results show that the tilting or distortion of the Ca/W/MoO6 octahedral framework and weakened Eu3+-O bonds have large impacts on thermal quenching performance of Eu3+ luminescence in the solid solutions. The research would benefit the design of novel red phosphors.

  1. Retraction - Request that it is necessary to retract paper: Thermal and electrical energy yield analysis of a directly water cooled photovoltaic module DOI:10.2298/TSCI130118144M

    National Research Council Canada - National Science Library

    Editorial

    2016-01-01

    Prof. Dr. Simeon Oka, Editor-in-chief of the journal THERMAL SCIENCE request that it is necessary to retract paper Thermal and electrical energy yield analysis of a directly water cooled photovoltaic module DOI...

  2. Assessment of changes following en-masse retraction with mini-implants anchorage compared to two-step retraction with conventional anchorage in patients with class II division 1 malocclusion: a randomized controlled trial.

    Science.gov (United States)

    Al-Sibaie, Salma; Hajeer, Mohammad Y

    2014-06-01

    No randomized controlled trial has tried to compare treatment outcomes between the sliding en-masse retraction of upper anterior teeth supported by mini-implants and the two-step sliding retraction technique employing conventional anchorage devices. To evaluate skeletal, dental, and soft tissue changes following anterior teeth retraction. Parallel-groups randomized controlled trial on patients with class II division 1 malocclusion treated at the University of Al-Baath Dental School in Hamah, Syria between July 2011 and May 2013. One hundred and thirty-three patients with an upper dentoalveolar protrusion were evaluated and 80 patients fulfilled the inclusion criteria. Randomization was performed using computer-generated tables; allocation was concealed using sequentially numbered opaque and sealed envelopes. Fifty-six participants were analysed (mean age 22.34 ± 4.56 years). They were randomly distributed into two groups with 28 patients in each group (1:1 allocation ratio). Following first premolar extraction, space closure was accomplished using either the en-masse technique with mini-implants or the two-step technique with transpalatal arches (TPAs). The antero-posterior displacements of upper incisal edges and upper first molars were measured on lateral cephalograms at three assessment times. Assessor blinding was employed. A bodily retraction (-4.42 mm; P upper anterior teeth was achieved in the mini-implants group, whereas upper anterior teeth retraction was achieved by controlled palatal tipping in the TPA group. When retracting anterior teeth in patients with moderate to severe protrusion, the en-masse retraction based on mini-implants anchorage gave superior results compared to the two-step retraction based on conventional anchorage in terms of speed, dental changes, anchorage loss, and aesthetic outcomes.

  3. Adult Drosophila sensory neurons specify dendritic territories independently of dendritic contacts through the Wnt5-Drl signaling pathway.

    Science.gov (United States)

    Yasunaga, Kei-ichiro; Tezuka, Akane; Ishikawa, Natsuko; Dairyo, Yusuke; Togashi, Kazuya; Koizumi, Hiroyuki; Emoto, Kazuo

    2015-08-15

    Sensory neurons with common functions are often nonrandomly arranged and form dendritic territories in stereotypic spatial patterns throughout the nervous system, yet molecular mechanisms of how neurons specify dendritic territories remain largely unknown. In Drosophila larvae, dendrites of class IV sensory (C4da) neurons completely but nonredundantly cover the whole epidermis, and the boundaries of these tiled dendritic fields are specified through repulsive interactions between homotypic dendrites. Here we report that, unlike the larval C4da neurons, adult C4da neurons rely on both dendritic repulsive interactions and external positional cues to delimit the boundaries of their dendritic fields. We identify Wnt5 derived from sternites, the ventral-most part of the adult abdominal epidermis, as the critical determinant for the ventral boundaries. Further genetic data indicate that Wnt5 promotes dendrite termination on the periphery of sternites through the Ryk receptor family kinase Derailed (Drl) and the Rho GTPase guanine nucleotide exchange factor Trio in C4da neurons. Our findings thus uncover the dendritic contact-independent mechanism that is required for dendritic boundary specification and suggest that combinatory actions of the dendritic contact-dependent and -independent mechanisms may ensure appropriate dendritic territories of a given neuron. © 2015 Yasunaga et al.; Published by Cold Spring Harbor Laboratory Press.

  4. Erratum: Retraction Note: Six-body bound system calculations in the case of effective α-core structure

    Science.gov (United States)

    The Publishers

    2017-10-01

    The paper has been retracted by the Editorial Board after an investigation on the possibility that part of the published results were obtained in collaboration with scientists not included in the author list.

  5. Retraction: Graphene-SnO2 nanocomposites decorated with quantum tunneling junctions: preparation strategies, microstructures and formation mechanism.

    Science.gov (United States)

    Simpson, Anna

    2017-09-20

    Retraction of 'Graphene-SnO2 nanocomposites decorated with quantum tunneling junctions: preparation strategies, microstructures and formation mechanism' by Qingxiu Wang et al., Phys. Chem. Chem. Phys., 2014, 16, 19351-19357.

  6. Open Access Works are as Reliable as Other Publishing Models at Retracting Flawed Articles from the Biomedical Literature

    Directory of Open Access Journals (Sweden)

    Elizabeth Margaret Stovold

    2014-09-01

    Full Text Available A Review of: Peterson, G.M. (2013. Characteristics of retracted open access biomedical literature: a bibliographic analysis. Journal of the American Society for Information Science and Technology. 64(12, 2428-2436. doi: 10.1002/asi.22944 Objective – To investigate whether the rate of retracted articles and citation rates post-retraction in the biomedical literature are comparable across open access, free-to-access, or pay-to-access journals. Design – Citation analysis. Setting – Biomedical literature. Subjects – 160 retracted papers published between 1st January 2001 and 31st December 2010. Methods – For the retracted papers, 100 records were retrieved from the PubMed database and 100 records from the PubMed Central (PMC open access subset. Records were selected at random, based on the PubMed identifier. Each article was assigned a number based on its accessibility using the specific criteria. Articles published in the PMC open access subset were assigned a 2; articles retrieved from PubMed that were freely accessible, but did not meet the criteria for open access were assigned a 1; and articles retrieved through PubMed which were pay-to-access were assigned a 0. This allowed articles to be grouped and compared by accessibility. Citation information was collected primarily from the Science Citation Index. Articles for which no citation information was available, and those with a lifetime citation of 0 (or 1 where the citation came from the retraction statement were excluded, leaving 160 articles for analysis. Information on the impact factor of the journals was retrieved and the analysis was performed twice; first with the entire set, and second after excluding articles published in journals with an impact factor of 10 or above (14% of the total. The average number of citations per month was used to compare citation rates, and the percentage change in citation rate pre- and post-retraction was calculated. Information was also collected

  7. Cd1d is expressed on dermal dendritic cells and monocyte-derived dendritic cells.

    Science.gov (United States)

    Gerlini, G; Hefti, H P; Kleinhans, M; Nickoloff, B J; Burg, G; Nestle, F O

    2001-09-01

    CD1 proteins are a family of cell surface molecules that present lipid antigens to T cells. We investigated skin dendritic cells and monocyte-derived dendritic cells for expression of CD1 molecules using a panel of 10 different monoclonal antibodies focusing on the recently described CD1d molecule. By immunohistochemical analysis, CD1d expression in normal human skin was restricted to dendritic appearing cells in the papillary dermis mainly located in a perivascular localization. Langerhans cells did not show detectable CD1d expression in situ. Epidermal/dermal cell suspensions analyzed by flow cytometry demonstrated distinct subpopulations of HLA-DR positive dermal dendritic cells expressing CD1a, CD1b, and CD1c. CD1d was expressed on HLA-DRbright dermal antigen-presenting cells in dermal suspensions (16% +/- 3.6%), as well as on highly enriched dermal dendritic cells migrating out of skin explants (60.5% +/- 8.0%). Migrated mature dermal dendritic cells coexpressed CD83 and CD1d. Western blot analysis on microdissected skin sections revealed the presence of a 50-55 kDa CD1d molecule in dermis, suggesting that CD1d is highly glycosylated in skin. Both immature and mature monocyte-derived dendritic cells cultured in autologous plasma expressed CD1d molecules. In contrast, culture in fetal bovine serum downregulated CD1d expression. In conclusion, antigen-presenting cells in skin express different sets of CD1 molecules including CD1d and might play a role in lipid antigen presentation in various skin diseases. Differential expression of CD1 molecules depending on culture conditions might have an impact on clinical applications of dendritic cells for immunotherapy.

  8. Dendritic outgrowth of myenteric plexus neurons in primary culture.

    Science.gov (United States)

    Mulholland, M W; Romanchuk, G; Flowe, K

    1992-04-01

    Myenteric plexus neurons derived from neonatal guinea pigs, when exposed to serum, demonstrated a characteristic pattern of growth, including a proliferating outgrowth zone of glial cells, peripheral extension of dendritic processes, and progressive dendritic growth. Serum effects upon dendritic growth, measured morphometrically, was strongly dose- and temporally dependent. Dendritic density was increased 10-fold (120 hr) by the addition of 6% serum, while mean dendritic length was increased 3-fold. Development of cholinergic function was reflected by release of [3H]ACh in response to cholecystokinin octapeptide, vasoactive intestinal peptide, substance P, and calcitonin gene-related peptide (10(-10) and 10(-8) M).

  9. Dendritic cells in peripheral tolerance and immunity

    DEFF Research Database (Denmark)

    Gad, Monika; Claesson, Mogens Helweg; Pedersen, Anders Elm

    2003-01-01

    Dendritic cells capable of influencing immunity exist as functionally distinct subsets, T cell-tolerizing and T cell-immunizing subsets. The present paper reviews how these subsets of DCs develop, differentiate and function in vivo and in vitro at the cellular and molecular level. In particular......, the role of DCs in the generation of regulatory T cells is highlighted....

  10. Dendritic Solidification in a Copper Nickel Alloy

    OpenAIRE

    DÜNDAR, Sacit

    2014-01-01

    The distribution of nickel in dendrite arms and in interdendritic regions of copper-10% nickel alloy solidified under production conditions designed to provide 4 different cooling rates was investigated. The results indicate that at different rates of solidification undercooling, diffusion and convection mechanisms affect the microsegregation of nickel and copper in the cast materials to various extents.

  11. Amyloid plaque formation precedes dendritic spine loss.

    Science.gov (United States)

    Bittner, Tobias; Burgold, Steffen; Dorostkar, Mario M; Fuhrmann, Martin; Wegenast-Braun, Bettina M; Schmidt, Boris; Kretzschmar, Hans; Herms, Jochen

    2012-12-01

    Amyloid-beta plaque deposition represents a major neuropathological hallmark of Alzheimer's disease. While numerous studies have described dendritic spine loss in proximity to plaques, much less is known about the kinetics of these processes. In particular, the question as to whether synapse loss precedes or follows plaque formation remains unanswered. To address this question, and to learn more about the underlying kinetics, we simultaneously imaged amyloid plaque deposition and dendritic spine loss by applying two-photon in vivo microscopy through a cranial window in double transgenic APPPS1 mice. As a result, we first observed that the rate of dendritic spine loss in proximity to plaques is the same in both young and aged animals. However, plaque size only increased significantly in the young cohort, indicating that spine loss persists even many months after initial plaque appearance. Tracking the fate of individual spines revealed that net spine loss is caused by increased spine elimination, with the rate of spine formation remaining constant. Imaging of dendritic spines before and during plaque formation demonstrated that spine loss around plaques commences at least 4 weeks after initial plaque formation. In conclusion, spine loss occurs, shortly but with a significant time delay, after the birth of new plaques, and persists in the vicinity of amyloid plaques over many months. These findings hence give further hope to the possibility that there is a therapeutic window between initial amyloid plaque deposition and the onset of structural damage at spines.

  12. Nanodiamonds suppress the growth of lithium dendrites.

    Science.gov (United States)

    Cheng, Xin-Bing; Zhao, Meng-Qiang; Chen, Chi; Pentecost, Amanda; Maleski, Kathleen; Mathis, Tyler; Zhang, Xue-Qiang; Zhang, Qiang; Jiang, Jianjun; Gogotsi, Yury

    2017-08-25

    Lithium metal has been regarded as the future anode material for high-energy-density rechargeable batteries due to its favorable combination of negative electrochemical potential and high theoretical capacity. However, uncontrolled lithium deposition during lithium plating/stripping results in low Coulombic efficiency and severe safety hazards. Herein, we report that nanodiamonds work as an electrolyte additive to co-deposit with lithium ions and produce dendrite-free lithium deposits. First-principles calculations indicate that lithium prefers to adsorb onto nanodiamond surfaces with a low diffusion energy barrier, leading to uniformly deposited lithium arrays. The uniform lithium deposition morphology renders enhanced electrochemical cycling performance. The nanodiamond-modified electrolyte can lead to a stable cycling of lithium | lithium symmetrical cells up to 150 and 200 h at 2.0 and 1.0 mA cm-2, respectively. The nanodiamond co-deposition can significantly alter the lithium plating behavior, affording a promising route to suppress lithium dendrite growth in lithium metal-based batteries.Lithium metal is an ideal anode material for rechargeable batteries but suffer from the growth of lithium dendrites and low Coulombic efficiency. Here the authors show that nanodiamonds serve as an electrolyte additive to co-deposit with lithium metal and suppress the formation of dendrites.

  13. Simultaneous torquing, aligning and retraction spring: A three-dimensional approach for blocked out canines

    Directory of Open Access Journals (Sweden)

    Abhay Kumar Jain

    2016-01-01

    Full Text Available Orthodontic management of a buccally blocked-out canine requires a substantial amount of bodily movement, which is difficult to perform because of its long and bulbous root. Even when orthodontic forces are applied in a desired direction, large hyalinized areas are created which impede the root movement. Palatal root torque is needed for the canine to increase the buccal bone thickness, decrease the risk of bone dehiscence and gingival recession. Closing loops generate a distal force along with an extrusive component which retracts the canine into the extraction space but lacks control on the torque of the canine. To overcome this limitation, this simultaneous torquing, aligning, and retraction spring was designed. It can be easily fabricated, activated at chairside for either simultaneous or sequential controlled three-dimensional tooth movements.

  14. Training in Brain Retraction Using a Self-Made Three-Dimensional Model.

    Science.gov (United States)

    Mashiko, Toshihiro; Konno, Takehiko; Kaneko, Naoki; Watanabe, Eiju

    2015-08-01

    A hollow brain model was created using soft urethane. A tube passing through the hollow was attached for use as a water inlet and manometer. Water sufficient in quantity to realize the intended initial pressure was infused through the tube. The brain model was retracted with a brain spatula and the surgical corridor was opened. By measuring local force with a sensor set on the brain spatula, the model could be used for training in brain retraction. At the same time, the water column of the manometer was measured and the relationship with the force of the brain spatula was investigated. A positive correlation between the water column and local force was confirmed. This indicated that it was possible to use this model without a force sensor for the same training using water column measurements. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. RETRACTED: Synthesis of silver nanoparticles using A. indicum leaf extract and their antibacterial activity

    Science.gov (United States)

    Ashokkumar, S.; Ravi, S.; Kathiravan, V.; Velmurugan, S.

    2015-01-01

    This article has been retracted: please see Elsevier Policy on Article Withdrawal. This article has been retracted at the request of the Editor. The article contains an image (Fig. 7D) which originates from an image previously published in the article "Rapid biological synthesis of silver nanoparticles using Leucas martinicensis leaf extract for catalytic and antibacterial activity" by S. Ashokkumar et al. in Environ Sci Pollut Res (2014) 21:11439-11446, DOI 10.1007/s11356-014-3012-7 (Fig. 7D), despite being attributed to different samples. Furthermore, Figures 8A and 8B show identical images despite the claim of different samples. Finally, Figure 3 displays duplicated data despite being described as different samples. The scientific community takes a very strong view on this scientific misbehavior and apologies are offered to readers of the journal that this was not detected during the submission process.

  16. RETRACTED: The Application of Symmetric Key Cryptographic Algorithms in Wireless Sensor Networks

    Science.gov (United States)

    Si, Lingling; Ji, Zhigang; Wang, Zhihui

    This article has been retracted: please see Elsevier Policy on Article Withdrawal. This article has been retracted at the request of the Publisher. The authors have plagiarized a paper that had already appeared in "Queen's 25th Biennial Symposium on Communications", page 168-172, print ISBN 978-1-4244-5709-0, http://dx.doi.org/10.1109/BSC.2010.5472979. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

  17. Retraction statement: In Bangladesh, overweight individuals have fewer symptoms of depression than nonoverweight individuals.

    Science.gov (United States)

    2015-12-01

    The above article, published online on 1 October 2009 in Wiley Online Library (wileyonlinelibrary.com), and in volume 18, pp. 1143-1145, has been retracted by agreement between the authors, the journal Editors-in-Chief, Eric Ravussin and Donna Ryan, the Obesity Society and Wiley Periodicals, Inc. Although there is no implication that the data collection was carried out unethically, the retraction has been agreed to because the subsequent data analysis was conducted without the required approval of the university ethics board while the published paper incorrectly stated that Norwegian ethical approval had been obtained. Asghar, S., Magnusson, A., Khan, A., Ali, K. and Hussain, A. In Bangladesh, overweight individuals have fewer symptoms of depression than nonoverweight individuals. Obesity 2010;18:1143-1145. doi: 10.1038/oby.2009.332. © 2015 The Obesity Society.

  18. Retracted: Postoperative pain after irrigation with Vibringe versus a conventional needle: a randomized controlled trial.

    Science.gov (United States)

    Bilgili, D; Yilmaz, S; Dumani, A; Yoldas, O

    2016-08-01

    The following article from International Endodontic Journal, 'Postoperative pain after irrigation with Vibringe versus a conventional needle: a randomized controlled trial' by D. Bilgili, S. Yilmaz, A. Dumani & O. Yoldas, published online on 29 February 2016 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the Journal Editor in Chief, Prof. Paul Dummer, and John Wiley & Sons Ltd. The retraction has been agreed because the corresponding author did not contact the first author who carried out the work before alterations to the article were made prior to submission. This damages the integrity of the work and there are additional concerns over the number of patients and the accuracy of the results and conclusions. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  19. Retracted: Worst Pattern Of Invasion and occult cervical metastases for oral squamous carcinoma.

    Science.gov (United States)

    Velosa, Claudia; Shi, Qiuying; Stevens, Todd M; Chiosea, Simion I; Purgina, Bibiana; Carroll, William; Rosenthal, Eben; Morlandt, Anthony; Loree, Thom; Brandwein-Weber, Margaret S

    2017-03-28

    The above article, published online in Wiley Online Library as the Version of Record on March 28, 2017 (doi 10.1002/hed.24754), has been retracted by agreement between the Editor-in-Chief, Ehab Y. Hanna, and Wiley Periodicals, Inc. The retraction has been agreed owing to a dispute as to authorship and inclusion of some data in the analysis. Velosa, C., Shi, Q., Stevens, T. M., Chiosea, S. I., Purgina, B., Carroll, W., Rosenthal, E., Morlandt, A., Loree, T. and Brandwein-Weber, M. S. (2017), Worst pattern of invasion and occult cervical metastases for oral squamous carcinoma. Head Neck. doi:10.1002/hed.24754. © 2017 Wiley Periodicals, Inc.

  20. An unusual case of spontaneous Mycobacterium chelonae corneal ulcer in a healthy middle-aged adult [Retraction

    Directory of Open Access Journals (Sweden)

    Bhandari V

    2017-07-01

    Full Text Available Bhandari V, Sriganesh R, Relekar K. An unusual case of spontanous Mycobacterium chelonae corneal ulcer in a healthy middle-aged adult. Int Med Case Rep J. 2016;9:121–124. The Editor-in-Chief and Publisher have retracted this paper because of duplicate publication in Case Reports in Ophthalmological Medicine on June 20, 2015. The retraction relates to this paper

  1. Kinematic analysis of the lower cervical spine in the protracted and retracted neck flexion positions.

    Science.gov (United States)

    Park, So Hyun

    2015-01-01

    [Purpose] The aim of this study was to analyze lower cervical spine kinematics in protracted and retracted neck flexion positions in healthy people. [Subjects and Methods] The craniovertebral angle (CVA) and intervertebral body angles of the lower cervical spine of 10 healthy individuals were analyzed using fluoroscopy in a neutral sitting with the head in the neutral (N), protracted (Pro), and retracted (Ret) positions and with the neck in full flexion with the head in the neutral (N-fx), protracted (Pro-fx), and retracted (Ret-fx) positions. [Results] There were significant differences in the CVA and intervertebral body angle at the C3-4 level, and the Ret position showed the highest values followed by the N and Pro positions. Regarding the intervertebral body angle at the C4-5 level, the Pro position showed a higher value than the N and Ret positions. At the C6-7 level, the Pro position showed the lowest value compared with the N and Ret positions. In the CVA, the Ret-fx position showed a higher value than the N-fx and Ret-fx positions. [Conclusion] The results suggest that in the neutral sitting position, protraction is an ineffective posture due to overstress of the C6-7 segment, which is placed in a hyperflexed position at this level. Instead, retraction is the recommend posture for the patient with C6-7 degeneration, which makes for a more flexed position in the upper cervical spine and a less flexed position in the lower cervical spine.

  2. Dendritic mitochondria reach stable positions during circuit development.

    Science.gov (United States)

    Faits, Michelle C; Zhang, Chunmeng; Soto, Florentina; Kerschensteiner, Daniel

    2016-01-07

    Mitochondria move throughout neuronal dendrites and localize to sites of energy demand. The prevailing view of dendritic mitochondria as highly motile organelles whose distribution is continually adjusted by neuronal activity via Ca(2+)-dependent arrests is based on observations in cultured neurons exposed to artificial stimuli. Here, we analyze the movements of mitochondria in ganglion cell dendrites in the intact retina. We find that whereas during development 30% of mitochondria are motile at any time, as dendrites mature, mitochondria all but stop moving and localize stably to synapses and branch points. Neither spontaneous nor sensory-evoked activity and Ca(2+) transients alter motility of dendritic mitochondria; and pathological hyperactivity in a mouse model of retinal degeneration elevates rather than reduces motility. Thus, our findings indicate that dendritic mitochondria reach stable positions during a critical developmental period of high motility, and challenge current views about the role of activity in regulating mitochondrial transport in dendrites.

  3. Filamin-A regulates neutrophil uropod retraction through RhoA during chemotaxis.

    Directory of Open Access Journals (Sweden)

    Chunxiang Sun

    Full Text Available Filamin-A (FLNa has been shown to be a key cross-linker of actin filaments in the leading edge of a motile melanoma cell line, however its role in neutrophils undergoing chemotaxis is unknown. Using a murine transgenic model in which FLNa is selectively deleted in granulocytes, we report that, while neutrophils lacking FLNa show normal polarization and pseudopod extension, they exhibit obvious defects in uropod retraction. This uropod retraction defect was found to be a direct result of reduced FLNa mediated activation of the small GTPase RhoA and myosin mediated actin contraction in the FLNa null cells. This results in a neutrophil recruitment defect in FLNa null mice. The compensatory increase in FLNb levels that was observed in the FLNa null neutrophils may be sufficient to compensate for the lack of FLNa at the leading edge allowing for normal polarization, however this compensation is unable to regulate RhoA activated tail retraction at the rear of the cell.

  4. On the evolution of a retracting straight liquid sheet edge: experimental study

    Science.gov (United States)

    Krechetnikov, Rouslan; Mayer, Hans C.

    2011-11-01

    The evolution of the initially straight edge of a retracting liquid sheet is still a subject of debate. Theoretical and numerical studies have provided conflicting results, and experimental efforts have, to our knowledge, never been attempted owing to the difficulty in achieving a uniform edge. However, recent advances in experimental techniques, specifically those presented in detail in Poster #72 of APS-DFD 2010 (H.C. Mayer and R. Krechetnikov), have allowed us to uniformly detach a soap film from a straight edge using an impulsively heated wire frame. The detachment, retraction, and breakup of soap films (h ~ 10 μm) is analyzed using high speed photography. Owing to the Plateau border that connects the uniform film to the wire frames (wire diameter 25-250 μm) - a feature not present when rupturing films from a point - the early stages of retraction are dominated by a relatively large rim mass. We explore the phenomena at very early times (t films which may add complexity to the problem of determining what instability mechanism(s) are responsible for their breakup.

  5. Audiologic and otologic phenotype in children with Duane's Retraction Syndrome: A rare ophthalmologic disorder.

    Science.gov (United States)

    Weir, Forest W; Kreicher, Kathryn L; Hatch, Jonathan L; Nguyen, Shaun A; Meyer, Ted A

    2016-10-01

    The focus of this study was to evaluate the prevalence, type, and severity of hearing impairment in patients with Duane's Retraction Syndrome and to relate these measures to patient demographics and other otologic and audiologic factors. Retrospective AudGen Database analysis Tertiary academic referral center Pediatric patients in AudGenDB with a diagnosis of Duane's Retraction Syndrome (DRS). Appropriate audiologic, otologic, and demographic data were recorded. Seventy-nine patients (n = 79) met inclusion criteria. The first encounter with available audiometric data or the first encounter with hearing loss were documented. Audiograms were stratified by type and severity of hearing loss, and common associated medical issues were documented. 57 children had normal hearing; 22 had hearing loss. 9 ears had pure conductive hearing loss, 1 had pure sensorineural, 14 ears had components of both, and 79 had hearing loss that could not be specified. Multivariate regression revealed episodes of chronic otitis and craniofacial anomalies are associated with worse hearing loss. This study presents a detailed characterization of hearing loss in patients with Duane's retraction syndrome. Conductive and sensorineural hearing loss are both prevalent among these children. Careful and early audiologic evaluation of all patients with DRS is important. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. The Phosphatase Inhibitor Calyculin-A Impairs Clot Retraction, Platelet Activation, and Thrombin Generation

    Directory of Open Access Journals (Sweden)

    Renáta Hudák

    2017-01-01

    Full Text Available The aim of this study was to investigate the effect of the serine/threonine protein phosphatase inhibitor, calyculin-A (CLA, on clot formation and on the procoagulant activity of human platelets. Platelet-rich plasma (PRP samples were preincubated with buffer or CLA and subsequently platelets were activated by the protease-activated receptor 1 (PAR-1 activator, thrombin receptor activating peptide (TRAP. Clot retraction was detected by observing clot morphology up to 1 hour, phosphatidylserine- (PS- expression was studied by flow cytometry, and thrombin generation was measured by a fluorimetric assay. For the intracellular Ca2+ assay, platelets were loaded with calcium-indicator dyes and the measurements were carried out using a ratiometric method with real-time confocal microscopy. CLA preincubation inhibited clot retraction, PS-expression, and thrombin formation. TRAP activation elicited Ca2+ response and PS-expression in a subset of platelets. The activated PRP displayed significantly faster and enhanced thrombin generation compared to nonactivated samples. CLA pretreatment abrogated PS-exposure and clot retraction also in TRAP-activated samples. As a consequence of the inhibitory effect on calcium elevation and PS-expression, CLA significantly downregulated thrombin generation in PRP. Our results show that CLA pretreatment may be a useful tool to investigate platelet activation mechanisms that contribute to clot formation and thrombin generation.

  7. Separated rupture and retraction of a bi-layer free film

    Science.gov (United States)

    Stewart, Peter; Feng, Jie; Griffiths, Ian

    2017-11-01

    We investigate the dynamics of a rising air bubble in an aqueous phase coated with a layer of oil. Recent experiments have shown that bubble rupture at the compound air/oil/aqueous interface can effectively disperse submicrometre oil droplets into the aqueous phase, suggesting a possible mechanism for clean-up of oil spillages on the surface of the ocean. Using a theoretical model we consider the stability of the long liquid free film formed as the bubble reaches the free surface, composed of two immiscible layers of differing viscosities, where each layer experiences a van der Waals force between its interfaces. For an excess of surfactant on one gas-liquid interface we show that the instability manifests as distinct rupture events, with the oil layer rupturing first and retracting over the in-tact water layer beneath, consistent with the experimental observations. We use our model to examine the dynamics of oil retraction, showing that it follows a power-law for short times, and examine the influence of retraction on the stability of the water layer.

  8. Retraction Statement: Mitochondrial protein acetylation mediates nutrient sensing of mitochondrial protein synthesis and mitonuclear protein balance.

    Science.gov (United States)

    2017-07-01

    IUBMB Life (2014) 66:793-802. DOI: 10.1002/iub.1328 The above article, published online on November 15, 2014 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal's Editors-in-Chief, Angelo Azzi and William J. Whelan, Corresponding Author Tina Wenz, the University of Cologne, and Wiley Periodicals, Inc. The article has been retracted on request of the University of Cologne that, after an investigation, established that the data reported in it are not reproducible. Note from the Corresponding Author: "The paper reports on the influence of mitochondrial acetylation on protein synthesis. After publication, several irregularities appeared and have been thoroughly investigated by the lab of the Corresponding Author in cooperation with the commission of Research integrity of the University of Cologne. Both came to the conclusion that data used for the publication are erroneous and that the presented data are not reproducible by the lab of the Corresponding Author and other labs. The Corresponding Author takes responsibility and regrets not having detected these issues before publication. The appropriate corrective action is retraction of the paper. The Corresponding Author apologizes to the scientific community." Antonella Di Domenico, Annette Hofer, Federica Tundo, Tina Wenz (2014), Mitochondrial protein acetylation mediates nutrient sensing of mitochondrial protein synthesis and mitonuclear protein balance, IUBMB Life. 66: 793-802, 2014. DOI: 10.1002/iub.1328 © 2017 IUBMB Life, 69(7):553-553, 2017. © 2016 International Union of Biochemistry and Molecular Biology.

  9. The Vibrio cholerae Minor Pilin TcpB Initiates Assembly and Retraction of the Toxin-Coregulated Pilus.

    Directory of Open Access Journals (Sweden)

    Dixon Ng

    2016-12-01

    Full Text Available Type IV pilus (T4P systems are complex molecular machines that polymerize major pilin proteins into thin filaments displayed on bacterial surfaces. Pilus functions require rapid extension and depolymerization of the pilus, powered by the assembly and retraction ATPases, respectively. A set of low abundance minor pilins influences pilus dynamics by unknown mechanisms. The Vibrio cholerae toxin-coregulated pilus (TCP is among the simplest of the T4P systems, having a single minor pilin TcpB and lacking a retraction ATPase. Here we show that TcpB, like its homolog CofB, initiates pilus assembly. TcpB co-localizes with the pili but at extremely low levels, equivalent to one subunit per pilus. We used a micropillars assay to demonstrate that TCP are retractile despite the absence of a retraction ATPase, and that retraction relies on TcpB, as a V. cholerae tcpB Glu5Val mutant is fully piliated but does not induce micropillars movements. This mutant is impaired in TCP-mediated autoagglutination and TcpF secretion, consistent with retraction being required for these functions. We propose that TcpB initiates pilus retraction by incorporating into the growing pilus in a Glu5-dependent manner, which stalls assembly and triggers processive disassembly. These results provide a framework for understanding filament dynamics in more complex T4P systems and the closely related Type II secretion system.

  10. The Vibrio cholerae Minor Pilin TcpB Initiates Assembly and Retraction of the Toxin-Coregulated Pilus.

    Science.gov (United States)

    Ng, Dixon; Harn, Tony; Altindal, Tuba; Kolappan, Subramania; Marles, Jarrad M; Lala, Rajan; Spielman, Ingrid; Gao, Yang; Hauke, Caitlyn A; Kovacikova, Gabriela; Verjee, Zia; Taylor, Ronald K; Biais, Nicolas; Craig, Lisa

    2016-12-01

    Type IV pilus (T4P) systems are complex molecular machines that polymerize major pilin proteins into thin filaments displayed on bacterial surfaces. Pilus functions require rapid extension and depolymerization of the pilus, powered by the assembly and retraction ATPases, respectively. A set of low abundance minor pilins influences pilus dynamics by unknown mechanisms. The Vibrio cholerae toxin-coregulated pilus (TCP) is among the simplest of the T4P systems, having a single minor pilin TcpB and lacking a retraction ATPase. Here we show that TcpB, like its homolog CofB, initiates pilus assembly. TcpB co-localizes with the pili but at extremely low levels, equivalent to one subunit per pilus. We used a micropillars assay to demonstrate that TCP are retractile despite the absence of a retraction ATPase, and that retraction relies on TcpB, as a V. cholerae tcpB Glu5Val mutant is fully piliated but does not induce micropillars movements. This mutant is impaired in TCP-mediated autoagglutination and TcpF secretion, consistent with retraction being required for these functions. We propose that TcpB initiates pilus retraction by incorporating into the growing pilus in a Glu5-dependent manner, which stalls assembly and triggers processive disassembly. These results provide a framework for understanding filament dynamics in more complex T4P systems and the closely related Type II secretion system.

  11. Maxillary Corticotomies With Bone-to-Bone Retraction and Mandibular Segmental Osteotomy for Correcting an Anterior Double Protrusion.

    Science.gov (United States)

    Kim, Kyung A; Lee, Baek-Soo; Akbulut, Ayse Selenge; Kim, Seong-Hun; Nelson, Gerald

    2017-11-01

    This article presents maxillary corticotomies with bone-to-bone retraction and anterior segmental osteotomy (ASO) as an alternative to 2-jaw orthognathics in the bimaxilary protrusion patient with partially anchylosed maxillary anterior tooth. The 18-year-old male, complaining of anterior protrusion, with a trauma history to the maxillary central incisor, and requesting rapid treatment, was treated with maxillary corticotomies in 2 stages and ASO in the mandible. The mandibular ASO and palatal corticotomy were done under local anesthesia and 2 weeks later, labial corticotomy followed. The anterior segment was retracted bodily using buccal C-tubes and a combination of the C-lingual retractor and palatal C-plate. Due to a concern about ankylosis of the maxillary right central incisor, retraction of the anterior bone/tooth segment was chosen over any attempt to move teeth through the bone. After bone-to-bone retraction, the remaining extraction space was closed by protraction of posteriors. The total treatment period was 18 months. There was good retraction of the anterior segment and retrusion of the lips. A combination of maxillary corticotomies with skeletal anchorage for bone-to-bone retraction and a mandibular ASO under local anesthesia might be an alternative treatment option for excellent profile change in a short treatment period.

  12. Eye retraction in the giant guitarfish, Rhynchobatus djiddensis (Elasmobranchii: Batoidea): a novel mechanism for eye protection in batoid fishes.

    Science.gov (United States)

    Tomita, Taketeru; Murakumo, Kiyomi; Miyamoto, Kei; Sato, Keiichi; Oka, Shin-ichiro; Kamisako, Haruka; Toda, Minoru

    2016-02-01

    Eye retraction behavior has evolved independently in some vertebrate linages such as mudskippers (fish), frogs and salamanders (amphibians), and cetaceans (mammals). In this paper, we report the eye retraction behavior of the giant guitarfish (Rhynchobatus djiddensis) for the first time, and discuss its mechanism and function. The eye retraction distance was nearly the same as the diameter of the eyeball itself, indicating that eye retraction in the giant guitarfish is probably one of the largest among vertebrates. Eye retraction is achieved by unique arrangement of the eye muscle: one of the anterior eye muscles (the obliquus inferior) is directed ventrally from the eyeball and attaches to the ventral surface of the neurocranium. Due to such muscle arrangement, the obliquus inferior can pull the eyeball ventrally. This mechanism was also confirmed by electrical stimulation of the obliquus inferior. The eye retraction ability of the giant guitarfish likely represents a novel eye protection behavior of elasmobranch fishes. Copyright © 2015 Elsevier GmbH. All rights reserved.

  13. [Effect of soft tissue thickness of upper lip on lip retraction in orthodontical-treated Class II, Division 1 females].

    Science.gov (United States)

    Zou, Lanyi; Chen, Yunjia; Liu, Henglang; Na, Bi; He, Jinlong; Fan, Xiaoping

    2016-04-01

    To establish the Chinese Han national criteria for the thickness of upper lip in Chongqing and to investigate the effect of lip thickness on lip retraction in orthodontic treatment.
 A total of 240 adult patients (male=120, female=120) of Chinese Han nationality aged 18-35 years in Chongqing were treated with cephalograms and measured the thickness of upper lip. We established the Chinese Han national criteria for the thickness of upper lip in Chongqing according to the results. Sixty-eight female patients with Angle II 1 from Department of Orthodontics Stomatological Hospital of Chongqing Medical University were treated with maxillary premolars extraction, and pre- and post-treated with lateral cephalograms, then divided into 3 groups according to our criteria: a thin lips group, a normal lips group and a thick lips group. The ratio of the incisors retraction and the upper lip retraction were measured and calculated. The correlation between incisors retraction and the upper lip retraction was analyzed by the Pearson correlation method.
 There was statistical significance in the thickness of upper lip between males and females (Pthick lips group, respectively.
 Gender differences exist in the thickness of upper lip. Upper lip retraction with the incisors was negatively correlated with the soft tissue thickness of the upper lip in females with Angle II 1.

  14. Regional differences in brain-derived neurotrophic factor levels and dendritic spine density confer resilience to inescapable stress.

    Science.gov (United States)

    Yang, Chun; Shirayama, Yukihiko; Zhang, Ji-Chun; Ren, Qian; Hashimoto, Kenji

    2015-01-07

    In the learned helplessness (LH) paradigm, approximately 35% of rats are resilient to inescapable stress. The roles of brain-derived neurotrophic factor (BDNF) and dendritic spine density in the brain regions of LH (susceptible) and non-LH rats (resilient) were examined. Western blot analysis and Golgi staining were performed. BDNF levels in the medial prefrontal cortex, CA3, and dentate gyrus (DG) were significantly lower in the LH group than in the control and non-LH groups, whereas BDNF levels in the nucleus accumbens (NAc) in the LH group but not the non-LH group were significantly higher than those in the control group. Furthermore, spine density in the prelimbic cortex, CA3, and DG was significantly lower in the LH group than in the control and non-LH groups, although spine density in the NAc was significantly higher in the LH group than in the control and non-LH groups. The results suggest that regional differences in BDNF levels and spine density in rat brain may contribute to resilience to inescapable stress. © The Author 2015. Published by Oxford University Press on behalf of CINP.

  15. Expression of c-Fos protein in medial septum/diagonal band of Broca and CA3 region, associated with the temporary inactivation of the supramammillary area.

    Science.gov (United States)

    Aranda, Lourdes

    2016-07-01

    The supramammillary (SuM) area is part of the diencephalic nuclei comprising the mammillary bodies, and is a key structure in the memory and spatial learning processes. It is a critical region in the modulation/generation of hippocampal theta rhythm. In addition, many papers have recently shown a clear involvement of this structure in the processes of spatial learning and memory in animal models, although it is still not known how it modulates spatial navigation and response emotional. The aim of the present research was to study the effect of the temporary inactivation of the SuM area on synaptic plasticity of crucial structures in the formation of spatial memory and emotional response. Sprague-Dawley rats were asigned in three groups: a control group where the animals were not subjected to any treatment, and two groups where the rats received microinjections of tetrodotoxin (TTX) in the SuM area (5ng diluted in 0.5μl of saline) or saline (0.5μl). The microinjections were administered 90min before the perfusion. Later, cellular activity in medial septum/diagonal band of Broca (MS/DBB) and CA3 region of the dorsal hippocampus was assessed, by measuring the immediate early gene c-fos. The results show a clear hiperactivity cellular in medial septum/diagonal band of Broca and a clear hypoactivity cellular in the CA3 region of the hippocampus when there was a functional inactivation of the SuM area. It suggests that the SuM area seems to be part of the connection and information input pathways to CA3 region of the hippocampal formation, key for proper functioning in spatial memory and emotional response. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Effects of third trimester-equivalent ethanol exposure on Cl(-) co-transporter expression, network activity, and GABAergic transmission in the CA3 hippocampal region of neonatal rats.

    Science.gov (United States)

    Everett, Julie C; Licón-Muñoz, Yamhilette; Valenzuela, C Fernando

    2012-09-01

    Fetal alcohol spectrum disorders are often associated with structural and functional hippocampal abnormalities, leading to long-lasting learning and memory deficits. The mechanisms underlying these abnormalities are not fully understood. Here, we investigated whether ethanol exposure during the 3rd trimester-equivalent period alters spontaneous network activity that is involved in neuronal circuit development in the CA3 hippocampal region. This activity is driven by GABA(A) receptors, which can have excitatory actions in developing neurons as a consequence of greater expression of the Cl(-) importer, NKCC1, with respect to expression of the Cl(-) exporter, KCC2, resulting in high [Cl(-)](i). Rat pups were exposed to ethanol vapor from postnatal day (P) 2-16 (4 h/day). Weight gain was significantly reduced in pups exposed to ethanol compared to control at P15 and 16. Brain slices were prepared immediately after the end of the 4-h exposure on P4-16 and experiments were also performed under ethanol-free conditions at the end of the exposure paradigm (P17-22). Ethanol exposure did not significantly affect expression of KCC2 or NKCC1, nor did it affect network activity in the CA3 hippocampal region. Ethanol exposure significantly decreased the frequency (at P9-11) and increased the amplitude (at P5-8 and P17-21) of GABA(A) receptor-mediated miniature postsynaptic currents. These data suggest that repeated in vivo exposure to ethanol during the 3rd trimester-equivalent period alters GABAergic transmission in the CA3 hippocampal region, an effect that could lead to abnormal circuit maturation and perhaps contribute to the pathophysiology of fetal alcohol spectrum disorders. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. The role of CA3-LS-VTA loop in the formation of conditioned place preference induced by context-associated reward memory for morphine.

    Science.gov (United States)

    Jiang, Jin-Xiang; Liu, Huan; Huang, Zhen-Zhen; Cui, Yue; Zhang, Xue-Qin; Zhang, Xiao-Long; Cui, Yu; Xin, Wen-Jun

    2016-11-11

    Addiction-related behaviors, such as conditioned place preference (CPP), require animals to remember an association between environmental cue and drug treatment, and exposure to environmental cue is one of the key contributing factors to relapse. However, how central neural circuit participates in the formation of CPP induced by stimulus of morphine-paired environment remains unknown. In the present study, we found that reexposure to morphine-paired environment significantly increased the activity of hippocampal CA3 neurons, increased the excitability of GABAergic neurons and expression of glutamic acid decarboxylase 65/67 in the caudal lateral septum (LSc) and decreased the activity of GABAergic neurons and GAD65/67 expression in ventral tegmental area (VTA), leading to activation (disinhibition) of dopaminergic neurons. Inactivation of CA3 neurons attenuated GABAergic neurons activity and decreased the upregulation of GAD65/67 in LSc, prevented the dopaminergic neurons activation,and GAD65/67 downregulation in VTA and ameliorated the CPP behavior following exposure to morphine-paired context. Blockade of NMDA receptor in LSc also prevented the upregulation of GAD65/67 in LSc and formation of CPP induced by stimulus of morphine-paired environment. Suppression of GAD activity in LSc also remarkably attenuated the dopaminergic neurons activation and the GAD65/67 downregulation in VTA and prevented the formation of CPP induced by reexposure to morphine-associated context. Collectively, these results, for the first time, illustrated the involvement of neural circuitry of CA3-LSc-VTA, through integration of the contexts and reward information, participated in the reinstatement of CPP induced by exposure to morphine-associated context, which advanced our understanding on neurobiological basis for the context-associated memory and rewarding behavior. © 2016 Society for the Study of Addiction.

  18. Dendritic cells derived from bone marrow cells fail to acquire and present major histocompatibility complex antigens from other dendritic cells

    Science.gov (United States)

    Bedford, Penelope A; Burke, Fiona; Stagg, Andrew J; Knight, Stella C

    2008-01-01

    Dendritic cells stimulate primary T-cell responses and a major activation route is via presentation of antigens pre-processed by other dendritic cells. This presentation of pre-processed antigens most likely proceeds through transfer of functional major histocompatibility complex (MHC) antigens through exosomes, ‘live nibbling’ or apoptotic vesicles. We hypothesized that not all dendritic cell populations may both donate MHC antigen to dendritic cells and present antigens acquired from other dendritic cells. All populations tested, including those derived from bone marrow precursor cells stimulated primary, allogeneic T-cell responses and acted as accessory cells for mitogen stimulation. Populations of responder type, splenic dendritic cells promoted allogeneic responses indirectly but those derived from bone marrow cells blocked rather than promoted T-cell proliferation. To identify mechanisms underlying this difference we studied transfer of I-A antigens between cells. Active, two-way transfer of allogeneic I-A occurred between splenic primary antigen presenting cells including CD8α+ lymphoid dendritic cells, CD8α− myeloid dendritic cells and B220+ cells; all these cell types donated as well as acquired MHC molecules. By contrast, the bone marrow-derived dendritic cells donated I-A antigens but acquired negligible amounts. Thus, dendritic cells derived directly from bone marrow cells may stimulate primary T-cell responses through transferring functional MHC to other dendritic cells but may not be able to acquire and present antigens from other dendritic cells. The evidence suggests that T-cell activation may be blocked by the presence of dendritic cells that have not matured through lymphoid tissues which are unable to acquire and present antigens pre-processed by other dendritic cells. PMID:18266716

  19. Notices and Policies for Retractions, Expressions of Concern, Errata and Corrigenda: Their Importance, Content, and Context.

    Science.gov (United States)

    Teixeira da Silva, Jaime A; Dobránszki, Judit

    2017-04-01

    A retraction notice is an essential scientific historical document because it should outline the reason(s) why a scientific manuscript was retracted, culpability (if any) and any other factors that have given reason for the authors, editors, or publisher, to remove a piece of the literature from science's history books. Unlike an expression of concern (EoC), erratum or corrigendum, a retraction will usually result in a rudimentary vestige of the work. Thus, any retraction notice that does not fully indicate a set of elements related to the reason and background for the retraction serves as a poor historical document. Moreover, poorly or incompletely worded retraction notices in fact do not serve their intended purpose, i.e., to hold all parties accountable, and to inform the scientific and wider public of the problem and reason for the paper's demise. This paper takes a look at the definitions and the policies of clauses for retractions, EoCs, errata and corrigenda in place by 15 leading science, technology and medicine (STM) publishers and four publishing-related bodies that we believe have the greatest influence on the current fields of science, technology and medicine. The primary purpose was to assess whether there is a consistency among these entities and publishers. Using an arbitrary 5-scale classification system, and evaluating the different categories of policies separately, we discovered that in almost all cases (88.9 %), the wording used to define these four categories of polices differs from that of the Committee on Publication Ethics (COPE), which is generally considered to be the guiding set of definitions in science publishing. In addition, as much as 61 % deviation in policies (wording and meaning), relative to COPE guidelines, was discovered. When considering the average pooled deviation across all categories of policies, we discovered that there was either no deviation or a small deviation, only in the wording, in the definition of policies when

  20. A case study of a retracted systematic review on interactive health communication applications: impact on media, scientists, and patients.

    Science.gov (United States)

    Rada, Roy

    2005-06-30

    In October 2004, a flawed systematic review entitled "Interactive Health Communication Applications for People with Chronic Disease" was published in the Cochrane Library, accompanied by several press releases in which authors warned the public of the negative health consequences of interactive health communication applications, including the Internet. Within days of the review's publication, scientists identified major coding errors and other methodological problems that invalidated the principal conclusions of the study and led to a retraction. While the original study results and their negative conclusions were widely publicized in the media, the retraction seemed to go unnoticed. This paper aims to document an unprecedented case of misinformation from a Cochrane review and its impact on media, scientists, and patients. As well, it aims to identify the generic factors leading to the incident and suggest remedies. This was a qualitative study of the events leading to the retraction of the publication and of the reactions from media, scientists, and patients. This includes a review and content analysis of academic and mass media articles responding to the publication and retraction. Mass media articles were retrieved in May 2005 from LexisNexis Academic and Google and were classified and tallied. The extended case method is employed, and the analysis is also applied to comparable publishing events. A search on LexisNexis Academic database with the query "Elizabeth Murray AND health" for the period of June 2004 to May 2005 revealed a total of 15 press reports, of which only 1 addressed the retraction. Google was searched for references to the review, and the first 200 retrieved hits were analyzed. Of these, 170 pages were not related to the review. Of the remaining 30 pages, 23 (77%) were reports about the original publication that did not mention the retraction, 1 (3%) was a bibliography not mentioning the retraction, and 6 (20%) addressed the retraction, of which

  1. Efecto del dopaje en la propiedades termoeléctricas de cerámicas Ca3Co4-xNixO9

    OpenAIRE

    Constantinescu, Gabriel; Rasekh, Shahed; Torres, Miguel Angel; Bosque, Pablo; Madre, Maria Antonieta; Sotelo, Andres; Diez, Juan Carlos

    2015-01-01

    [EN]: Ca3Co4-xNixO9 (x=0.01, 0.03, and 0.05) polycrystalline thermoelectric ceramics have been prepared by the classical solid state method. As a result of the Ni addition an increase in porosity has been detected. Moreover, the presence of Ni has been related with the increase of Ca2Co3O6 secondary phase and the appearance of a new NiO-CoO solid solution. However, for the 0.01-Ni doped samples an improvement in the thermoelectric performances has been measured. This effect has been related w...

  2. Effects of conducting oxide barrier layers on the stability of Crofer® 22 APU/Ca3Co4O9 interfaces

    DEFF Research Database (Denmark)

    Holgate, Tim C.; Han, Li; Wu, NingYu

    2014-01-01

    Practical implementation of oxide thermoelectrics on an industrial or commercial scale for waste heat energy conversion requires the development of chemically stable interfaces between metal interconnects and oxide thermoelements that exhibit low electrical contact resistances. A commercially...... available high-chrome iron alloy (i.e., Crofer® 22 APU) serving as the interconnect metal was spray coated with LaNi0.6Fe0.4O3 (LNFO) or (Mn,Co)3O4 spinel and then interfaced with a p-type thermoelectric material—calcium cobaltate (Ca3Co4O9)—using spark plasma sintering. The interfaces have been...

  3. Rapamycin inhibits mTOR/p70S6K activation in CA3 region of the hippocampus of the rat and impairs long term memory.

    Science.gov (United States)

    Lana, D; Di Russo, J; Mello, T; Wenk, G L; Giovannini, M G

    2017-01-01

    The present study was aimed at establishing whether the mTOR pathway and its downstream effector p70S6K in CA3 pyramidal neurons are under the modulation of the cholinergic input to trigger the formation of long term memories, similar to what we demonstrated in CA1 hippocampus. We performed in vivo behavioral experiments using the step down inhibitory avoidance test in adult Wistar rats to evaluate memory formation under different conditions. We examined the effects of rapamycin, an inhibitor of mTORC1 formation, scopolamine, a muscarinic receptor antagonist or mecamylamine, a nicotinic receptor antagonist, on short and long term memory formation and on the functionality of the mTOR pathway. Acquisition was conducted 30min after i.c.v. injection of rapamycin. Recall testing was performed 1h, 4h or 24h after acquisition. We found that (1) mTOR and p70S6K activation in CA3 pyramidal neurons were involved in long term memory formation; (2) rapamycin significantly inhibited mTOR and of p70S6K activation at 4h, and long term memory impairment 24h after acquisition; (3) scopolamine impaired short but not long term memory, with an early increase of mTOR/p70S6K activation at 1h followed by stabilization at longer times; (4) mecamylamine and scopolamine co-administration impaired short term memory at 1h and 4h and reduced the scopolamine-induced increase of mTOR/p70S6K activation at 1h and 4h; (5) mecamylamine and scopolamine treatment did not impair long term memory formation; (6) unexpectedly, rapamycin increased mTORC2 activation in microglial cells. Our results demonstrate that in CA3 pyramidal neurons the mTOR/p70S6K pathway is under the modulation of the cholinergic system and is involved in long-term memory encoding, and are consistent with the hypothesis that the CA3 region of the hippocampus is involved in memory mechanisms based on rapid, one-trial object-place learning and recall. Furthermore, our results are in accordance with previous reports that selective

  4. Chemical Retraction Agents - in vivo and in vitro Studies into their Physico-Chemical Properties, Biocompatibility with Gingival Margin Tissues and Compatibility with Elastomer Impression Materials.

    Science.gov (United States)

    Nowakowska, Danuta; Saczko, Jolanta; Kulbacka, Julita; Wicckiewicz, Wlodzimierz

    2017-01-01

    Gingival margin retraction/displacement (GMR/D) is a commonly accepted procedure in restorative dentistry. Of the various retraction methods, the chemo-mechanical approach with retraction media and chemical retraction agents (ChRAs) is mostly used. Different local and/or systemic side effects were observed after "chemical attacks" from these retraction agents. Moreover, no consensus exists as to the compatibility of chemical agents with different impression materials. This paper reports the findings of in vivo and in vitro studies and we discuss the physico-chemical properties of chemical retraction agents, their undesirable clinical side effects, biological activity and compatibility with selected groups of elastomer impression materials. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  5. A Genome-Wide Screen for Dendritically Localized RNAs Identifies Genes Required for Dendrite Morphogenesis

    Directory of Open Access Journals (Sweden)

    Mala Misra

    2016-08-01

    Full Text Available Localizing messenger RNAs at specific subcellular sites is a conserved mechanism for targeting the synthesis of cytoplasmic proteins to distinct subcellular domains, thereby generating the asymmetric protein distributions necessary for cellular and developmental polarity. However, the full range of transcripts that are asymmetrically distributed in specialized cell types, and the significance of their localization, especially in the nervous system, are not known. We used the EP-MS2 method, which combines EP transposon insertion with the MS2/MCP in vivo fluorescent labeling system, to screen for novel localized transcripts in polarized cells, focusing on the highly branched Drosophila class IV dendritic arborization neurons. Of a total of 541 lines screened, we identified 55 EP-MS2 insertions producing transcripts that were enriched in neuronal processes, particularly in dendrites. The 47 genes identified by these insertions encode molecularly diverse proteins, and are enriched for genes that function in neuronal development and physiology. RNAi-mediated knockdown confirmed roles for many of the candidate genes in dendrite morphogenesis. We propose that the transport of mRNAs encoded by these genes into the dendrites allows their expression to be regulated on a local scale during the dynamic developmental processes of dendrite outgrowth, branching, and/or remodeling.

  6. Endoplasmic reticulum calcium stores in dendritic spines.

    Science.gov (United States)

    Segal, Menahem; Korkotian, Eduard

    2014-01-01

    Despite decades of research, the role of calcium stores in dendritic spines structure, function and plasticity is still debated. The reasons for this may have to do with the multitude of overlapping calcium handling machineries in the neuron, including stores, voltage and ligand gated channels, pumps and transporters. Also, different cells in the brain are endowed with calcium stores that are activated by different receptor types, and their differential compartmentalization in dendrites, spines and presynaptic terminals complicates their analysis. In the present review we address several key issues, including the role of calcium stores in synaptic plasticity, their role during development, in stress and in neurodegenerative diseases. Apparently, there is increasing evidence for a crucial role of calcium stores, especially of the ryanodine species, in synaptic plasticity and neuronal survival.

  7. Macrophages, Dendritic Cells, and Regression of Atherosclerosis

    Directory of Open Access Journals (Sweden)

    Jonathan E. Feig

    2012-07-01

    Full Text Available Atherosclerosis is the number one cause of death in the Western world. It results from the interaction between modified lipoproteins and monocyte-derived cells such as macrophages, dendritic cells, T cells, and other cellular elements of the arterial wall. This inflammatory process can ultimately lead to the development of complex lesions, or plaques, that protrude into the arterial lumen. Ultimately, plaque rupture and thrombosis can occur leading to the clinical complications of myocardial infarction or stroke. Although each of the cell types plays roles in the pathogenesis of atherosclerosis, in this review, the focus will be primarily on the monocyte derived cells- macrophages and dendritic cells. The roles of these cell types in atherogenesis will be highlighted. Finally, the mechanisms of atherosclerosis regression as it relates to these cells will be discussed.

  8. Evolution of neck vertebral shape and neck retraction at the transition to modern turtles: an integrated geometric morphometric approach.

    Science.gov (United States)

    Werneburg, Ingmar; Wilson, Laura A B; Parr, William C H; Joyce, Walter G

    2015-03-01

    The unique ability of modern turtles to retract their head and neck into the shell through a side-necked (pleurodiran) or hidden-necked (cryptodiran) motion is thought to have evolved independently in crown turtles. The anatomical changes that led to the vertebral shapes of modern turtles, however, are still poorly understood. Here we present comprehensive geometric morphometric analyses that trace turtle vertebral evolution and reconstruct disparity across phylogeny. Disparity of vertebral shape was high at the dawn of turtle evolution and decreased after the modern groups evolved, reflecting a stabilization of morphotypes that correspond to the two retraction modes. Stem turtles, which had a very simple mode of retraction, the lateral head tuck, show increasing flexibility of the neck through evolution towards a pleurodiran-like morphotype. The latter was the precondition for evolving pleurodiran and cryptodiran vertebrae. There is no correlation between the construction of formed articulations in the cervical centra and neck mobility. An increasing mobility between vertebrae, associated with changes in vertebral shape, resulted in a more advanced ability to retract the neck. In this regard, we hypothesize that the lateral tucking retraction of stem turtles was not only the precondition for pleurodiran but also of cryptodiran retraction. For the former, a kink in the middle third of the neck needed to be acquired, whereas for the latter modification was necessary between the eighth cervical vertebra and first thoracic vertebra. Our paper highlights the utility of 3D shape data, analyzed in a phylogenetic framework, to examine the magnitude and mode of evolutionary modifications to vertebral morphology. By reconstructing and visualizing ancestral anatomical shapes, we provide insight into the anatomical features underlying neck retraction mode, which is a salient component of extant turtle classification. © The Author(s) 2014. Published by Oxford University Press

  9. A stepping stone in treating dendritic keratitis

    Directory of Open Access Journals (Sweden)

    Hosam Sheha, MD, PhD

    2017-09-01

    Conclusions and importance: Self-retained amniotic membrane after debridement appears effective in treating dendritic keratitis. While early debridement is crucial to remove the infected corneal epithelium, amniotic membrane was shown to enhance the healing without scarring or recurrence. Besides the known anti-inflammatory and anti-scarring effects of the amniotic membrane, it may have a potential topical antiviral effect that warrants further investigation.

  10. Role of Dendritic Cells in Immune Dysfunction

    Science.gov (United States)

    Savary, Cherylyn A.

    1997-01-01

    Specific aims include: (1) Application of the bioreactor to enhance cytokine-regulated proliferation and maturation of dendritic cells (DC); (2) Based on clues from spaceflight: compare the frequency and function of DC in normal donors and immunocompromised cancer patients; and (3) Initiate studies on the efficiency of cytokine therapy and DC-assisted immunotherapy (using bioreactor-expanded DC) in animal models of experimental fungal infections.

  11. Nanodiamonds suppress the growth of lithium dendrites

    OpenAIRE

    Cheng, Xin-Bing; Zhao, Meng-Qiang; Chen, Chi; Pentecost, Amanda; Maleski, Kathleen; Mathis, Tyler; Zhang, Xue-Qiang; ZHANG, QIANG; Jiang, Jianjun; Gogotsi, Yury

    2017-01-01

    Lithium metal has been regarded as the future anode material for high-energy-density rechargeable batteries due to its favorable combination of negative electrochemical potential and high theoretical capacity. However, uncontrolled lithium deposition during lithium plating/stripping results in low Coulombic efficiency and severe safety hazards. Herein, we report that nanodiamonds work as an electrolyte additive to co-deposit with lithium ions and produce dendrite-free lithium deposits. First-...

  12. Mechanism-Based and Input-Output Modeling of the Key Neuronal Connections and Signal Transformations in the CA3-CA1 Regions of the Hippocampus.

    Science.gov (United States)

    Geng, Kunling; Shin, Dae C; Song, Dong; Hampson, Robert E; Deadwyler, Samuel A; Berger, Theodore W; Marmarelis, Vasilis Z

    2018-01-01

    This letter examines the results of input-output (nonparametric) modeling based on the analysis of data generated by a mechanism-based (parametric) model of CA3-CA1 neuronal connections in the hippocampus. The motivation is to obtain biological insight into the interpretation of such input-output (Volterra-equivalent) models estimated from synthetic data. The insights obtained may be subsequently used to interpretat input-output models extracted from actual experimental data. Specifically, we found that a simplified parametric model may serve as a useful tool to study the signal transformations in the hippocampal CA3-CA1 regions. Input-output modeling of model-based synthetic data show that GABAergic interneurons are responsible for regulating neuronal excitation, controlling the precision of spike timing, and maintaining network oscillations, in a manner consistent with previous studies. The input-output model obtained from real data exhibits intriguing similarities with its synthetic-data counterpart, demonstrating the importance of a dynamic resonance in the system/model response around 2 Hz to 3 Hz. Using the input-output model from real data as a guide, we may be able to amend the parametric model by incorporating more mechanisms in order to yield better-matching input-output model. The approach we present can also be applied to the study of other neural systems and pathways.

  13. Structural and optical properties of Tb and Na–Tb co-doped Ca3V2O8 phosphors prepared by sol–gel process

    Science.gov (United States)

    Parab, Shambhu S.; Salker, A. V.

    2018-01-01

    A malic acid assisted sol–gel route was successfully employed to prepare two distinct series of green emitting Ca3V2O8 phosphors. In the first series, Tb was solely doped whereas in the second series Na and Tb were doped simultaneously in the Ca3V2O8 crystal lattice. X-ray diffraction studies proved the utility of adopted preparative method by confirming the monophasic formation of all compounds from both the series. Spectral analysis like Raman spectroscopy, UV-DRS were undertaken to analyse the local structure, crystallinity and absorptive characteristics. XPS validated the presence of desired oxidation states of all the elements present. Finally, photoluminescence studies were done to elucidate the scope of prepared compounds as green emitting phosphors and also to understand the effect of both doping schemes on the luminescence. Intense green emission was observed in both the cases. Tb concentration of 0.08 was found to be optimum in case of Tb singly doped compounds whereas Tb = 0.12 showed highest intensity among the Na–Tb co-doped samples. Moreover, a red shift in the excitation wavelength was observed after Na doping signifying a change in the local electronic environment which in turn has affected the luminescence pattern. Local crystallinity and vacancy concentrations were found to have a major say on the emission intensities.

  14. Laser-induced transverse voltage effect and thermopower anisotropy of c-axis inclined Ca3Co4O9 thin film

    Science.gov (United States)

    Song, Shijin; Yu, Lan; Hu, Jianli; Liu, Anan; Zhong, Yi

    2017-09-01

    Ca3Co4O9+δ thin films were prepared on 5° vicinal cut LaAlO3 (001) substrates by pulsed laser deposition and subsequently annealed at various temperatures. Under the irradiation energy density of 8 mJ cm-2, a large laser-induced transverse voltage (LITV) signal with 6.4 V peak voltage and 33 ns rising edge was obtained in the 800 °C annealed film, which was nearly 11 times larger and 2 times faster than that in the as-grown film without annealing (0.54 V, 100 ns). The results suggested that the significant enhancement of LITV by annealing was mainly owing to the improved crystallization and electrical transport property. Based on the LITV results and heat flow model, a nearly intrinsic Seebeck coefficient anisotropy Δ S = | S ab- S c | ≈ 33.4 μV K-1 was obtained, demonstrating the c-axis inclined Ca3Co4O9+δ thin film with large thermopower anisotropy has great application potentials in high sensitive and fast response thermoelectric detectors.

  15. The Alterations of IL-1Beta, IL-6, and TGF-Beta Levels in Hippocampal CA3 Region of Chronic Restraint Stress Rats after Electroacupuncture (EA Pretreatment

    Directory of Open Access Journals (Sweden)

    Tianwei Guo

    2014-01-01

    Full Text Available Immunological reactions induced by proinflammatory cytokines have been involved in the pathogenesis of depressive disorders. Recent studies showed that Electroacupuncture (EA was able to reduce depressive symptoms; however, the underlying mechanism and its potential targets remain unknown. In the present study, we used a 21-day chronic restraint stress rats as a model to investigate how EA could alleviate depression. Open field test was carried out to evaluate the depressive symptoms at selected time points. At the end of study, immunohistochemistry (IHC was performed to detect the expressions of IL-1beta, IL-6, and TGF-beta in hippocampal CA3 region. We found that chronic restraint stress significantly decreased behavioral activities, whereas EA stimulation at points Baihui (GV 20 and Yintang (GV 29 showed protective effect during the test period. In addition, the IL-1beta, IL-6, and TGF-beta increased in rats exposed to chronic restraint stress, while EA downregulated the levels of IL-1beta and IL-6. These findings implied that EA pretreatment could alleviate depression through modulating IL-1beta and IL-6 expression levels in hippocampal CA3 region.

  16. Effect of Exercise Preconditioning on Memory Deficits and Neuronal Cell Death in the CA3 Pyramidal Cells of the Rat Hippocampus Following Transient Global Cerebral Ischemia

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    N Shamsaei

    2015-09-01

    Full Text Available Background & objectives: Brain ischemia leads to irreversible functional and structural damage in various regions of the brain, especially in the hippocampus. There is an evidence indicating the physical exercise has neuroprotective effects and may decrease the cerebral ischemia/ reperfusion injury in rats. The purpose of this study was the study of the effect of exercise preconditioning on memory deficits and neuronal cell death in CA3 pyramidal cells of the rat hippocampus following transient global ischemia.   Methods: 21 male rats weighing 260-300g were randomly selected and allocated into three groups (sham, ischemia and exercise+ischemia. The rats in exercise group were trained to run on a treadmill 5 days a week for 4 weeks. Ischemia induced by occlusion both common carotid arteries (CCA for 20 minutes. The passive avoidance memory test using a Shuttle box used to assess the impairment of memory. The amount of cell death was measured using cresyl violet staining method.   Results: The results showed that cerebral ischemia is associated with memory impairment, and physical activity before ischemia improves ischemia-induced memory impairments significantly (p<0.05. In addition, ischemia leads to cell death in hippocampal CA3 area neurons and exercise also reduces ischemia-induced cell death significantly (p<0.05.   Conclusion: This study showed that exercise, when is used as a preconditioning stimulant , has a neuroprotective effects against brain ischemia.

  17. Selective reinnervation of hippocampal area CA1 and the fascia dentata after destruction of CA3-CA4 afferents with kainic acid.

    Science.gov (United States)

    Nadler, J V; Perry, B W; Cotman, C W

    1980-01-20

    Intraventricular injections of kainic acid were used to destroy the hippocampal CA3-CA4 cells, thus denervating the inner third of the molecular layer of the fascia dentata and stratum radiatum and stratum oriens of area CA1. The responses of intact afferents to such lesions were then examined histologically. The hippocampal mossy fibers densely reinnervated the inner portion of the dentate molecular layer after bilateral destruction of CA4 neurons and to a lesser extent after unilateral destruction. Septohippocampal fibers replaced CA4-derived fibers in the dentate molecular layer only after particularly extensive bilateral CA4 lesions. Medial perforant path fibers showed no anatomical response to any of these lesions. Neither septohippocampal, temporoammonic nor mossy fibers proliferated in or grew into the denervated laminae of area CA1. These results show a preferential ordering in the reinnervation of dentate granule cells which is not readily explained by proximity to the degenerating fibers and also that removal of CA3-CA4-derived innervation more readily elicits translaminar growth in the fascia dentata than in area CA1. These results may be relevant to clinical situations in which neurons of the hippocampal end-blade are lost.

  18. The Isothermal Dendritic Growth Experiment Archive

    Science.gov (United States)

    Koss, Matthew

    2009-03-01

    The growth of dendrites is governed by the interplay between two simple and familiar processes---the irreversible diffusion of energy, and the reversible work done in the formation of new surface area. To advance our understanding of these processes, NASA sponsored a project that flew on the Space Shuttle Columbia is 1994, 1996, and 1997 to record and analyze benchmark data in an apparent-microgravity ``laboratory.'' In this laboratory, energy transfer by gravity driven convection was essentially eliminated and one could test independently, for the first time, both components of dendritic growth theory. The analysis of this data shows that although the diffusion of energy can be properly accounted for, the results from interfacial physics appear to be in disagreement and alternate models should receive increased attention. Unfortunately, currently and for the foreseeable future, there is no access or financial support to develop and conduct additional experiments of this type. However, the benchmark data of 35mm photonegatives, video, and all supporting instrument data are now available at the IDGE Archive at the College of the Holy Cross. This data may still have considerable relevance to researchers working specifically with dendritic growth, and more generally those working in the synthesis, growth & processing of materials, multiscale computational modeling, pattern formation, and systems far from equilibrium.

  19. Drosophila motor neuron retraction during metamorphosis is mediated by inputs from TGF-β/BMP signaling and orphan nuclear receptors.

    Science.gov (United States)

    Boulanger, Ana; Farge, Morgane; Ramanoudjame, Christophe; Wharton, Kristi; Dura, Jean-Maurice

    2012-01-01

    Larval motor neurons remodel during Drosophila neuro-muscular junction dismantling at metamorphosis. In this study, we describe the motor neuron retraction as opposed to degeneration based on the early disappearance of β-Spectrin and the continuing presence of Tubulin. By blocking cell dynamics with a dominant-negative form of Dynamin, we show that phagocytes have a key role in this process. Importantly, we show the presence of peripheral glial cells close to the neuro-muscular junction that retracts before the motor neuron. We show also that in muscle, expression of EcR-B1 encoding the steroid hormone receptor required for postsynaptic dismantling, is under the control of the ftz-f1/Hr39 orphan nuclear receptor pathway but not the TGF-β signaling pathway. In the motor neuron, activation of EcR-B1 expression by the two parallel pathways (TGF-β signaling and nuclear receptor) triggers axon retraction. We propose that a signal from a TGF-β family ligand is produced by the dismantling muscle (postsynapse compartment) and received by the motor neuron (presynaptic compartment) resulting in motor neuron retraction. The requirement of the two pathways in the motor neuron provides a molecular explanation for the instructive role of the postsynapse degradation on motor neuron retraction. This mechanism insures the temporality of the two processes and prevents motor neuron pruning before postsynaptic degradation.

  20. Drosophila motor neuron retraction during metamorphosis is mediated by inputs from TGF-β/BMP signaling and orphan nuclear receptors.

    Directory of Open Access Journals (Sweden)

    Ana Boulanger

    Full Text Available Larval motor neurons remodel during Drosophila neuro-muscular junction dismantling at metamorphosis. In this study, we describe the motor neuron retraction as opposed to degeneration based on the early disappearance of β-Spectrin and the continuing presence of Tubulin. By blocking cell dynamics with a dominant-negative form of Dynamin, we show that phagocytes have a key role in this process. Importantly, we show the presence of peripheral glial cells close to the neuro-muscular junction that retracts before the motor neuron. We show also that in muscle, expression of EcR-B1 encoding the steroid hormone receptor required for postsynaptic dismantling, is under the control of the ftz-f1/Hr39 orphan nuclear receptor pathway but not the TGF-β signaling pathway. In the motor neuron, activation of EcR-B1 expression by the two parallel pathways (TGF-β signaling and nuclear receptor triggers axon retraction. We propose that a signal from a TGF-β family ligand is produced by the dismantling muscle (postsynapse compartment and received by the motor neuron (presynaptic compartment resulting in motor neuron retraction. The requirement of the two pathways in the motor neuron provides a molecular explanation for the instructive role of the postsynapse degradation on motor neuron retraction. This mechanism insures the temporality of the two processes and prevents motor neuron pruning before postsynaptic degradation.

  1. Comparative photoelastic study of dental and skeletal anchorages in the canine retraction

    Directory of Open Access Journals (Sweden)

    Cristiane Aparecida de Assis Claro

    2014-01-01

    Full Text Available OBJECTIVE: To compare dental and skeletal anchorages in mandibular canine retraction by means of a stress distribution analysis. METHODS: A photoelastic model was produced from second molar to canine, without the first premolar, and mandibular canine retraction was simulated by a rubber band tied to two types of anchorage: dental anchorage, in the first molar attached to adjacent teeth, and skeletal anchorage with a hook simulating the mini-implant. The forces were applied 10 times and observed in a circular polariscope. The stresses located in the mandibular canine were recorded in 7 regions. The Mann-Whitney test was employed to compare the stress in each region and between both anchorage systems. The stresses in the mandibular canine periradicular regions were compared by the Kruskal-Wallis test. RESULTS: Stresses were similar in the cervical region and the middle third. In the apical third, the stresses associated with skeletal anchorage were higher than the stresses associated with dental anchorage. The results of the Kruskal-Wallis test showed that the highest stresses were identified in the cervical-distal, apical-distal, and apex regions with the use of dental anchorage, and in the apical-distal, apical-mesial, cervical-distal, and apex regions with the use of skeletal anchorage. CONCLUSIONS: The use of skeletal anchorage in canine retraction caused greater stress in the apical third than the use of dental anchorage, which indicates an intrusive component resulting from the direction of the force due to the position of the mini-implant and the bracket hook of the canine.

  2. Retraction and fibroplasia in a polypropylene prosthesis: experimental study in rats.

    Science.gov (United States)

    Zogbi, L; Portella, A O V; Trindade, M R M; Trindade, E N

    2010-06-01

    The treatment of hernia, independent of anatomical site and technique utilized, generally involves using prostheses, which may cause complications, despite their unarguable advantage in allowing safe reinforcement. An example of this is possible retraction, which causes discomfort and hernia recurrence. Polypropylene is still the most often used biomaterial of the great number available. The purpose of this study is to evaluate the amount of retraction of the polypropylene mesh, as well as the histological reactions that accompany this phenomenon. Polypropylene meshes (Marlex) were inserted in an anterior position to the whole abdominal aponeurosis of 25 Wistar rats (Rattus norvegicus albinus). The animals were divided into groups and another intervention was performed 7, 28, and 90 days later to measure the dimensions of the prostheses and to calculate the final area. Histological analysis was performed with hematoxylin-eosin to evaluate neutrophils, macrophages, giant cells, and lymphocytes surrounding the mesh threads in ten random fields of each slide. Seven days after the mesh was inserted, the mean rate of retraction was 1.75% (P = 0.64); at 28 days, it was 3.75% (P = 0.02); and at 90 days, it was 2.5% (P = 0.01). As to the histological analysis, there was a total decline of neutrophils and a progressive increase of macrophages, giant cells, and lymphocytes proportional to the post-implant time of the mesh (P prosthesis was inserted. There is a well-established sequence of cellular events which aim at synthesizing new connective tissue to reinforce the mesh.

  3. Two-port laparoscopic cholecystectomy with modified suture retraction of the fundus: A practical approach

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    Ming G Tian

    2013-01-01

    Full Text Available Context: Although transumbilical single incision laparoscopic cholecystectomy (SILC has been demonstrated to be superior cosmetic, it is only limited to simple cases at present. In complex cases, the standard four- or three-port LC is still the treatment of choice. Aim: To summarize the clinical effect of a modified technique in two-port LC. Settings and Design: A consecutive series of patients with benign gallbladder diseases admitted to the provincial teaching hospital who underwent LC in the past 4 years were included. A modified two-port LC was the first choice except for those requiring laparoscopic common bile duct exploration (LCBDE. Materials and Methods: The operation was done with suture retraction of the fundus by a needle-like retractor. The patients′ data, including the operative time, time consumed by gallbladder retraction, operative bleeding, conversion rate, rate of adding trocars, and postoperative complications were recorded. Statistical Analysis: Data were expressed as percentage and mean with standard deviation. Results: Total 107 patients with chronic calculous cholecystitis (N = 61, acute calculous cholecystitis (N = 43, and cholecystic polyps (N = 3 received two-port LC. The procedure was successful in 99 out of 107 cases (success rate, 92.5%, and a third trocar was added in the remaining 8 cases (7.5% due to severe pathological changes. The operative time was 47.2 (±13.21 min. There was no conversion to open surgery. Conclusion: Two-port LC using a needle-like retractor for suture retraction of the gallbladder fundus is a practical approach when considering the safety, convenience, and indications as well as relatively minimal invasion.

  4. Comparative photoelastic study of dental and skeletal anchorages in the canine retraction

    Science.gov (United States)

    Claro, Cristiane Aparecida de Assis; Chagas, Rosana Villela; Neves, Ana Christina Elias Claro; da Silva-Concílio, Laís Regiane

    2014-01-01

    Objective To compare dental and skeletal anchorages in mandibular canine retraction by means of a stress distribution analysis. Methods A photoelastic model was produced from second molar to canine, without the first premolar, and mandibular canine retraction was simulated by a rubber band tied to two types of anchorage: dental anchorage, in the first molar attached to adjacent teeth, and skeletal anchorage with a hook simulating the mini-implant. The forces were applied 10 times and observed in a circular polariscope. The stresses located in the mandibular canine were recorded in 7 regions. The Mann-Whitney test was employed to compare the stress in each region and between both anchorage systems. The stresses in the mandibular canine periradicular regions were compared by the Kruskal-Wallis test. Results Stresses were similar in the cervical region and the middle third. In the apical third, the stresses associated with skeletal anchorage were higher than the stresses associated with dental anchorage. The results of the Kruskal-Wallis test showed that the highest stresses were identified in the cervical-distal, apical-distal, and apex regions with the use of dental anchorage, and in the apical-distal, apical-mesial, cervical-distal, and apex regions with the use of skeletal anchorage. Conclusions The use of skeletal anchorage in canine retraction caused greater stress in the apical third than the use of dental anchorage, which indicates an intrusive component resulting from the direction of the force due to the position of the mini-implant and the bracket hook of the canine. PMID:24713566

  5. Crash in Publication Ethics in 2016 in a Glance: Avoid Paper Retraction

    Directory of Open Access Journals (Sweden)

    Mohammad H. Ebrahimzadeh

    2017-01-01

    Full Text Available On November 1st  2016, Springer Nature announced that Springer and BioMed Central are retracting 58 articles published by Iran-based authors across seven journals. The decision was made after thorough investigation following receiving allegations of plagiarism, peer review, and authorship manipulation in an effort to mislead the review system (1, 2. Not all papers were involved with all of the above issues, but each showed the evidence of at least one of these issues. At this time, we are not able to comment on the involvement of each individual author, but this has already added a black sheath to his or her records....

  6. Theoretical modelling of wakes from retractable flapping wings in forward flight.

    Science.gov (United States)

    Parslew, Ben; Crowther, William J

    2013-01-01

    A free-wake method is used to simulate the wake from retractable, jointed wings. The method serves to complement existing experimental studies that visualise flying animal wakes. Simulated wakes are shown to be numerically convergent for a case study of the Rock Pigeon in minimum power cruising flight. The free-wake model is robust in simulating wakes for a range of wing geometries and dynamics without requiring changes to the numerical method. The method is found to be useful for providing low order predictions of wake geometries. However, it is not well suited to reconstructing 3d flowfields as solutions are sensitive to the numerical mesh node locations.

  7. Theoretical modelling of wakes from retractable flapping wings in forward flight

    Directory of Open Access Journals (Sweden)

    Ben Parslew

    2013-07-01

    Full Text Available A free-wake method is used to simulate the wake from retractable, jointed wings. The method serves to complement existing experimental studies that visualise flying animal wakes. Simulated wakes are shown to be numerically convergent for a case study of the Rock Pigeon in minimum power cruising flight. The free-wake model is robust in simulating wakes for a range of wing geometries and dynamics without requiring changes to the numerical method. The method is found to be useful for providing low order predictions of wake geometries. However, it is not well suited to reconstructing 3d flowfields as solutions are sensitive to the numerical mesh node locations.

  8. Time-Dependent Response of Polypropylene/Clay Nanocomposites Under Tension and Retraction

    DEFF Research Database (Denmark)

    Drozdov, Aleksey; Christiansen, Jesper de Claville

    2013-01-01

    Observations are reported in relaxation tests under tension and retraction on polypropylene/clay nanocomposites with various contents of filler. A two-phase constitutive model is developed in cyclic viscoelasticity and viscoplasticity of nanocomposites. Adjustable parameters in the stress......–strain relations are found by fitting the observations. Ability of the constitutive equations to describe characteristic features of the timedependent behavior of nanocomposites under cyclic deformation is confirmed by numerical simulation. POLYM. ENG. SCI., 00:000–000, 2012. ª2012 Society of Plastics Engineers...

  9. Retracted article: Flexible Fourier Stationary Test in GDP per capita for Central Eastern European Countries

    Directory of Open Access Journals (Sweden)

    Meng-Nan Zhu

    2011-06-01

    Full Text Available Statement of Retraction (http://www.efri.uniri.hr/prikaz.asp?txt_id=7366 This is to notify our respectful reading public that the Editorial Board of the journal Zbornik radova Ekonomskog fakulteta u Rijeci, časopis za ekonomsku teoriju i praksu/ Proceedings of Rijeka Faculty of Economics, Journal of Economics and Business has retracted the following article from publication: “Flexible Fourier Stationary Test in GDP per capita for Central Eastern European Countries“, by Hsu-Ling Chang, Chi-Wei Su, Meng-Nan Zhu, published in our journal Zbornik radova Ekonomskog fakulteta u Rijeci, časopis za ekonomsku teoriju i praksu/ Proceedings of Rijeka Faculty of Economics, Journal of Economics and Business, 2011, vol. 29 (1, pp. 51-63 and almost concurrently published in the journal Eastern European Economics, 2011, vol. 49 (3, pp. 54-65. Being in contact with Josef C Brada, Professor Emeritus, Editor of the journal Eastern European Economics (EEE, we realized that the paper had been sent to both journals, although first published in the EEE and then in our Journal. According to professor Brada’s and our analysis, the paper published in these two journals is exactly the same, except for minor differences in wording, most likely due to editing the text before publication. The outstanding differences are in the title and the fact that the paper published in our Journal has three authors and in EEE journal has two. Whatsoever, owing to the fact that the article had been sent to both journals almost at the same time, it had been impossible to find out the case during the review procedure. Due to this unpleasant situation, our Editorial Board would like to inform our valuable readers that all the necessary measures to retract the paper from our publication have been undertaken and according to publishing ethical principles, cooperation with the authors of the retracted paper have been stopped. Although, in this case neither EEE nor our Journal had any

  10. Rapid Canine Retraction with Dentoalveolar Distraction Osteogenesis: An in vivo Study

    Directory of Open Access Journals (Sweden)

    Allwin Benjamin Raj

    2013-01-01

    Full Text Available The aim of this clinical study is to assess the effectiveness of a new technique of rapid canine retraction through distraction osteogenesis. The effects of dentoalveolar distraction on the dentofacial structures, the dental changes that has been produced by dentoalveolar distraction and the vitality of the distracted canine immediately after distraction and 3 months postdistraction using pulp vitality test were also evaluated. Custom made canine distractors were used for distraction. Pre and postdistraction lateral cephalogram, OPG, Model analysis and electrical pulp vitality testing is carried out and results were evaluated.

  11. Inhibition of lysophosphatidic acid-induced neurite retraction and cell rounding by SR 57746A.

    Science.gov (United States)

    Magazin, M; Schiltz, P; Zachayus, J L; Cavrois, E; Caput, D; Ferrara, P

    1998-01-01

    Rapid neurite retraction and transient rounding of serum-starved NG108-15 and PC12 cells by lysophosphatidic acid (LPA) is retarded and reduced by pre-incubation of the cells with the small non-peptidic molecule, SR 57746A, which exhibits neurotrophic properties. The compound also antagonizes the redistribution of filamentous actin by LPA in both cell types. We hypothesize that the SR 57746A attenuation of LPA-induced effects may account for at least some of the neuroprotective properties of this molecule.

  12. Dentate gyrus supports slope recognition memory, shades of grey-context pattern separation and recognition memory, and CA3 supports pattern completion for object memory.

    Science.gov (United States)

    Kesner, Raymond P; Kirk, Ryan A; Yu, Zhenghui; Polansky, Caitlin; Musso, Nick D

    2016-03-01

    In order to examine the role of the dorsal dentate gyrus (dDG) in slope (vertical space) recognition and possible pattern separation, various slope (vertical space) degrees were used in a novel exploratory paradigm to measure novelty detection for changes in slope (vertical space) recognition memory and slope memory pattern separation in Experiment 1. The results of the experiment indicate that control rats displayed a slope recognition memory function with a pattern separation process for slope memory that is dependent upon the magnitude of change in slope between study and test phases. In contrast, the dDG lesioned rats displayed an impairment in slope recognition memory, though because there was no significant interaction between the two groups and slope memory, a reliable pattern separation impairment for slope could not be firmly established in the DG lesioned rats. In Experiment 2, in order to determine whether, the dDG plays a role in shades of grey spatial context recognition and possible pattern separation, shades of grey were used in a novel exploratory paradigm to measure novelty detection for changes in the shades of grey context environment. The results of the experiment indicate that control rats displayed a shades of grey-context pattern separation effect across levels of separation of context (shades of grey). In contrast, the DG lesioned rats displayed a significant interaction between the two groups and levels of shades of grey suggesting impairment in a pattern separation function for levels of shades of grey. In Experiment 3 in order to determine whether the dorsal CA3 (dCA3) plays a role in object pattern completion, a new task requiring less training and using a choice that was based on choosing the correct set of objects on a two-choice discrimination task was used. The results indicated that control rats displayed a pattern completion function based on the availability of one, two, three or four cues. In contrast, the dCA3 lesioned rats

  13. A detailed observation of the ejection and retraction of defense tissue acontia in sea anemone (Exaiptasia pallida).

    Science.gov (United States)

    Lam, Julie; Cheng, Ya-Wen; Chen, Wan-Nan U; Li, Hsing-Hui; Chen, Chii-Shiarng; Peng, Shao-En

    2017-01-01

    Acontia, located in the gastrovascular cavity of anemone, are thread-like tissue containing numerous stinging cells which serve as a unique defense tissue against predators of the immobile acontiarian sea anemone. Although its morphology and biological functions, such as defense and digestion, have been studied, the defense behavior and the specific events of acontia ejection and retraction are unclear. The aim of this study is to observe and record the detailed process of acontia control in anemones. Observations reveal that the anemone, Exaiptasia pallida, possibly controls a network of body muscles and manipulates water pressure in the gastrovascular cavity to eject and retract acontia. Instead of resynthesizing acontia after each ejection, the retraction and reuse of acontia enables the anemone to respond quickly at any given time, thus increasing its overall survivability. Since the Exaiptasia anemone is an emerging model for coral biology, this study provides a foundation to further investigate the biophysics, neuroscience, and defense biology of this marine model organism.

  14. Retracted: Aetiology and clinical profile of children with 46, XY differences of sex development at an Indian referral centre.

    Science.gov (United States)

    Chauhan, V; Dada, R; Jain, V

    2017-11-01

    Retraction: 'Aetiology and clinical profile of children with 46, XY differences of sex development at an Indian referral centre' by Vasundhera Chauhan, Rima Dada, Vandana Jain The above article, published online on 8 August 2016 in Wiley Online Library (http://wileyonlinelibrary.com), has been retracted by agreement between the authors, the Journal Editors-in-Chief, Wolf-Bernhard Schill and Ralf Henkel, and Blackwell Verlag GmbH. The retraction has been agreed as the result of an unresolved dispute between the first author and a colleague research fellow due to the inclusion of data from patients who were simultaneously enrolled in two studies being conducted separately by the two parties. Reference Chauhan, V., Dada, R. and Jain, V. (2016), Aetiology and clinical profile of children with 46, XY differences of sex development at an Indian referral centre. Andrologia. doi:10.1111/and.12663. © 2016 Blackwell Verlag GmbH.

  15. Retraction statement: 'Species distributions shift downward across western North America' by M.A. Harsch and J. Hille Ris Lambers.

    Science.gov (United States)

    2015-03-01

    The above article, published online on 18 August 2014 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, Dr Melanie Harsch and Associate Professor Janneke Hille Ris Lambers, journal Editor-in-Chief, Professor Stephen Long, and John Wiley & Sons Ltd. The retraction has been agreed for the following reasons: a coding error affected the results and therefore invalidated the broadscale conclusions presented in the article. The article presented broad-scale patterns of species distribution shifts in response to recent climate change. Unfortunately, it has since been found that one approach used to account for sampling bias, the null model approach, was affected by the coding error. Following the identification of the coding error, we are therefore retracting the article. We thank Drs Adam Wolf and William Anderegg for bringing this issue to our attention.

  16. Retractable Contracts

    Directory of Open Access Journals (Sweden)

    Franco Barbanera

    2016-02-01

    Full Text Available In calculi for modelling communication protocols, internal and external choices play dual roles. Two external choices can be viewed naturally as dual too, as they represent an agreement between the communicating parties. If the interaction fails, the past agreements are good candidates as points where to roll back, in order to take a different agreement. We propose a variant of contracts with synchronous rollbacks to agreement points in case of deadlock. The new calculus is equipped with a compliance relation which is shown to be decidable.

  17. Ternary eutectic dendrites: Pattern formation and scaling properties

    Science.gov (United States)

    Rátkai, László; Szállás, Attila; Pusztai, Tamás; Mohri, Tetsuo; Gránásy, László

    2015-04-01

    Extending previous work [Pusztai et al., Phys. Rev. E 87, 032401 (2013)], we have studied the formation of eutectic dendrites in a model ternary system within the framework of the phase-field theory. We have mapped out the domain in which two-phase dendritic structures grow. With increasing pulling velocity, the following sequence of growth morphologies is observed: flat front lamellae → eutectic colonies → eutectic dendritesdendrites with target pattern → partitionless dendrites → partitionless flat front. We confirm that the two-phase and one-phase dendrites have similar forms and display a similar scaling of the dendrite tip radius with the interface free energy. It is also found that the possible eutectic patterns include the target pattern, and single- and multiarm spirals, of which the thermal fluctuations choose. The most probable number of spiral arms increases with increasing tip radius and with decreasing kinetic anisotropy. Our numerical simulations confirm that in agreement with the assumptions of a recent analysis of two-phase dendrites [Akamatsu et al., Phys. Rev. Lett. 112, 105502 (2014)], the Jackson-Hunt scaling of the eutectic wavelength with pulling velocity is obeyed in the parameter domain explored, and that the natural eutectic wavelength is proportional to the tip radius of the two-phase dendrites. Finally, we find that it is very difficult/virtually impossible to form spiraling two-phase dendrites without anisotropy, an observation that seems to contradict the expectations of Akamatsu et al. Yet, it cannot be excluded that in isotropic systems, two-phase dendrites are rare events difficult to observe in simulations.

  18. Effects of Al substitution for Ca3Ta(Ga1-xAlx)3Si2O14 piezoelectric single crystals

    Science.gov (United States)

    Yokota, Yuui; Ohashi, Yuji; Kudo, Tetsuo; Kochurikhin, Vladimir V.; Medvedev, Andrey; Kurosawa, Shunsuke; Kamada, Kei; Yoshikawa, Akira

    2017-06-01

    Ca3Ta(Ga1-xAlx)3Si2O14 [CTGAS] material is a piezoelectric material belonging to the Langasite-type group (space group: P321).and the CTGAS single crystals (x=0, 0.25, 0.50, 0.75) with a diameter of 1 in. were grown by a Czochralski [Cz] method using an Ir crucible under Ar+2%O2. The CTGAS single crystals without any cracks could be grown using a CTGAS seed crystal in the x range of 0≤x≤0.75. Cell parameters, a and c, decrease while the a/c ratio increased with the Al concentration. Piezoelectric constant d11 and electromechanical coupling factor k12 for the X-cut specimens of the CTGAS single crystals were increased by the Al substitution.

  19. On 3d bonding in the transition metal trimers - The electronic structure of equilateral triangle Ca3, Sc3, Sc3(+), and Ti3(+)

    Science.gov (United States)

    Walch, S. P.; Bauschlicher, C. W., Jr.

    1985-01-01

    It is pointed out that transition metals and transition metal (TM) compounds are currently of considerable interest because of their relevance to catalysis and to materials science problems such as hydrogen embrittlement and crack propagation in metals. The present paper is concerned with complete active space Self-Consistent Field (SCF) externally contracted configuration interaction (CASSCF/CCI) calculations for the low-lying states of Sc3 and Sc3(+). A comparison is conducted regarding the bonding in the Ca3, Sc3, and Cu3 molecules. This comparison makes it possible to predict general trends for the TM trimers. Attention is given to the qualitative features of the bonding in the TM trimers, the basis sets and other technical details of the calculations, the calculated results for Sc3 and Sc3(+), and conclusions from this work.

  20. Tuite, γ-Ca3(PO4)2, formed by chlorapatite decomposition in a shock vein of the Suizhou L6 chondrite

    Science.gov (United States)

    Xie, Xiande; Zhai, Shuangmeng; Chen, Ming; Yang, Hexiong

    2013-08-01

    Tuite, γ-Ca3(PO4)2, was first discovered as the high-pressure phase of whitlockite in shock veins of the Suizhou L6 meteorite. This study reports the finding of tuite in a shock vein of the same Suizhou chondrite as a product of decomposition of chlorapatite, where it coexists with coarse-grained ringwoodite, majorite, lingunite, fine-grained majorite-pyrope solid solution, and magnesiowüstite. Moreover, we also successfully synthesized tuite with a multianvil apparatus from chlorapatite at 15 GPa and 1573 K over 24 h. Both natural and synthetic tuite crystals were examined by means of optical microscopy, scanning electron microscope, electron microprobe analysis, X-ray diffraction, and Raman spectroscopy. Our results suggest that the Na2O, MgO, and Cl contents in natural tuite may serve as good indicators for distinguishing the precursor phosphate mineral, chlorapatite or whitlockite.

  1. Crystal Growth of Ca3Nb(Ga1−xAlx3Si2O14 Piezoelectric Single Crystals with Various Al Concentrations

    Directory of Open Access Journals (Sweden)

    Yuui Yokota

    2015-08-01

    Full Text Available Ca3Nb(Ga1−xAlx3Si2O14 (CNGAS single crystals with various Al concentrations were grown by a micro-pulling-down (µ-PD method and their crystal structures, chemical compositions, crystallinities were investigated. CNGAS crystals with x = 0.2, 0.4 and 0.6 indicated a single phase of langasite-type structure without any secondary phases. In contrast, the crystals with x = 0.8 and 1 included some secondary phases in addition to the langasite-type phase. Lattice parameters, a- and c-axes lengths, of the langasite-type phase systematically decreased with an increase of Al concentration. The results of chemical composition analysis revealed that the actual Al concentrations in as-grown crystals were almost consistent with the nominal compositions. In addition, there was no large segregation of each cation along the growth direction.

  2. Effects of Yttrium and Iron co-doping on the high temperature thermoelectric properties of Ca3Co4O9+δ

    DEFF Research Database (Denmark)

    Wu, NingYu; Van Nong, Ngo; Pryds, Nini

    2015-01-01

    A series of Y and Fe co-doped Ca3−xYxCo4−yFeyO9+δ (0 ⩽ x ⩽ 0.3, 0 ⩽ y ⩽ 0.1) samples synthesized by auto-combustion reaction and followed by a spark plasma sintering (SPS) processing with the effects of Fe and Y doping on the high temperature (RT to 800 °C) thermoelectric properties were systemat......A series of Y and Fe co-doped Ca3−xYxCo4−yFeyO9+δ (0 ⩽ x ⩽ 0.3, 0 ⩽ y ⩽ 0.1) samples synthesized by auto-combustion reaction and followed by a spark plasma sintering (SPS) processing with the effects of Fe and Y doping on the high temperature (RT to 800 °C) thermoelectric properties were...... systematically investigated. For the Fe-doped system (x = 0, y ⩽ 0.1), the electrical resistivity (ρ) decreased over the whole measured temperature range, while the Seebeck coefficient (S) remained almost the same. For the co-doped system, at any fixed Fe doping content, both ρ and S tended to increase...... with increasing Y dopants, however, the effect is more substantial on ρ than on S, particularly in the low temperature regime. In contrast to ρ and S, the in-plane thermal conductivity (κ) is only slightly influenced by Y and Fe substitutions. Among all the investigated samples, the co-doped sample with x = 0...

  3. Ceramic Materials in a Ti–C–Co–Ca3(PO42–Ag–Mg System Obtained by MA SHS for the Deposition of Biomedical Coatings

    Directory of Open Access Journals (Sweden)

    Artem Potanin

    2017-09-01

    Full Text Available This study aimed to obtain biocompatible ceramic materials in a Ti–C–Co–Ca3(PO42–Ag–Mg system by the combustion mode of mechanically activated (MA reaction mixtures. The influence of the MA time on the reaction ability capability of the mixtures, on their structural and chemical homogeneity, on the combustion parameters and structural-phase conversions in the combustion wave, as well as on the structure and phase composition of the electrode materials has been researched. It was found that the intense treatment of powder mixtures causes plastic deformation of components, the formation of lamellar composite granules, a reduction in the sizes of coherent scattering regions, and also the formation of minor amounts of products. The influence of the activation duration of the ignition temperature and heat release during the combustion of the reaction mixtures was studied. By the method of quenching the combustion front, it was demonstrated that in a combustion wave, chemical transformations occur within the lamellar structures formed during the process of mechanoactivation. It was shown that in the combustion wave, parallel chemical reactions of Ti with C as well as Ti with Co and Ca3(PO42 occur, with a Ti–Co-based melt forming the reaction surface. Ceramic electrodes with different contents of Ag and Mg were synthesized by force self-propagating high-temperature synthesis (SHS-pressing technology using the MA mixtures. The microstructure of the materials consisted of round-shaped grains of nonstoichiometric titanium carbide TiCx grains, intermetallic matrix (TiCo, TiCo2, CoTiP, inclusions of Ca and Mg oxides, and grains of the Ag-based solid solution. An increased content of Ag and Mg in the composition of the electrodes, as well as an increased MA duration, leads to an enlargement of the inclusions of the Ag-containing phase size and deterioration in the uniformity of their distribution.

  4. The potential of prolonged tissue culture to reduce stress generation and retraction in engineered heart valve tissues.

    Science.gov (United States)

    van Vlimmeren, Marijke A A; Driessen-Mol, Anita; Oomens, Cees W J; Baaijens, Frank P T

    2013-03-01

    In tissue-engineered (TE) heart valves, cell-mediated processes cause tissue compaction during culture and leaflet retraction at time of implantation. We have quantified and correlated stress generation, compaction, retraction, and tissue quality during a prolonged culture period of 8 weeks. Polyglycolic acid/poly-4-hydroxybutyrate strips were seeded with vascular-derived cells and cultured for 4-8 weeks. Compaction in width, generated force, and stress was measured during culture. Retraction in length, generated force, and stress was measured after release of constraints at weeks 4, 6, and 8. Further, the amount of DNA, glycosaminoglycans (GAGs), collagen, and collagen cross-links was assessed. During culture, compaction and force generation increased to, respectively, 63.9% ± 0.8% and 43.7 ± 4.3 mN at week 4, after which they remained stable. Stress generation reached 27.7 ± 3.2 kPa at week 4, after which it decreased to ∼8.5 kPa. At release of constraints, tissue retraction was 44.0% ± 3.7% at week 4 and decreased to 29.2% ± 2.8% and 26.1% ± 2.2% at, respectively, 6 and 8 weeks. Generated force (8-16 mN) was lower at week 6 than at weeks 4 and 8. Generated stress decreased from 11.8 ± 0.9 kPa at week 4 to 1.4 ± 0.3 and 2.4 ± 0.4 kPa at, respectively, weeks 6 and 8. The amount of GAGs increased at weeks 6 and 8 compared to week 4 and correlated to the reduced stress and retraction. In summary, prolonged culture resulted in decreased stress generation and retraction, likely as a result of the increased amount of GAGs. These results demonstrate the potential of prolonged tissue culture in developing functional, nonretracting, TE heart valves.

  5. Evaluating the effects of consolidation on intrusion and retraction using temporary anchorage devices—a FEM study

    Directory of Open Access Journals (Sweden)

    Monica Namburi

    2017-01-01

    Full Text Available Abstract Background Extraction of premolars and retracting the anterior teeth using mini-implants and anterior retraction hooks became advent now a day. In such treatments, consolidation of arches is not done in regular practice. So, the present study is concentrated on effects of consolidation in two implant and three implant combinations of retraction and intrusion. Methods A three-dimensional FEM model of maxillary teeth and periodontal ligament housed in the alveolar bone with the first premolars extracted is generated with appropriate number of elements and nodes. The models were broadly divided into two groups according to the no. of implants. Mini-implants were placed bilaterally between the second premolar and molar at varying heights (7, 10, 13 mm in group I, and along with bilateral implants, an additional mid-implant is placed between the central incisors as group II. Brackets with 0.022 slot were placed on the teeth, 19 × 25 SS wire is placed in the brackets, an anterior retraction hook was placed at 9 mm height, and analysis was done to evaluate the stresses and displacement patterns in consolidation and non-consolidation models. Results The results showed that consolidation of the anterior teeth during intrusion and retraction shows various advantages such as less stresses on the bone, PDL, implant, teeth, and no labial flaring of the anterior teeth and three implant system, i.e., two bilateral implant at 10 mm and a mid-implant at 12 mm between the centrals has shown to be better than other models as bodily movement is observed. Conclusion Consolidation is better than non consolidation during enmasse retraction and intrusion.

  6. Evaluating the effects of consolidation on intrusion and retraction using temporary anchorage devices-a FEM study.

    Science.gov (United States)

    Namburi, Monica; Nagothu, Sleevaraju; Kumar, Chetan S; Chakrapani, N; Hanumantharao, C H; Kumar, Supradeep K

    2017-12-01

    Extraction of premolars and retracting the anterior teeth using mini-implants and anterior retraction hooks became advent now a day. In such treatments, consolidation of arches is not done in regular practice. So, the present study is concentrated on effects of consolidation in two implant and three implant combinations of retraction and intrusion. A three-dimensional FEM model of maxillary teeth and periodontal ligament housed in the alveolar bone with the first premolars extracted is generated with appropriate number of elements and nodes. The models were broadly divided into two groups according to the no. of implants. Mini-implants were placed bilaterally between the second premolar and molar at varying heights (7, 10, 13 mm) in group I, and along with bilateral implants, an additional mid-implant is placed between the central incisors as group II. Brackets with 0.022 slot were placed on the teeth, 19 × 25 SS wire is placed in the brackets, an anterior retraction hook was placed at 9 mm height, and analysis was done to evaluate the stresses and displacement patterns in consolidation and non-consolidation models. The results showed that consolidation of the anterior teeth during intrusion and retraction shows various advantages such as less stresses on the bone, PDL, implant, teeth, and no labial flaring of the anterior teeth and three implant system, i.e., two bilateral implant at 10 mm and a mid-implant at 12 mm between the centrals has shown to be better than other models as bodily movement is observed. Consolidation is better than non consolidation during enmasse retraction and intrusion.

  7. Structural Optimization of the Retractable Dome for Four Meter Telescope (FMT)

    Science.gov (United States)

    Pan, Nian; Li, Yuxi; Fan, Yue; Ma, Wenli; Huang, Jinlong; Jiang, Ping; Kong, Sijie

    2017-03-01

    Dome seeing degrades the image quality of ground-based telescopes. To achieve dome seeing of the Four Meter Telescope (FMT) less than 0.5 arcsec, structural optimizations based on computational fluid dynamics (CFD) simulation were proposed. The results of the simulation showed that dome seeing of FMT was 0.42 arcsec, which was mainly caused by the slope angle of the dome when the slope angle was 15° and the wind speed was 10 m/s. Furthermore, the lower the air speed was, the less dome seeing would be. Wind tunnel tests (WT) with a 1:120 scaled model of the retractable dome and FMT indicated that the calculated deviations of the CFD simulation used in this paper were less than 20% and the same variations of the refractive index derived from the WT would be a convincing argument for the validity of the simulations. Thus, the optimization of the retractable dome was reliable and the method expressed in this paper provided a reference for the design of next generation of ground-based telescope dome.

  8. Single-Incision Sleeve Gastrectomy Using a Novel Technique for Liver Retraction

    Science.gov (United States)

    Choh, Mark; Gorodner, Maria V.

    2010-01-01

    Introduction: Laparoscopic sleeve gastrectomy has rapidly gained popularity in the field of bariatric surgery, mainly due to its low morbidity and mortality. Traditionally, 4 to 6 trocars are used. Single-access surgery has emerged as an attempt to decrease incisional morbidity and enhance cosmetic benefits. We present our initial 7 patients undergoing single-incision laparoscopic sleeve gastrectomy using a novel technique for liver retraction. Methods: Patients who underwent single-incision laparoscopic sleeve gastrectomy between March 2009 and May 2009 were analyzed. A 4-cm left paramedian incision was used. Laparoscopic sleeve gastrectomy was performed in a standard fashion using a 40 French bougie. Results: Seven patients underwent single-incision sleeve gastrectomy at the University of Illinois at Chicago. They were all female with a mean age of 34 years. Preoperative BMI was 49kg/m2 (range, 39 to 64). There were no intraoperative complications. Mean operative time was 103 minutes. Estimated blood loss was minimal. All 7 patients were discharged on postoperative day 2 and were doing well without any complications at 3.1±0.7 months after surgery. Conclusion: Single-incision laparoscopic sleeve gastrectomy is safe and feasible and can be performed without changing the existing principles of the procedure. Our technique for internal liver retraction provides adequate exposure and is reproducible. Development of improved standard instrumentation is required for this technique to become popular. PMID:20932374

  9. Retracted: Multilevel Predictors of Math Classroom Climate: A Comparison Study of Student and Teacher Perceptions.

    Science.gov (United States)

    Wang, Ming-Te; Eccles, Jacquelynne S

    2016-09-01

    The above article, published online on June 23, 2014 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor-in-Chief, Nancy Guerra, and Wiley Periodicals, Inc. The retraction has been agreed upon following the discovery that this article contained inaccurate data. It came to the author's attention that the names of some of the items reported in the Measures section of the paper could not be correct because such items did not exist in the surveys. The authors tried to identify exactly which items had been used in the data analyses but they could not establish without some doubt exactly which items had actually been used. Reference Wang, M.-T. and Eccles, J. S. (2014), Multilevel Predictors of Math Classroom Climate: A Comparison Study of Student and Teacher Perceptions. Journal of Research on Adolescence. doi: 10.1111/jora.12153. © 2014 The Authors. Journal of Research on Adolescence © 2014 Society for Research on Adolescence.

  10. RETRACTED: Effect of phentolamine on myocardial extracellular matrix of cardiac remodeling in rats.

    Science.gov (United States)

    Yin, Yi-Gang; Wang, Ru-Zhu; Ruan, Zhong-Bao; Zhu, Li

    2014-08-01

    This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the journal Editorial Office. The authors have plagiarized part of a paper that had already appeared in Chinese Journal of Arteriosclerosis 2014, 4, 362–366. article id: 1007–3949 (2014) 22-04-0362-05. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents an abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  11. Dll4-containing exosomes induce capillary sprout retraction in a 3D microenvironment

    Science.gov (United States)

    Sharghi-Namini, Soheila; Tan, Evan; Ong, Lee-Ling Sharon; Ge, Ruowen; Asada, H. Harry

    2014-01-01

    Delta-like 4 (Dll4), a membrane-bound Notch ligand, plays a fundamental role in vascular development and angiogenesis. Dll4 is highly expressed in capillary endothelial tip cells and is involved in suppressing neighboring stalk cells to become tip cells during angiogenesis. Dll4-Notch signaling is mediated either by direct cell-cell contact or by Dll4-containing exosomes from a distance. However, whether Dll4-containing exosomes influence tip cells of existing capillaries is unknown. Using a 3D microfluidic device and time-lapse confocal microscopy, we show here for the first time that Dll4-containing exosomes causes tip cells to lose their filopodia and trigger capillary sprout retraction in collagen matrix. We demonstrate that Dll4 exosomes can freely travel through 3D collagen matrix and transfer Dll4 protein to distant tip cells. Upon reaching endothelial sprout, it causes filopodia and tip cell retraction. Continuous application of Dll4 exosomes from a distance lead to significant reduction of sprout formation. This effect correlates with Notch signaling activation upon Dll4-containing exosome interaction with recipient endothelial cells. Furthermore, we show that Dll4-containing exosomes increase endothelial cell motility while suppressing their proliferation. These data revealed novel functions of Dll4 in angiogenesis through exosomes. PMID:24504253

  12. RETRACTED: Adaptive neuro-fuzzy prediction of modulation transfer function of optical lens system

    Science.gov (United States)

    Petković, Dalibor; Shamshirband, Shahaboddin; Anuar, Nor Badrul; Md Nasir, Mohd Hairul Nizam; Pavlović, Nenad T.; Akib, Shatirah

    2014-07-01

    This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor. Sections ;1. Introduction; and ;2. Modulation transfer function;, as well as Figures 1-3, plagiarize the article published by N. Gül and M. Efe in Turk J Elec Eng & Comp Sci 18 (2010) 71 (http://journals.tubitak.gov.tr/elektrik/issues/elk-10-18-1/elk-18-1-6-0811-9.pdf). Sections ;4. Adaptive neuro-fuzzy inference system; and ;6. Conclusion; duplicate parts of the articles previously published by the corresponding author et al in ;Expert Systems with Applications; 39 (2012) 13295-13304, http://dx.doi.org/10.1016/j.eswa.2012.05.072 and ;Expert Systems with Applications; 40 (2013) 281-286, http://dx.doi.org/10.1016/j.eswa.2012.07.076. One of the conditions of submission of a paper for publication is that authors declare explicitly that the paper is not under consideration for publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents an abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

  13. Effect of intrusive and retraction forces in labial and lingual orthodontics: A finite element study

    Directory of Open Access Journals (Sweden)

    Rohan Mascarenhas

    2014-01-01

    Full Text Available Objectives: Lingual orthodontics differs in biomechanics as compared to labial system and has biomechanical advantages. Although theoretical approaches have explained the differences between labial and lingual orthodontics, the finite element method (FEM may be better suited to analyze these differences. This study analyzes the effect of vertical and horizontal forces together on the tooth using FEM. Materials and Methods: An extracted right maxillary central incisor was radiographed and was used to create a solid model using ANSYS. The geometric model was converted into a finite element model with the help of ANSYS software. The model consists of 27,000 elements and 30,000 nodes. Two force vectors (vertical and horizontal were applied labially and lingually at 3 different heights- 4 mm, 5 mm and 6 mm from the incisal edge. Results: In the labial system, the net force vector passes through the center of resistance (CR and brings about intrusion. The net force vector in lingual orthodontics does not pass through the center of resistance and produces lingual tipping of the incisors. Conclusion: Intrusion and retraction forces bring about tipping of incisors in lingual orthodontics. The same amount of intrusion and retraction forces brings about intrusion of incisors in labial orthodontics. Therefore, direction and amount of forces should be carefully and judiciously applied after taking into consideration the resultant biomechanical differences.

  14. Retraction: Sleep Organisation in Depression and Schizophrenia: Index of Endogenous Periodicity of Sleep as a State Marker

    Directory of Open Access Journals (Sweden)

    Mirko Spiroski

    2014-06-01

    Full Text Available The article published by Ilankovic et al., 2013 [1] has been retracted by Editor-in-Chief because corresponding author published the similar paper in Psychiatria Danubina in 2014 [2]. An internal investigation has raised sufficient evidence of the originality in the first paper [1] and self plagiarism in the second paper [2]; as such, we retract this article from the literature on request by corresponding author and in accordance with guidelines and best editorial practices from the Committee on Publication Ethics. We apologize to our audience about this unfortunate situation.

  15. RETRACTED: Carotenoids, Mycosporine-Like Amino Acid Compounds, Phycobiliproteins, And Scytonemin In The Genus Scytonema (Cyanobacteria): A Chemosystematic Study(1).

    Science.gov (United States)

    Asencio, Antonia D; García-Pichel, Ferrán; Hoffmann, Lucien

    2011-08-22

    The following article from the Journal of Phycology, "Carotenoids, Mycosporine-Like Amino Acid Compounds, Phycobiliproteins, And Scytonemin In The Genus Scytonema (Cyanobacteria): A Chemosystematic Study," submitted by Antonia D. Asencio, and published online on August 22, 2011 on Wiley Online Library (http://www.wileyonlinelibrary.com), has been retracted by agreement between the journal Editor, Robert Sheath, and Wiley Periodicals, Inc. The retraction has been agreed upon request by Ferran Garcia-Pichel, listed as co-author, but not having agreed to the submission or publication of the manuscript. © 2011 Phycological Society of America.

  16. Gliadin fragments promote migration of dendritic cells

    Czech Academy of Sciences Publication Activity Database

    Chládková, Barbara; Kamanová, Jana; Palová-Jelínková, Lenka; Cinová, Jana; Šebo, Peter; Tučková, Ludmila

    2011-01-01

    Roč. 15, č. 4 (2011), 938-948 ISSN 1582-1838 R&D Projects: GA ČR GA310/07/0414; GA ČR GD310/08/H077; GA ČR GA310/08/0447; GA AV ČR IAA500200801; GA AV ČR IAA500200914 Institutional research plan: CEZ:AV0Z50200510 Keywords : celiac disease * gliadin * dendritic cell Subject RIV: EC - Immunology Impact factor: 4.125, year: 2011

  17. Viruses, dendritic cells and the lung

    Directory of Open Access Journals (Sweden)

    Graham Barney S

    2001-06-01

    Full Text Available Abstract The interaction between viruses and dendritic cells (DCs is varied and complex. DCs are key elements in the development of a host response to pathogens such as viruses, but viruses have developed survival tactics to either evade or diminish the immune system that functions to kill and eliminate these micro-organisms. In the present review we summarize current concepts regarding the function of DCs in the immune system, our understanding of how viruses alter DC function to attenuate both the virus-specific and global immune response, and how we may be able to exploit DC function to prevent or treat viral infections.

  18. Dendritic Cells as Danger-Recognizing Biosensors

    Directory of Open Access Journals (Sweden)

    Seokmann Hong

    2009-08-01

    Full Text Available Dendritic cells (DCs are antigen presenting cells that are characterized by a potent capacity to initiate immune responses. DCs comprise several subsets with distinct phenotypes. After sensing any danger(s to the host via their innate immune receptors such as Toll-like receptors, DCs become mature and subsequently present antigens to CD4+ T cells. Since DCs possess the intrinsic capacity to polarize CD4+ helper cells, it is critical to understand the immunological roles of DCs for clinical applications. Here, we review the different DC subsets, their danger-sensing receptors and immunological functions. Furthermore, the cytokine reporter mouse model for studying DC activation is introduced.

  19. Evaluation of Optimal Implant Positions and Height of Retraction Hook for Intrusive and Bodily Movement of Anterior Teeth in Sliding Mechanics: A FEM Study

    Directory of Open Access Journals (Sweden)

    Shrinivas S Ashekar

    2013-01-01

    Results and conclusions: In low OMI (6 mm anteriors showed tipping movement. Mid implant condition (8 mm showed more of bodily movement during retraction as the force passes near or through the CRs of all the six anterior teeth. In high OMI (10 mm and 0 mm ARH condition, all the six anterior teeth showed intrusion with retraction.

  20. Orexin A Inhibits Propofol-Induced Neurite Retraction by a Phospholipase D/Protein Kinase Cε-Dependent Mechanism in Neurons

    Science.gov (United States)

    Björnström, Karin; Turina, Dean; Strid, Tobias; Sundqvist, Tommy; Eintrei, Christina

    2014-01-01

    Background The intravenous anaesthetic propofol retracts neurites and reverses the transport of vesicles in rat cortical neurons. Orexin A (OA) is an endogenous neuropeptide regulating wakefulness and may counterbalance anaesthesia. We aim to investigate if OA interacts with anaesthetics by inhibition of the propofol-induced neurite retraction. Methods In primary cortical cell cultures from newborn rats’ brains, live cell light microscopy was used to measure neurite retraction after propofol (2 µM) treatment with or without OA (10 nM) application. The intracellular signalling involved was tested using a protein kinase C (PKC) activator [phorbol 12-myristate 13-acetate (PMA)] and inhibitors of Rho-kinase (HA-1077), phospholipase D (PLD) [5-fluoro-2-indolyl des-chlorohalopemide (FIPI)], PKC (staurosporine), and a PKCε translocation inhibitor peptide. Changes in PKCε Ser729 phosphorylation were detected with Western blot. Results The neurite retraction induced by propofol is blocked by Rho-kinase and PMA. OA blocks neurite retraction induced by propofol, and this inhibitory effect could be prevented by FIPI, staurosporine and PKCε translocation inhibitor peptide. OA increases via PLD and propofol decreases PKCε Ser729 phosphorylation, a crucial step in the activation of PKCε. Conclusions Rho-kinase is essential for propofol-induced neurite retraction in cortical neuronal cells. Activation of PKC inhibits neurite retraction caused by propofol. OA blocks propofol-induced neurite retraction by a PLD/PKCε-mediated pathway, and PKCε maybe the key enzyme where the wakefulness and anaesthesia signal pathways converge. PMID:24828410

  1. DaPeCa-3

    DEFF Research Database (Denmark)

    Jakobsen, Jakob K; Alslev, Louise; Ipsen, Pia

    2015-01-01

    OBJECTIVES: To estimate the diagnostic accuracy of sentinel node biopsy (SNB) combined with preoperative (18) F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) for inguinal lymph node (LN) evaluation in patients with invasive penile squamous cell carcinoma (PSCC...... centres treating penile cancer in Denmark. All patients had FDG PET/CT before SNB. The sentinel LNs were preoperatively located by planar lymphoscintigraphy in 134 groins (68 patients) and by single-photon emission CT/CT in 120 groins (61 patients). The primary endpoints were the sensitivity, specificity.......4% (95% confidence interval [CI] 81-99%) per groin. The false-negative rate was 5.6% (95% CI 1-19%) per groin. In 15 patients (11.6%) there were 25 SNB-related complications of Clavien-Dindo grades I-IIIa. The only Clavien-Dindo IIIa complication was an inguinal lymphocele treated by aspiration...

  2. Musical representation of dendritic spine distribution: a new exploratory tool.

    Science.gov (United States)

    Toharia, Pablo; Morales, Juan; de Juan, Octavio; Fernaud, Isabel; Rodríguez, Angel; DeFelipe, Javier

    2014-04-01

    Dendritic spines are small protrusions along the dendrites of many types of neurons in the central nervous system and represent the major target of excitatory synapses. For this reason, numerous anatomical, physiological and computational studies have focused on these structures. In the cerebral cortex the most abundant and characteristic neuronal type are pyramidal cells (about 85 % of all neurons) and their dendritic spines are the main postsynaptic target of excitatory glutamatergic synapses. Thus, our understanding of the synaptic organization of the cerebral cortex largely depends on the knowledge regarding synaptic inputs to dendritic spines of pyramidal cells. Much of the structural data on dendritic spines produced by modern neuroscience involves the quantitative analysis of image stacks from light and electron microscopy, using standard statistical and mathematical tools and software developed to this end. Here, we present a new method with musical feedback for exploring dendritic spine morphology and distribution patterns in pyramidal neurons. We demonstrate that audio analysis of spiny dendrites with apparently similar morphology may "sound" quite different, revealing anatomical substrates that are not apparent from simple visual inspection. These morphological/music translations may serve as a guide for further mathematical analysis of the design of the pyramidal neurons and of spiny dendrites in general.

  3. Blastic Plasmacytoid Dendritic Cell Leukemia in a Black Malian

    African Journals Online (AJOL)

    2017-06-28

    Jun 28, 2017 ... adhesion molecule 1) by blastic plasmacytoid dendritic cell neoplasms. JAMA Dermatology 2014;150:73‑6. 11. Goren Sahin D, Akay OM, Uskudar Teke H, Andic N, Gunduz E. Gulbas Z. Blastic plasmacytoid dendritic cell leukemia successfully treated by autologous hematopoietic stem cell transplantation ...

  4. Barriers in the brain : resolving dendritic spine morphology and compartmentalization

    NARCIS (Netherlands)

    Adrian, Max; Kusters, Remy; Wierenga, Corette J; Storm, Cornelis; Hoogenraad, Casper C; Kapitein, Lukas C

    2014-01-01

    Dendritic spines are micron-sized protrusions that harbor the majority of excitatory synapses in the central nervous system. The head of the spine is connected to the dendritic shaft by a 50-400 nm thin membrane tube, called the spine neck, which has been hypothesized to confine biochemical and

  5. Redefining the gonadotrophin-releasing hormone neurone dendrite.

    Science.gov (United States)

    Campbell, R E; Suter, K J

    2010-07-01

    Gonadotrophin-releasing hormone (GnRH) neurones are the final output neurones of the complex synaptic network responsible for the central control of fertility. This scattered population of neurones has been shown to have remarkably long dendritic processes by cell-filling of GnRH neurones in situ with low-molecular weight dyes. This review focuses on how the functional significance of these long dendritic extensions is being explored through dual somatic-dendritic electrophysiological recordings, computational modelling, immunolabelling for specific channels and multiple modes of microscopy and imaging. Remarkably, recent work has discovered that GnRH neurone dendrites not only actively propagate action potentials, but also comprise the primary site of action potential initiation. These findings, along with the discovery of regionalized expression of active conductances, highlight dendrites of single GnRH neurones as being central sites of signal integration. Moreover, imaging studies have shown that the long dendrites of GnRH neurones intertwine and bundle with one another. The presence of shared synaptic input to bundling dendrites, coupled with their active properties and the increased potency of distally placed synaptic inputs, is suggestive of a novel mechanism of GnRH neurone synchronisation, a feature critical for mammalian reproduction. Together, these discoveries of the GnRH neurone dendrite structure and function are changing the way that we view the central regulation of fertility.

  6. Differential expression of tetraspanin superfamily members in dendritic cell subsets

    NARCIS (Netherlands)

    M. Zuidscherwoude (Malou); K. Worah (Kuntal); A. Van Der Schaaf (Alie); S.I. Buschow (Sonja I.); A.B. Spriel (Annemiek )

    2017-01-01

    textabstractDendritic cells (DCs), which are essential for initiating immune responses, are comprised of different subsets. Tetraspanins organize dendritic cell membranes by facilitating protein-protein interactions within the so called tetraspanin web. In this study we analyzed expression of the

  7. Differential expression of tetraspanin superfamily members in dendritic cell subsets

    NARCIS (Netherlands)

    Zuidscherwoude, M.C.; Worah, K.; Schaaf, A. van der; Buschow, S.I.; Spriel, A.B. van

    2017-01-01

    Dendritic cells (DCs), which are essential for initiating immune responses, are comprised of different subsets. Tetraspanins organize dendritic cell membranes by facilitating protein-protein interactions within the so called tetraspanin web. In this study we analyzed expression of the complete

  8. Dendritic cell-based immunotherapy in ovarian cancer.

    Science.gov (United States)

    Coosemans, An; Vergote, Ignace; Van Gool, Stefaan W

    2013-12-01

    Worldwide, 80% of patients with ovarian cancer die of the disease. New treatments for this aggressive disease are therefore being intensively searched. Although dendritic cell-based vaccines against gynecological malignancies are in their infancy, this immunotherapeutic approach holds much promise. Here, we present our view on an optimal dendritic cell-based immunotherapeutic strategy against ovarian cancer.

  9. Retraction: Association between the use of biomass fuels on respiratory health of workers in food catering enterprises in Nairobi Kenya. Pan Afr Med J. 2013 May 6;15:12. doi: 10.11604/pamj.2013.15.12.1831.

    Science.gov (United States)

    2014-01-01

    The editors of the Pan African Medical Journal retract the manuscript above. The manuscript has been the subject of a protracted and unresolved authors dispute. Not all the authors listed in this manuscript consented to the retraction.

  10. Retracted article: Kokorina A.A., Pavlutsky D.A. Problems of the land tax in the Republic Buryatia. Statistics and Economics. 2016;(3:21-25. (In Russ. DOI:10.21686/2500-3925-2016-3-21-25

    Directory of Open Access Journals (Sweden)

    article Editorial

    2017-01-01

    Full Text Available This article by Anna A. Kokorina, Darya A. Pavlutsky has been retracted (i.e. withdrawn from the press by the editor with permission of the publisher.Retracted article due to duplicate publication.

  11. Immune monitoring using mRNA-transfected dendritic cells

    DEFF Research Database (Denmark)

    Borch, Troels Holz; Svane, Inge Marie; Met, Özcan

    2016-01-01

    Dendritic cells are known to be the most potent antigen presenting cell in the immune system and are used as cellular adjuvants in therapeutic anticancer vaccines using various tumor-associated antigens or their derivatives. One way of loading antigen into the dendritic cells is by m......RNA electroporation, ensuring presentation of antigen through major histocompatibility complex I and potentially activating T cells, enabling them to kill the tumor cells. Despite extensive research in the field, only one dendritic cell-based vaccine has been approved. There is therefore a great need to elucidate...... and understand the immunological impact of dendritic cell vaccination in order to improve clinical benefit. In this chapter, we describe a method for performing immune monitoring using peripheral blood mononuclear cells and autologous dendritic cells transfected with tumor-associated antigen-encoding mRNA....

  12. Dendrite coherency point: determination and significance

    Energy Technology Data Exchange (ETDEWEB)

    Veldman, N.L.M.; St John, D.H. [Queensland Univ., St. Lucia, QLD (Australia); Dahle, A.K.; Arnberg, L. [Norwegian University of Science and Technology, Trondheim (Norway)

    1996-09-01

    Measurements of the rheological properties of solidifying alloys have shown that the fraction solid at which dendrite coherency is reached varies systematically as a function of both alloy and solidification parameters. The coherency point of the alloys under investigation was determined in two different ways. Each method is based on indirect measurements of a physical property of the material which is assumed to undergo a significant liquid-solid transition at the dendrite coherency point. The coherency fraction solid for Al-Cu-Si alloys was found to decrease with increasing solute concentration. AA601 was found to have a higher coherency fraction solid than binary Al-7 wt%Si. Increasing the cooling rate was found to increase the coherency fraction solid of the alloys, as measured with the thermal analysis technique. Variation between the coherency fraction solids determined by rheological and thermal analysis methods are considered to be related to the different coherency criterion used in each experimental method. 15 refs., 6 figs.

  13. Dendritic growth model of multilevel marketing

    Science.gov (United States)

    Pang, James Christopher S.; Monterola, Christopher P.

    2017-02-01

    Biologically inspired dendritic network growth is utilized to model the evolving connections of a multilevel marketing (MLM) enterprise. Starting from agents at random spatial locations, a network is formed by minimizing a distance cost function controlled by a parameter, termed the balancing factor bf, that weighs the wiring and the path length costs of connection. The paradigm is compared to an actual MLM membership data and is shown to be successful in statistically capturing the membership distribution, better than the previously reported agent based preferential attachment or analytic branching process models. Moreover, it recovers the known empirical statistics of previously studied MLM, specifically: (i) a membership distribution characterized by the existence of peak levels indicating limited growth, and (ii) an income distribution obeying the 80 - 20 Pareto principle. Extensive types of income distributions from uniform to Pareto to a "winner-take-all" kind are also modeled by varying bf. Finally, the robustness of our dendritic growth paradigm to random agent removals is explored and its implications to MLM income distributions are discussed.

  14. Analyzing dendritic growth in a population of immature neurons in the adult dentate gyrus using laminar quantification of disjointed dendrites

    Directory of Open Access Journals (Sweden)

    Shira eRosenzweig

    2011-03-01

    Full Text Available In the dentate gyrus of the hippocampus, new granule neurons are continuously produced throughout adult life. A prerequisite for the successful synaptic integration of these neurons is the sprouting and extension of dendrites into the molecular layer of the dentate gyrus. Thus, studies aimed at investigating the developmental stages of adult neurogenesis often use dendritic growth as an important indicator of neuronal health and maturity. Based on the known topography of the dentate gyrus, characterized by distinct laminar arrangement of granule neurons and their extensions, we have developed a new method for analysis of dendritic growth in immature adult-born granule neurons. The method is comprised of laminar quantification of cell bodies, primary, secondary and tertiary dendrites separately and independently from each other. In contrast to most existing methods, laminar quantification of dendrites does not require the use of exogenous markers and does not involve arbitrary selection of individual neurons. The new method relies on immonuhistochemical detection of endogenous markers such as doublecortin to perform a comprehensive analysis of a sub-population of immature neurons. Disjointed, orphan dendrites that often appear in the thin histological sections are taken into account. Using several experimental groups of rats and mice, we demonstrate here the suitable techniques for quantifying neurons and dendrites, and explain how the ratios between the quantified values can be used in a comparative analysis to indicate variations in dendritic growth and complexity.

  15. Loss of Dendritic Complexity Precedes Neurodegeneration in a Mouse Model with Disrupted Mitochondrial Distribution in Mature Dendrites

    Directory of Open Access Journals (Sweden)

    Guillermo López-Doménech

    2016-10-01

    Full Text Available Correct mitochondrial distribution is critical for satisfying local energy demands and calcium buffering requirements and supporting key cellular processes. The mitochondrially targeted proteins Miro1 and Miro2 are important components of the mitochondrial transport machinery, but their specific roles in neuronal development, maintenance, and survival remain poorly understood. Using mouse knockout strategies, we demonstrate that Miro1, as opposed to Miro2, is the primary regulator of mitochondrial transport in both axons and dendrites. Miro1 deletion leads to depletion of mitochondria from distal dendrites but not axons, accompanied by a marked reduction in dendritic complexity. Disrupting postnatal mitochondrial distribution in vivo by deleting Miro1 in mature neurons causes a progressive loss of distal dendrites and compromises neuronal survival. Thus, the local availability of mitochondrial mass is critical for generating and sustaining dendritic arbors, and disruption of mitochondrial distribution in mature neurons is associated with neurodegeneration.

  16. Differential gating of dendritic spikes by compartmentalized inhibition

    Directory of Open Access Journals (Sweden)

    Katharina Anna Wilmes

    2014-03-01

    Full Text Available Different types of local inhibitory interneurons innervate different dendritic sites of pyramidal neurons in cortex and hippocampus (Klausberger 2009. What could be the functional role of compartmentalized inhibition? Pyramidal cell dendrites support different forms of active signal propagation, which are important not only for dendritic and neuronal signal processing (Smith et al. 2013, but also for synaptic plasticity. While back-propagating action potentials signal post-synaptic activity to synapses in apical oblique and basal dendrites (Markram et al. 1997, Cho et al. 2006, calcium spikes cause plasticity of distal apical tuft synapses (Golding et al. 2002. Suspiciously, the associated regions of the dendrite are targeted by different interneuron populations. Parvalbumin-positive interneurons typically target the proximal dendritic and somatic parts of the neuron, while somatostatin-positive interneurons target the apical dendrite. The matching compartmentalization in terms of dendritic spikes and inhibitory control suggests that inhibition could differentially regulate different dendritic spikes and thereby introduce a compartment-specific modulation of synaptic plasticity. We evaluate this hypothesis in a biophysical multi-compartment model of a pyramidal neuron, receiving shunting inhibition at different locations on the dendrite. The model shows that, first, inhibition can gate dendritic spikes in an all-or-none manner. Second, spatially selective inhibition can individually suppress back-propagating action potentials and calcium spikes, thereby allowing a compartment-specific switch for synaptic plasticity. In our model, proximal inhibition on the apical dendrite eliminated both the back-propagating action potential and the calcium spike, thus influencing plasticity in the whole apical dendrite. Distal apical inhibition could selectively affect calcium spikes and thus distal plasticity, without suppressing back­propagation of action

  17. Real-time CARS imaging reveals a calpain-dependent pathway for paranodal myelin retraction during high-frequency stimulation.

    Directory of Open Access Journals (Sweden)

    Terry B Huff

    2011-03-01

    Full Text Available High-frequency electrical stimulation is becoming a promising therapy for neurological disorders, however the response of the central nervous system to stimulation remains poorly understood. The current work investigates the response of myelin to electrical stimulation by laser-scanning coherent anti-Stokes Raman scattering (CARS imaging of myelin in live spinal tissues in real time. Paranodal myelin retraction at the nodes of Ranvier was observed during 200 Hz electrical stimulation. Retraction was seen to begin minutes after the onset of stimulation and continue for up to 10 min after stimulation was ceased, but was found to reverse after a 2 h recovery period. The myelin retraction resulted in exposure of Kv 1.2 potassium channels visualized by immunofluorescence. Accordingly, treating the stimulated tissue with a potassium channel blocker, 4-aminopyridine, led to the appearance of a shoulder peak in the compound action potential curve. Label-free CARS imaging of myelin coupled with multiphoton fluorescence imaging of immuno-labeled proteins at the nodes of Ranvier revealed that high-frequency stimulation induced paranodal myelin retraction via pathologic calcium influx into axons, calpain activation, and cytoskeleton degradation through spectrin break-down.

  18. Filopodial retraction force is generated by cortical actin dynamics and controlled by reversible tethering at the tip

    DEFF Research Database (Denmark)

    Bornschlögl, Thomas; Romero, Stéphane; Vestergaard, Christian L.

    2013-01-01

    Filopodia are dynamic, finger-like plasma membrane protrusions that sense the mechanical and chemical surroundings of the cell. Here, we show in epithelial cells that the dynamics of filopodial extension and retraction are determined by the difference between the actin polymerization rate at the ...

  19. The effect of maxillary first premolar extraction and incisor retraction on mandibular position: testing the central dogma of "functional orthodontics".

    Science.gov (United States)

    Luecke, P E; Johnston, L E

    1992-01-01

    It has been argued by a vocal coterie of disaffected dentists that premolar extraction, incisor retraction, and "backward-pulling" mechanics conspire to "distalize" the condyles and, pari passu, to produce craniomandibular dysfunction. Given the gravity of this conjecture, it seemed appropriate to test the predictions it generates in a sample of patients of the type most often said to be at risk: 42 "edgewise" patients with Class II, Division 1 malocclusions, treated in conjunction with the extraction of two maxillary first premolars. Regional and anterior cranial-base cephalometric superimpositions were used to quantify the individual components of the molar and overjet corrections, to measure both at the chin and condyles the mandibular displacement seen during treatment, and to examine the extent to which this displacement is related to the correction of maxillary incisor protrusion. Although the present patients underwent marked upper incisor retraction (on average, about 5 mm), lip retraction was much less pronounced, and 70% of the sample showed a net forward displacement of mandibular basal bone. Significantly, changes in condylar position were not correlated with incisor retraction, as the "functional orthodontists" would have it, but rather with the changes in the buccal occlusion and the growth of the maxilla. Thus, 30% of the patients who showed evidence of distal displacement were generally nongrowing patients who underwent more than average anchorage loss in the mandible and less than average loss in the maxilla.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. RETRACTION: Reply to Editorial Comment Regarding "X:Y Sperm Ratio in Boron Exposed Men," by Robbins et al. 2008.

    Science.gov (United States)

    Robbins, Wendie A; Elashoff, David A; Xun, Lin; Jia, Juan

    2011-06-30

    The Editorial Response listed above, which did not appear in the print journal, was retracted by the Editors of the Journal of Andrology with the consent of the authors because the significant delay in processing the Editorial Response has rendered the information contained in it not currently relevant. The Editors extend their apologies to the authors and to the scientific community.

  1. Rotator cuff muscles lose responsiveness to anabolic steroids after tendon tear and musculotendinous retraction: an experimental study in sheep.

    Science.gov (United States)

    Gerber, Christian; Meyer, Dominik C; Von Rechenberg, Brigitte; Hoppeler, Hans; Frigg, Robert; Farshad, Mazda

    2012-11-01

    Long-standing rotator cuff tendon tearing is associated with retraction, loss of work capacity, irreversible fatty infiltration, and atrophy of the rotator cuff muscles. Although continuous musculotendinous relengthening can experimentally restore muscular architecture, restoration of atrophy and fatty infiltration is hitherto impossible. Continuous relengthening with pharmacological stimulation of muscle growth using an anabolic steroid or insulin-like growth factor (IGF) can reverse atrophy and fatty infiltration as well as improve the work capacity of chronically retracted rotator cuff muscles in sheep. Controlled laboratory study. Sixteen weeks after tenotomy of the infraspinatus (ISP) tendon, atrophy and fatty infiltration had developed in the retracted ISP muscle. The musculotendinous unit was continuously relengthened in 14 sheep during 6 weeks: Four sheep were treated without pharmacological stimulation, 4 with intramuscular administration of an anabolic steroid, and 6 with IGF before final repair and rehabilitation (12 weeks). Changes were documented by intraoperative measurements of muscle work capacity, histology, and computed tomography/magnetic resonance imaging. Musculotendinous relengthening by continuous traction resulted in gains of length ranging from 0.7 cm in the IGF group to 1.3 cm in the control group. Fatty infiltration progressed in all groups, and the muscle's cross-sectional area ranged from 71% to 74% of the contralateral side at sacrifice and did not show any differences between groups in weight, volume, histological composition, or work capability of the muscle. The contralateral muscles in the anabolic steroid group, however, showed significantly higher (mean ± standard deviation) muscle work capacity of 10 ± 0.9 N·m than the contralateral muscles of the control group (6.8 ± 2.4 N·m) (P muscle fiber area as well as by an unusual gain in the animals' weight after injection of the anabolic steroid. Subcutaneous continuous

  2. Relative efficacy of transcranial motor evoked potentials, mechanically-elicited electromyography, and evoked EMG to assess nerve root function during sustained retraction in a porcine model.

    Science.gov (United States)

    Lyon, Russ; Lieberman, Jeremy A; Feiner, John; Burch, Shane

    2009-07-15

    This is an animal experiment using transcranial motor evoked potentials (TcMEP), mechanically elicited electromyography (EMG), and evoked EMG during spinal nerve root retraction in a pig model. To compare the sensitivity of these 3 electrophysiological measures for a constant retraction force applied to an isolated lumbar nerve root for a specific duration of time. The incidence of nerve root injury during lumbar spine surgery ranges from 0.2% to 31%. Direct retraction of spinal nerve roots may cause these injuries, but the amount and duration of force that may safely be applied is not clear. Using an established porcine model, we examined the changes occurring to multimyotomal TcMEPs, mechanically elicited EMGs, and evoked EMGs during continuous retraction of a nerve root at a constant force applied over 10 minutes. TcMEP, mechanically elicited EMG, and evoked EMG responses were recorded from the tibialis anterior (TA) muscle in 10 experiments. The dominant root innervating the TA was determined with evoked EMG; preretraction TcMEP and nerve root stimulation threshold (NRT) was obtained. The dominant root was retracted at 2 Newton (N) for 10 minutes. TcMEP trials were elicited every minute during retraction. NRT was measured immediately after retraction. TcMEP and NRT were measured after 10 minutes of recovery. RESULTS.: During the 10 minutes of retraction at 2 N, the amplitude of the TA muscle progressively decreased in all trials in a highly significant curvilinear fashion. The mean TcMEP amplitude decreased 59% +/- 14% from baseline values. The mean NRT after 10 minutes of retraction at 2 N rose to 1.8 +/- 0.7 mA (P EMG activity was variable; tonic EMG was observed in only 2 nerve roots (20%). Three electrophysiologic methods were used intraoperatively to assess neural function during retraction of a single nerve root. Retraction produced consistent changes in TcMEPs and evoked EMG. These 2 methods show promise for assessing the limits on the force and duration

  3. Human CHN1 mutations hyperactivate α2-chimaerin and cause Duane’s retraction syndrome

    Science.gov (United States)

    Miyake, Noriko; Chilton, John; Psatha, Maria; Cheng, Long; Andrews, Caroline; Chan, Wai-Man; Law, Krystal; Crosier, Moira; Lindsay, Susan; Cheung, Michelle; Allen, James; Gutowski, Nick J; Ellard, Sian; Young, Elizabeth; Iannaccone, Alessandro; Appukuttan, Binoy; Stout, J. Timothy; Christiansen, Stephen; Ciccarelli, Maria Laura; Baldi, Alfonso; Campioni, Mara; Zenteno, Juan C.; Davenport, Dominic; Mariani, Laura E.; Sahin, Mustafa; Guthrie, Sarah; Engle, Elizabeth C.

    2008-01-01

    The RacGAP molecule α2-chimaerin is implicated in neuronal signaling pathways required for precise guidance of developing corticospinal axons. We now demonstrate that a variant of Duane’s retraction syndrome, a congenital eye movement disorder in which affected individuals show aberrant development of axon projections to the extraocular muscles, can result from gain-of-function heterozygous missense mutations in CHN1 that increase α2-chimaerin RacGAP activity in vitro. A subset of mutations enhances α2-chimaerin membrane translocation and/or α2-chimaerin’s previously unrecognized ability to form a complex with itself. In ovo expression of mutant CHN1 alters the development of ocular motor axons. These data demonstrate that human CHN1 mutations can hyperactivate α2-chimaerin and result in aberrant cranial motor neuron development. PMID:18653847

  4. Dendritic mitochondria reach stable positions during circuit development

    Science.gov (United States)

    Faits, Michelle C; Zhang, Chunmeng; Soto, Florentina; Kerschensteiner, Daniel

    2016-01-01

    Mitochondria move throughout neuronal dendrites and localize to sites of energy demand. The prevailing view of dendritic mitochondria as highly motile organelles whose distribution is continually adjusted by neuronal activity via Ca2+-dependent arrests is based on observations in cultured neurons exposed to artificial stimuli. Here, we analyze the movements of mitochondria in ganglion cell dendrites in the intact retina. We find that whereas during development 30% of mitochondria are motile at any time, as dendrites mature, mitochondria all but stop moving and localize stably to synapses and branch points. Neither spontaneous nor sensory-evoked activity and Ca2+ transients alter motility of dendritic mitochondria; and pathological hyperactivity in a mouse model of retinal degeneration elevates rather than reduces motility. Thus, our findings indicate that dendritic mitochondria reach stable positions during a critical developmental period of high motility, and challenge current views about the role of activity in regulating mitochondrial transport in dendrites. DOI: http://dx.doi.org/10.7554/eLife.11583.001 PMID:26742087

  5. Adolescent cocaine exposure simplifies orbitofrontal cortical dendritic arbors

    Directory of Open Access Journals (Sweden)

    Lauren M DePoy

    2014-10-01

    Full Text Available Cocaine and amphetamine remodel dendritic spines within discrete cortico-limbic brain structures including the orbitofrontal cortex (oPFC. Whether dendrite structure is similarly affected, and whether pre-existing cellular characteristics influence behavioral vulnerabilities to drugs of abuse, remain unclear. Animal models provide an ideal venue to address these issues because neurobehavioral phenotypes can be defined both before, and following, drug exposure. We exposed mice to cocaine from postnatal days 31-35, corresponding to early adolescence, using a dosing protocol that causes impairments in an instrumental reversal task in adulthood. We then imaged and reconstructed excitatory neurons in deep-layer oPFC. Prior cocaine exposure shortened and simplified arbors, particularly in the basal region. Next, we imaged and reconstructed orbital neurons in a developmental-genetic model of cocaine vulnerability – the p190rhogap+/- mouse. p190RhoGAP is an actin cytoskeleton regulatory protein that stabilizes dendrites and dendritic spines, and p190rhogap+/- mice develop rapid and robust locomotor activation in response to cocaine. Despite this, oPFC dendritic arbors were intact in drug-naïve p190rhogap+/- mice. Together, these findings provide evidence that adolescent cocaine exposure has long-term effects on dendrite structure in the oPFC, and they suggest that cocaine-induced modifications in dendrite structure may contribute to the behavioral effects of cocaine more so than pre-existing structural abnormalities in this cell population.

  6. Germ band retraction as a landmark in glucose metabolism during Aedes aegypti embryogenesis

    Directory of Open Access Journals (Sweden)

    Logullo Carlos

    2010-02-01

    Full Text Available Abstract Background The mosquito A. aegypti is vector of dengue and other viruses. New methods of vector control are needed and can be achieved by a better understanding of the life cycle of this insect. Embryogenesis is a part of A. aegypty life cycle that is poorly understood. In insects in general and in mosquitoes in particular energetic metabolism is well studied during oogenesis, when the oocyte exhibits fast growth, accumulating carbohydrates, lipids and proteins that will meet the regulatory and metabolic needs of the developing embryo. On the other hand, events related with energetic metabolism during A. aegypti embryogenesis are unknown. Results Glucose metabolism was investigated throughout Aedes aegypti (Diptera embryonic development. Both cellular blastoderm formation (CBf, 5 h after egg laying - HAE and germ band retraction (GBr, 24 HAE may be considered landmarks regarding glucose 6-phosphate (G6P destination. We observed high levels of glucose 6-phosphate dehydrogenase (G6PDH activity at the very beginning of embryogenesis, which nevertheless decreased up to 5 HAE. This activity is correlated with the need for nucleotide precursors generated by the pentose phosphate pathway (PPP, of which G6PDH is the key enzyme. We suggest the synchronism of egg metabolism with carbohydrate distribution based on the decreasing levels of phosphoenolpyruvate carboxykinase (PEPCK activity and on the elevation observed in protein content up to 24 HAE. Concomitantly, increasing levels of hexokinase (HK and pyruvate kinase (PK activity were observed, and PEPCK reached a peak around 48 HAE. Glycogen synthase kinase (GSK3 activity was also monitored and shown to be inversely correlated with glycogen distribution during embryogenesis. Conclusions The results herein support the hypothesis that glucose metabolic fate changes according to developmental embryonic stages. Germ band retraction is a moment that was characterized as a landmark in glucose

  7. Rapid maxillary anterior teeth retraction en masse by bone compression: a canine model.

    Directory of Open Access Journals (Sweden)

    Chufeng Liu

    Full Text Available OBJECTIVE: The present study sought to establish an animal model to study the feasibility and safety of rapid retraction of maxillary anterior teeth en masse aided by alveolar surgery in order to reduce orthodontic treatment time. METHOD: Extraction of the maxillary canine and alveolar surgery were performed on twelve adult beagle dogs. After that, the custom-made tooth-borne distraction devices were placed on beagles' teeth. Nine of the dogs were applied compression at 0.5 mm/d for 12 days continuously. The other three received no force as the control group. The animals were killed in 1, 14, and 28 days after the end of the application of compression. RESULTS: The tissue responses were assessed by craniometric measurement as well as histological examination. Gross alterations were evident in the experimental group, characterized by anterior teeth crossbite. The average total movements of incisors within 12 days were 4.63±0.10 mm and the average anchorage losses were 1.25±0.12 mm. Considerable root resorption extending into the dentine could be observed 1 and 14 days after the compression. But after consolidation of 28 days, there were regenerated cementum on the dentine. There was no apparent change in the control group. No obvious tooth loosening, gingival necrosis, pulp degeneration, or other adverse complications appeared in any of the dogs. CONCLUSIONS: This is the first experimental study for testing the technique of rapid anterior teeth retraction en masse aided by modified alveolar surgery. Despite a preliminary animal model study, the current findings pave the way for the potential clinical application that can accelerate orthodontic tooth movement without many adverse complications. CLINICAL RELEVANCE: It may become a novel method to shorten the clinical orthodontic treatment time in the future.

  8. Three-dimensional canine displacement patterns in response to translation and controlled tipping retraction strategies.

    Science.gov (United States)

    Li, Shuning; Xia, Zeyang; Liu, Sean Shih-Yao; Eckert, George; Chen, Jie

    2015-01-01

    To validate whether applying a well-defined initial three-dimensional (3D) load can create consistently expected tooth movement in patients. Twenty-one patients who needed bilateral canine retraction to close extraction space were selected for this split-mouth clinical trial. After initial alignment and leveling, two canines in each patient were randomly assigned to receive either translation (TR) or controlled tipping (CT) load. The load was delivered by segmental T-loops designed to give specific initial moment/force ratios to the canines in each treatment interval (TI), verified with an orthodontic force tester. Maxillary dental casts were made before canine retraction and after each TI. The casts were digitized with a 3D laser scanner. The digital models were superimposed on the palatal rugae region. The 3D canine displacements and the displacement patterns in terms of TR, CT, and torque were calculated for each TI. The method can reliably detect a TR displacement greater than 0.3 mm and a rotation greater than 1.5°. Ninety-two TIs had displacements that were greater than 0.3 mm and were used for further analysis. Most displacements were oriented within ±45° from the distal direction. The displacement pattern in terms of TR or CT was not uniquely controlled by the initial moment/force ratio. The initial load system is not the only key factor controlling tooth movement. Using a segmental T-loop with a well-controlled load system, large variations in canine displacement can be expected clinically.

  9. Elastic Behavior and Platelet Retraction in Low- and High-Density Fibrin Gels

    Science.gov (United States)

    Wufsus, Adam R.; Rana, Kuldeepsinh; Brown, Andrea; Dorgan, John R.; Liberatore, Matthew W.; Neeves, Keith B.

    2015-01-01

    Fibrin is a biopolymer that gives thrombi the mechanical strength to withstand the forces imparted on them by blood flow. Importantly, fibrin is highly extensible, but strain hardens at low deformation rates. The density of fibrin in clots, especially arterial clots, is higher than that in gels made at plasma concentrations of fibrinogen (3–10 mg/mL), where most rheology studies have been conducted. Our objective in this study was to measure and characterize the elastic regimes of low (3–10 mg/mL) and high (30–100 mg/mL) density fibrin gels using shear and extensional rheology. Confocal microscopy of the gels shows that fiber density increases with fibrinogen concentration. At low strains, fibrin gels act as thermal networks independent of fibrinogen concentration. Within the low-strain regime, one can predict the mesh size of fibrin gels by the elastic modulus using semiflexible polymer theory. Significantly, this provides a link between gel mechanics and interstitial fluid flow. At moderate strains, we find that low-density fibrin gels act as nonaffine mechanical networks and transition to affine mechanical networks with increasing strains within the moderate regime, whereas high-density fibrin gels only act as affine mechanical networks. At high strains, the backbone of individual fibrin fibers stretches for all fibrin gels. Platelets can retract low-density gels by >80% of their initial volumes, but retraction is attenuated in high-density fibrin gels and with decreasing platelet density. Taken together, these results show that the nature of fibrin deformation is a strong function of fibrin fiber density, which has ramifications for the growth, embolization, and lysis of thrombi. PMID:25564864

  10. Retração rápida de caninos Rapid canine retraction

    Directory of Open Access Journals (Sweden)

    Paulo Renato Carvalho Ribeiro

    2011-02-01

    Full Text Available INTRODUÇÃO: a retração rápida de caninos por distração do ligamento periodontal é uma técnica de movimentação dentária que permite o fechamento de espaço da extração de primeiros pré-molares em um intervalo de duas ou três semanas, proporcionando uma redução significativa no tempo do tratamento ortodôntico. OBJETIVO: apresentar modificações propostas na técnica cirúrgica original e no posicionamento dos distratores. CONCLUSÕES: a retração rápida de caninos é uma técnica que proporciona uma redução significativa no tempo de tratamento ortodôntico. A modificação na técnica cirúrgica proporcionou maior velocidade e segurança ao ato cirúrgico. O distrator posicionado por palatina, no mínimo, proporcionou a preservação da tábua óssea vestibular e evitou a vestibularização dos caninos.INTRODUCTION: Rapid canine retraction through distraction of the periodontal ligament is a tooth movement technique that allows the closure of first premolar extraction space within a period of two to three weeks while providing significant reduction in orthodontic treatment time. OBJECTIVE: To propose changes in the original surgical technique and in the placement of distractors. CONCLUSIONS: Rapid canine retraction is a technique that provides significant reduction in orthodontic treatment time. Changes in the surgical technique provided greater speed and safety in surgery. As a minimum benefit, when positioned palatally, distractors helped to preserve the buccal bone plate and prevented canine proclination.

  11. Arm retraction dynamics of entangled star polymers: A forward flux sampling method study.

    Science.gov (United States)

    Zhu, Jian; Likhtman, Alexei E; Wang, Zuowei

    2017-07-28

    The study of dynamics and rheology of well-entangled branched polymers remains a challenge for computer simulations due to the exponentially growing terminal relaxation times of these polymers with increasing molecular weights. We present an efficient simulation algorithm for studying the arm retraction dynamics of entangled star polymers by combining the coarse-grained slip-spring (SS) model with the forward flux sampling (FFS) method. This algorithm is first applied to simulate symmetric star polymers in the absence of constraint release (CR). The reaction coordinate for the FFS method is determined by finding good agreement of the simulation results on the terminal relaxation times of mildly entangled stars with those obtained from direct shooting SS model simulations with the relative difference between them less than 5%. The FFS simulations are then carried out for strongly entangled stars with arm lengths up to 16 entanglements that are far beyond the accessibility of brute force simulations in the non-CR condition. Apart from the terminal relaxation times, the same method can also be applied to generate the relaxation spectra of all entanglements along the arms which are desired for the development of quantitative theories of entangled branched polymers. Furthermore, we propose a numerical route to construct the experimentally measurable relaxation correlation functions by effectively linking the data stored at each interface during the FFS runs. The obtained star arm end-to-end vector relaxation functions Φ(t) and the stress relaxation function G(t) are found to be in reasonably good agreement with standard SS simulation results in the terminal regime. Finally, we demonstrate that this simulation method can be conveniently extended to study the arm-retraction problem in entangled star polymer melts with CR by modifying the definition of the reaction coordinate, while the computational efficiency will depend on the particular slip-spring or slip-link model

  12. Discovery of a novel neurophysin-associated neuropeptide that triggers cardiac stomach contraction and retraction in starfish.

    Science.gov (United States)

    Semmens, Dean C; Dane, Robyn E; Pancholi, Mahesh R; Slade, Susan E; Scrivens, James H; Elphick, Maurice R

    2013-11-01

    Feeding in starfish is a remarkable process in which the cardiac stomach is everted over prey and then retracted when prey tissue has been resorbed. Previous studies have revealed that SALMFamide-type neuropeptides trigger cardiac stomach relaxation and eversion in the starfish Asterias rubens. We hypothesized, therefore, that a counteracting neuropeptide system controls cardiac stomach contraction and retraction. Members of the NG peptide family cause muscle contraction in other echinoderms (e.g. NGFFFamide in sea urchins and NGIWYamide in sea cucumbers), so we investigated NG peptides as candidate regulators of cardiac stomach retraction in starfish. Generation and analysis of neural transcriptome sequence data from A. rubens revealed a precursor protein comprising two copies of a novel NG peptide, NGFFYamide, which was confirmed by mass spectrometry. A noteworthy feature of the NGFFYamide precursor is a C-terminal neurophysin domain, indicative of a common ancestry with vasopressin/oxytocin-type neuropeptide precursors. Interestingly, in precursors of other NG peptides the neurophysin domain has been retained (e.g. NGFFFamide) or lost (e.g. NGIWYamide and human neuropeptide S) and its functional significance remains to be determined. Investigation of the pharmacological actions of NGFFYamide in starfish revealed that it is a potent stimulator of cardiac stomach contraction in vitro and that it triggers cardiac stomach retraction in vivo. Thus, discovery of NGFFYamide provides a novel insight into neural regulation of cardiac stomach retraction as well as a rationale for chemically based strategies to control starfish that feed on economically important shellfish (e.g. mussels) or protected marine fauna (e.g. coral).

  13. Preparation and Physical Properties of Segmented Thermoelectric YBa2Cu3O7‑x -Ca3Co4O9 Ceramics

    Science.gov (United States)

    Wannasut, P.; Keawprak, N.; Jaiban, P.; Watcharapasorn, A.

    2018-01-01

    Segmented thermoelectric ceramics are now well known for their high conversion efficiency and are currently being investigated in both basic and applied energy researches. In this work, the successful preparation of the segmented thermoelectric YBa2Cu3O7‑x -Ca3Co4O9 (YBCO-CCO) ceramic by hot pressing method and the study on its physical properties were presented. Under the optimum hot pressing condition of 800 °C temperature, 1-hour holding time and 1-ton weight, the segmented YBCO-CCO sample showed two strongly connected layers with the relative density of about 96%. The X-ray diffraction (XRD) patterns indicated that each segment showed pure phase corresponding to each respective composition. Scanning electron microscopy (SEM) results confirmed the sharp interface and good adhesion between YBCO and CCO layers. Although the chemical analysis indicated the limited inter-layer diffusion near the interface, some elemental diffusion at the boundary was expected to be the source of this strong bonding.

  14. Dietary Supplementation ofHericium erinaceusIncreases Mossy Fiber-CA3 Hippocampal Neurotransmission and Recognition Memory in Wild-Type Mice.

    Science.gov (United States)

    Brandalise, Federico; Cesaroni, Valentina; Gregori, Andrej; Repetti, Margherita; Romano, Chiara; Orrù, Germano; Botta, Laura; Girometta, Carolina; Guglielminetti, Maria Lidia; Savino, Elena; Rossi, Paola

    2017-01-01

    Hericium erinaceus (Bull.) Pers. is a medicinal mushroom capable of inducing a large number of modulatory effects on human physiology ranging from the strengthening of the immune system to the improvement of cognitive functions. In mice, dietary supplementation with H. erinaceus prevents the impairment of spatial short-term and visual recognition memory in an Alzheimer model. Intriguingly other neurobiological effects have recently been reported like the effect on neurite outgrowth and differentiation in PC12 cells. Until now no investigations have been conducted to assess the impact of this dietary supplementation on brain function in healthy subjects. Therefore, we have faced the problem by considering the effect on cognitive skills and on hippocampal neurotransmission in wild-type mice. In wild-type mice the oral supplementation with H. erinaceus induces, in behaviour test, a significant improvement in the recognition memory and, in hippocampal slices, an increase in spontaneous and evoked excitatory synaptic current in mossy fiber-CA3 synapse. In conclusion, we have produced a series of findings in support of the concept that H. erinaceus induces a boost effect onto neuronal functions also in nonpathological conditions.

  15. Dietary Supplementation of Hericium erinaceus Increases Mossy Fiber-CA3 Hippocampal Neurotransmission and Recognition Memory in Wild-Type Mice

    Science.gov (United States)

    Cesaroni, Valentina; Gregori, Andrej; Repetti, Margherita; Romano, Chiara; Orrù, Germano; Botta, Laura; Girometta, Carolina; Guglielminetti, Maria Lidia; Savino, Elena

    2017-01-01

    Hericium erinaceus (Bull.) Pers. is a medicinal mushroom capable of inducing a large number of modulatory effects on human physiology ranging from the strengthening of the immune system to the improvement of cognitive functions. In mice, dietary supplementation with H. erinaceus prevents the impairment of spatial short-term and visual recognition memory in an Alzheimer model. Intriguingly other neurobiological effects have recently been reported like the effect on neurite outgrowth and differentiation in PC12 cells. Until now no investigations have been conducted to assess the impact of this dietary supplementation on brain function in healthy subjects. Therefore, we have faced the problem by considering the effect on cognitive skills and on hippocampal neurotransmission in wild-type mice. In wild-type mice the oral supplementation with H. erinaceus induces, in behaviour test, a significant improvement in the recognition memory and, in hippocampal slices, an increase in spontaneous and evoked excitatory synaptic current in mossy fiber-CA3 synapse. In conclusion, we have produced a series of findings in support of the concept that H. erinaceus induces a boost effect onto neuronal functions also in nonpathological conditions. PMID:28115973

  16. Dietary Supplementation of Hericium erinaceus Increases Mossy Fiber-CA3 Hippocampal Neurotransmission and Recognition Memory in Wild-Type Mice

    Directory of Open Access Journals (Sweden)

    Federico Brandalise

    2017-01-01

    Full Text Available Hericium erinaceus (Bull. Pers. is a medicinal mushroom capable of inducing a large number of modulatory effects on human physiology ranging from the strengthening of the immune system to the improvement of cognitive functions. In mice, dietary supplementation with H. erinaceus prevents the impairment of spatial short-term and visual recognition memory in an Alzheimer model. Intriguingly other neurobiological effects have recently been reported like the effect on neurite outgrowth and differentiation in PC12 cells. Until now no investigations have been conducted to assess the impact of this dietary supplementation on brain function in healthy subjects. Therefore, we have faced the problem by considering the effect on cognitive skills and on hippocampal neurotransmission in wild-type mice. In wild-type mice the oral supplementation with H. erinaceus induces, in behaviour test, a significant improvement in the recognition memory and, in hippocampal slices, an increase in spontaneous and evoked excitatory synaptic current in mossy fiber-CA3 synapse. In conclusion, we have produced a series of findings in support of the concept that H. erinaceus induces a boost effect onto neuronal functions also in nonpathological conditions.

  17. An occurrence of tuite, γ-Ca3(PO4)2, partly transformed from Ca-phosphates in the Suizhou meteorite

    Science.gov (United States)

    Xie, Xiande; Gu, Xiangping; Chen, Ming

    2016-01-01

    Tuite is a high-pressure γ-form of Ca3(PO4)2. An occurrence of tuite partly transformed from merrillite and chlorapatite was observed in the chondritic area adjacent to the shock veins in the Suizhou meteorite. Tuite grains are found in contact with both merrillite and chlorapatite, indicating two different transformation pathways. Tuite isochemically transformed from merrillite contains much higher contents of Na2O and MgO than those transformed from chlorapatite. Tuite transformed from merrillite does not contain Cl, but tuite transformed from chlorapatite contains 1.90-3.91 wt% of Cl, hence indicating an incomplete phase transformation from chlorapatite to tuite. P-T conditions of above 12 GPa and 1100 °C are probably required for the transformation from merrillite and chlorapatite to tuite. A temperature gradient from the hot vein at 2000 °C to the surrounding chondritic area at 1000 °C corresponds to the partial phase transitions in the Suizhou phosphates. Fast cooling of the thin shock veins plays a key role in the preservation of phosphates that suffered partial high-pressure phase transformation.

  18. Investigation of the Geochemical Preservation of ca. 3.0 Ga Permineralized and Encapsulated Microfossils by Nanoscale Secondary Ion Mass Spectrometry

    Science.gov (United States)

    Delarue, Frédéric; Robert, François; Sugitani, Kenichiro; Tartèse, Romain; Duhamel, Rémi; Derenne, Sylvie

    2017-12-01

    Observations of Archean organic-walled microfossils suggest that their fossilization took place through both encapsulation and permineralization. In this study, we investigated microfossils from the ca. 3.0 Ga Farrel Quartzite (Pilbara, Western Australia) using transmitted light microscopy, scanning electron microscopy, Raman microspectrometry, and nanoscale secondary ion mass spectrometry (NanoSIMS) ion microprobe analyses. In contrast to previous studies, we demonstrated that permineralized microfossils were not characterized by the micrometric spatial relationships between Si and C-N as observed in thin sections. Permineralized microfossils are composed of carbonaceous globules that did not survive the acid treatment, whereas encapsulated microfossils were characterized due to their resistance to the acid maceration procedure. We also investigated the microscale relationship between the 12C14N- and 12C2- ion emission as a proxy of the N/C atomic ratio in both permineralized and encapsulated microfossils. After considering any potential matrix and microtopography effects, we demonstrate that the encapsulated microfossils exhibit the highest level of geochemical preservation. This finding shows that the chemical heterogeneity of the microfossils, observed at a spatial resolution of a few hundreds of micrometers, can be related to fossilization processes.

  19. Zinc Nanoparticles at Intercrystallite Sites of (Cu0.5Tl0.5Ba2Ca3Cu4O12−δ Superconductor

    Directory of Open Access Journals (Sweden)

    Irfan Qasim

    2016-01-01

    Full Text Available We synthesized Znx/(Cu0.5Tl0.5Ba2Ca3Cu4O12-δ  {Znx/CuTl-1234}(x = 0~3 wt.% nanoparticles-superconductor composites by solid-state reaction technique and examined the effects of zinc (Zn nanoparticles on structural and superconducting properties of CuTl-1234 phase. Unaltered crystal structure of host CuTl-1234 phase confirmed the existence of Zn nanoparticles at intercrystallite sites. We observed an improvement in grains size and intergrains connectivity by healing up the voids after incorporation of Zn nanoparticles in CuTl-1234 superconductor. Superconducting properties of Znx/CuTl-1234 composites were suppressed for all Zn nanoparticles concentrations. Suppression of zero resistivity critical temperature {Tc(0} and variation in normal state resistivity {ρ300 K (Ω-cm} were attributed to reduction of superconducting volume fractions and enhanced scattering cross section of mobile carriers.

  20. Dendritic cells and aging: consequences for autoimmunity.

    Science.gov (United States)

    Agrawal, Anshu; Sridharan, Aishwarya; Prakash, Sangeetha; Agrawal, Harsh

    2012-01-01

    The immune system has evolved to mount immune responses against foreign pathogens and to remain silent against self-antigens. A balance between immunity and tolerance is required as any disturbance may result in chronic inflammation or autoimmunity. Dendritic cells (DCs) actively participate in maintaining this balance. Under steady-state conditions, DCs remain in an immature state and do not mount an immune response against circulating self-antigens in the periphery, which maintains a state of tolerance. By contrast, foreign antigens result in DC maturation and DC-induced T-cell activation. Inappropriate maturation of DCs due to infections or tissue injury may cause alterations in the balance between the tolerogenic and immunogenic functions of DCs and instigate the development of autoimmune diseases. This article provides an overview of the effects of advancing age on DC functions and their implications in autoimmunity.

  1. Towards deep learning with segregated dendrites.

    Science.gov (United States)

    Guerguiev, Jordan; Lillicrap, Timothy P; Richards, Blake A

    2017-12-05

    Deep learning has led to significant advances in artificial intelligence, in part, by adopting strategies motivated by neurophysiology. However, it is unclear whether deep learning could occur in the real brain. Here, we show that a deep learning algorithm that utilizes multi-compartment neurons might help us to understand how the neocortex optimizes cost functions. Like neocortical pyramidal neurons, neurons in our model receive sensory information and higher-order feedback in electrotonically segregated compartments. Thanks to this segregation, neurons in different layers of the network can coordinate synaptic weight updates. As a result, the network learns to categorize images better than a single layer network. Furthermore, we show that our algorithm takes advantage of multilayer architectures to identify useful higher-order representations-the hallmark of deep learning. This work demonstrates that deep learning can be achieved using segregated dendritic compartments, which may help to explain the morphology of neocortical pyramidal neurons.

  2. Induction of RNA interference in dendritic cells.

    Science.gov (United States)

    Li, Mu; Qian, Hua; Ichim, Thomas E; Ge, Wei-Wen; Popov, Igor A; Rycerz, Katarzyna; Neu, John; White, David; Zhong, Robert; Min, Wei-Ping

    2004-01-01

    Dendritic cells (DC) reside at the center of the immunological universe, possessing the ability both to stimulate and inhibit various types of responses. Tolerogenic/regulatory DC with therapeutic properties can be generated through various means of manipulations in vitro and in vivo. Here we describe several attractive strategies for manipulation of DC using the novel technique of RNA interference (RNAi). Additionally, we overview some of our data regarding yet undescribed characteristics of RNAi in DC such as specific transfection strategies, persistence of gene silencing, and multi-gene silencing. The advantages of using RNAi for DC genetic manipulation gives rise to the promise of generating tailor-made DC that can be used effectively to treat a variety of immunologically mediated diseases.

  3. Killer dendritic cells: IKDC and the others.

    Science.gov (United States)

    Bonmort, Mathieu; Dalod, Marc; Mignot, Grégoire; Ullrich, Evelyn; Chaput, Nathalie; Zitvogel, Laurence

    2008-10-01

    Tumors can regress as a result of invading myeloid and lymphoid cells that act in concert. Although the myeloid cells are widely recognized as antigen presenters and lymphoid cells as classical effectors, recent evidence revealed the capacity of dendritic cells (DC) to kill tumor cells. The functional concept of 'natural killer (NK) myeloid DC' is supported by mouse and human in vitro data that may be clinically relevant because human killer DC can contribute to tumor shrinking during topical therapy with toll-like receptor (TLR) agonists. Whether tumor killing by DC is a 'catalyzing' step for efficient crosspresentation and/or a promoting step for an immunogenic cell death pathway remains an open question. We also discuss how interferon-producing killer DC (IKDC) may participate in the control of tumor progression.

  4. Maturation of dendritic cells by bacterial immunomodulators.

    Science.gov (United States)

    Spisek, Radek; Brazova, Jitka; Rozkova, Daniela; Zapletalova, Katerina; Sediva, Anna; Bartunkova, Jirina

    2004-07-29

    Dendritic cells (DC) become fully functional upon maturation by various stimuli. We tested whether an immunostimulatory effect of clinically used immunomodulators (Luivac, Biostim, Ribomunyl, Imudon, Bronchovaxom) is caused by direct DC activation. We found that Luivac, Biostim and Ribomunyl have a very high DC stimulatory potential in vitro. The level of DC activation was comparable or higher than DC maturation induced by standard maturation stimuli, Poly (I:C) or lipopolysaccharide. Treated DC had activated phenotype, reduced phagocytic activity and they induced the proliferation of allogeneic T lymphocytes. These results are important for understanding the physiology of action of these widely prescribed agents. Administration of bacterial immunomodulators should be considered with care to avoid the potential risk of inducing an autoimmune disease. They could also be used as well-defined maturating agents in the protocols used for the ex vivo production of DC-based vaccines for clinical trials.

  5. Targeting dendritic cells--why bother?

    Science.gov (United States)

    Kreutz, Martin; Tacken, Paul J; Figdor, Carl G

    2013-04-11

    Vaccination is among the most efficient forms of immunotherapy. Although sometimes inducing lifelong protective B-cell responses, T-cell-mediated immunity remains challenging. Targeting antigen to dendritic cells (DCs) is an extensively explored concept aimed at improving cellular immunity. The identification of various DC subsets with distinct functional characteristics now allows for the fine-tuning of targeting strategies. Although some of these DC subsets are regarded as superior for (cross-) priming of naive T cells, controversies still remain about which subset represents the best target for immunotherapy. Because targeting the antigen alone may not be sufficient to obtain effective T-cell responses, delivery systems have been developed to target multiple vaccine components to DCs. In this Perspective, we discuss the pros and cons of targeting DCs: if targeting is beneficial at all and which vaccine vehicles and immunization routes represent promising strategies to reach and activate DCs.

  6. Human dendritic cell culture and bacterial infection.

    Science.gov (United States)

    Jones, Hannah E; Klein, Nigel; Dixon, Garth L J

    2012-01-01

    Dendritic cells (DC) play a key role in the development of natural immunity to microbes. The DC form a bridge between the innate and adaptive immune system by providing key instructions particularly to antigen naïve T-cells. The interaction of DC with T lymphocytes involves three signals: (1) antigen processing and presentation in context of MHC Class I and/or II, (2) expression of T cell co-stimulatory molecules, and (3) cytokine production. Studying the interactions of DCs with specific pathogens allows for better understanding of how protective immunity is generated, and may be particularly useful for assessing vaccine components. In this chapter, we describe methods to generate human monocyte-derived DCs and assess their maturation, activation, and function, using interaction with the gram-negative bacterial pathogen Neisseria meningitidis as a model.

  7. Influence of dendritic cells on viral pathogenicity.

    Science.gov (United States)

    Freer, Giulia; Matteucci, Donatella

    2009-07-01

    Although most viral infections cause minor, if any, symptoms, a certain number result in serious illness. Viral disease symptoms result both from direct viral replication within host cells and from indirect immunopathological consequences. Dendritic cells (DCs) are key determinants of viral disease outcome; they activate immune responses during viral infection and direct T cells toward distinct T helper type responses. Certain viruses are able to skew cytokine secretion by DCs inducing and/or downregulating the immune system with the aim of facilitating and prolonging release of progeny. Thus, the interaction of DCs with viruses most often results in the absence of disease or complete recovery when natural functions of DCs prevail, but may lead to chronic illness or death when these functions are outmanoeuvred by viruses in the exploitation of DCs.

  8. Influence of dendritic cells on viral pathogenicity.

    Directory of Open Access Journals (Sweden)

    Giulia Freer

    2009-07-01

    Full Text Available Although most viral infections cause minor, if any, symptoms, a certain number result in serious illness. Viral disease symptoms result both from direct viral replication within host cells and from indirect immunopathological consequences. Dendritic cells (DCs are key determinants of viral disease outcome; they activate immune responses during viral infection and direct T cells toward distinct T helper type responses. Certain viruses are able to skew cytokine secretion by DCs inducing and/or downregulating the immune system with the aim of facilitating and prolonging release of progeny. Thus, the interaction of DCs with viruses most often results in the absence of disease or complete recovery when natural functions of DCs prevail, but may lead to chronic illness or death when these functions are outmanoeuvred by viruses in the exploitation of DCs.

  9. Dendritic cell immunotherapy in uterine cancer.

    Science.gov (United States)

    Coosemans, An; Tuyaerts, Sandra; Vanderstraeten, Anke; Vergote, Ignace; Amant, Frédéric; Van Gool, Stefaan W

    2014-01-01

    Uterine cancer is the most common pelvic gynecological malignancy. Uterine sarcomas and relapsed uterine carcinomas have limited treatment options. The search for new therapies is urgent. Dendritic cell (DC) immunotherapy holds much promise, though has been poorly explored in uterine cancer. This commentary gives an insight in existing DC immunotherapy studies in uterine cancer and summarizes the possibilities and the importance of the loading of tumor antigens onto DC and their subsequent maturation. However, the sole application of DC immunotherapy to target uterine cancer will be insufficient because of tumor-induced immunosuppression, which will hamper the establishment of an effective anti-tumor immune response. The authors give an overview on the limited existing immunosuppressive data and propose a novel approach on DC immunotherapy in uterine cancer.

  10. Communications: Mechanical Deformation of Dendrites by Fluid Flow

    Science.gov (United States)

    Pilling, J.; Hellawell, A.

    1996-01-01

    It is generally accepted that liquid agitation during alloy solidification assists in crystal multiplication, as in dendrite fragmentation and the detachment of side arms in the mushy region of a casting. Even without deliberate stirring by electromagnetic or mechanical means, there is often vigorous interdendritic fluid flow promoted by natural thermosolutal convection. In this analysis, we shall estimate the stress at the root of a secondary dendrite arm of aluminum arising from the action of a flow of molten metal past the dendrite arm.

  11. Dendritic Growth of Hard-Sphere Crystals. Experiment 34

    Science.gov (United States)

    Russel, W. B.; Chaikin, P. M.; Zhu, Ji-Xiang; Meyer, W. V.; Rogers, R.

    1998-01-01

    Recent observations of the disorder-order transition for colloidal hard spheres under microgravity revealed dendritic crystallites roughly 1-2 mm in size for samples in the coexistence region of the phase diagram. Order-of-magnitude estimates rationalize the absence of large or dendritic crystals under normal gravity and their stability to annealing in microgravity. A linear stability analysis of the Ackerson and Schaetzel model for crystallization of hard spheres establishes the domain of instability for diffusion-limited growth at small supersaturations. The relationship between hard-sphere and molecular crystal growth is established and exploited to relate the predicted linear instability to the well-developed dendrites observed.

  12. Antibacterial activities of dendritic amphiphiles against nontuberculous mycobacteria.

    Science.gov (United States)

    Falkinham, Joseph O; Macri, Richard V; Maisuria, Bhadreshkumar B; Actis, Marcelo L; Sugandhi, Eko W; Williams, André A; Snyder, Alyson V; Jackson, Faunice R; Poppe, Michael A; Chen, Liang; Ganesh, Krithika; Gandour, Richard D

    2012-03-01

    The anti-mycobacterial activities of nine series of dicarboxyl and tricarboxyl dendritic amphiphiles with one alkyl, two alkyl, and cholestanyl tails against Mycobacterium abscessus, Mycobacterium avium, Mycobacterium chelonae, Mycobacterium marinum and Mycobacterium smegmatis have been measured. The dendritic amphiphiles overcame the limited aqueous solubility of natural long-chain fatty acids, alcohols, and amines to enable profiling the susceptibilities of the different mycobacterial species to the physicochemical properties of these amphiphiles. Several dendritic amphiphiles showed strong anti-mycobacterial activity with high critical micelle concentrations and low hemolytic activities thereby offering platforms for the development of antibiotics of higher activity against nontuberculous mycobacteria. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. CD163 positive subsets of blood dendritic cells

    DEFF Research Database (Denmark)

    Maniecki, Maciej Bogdan; Møller, Holger Jon; Moestrup, Søren Kragh

    2006-01-01

    expression in dendritic cells (DCs) was investigated using multicolor flow cytometry in peripheral blood from 31 healthy donors and 15 HIV-1 patients in addition to umbilical cord blood from 5 newborn infants. Total RNA was isolated from MACS purified DCs and CD163 mRNA was determined with real-time reverse...... transcriptase polymerase chain reaction. The effect of glucocorticoid and phorbol ester stimulation on monocyte and dendritic cell CD163 and CD91 expression was investigated in cell culture of mononuclear cells using multicolor flow cytometry. We identified two CD163+ subsets in human blood with dendritic cell...

  14. Experimental Compaction in a Growing Dendritic Zone

    Science.gov (United States)

    Deguen, R.; Alboussière, T.; Brito, D.; La Rizza, P.; Masson, J.

    2007-12-01

    The Earth inner core is thought to be in a state of dynamical equilibrium between dendritic solidification and compaction of the resulting solid-liquid region (or 'mushy zone') (Sumita et al.,1996). One important question is how much liquid can be trapped in the inner core, or how efficient is compaction to squeeze out the liquid phase. While this can be estimated theoretically in the case of non-reacting liquid and solid phases, this problem is somewhat more complicated in the case of a crystallizing mushy zone, as it involves a continuous mass transfer between the two phases as the system evolves. Consequences on the evolution of the connectivity of the melt as solidification proceed are difficult to assess, making the dependence of the permeability on porosity difficult to predict theoretically, particularly when the liquid fraction becomes small. Other open questions includes how does compaction and convection compete in the mushy zone? What are the effects of compaction on the thickness of the convecting zone? on the interdendritic spacing? on the structure and dimensions of chimneys? We present here preliminary results of an experiment devoted to the study of compaction during the dendritic crystallization of a model material. In our experimental set-up, compaction is promoted by a high apparent gravity, which is imposed by putting the crystallizing sample in a standard lab centrifuge, where the centrifuge acceleration can reach a few thousand g. While solidification proceed, the sample is scanned in situ with ultrasounds, allowing us to follow the propagation of the solidification front and to investigate the variations of ultrasound velocity and attenuation in the liquid, mush and solid domains.

  15. Participación de los receptores muscarínicos en el efecto del β - amiloide (25-35) sobre las neuronas piramidales de la región CA3 del hipocampo. Estudio Electrofisiológico

    OpenAIRE

    Sanabria Castro, Alfredo

    2011-01-01

    [ES] El objetivo general de esta Tesis Doctoral es estudiar el efecto del péptido β - amiloide (25 - 35) y sus mecanismos de acción en neuronas piramidales pertenecientes a la región CA3 del hipocampo de rata por medio de técnicas electrofisiológicas de registro intracelular. [EN] The overall objective of this Thesis is to study the effect of β peptide - amyloid (25 - 35) and their mechanisms of action in pyramidal neurons belonging to the region of rat hippocampal CA3 through electrophysi...

  16. High-resolution in vivo imaging of regenerating dendrites of Drosophila sensory neurons during metamorphosis: local filopodial degeneration and heterotypic dendrite-dendrite contacts.

    Science.gov (United States)

    Satoh, Daisuke; Suyama, Ritsuko; Kimura, Ken-ichi; Uemura, Tadashi

    2012-12-01

    Neuronal circuits that are formed in early development are reorganized at later developmental stages to support a wide range of adult behaviors. At Drosophila pupal stages, one example of this reorganization is dendritic remodeling of multidendritic neurons, which is accomplished by pruning and subsequent regeneration of branches in environments quite distinct from those in larval life. Here, we used long-term in vivo time-lapse recordings at high spatiotemporal resolution and analyzed the dynamics of two adjacent cell types that remodel dendritic arbors, which eventually innervate the lateral plate of the adult abdomen. These neurons initially exhibited dynamic extension, withdrawal and local degeneration of filopodia that sprouted from all along the length of regenerating branches. At a midpupal stage, branches extending from the two cell types started fasciculating with each other, which prompted us to test the hypothesis that this heterotypic contact may serve as a guiding scaffold for shaping dendritic arbors. Unexpectedly, our cell ablation study gave only marginal effects on the branch length and the arbor shape. This result suggests that the arbor morphology of the adult neurons in this study can be specified mostly in the absence of the dendrite-dendrite contact. © 2012 The Authors Genes to Cells © 2012 by the Molecular Biology Society of Japan and Wiley Publishing Asia Pty Ltd.

  17. Metabolism Is Central to Tolerogenic Dendritic Cell Function

    Directory of Open Access Journals (Sweden)

    Wen Jing Sim

    2016-01-01

    Full Text Available Immunological tolerance is a fundamental tenant of immune homeostasis and overall health. Self-tolerance is a critical component of the immune system that allows for the recognition of self, resulting in hyporeactivity instead of immunogenicity. Dendritic cells are central to the establishment of dominant immune tolerance through the secretion of immunosuppressive cytokines and regulatory polarization of T cells. Cellular metabolism holds the key to determining DC immunogenic or tolerogenic cell fate. Recent studies have demonstrated that dendritic cell maturation leads to a shift toward a glycolytic metabolic state and preferred use of glucose as a carbon source. In contrast, tolerogenic dendritic cells favor oxidative phosphorylation and fatty acid oxidation. This dichotomous metabolic reprogramming of dendritic cells drives differential cellular function and plays a role in pathologies, such as autoimmune disease. Pharmacological alterations in metabolism have promising therapeutic potential.

  18. Breast Cancer Vaccines Based on Dendritic Cells and the Chemokines

    National Research Council Canada - National Science Library

    Mule, James

    1998-01-01

    The major objective of this project is to establish a new modality for the treatment of breast cancer that employs the combination of chemokine gene-modified fibroblasts with breast tumor-pulsed dendritic cells (DC...

  19. Breast Cancer Vaccines Based on Dendritic Cells and the Chemokines

    National Research Council Canada - National Science Library

    Mule, James

    1997-01-01

    The major objective of this project is to establish a new modality for the treatment of breast cancer that employs the combination of chemokine gene modified fibroblasts with breast tumor pulsed dendritic cells (DC...

  20. Molecule Matters-Dendritic Architecture-A Clever Route to ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 1. Molecule Matters - Dendritic Architecture - A Clever Route to Monodispersed Macromolecules. N Jayaraman. Feature Article Volume 12 Issue 1 January 2007 pp 60-66 ...

  1. Supramolecular effects in dendritic systems containing photoactive groups

    Directory of Open Access Journals (Sweden)

    GIANLUCA CAMILLO AZZELLINI

    2000-03-01

    Full Text Available In this article are described dendritic structures containing photoactive groups at the surface or in the core. The observed supramolecular effects can be attributed to the nature of the photoactive group and their location in the dendritic architecture. The peripheric azobenzene groups in these dendrimeric compounds can be regarded as single residues that retain the spectroscopic and photochemical properties of free azobenzene moiety. The E and Z forms of higher generation dendrimer, functionalized with azobenzene groups, show different host ability towards eosin dye, suggesting the possibility of using such dendrimer in photocontrolled host-guest systems. The photophysical properties of many dendritic-bipyridine ruthenium complexes have been investigated. Particularly in aerated medium more intense emission and a longer excited-state lifetime are observed as compared to the parent unsubstituted bipyridine ruthenium complexes. These differences can be attributed to a shielding effect towards dioxygen quenching originated by the dendritic branches.

  2. Use and abuse of dendritic cells by Toxoplasma gondii

    Science.gov (United States)

    Sanecka, Anna; Frickel, Eva-Maria

    2012-01-01

    The ubiquitous apicomplexan parasite Toxoplasma gondii stimulates its host’s immune response to achieve quiescent chronic infection. Central to this goal are host dendritic cells. The parasite exploits dendritic cells to disseminate through the body, produce pro-inflammatory cytokines, present its antigens to the immune system and yet at the same time subvert their signaling pathways in order to evade detection. This carefully struck balance by Toxoplasma makes it the most successful parasite on this planet. Recent progress has highlighted specific parasite and host molecules that mediate some of these processes particularly in dendritic cells and in other cells of the innate immune system. Critically, there are several important factors that need to be taken into consideration when concluding how the dendritic cells and the immune system deal with a Toxoplasma infection, including the route of administration, parasite strain and host genotype. PMID:23221473

  3. Dendritic inhibition in the hippocampus supports fear learning.

    Science.gov (United States)

    Lovett-Barron, Matthew; Kaifosh, Patrick; Kheirbek, Mazen A; Danielson, Nathan; Zaremba, Jeffrey D; Reardon, Thomas R; Turi, Gergely F; Hen, René; Zemelman, Boris V; Losonczy, Attila

    2014-02-21

    Fear memories guide adaptive behavior in contexts associated with aversive events. The hippocampus forms a neural representation of the context that predicts aversive events. Representations of context incorporate multisensory features of the environment, but must somehow exclude sensory features of the aversive event itself. We investigated this selectivity using cell type-specific imaging and inactivation in hippocampal area CA1 of behaving mice. Aversive stimuli activated CA1 dendrite-targeting interneurons via cholinergic input, leading to inhibition of pyramidal cell distal dendrites receiving aversive sensory excitation from the entorhinal cortex. Inactivating dendrite-targeting interneurons during aversive stimuli increased CA1 pyramidal cell population responses and prevented fear learning. We propose subcortical activation of dendritic inhibition as a mechanism for exclusion of aversive stimuli from hippocampal contextual representations during fear learning.

  4. Simulation of dendritic growth of magnesium alloys with fluid flow

    Directory of Open Access Journals (Sweden)

    Meng-wu Wu

    2017-11-01

    Full Text Available Fluid flow has a significant impact on the microstructure evolution of alloys during solidification. Based on the previous work relating simulation of the dendritic growth of magnesium alloys with hcp (hexagonal close-packed structure, an extension was made to the formerly established CA (cellular automaton model with the purpose of studying the effect of fluid flow on the dendritic growth of magnesium alloys. The modified projection method was used to solve the transport equations of flow field. By coupling the flow field with the solute field, simulation results of equiaxed and columnar dendritic growth of magnesium alloys with fluid flow were achieved. The simulated results were quantitatively compared with those without fluid flow. Moreover, a comparison was also made between the present work and previous works conducted by others. It can be concluded that a deep understanding of the dendritic growth of magnesium alloys with fluid flow can be obtained by applying the present numerical model.

  5. Actin Remodeling and Polymerization Forces Control Dendritic Spine Morphology

    CERN Document Server

    Miermans, Karsten; Storm, Cornelis; Hoogenraad, Casper

    2015-01-01

    Dendritic spines are small membranous structures that protrude from the neuronal dendrite. Each spine contains a synaptic contact site that may connect its parent dendrite to the axons of neighboring neurons. Dendritic spines are markedly distinct in shape and size, and certain types of stimulation prompt spines to evolve, in fairly predictable fashion, from thin nascent morphologies to the mushroom-like shapes associated with mature spines. This striking progression is coincident with the (re)configuration of the neuronal network during early development, learning and memory formation, and has been conjectured to be part of the machinery that encodes these processes at the scale of individual neuronal connections. It is well established that the structural plasticity of spines is strongly dependent upon the actin cytoskeleton inside the spine. A general framework that details the precise role of actin in directing the transitions between the various spine shapes is lacking. We address this issue, and present...

  6. Dendritic biomimicry: microenvironmental hydrogen-bonding effects on tryptophan fluorescence.

    Science.gov (United States)

    Koenig, S; Müller, L; Smith, D K

    2001-03-02

    Two series of dendritically modified tryptophan derivatives have been synthesised and their emission spectra measured in a range of different solvents. This paper presents the syntheses of these novel dendritic structures and discusses their emission spectra in terms of both solvent and dendritic effects. In the first series of dendrimers, the NH group of the indole ring is available for hydrogen bonding, whilst in the second series, the indole NH group has been converted to NMe. Direct comparison of the emission wavelengths of analogous NH and NMe derivatives indicates the importance of the Kamlet-Taft solvent beta3 parameter, which reflects the ability of the solvent to accept a hydrogen bond from the NH group, an effect not possible for the NMe series of dendrimers. For the NH dendrimers, the attachment of a dendritic shell to the tryptophan subunit leads to a red shift in emission wavelength. This dendritic effect only operates in non-hydrogen-bonding solvents. For the NMe dendrimers, however, the attachment of a dendritic shell has no effect on the emission spectra of the indole ring. This proves the importance of hydrogen bonding between the branched shell and the indole NH group in causing the dendritic effect. This is the first time a dendritic effect has been unambiguously assigned to individual hydrogen-bonding interactions and indicates that such intramolecular interactions are important in dendrimers, just as they are in proteins. Furthermore, this paper sheds light on the use of tryptophan residues as a probe of the microenvironment within proteins--in particular, it stresses the importance of hydrogen bonds formed by the indole NH group.

  7. Numerical Simulation of Three-Dimensional Dendritic Growth

    Energy Technology Data Exchange (ETDEWEB)

    Karma, A.; Rappel, W. [Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115 (United States)

    1996-11-01

    Dendritic crystal growth in a pure undercooled melt is simulated quantitatively in three dimensions using a phase-field approach. The classic parameter {sigma}{sup *} that characterizes the dynamically selected operating state of the dendrite tip as well as the full nonaxisymmetric tip morphology are determined as a function of anisotropy for a crystal with a cubic symmetry. Results are compared to experiment and used to critically test solvability theory. {copyright} {ital 1996 The American Physical Society.}

  8. The dendritic spine story: an intriguing process of discovery

    OpenAIRE

    Javier eDeFelipe

    2015-01-01

    Dendritic spines are key components of a variety of microcircuits and they represent the majority of postsynaptic targets of glutamatergic axon terminals in the brain. The present article will focus on the discovery of dendritic spines, which was possible thanks to the application of the Golgi technique to the study of the nervous system, and will also explore the early interpretation of these elements. This discovery represents an interesting chapter in the history of neuroscience as it show...

  9. The dendritic cell niche in chronic obstructive pulmonary disease

    OpenAIRE

    Haczku, Angela

    2012-01-01

    Abstract The pulmonary innate immune system is heavily implicated in the perpetual airway inflammation and impaired host defense characterizing Chronic Obstructive Pulmonary Disease (COPD). The airways of patients suffering from COPD are infiltrated by various immune and inflammatory cells including macrophages, neutrophils, T lymphocytes, and dendritic cells. While the role of macrophages, neutrophils and T lymphocytes is well characterized, the contribution of dendritic cells to COPD pathog...

  10. Genetic strain differences in learned fear inhibition associated with variation in neuroendocrine, autonomic, and amygdala dendritic phenotypes.

    Science.gov (United States)

    Camp, Marguerite C; Macpherson, Kathryn P; Lederle, Lauren; Graybeal, Carolyn; Gaburro, Stefano; Debrouse, Lauren M; Ihne, Jessica L; Bravo, Javier A; O'Connor, Richard M; Ciocchi, Stephane; Wellman, Cara L; Lüthi, Andreas; Cryan, John F; Singewald, Nicolas; Holmes, Andrew

    2012-05-01

    Mood and anxiety disorders develop in some but not all individuals following exposure to stress and psychological trauma. However, the factors underlying individual differences in risk and resilience for these disorders, including genetic variation, remain to be determined. Isogenic inbred mouse strains provide a valuable approach to elucidating these factors. Here, we performed a comprehensive examination of the extinction-impaired 129S1/SvImJ (S1) inbred mouse strain for multiple behavioral, autonomic, neuroendocrine, and corticolimbic neuronal morphology phenotypes. We found that S1 exhibited fear overgeneralization to ambiguous contexts and cues, impaired context extinction and impaired safety learning, relative to the (good-extinguishing) C57BL/6J (B6) strain. Fear overgeneralization and impaired extinction was rescued by treatment with the front-line anxiety medication fluoxetine. Telemetric measurement of electrocardiogram signals demonstrated autonomic disturbances in S1 including poor recovery of fear-induced suppression of heart rate variability. S1 with a history of chronic restraint stress displayed an attenuated corticosterone (CORT) response to a novel, swim stressor. Conversely, previously stress-naive S1 showed exaggerated CORT responses to acute restraint stress or extinction training, insensitivity to dexamethasone challenge, and reduced hippocampal CA3 glucocorticoid receptor mRNA, suggesting downregulation of negative feedback control of the hypothalamic-pituitary-adrenal axis. Analysis of neuronal morphology in key neural nodes within the fear and extinction circuit revealed enlarged dendritic arbors in basolateral amygdala neurons in S1, but normal infralimbic cortex and prelimbic cortex dendritic arborization. Collectively, these data provide convergent support for the utility of the S1 strain as a tractable model for elucidating the neural, molecular and genetic basis of persistent, excessive fear.

  11. Dim light at night provokes depression-like behaviors and reduces CA1 dendritic spine density in female hamsters.

    Science.gov (United States)

    Bedrosian, Tracy A; Fonken, Laura K; Walton, James C; Haim, Abraham; Nelson, Randy J

    2011-08-01

    The prevalence of major depression has increased in recent decades; however, the underlying causes of this phenomenon remain unspecified. One environmental change that has coincided with elevated rates of depression is increased exposure to artificial light at night. Shift workers and others chronically exposed to light at night are at increased risk of mood disorders, suggesting that nighttime illumination may influence brain mechanisms mediating affect. We tested the hypothesis that exposure to dim light at night may impact affective responses and alter morphology of hippocampal neurons. Ovariectomized adult female Siberian hamsters (Phodopus sungorus) were housed for 8 weeks in either a light/dark cycle (LD) or a light/dim light cycle (DM), and then behavior was assayed. DM-hamsters displayed more depression-like responses in the forced swim and the sucrose anhedonia tests compared with LD-hamsters. Conversely, in the elevated plus maze DM-hamsters reduced anxiety-like behaviors. Brains from the same animals were processed using the Golgi-Cox method and hippocampal neurons within CA1, CA3, and the dentate gyrus were analyzed for morphological characteristics. In CA1, DM-hamsters significantly reduced dendritic spine density on both apical and basilar dendrites, an effect which was not mediated by baseline cortisol, as concentrations were equivalent between groups. These results demonstrate dim light at night is sufficient to reduce synaptic spine connections to CA1. Importantly, the present results suggest that night-time low level illumination, comparable to levels that are pervasive in North America and Europe, may contribute to the increasing prevalence of mood disorders. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. The unfolded protein response is required for dendrite morphogenesis

    Science.gov (United States)

    Wei, Xing; Howell, Audrey S; Dong, Xintong; Taylor, Caitlin A; Cooper, Roshni C; Zhang, Jianqi; Zou, Wei; Sherwood, David R; Shen, Kang

    2015-01-01

    Precise patterning of dendritic fields is essential for the formation and function of neuronal circuits. During development, dendrites acquire their morphology by exuberant branching. How neurons cope with the increased load of protein production required for this rapid growth is poorly understood. Here we show that the physiological unfolded protein response (UPR) is induced in the highly branched Caenorhabditis elegans sensory neuron PVD during dendrite morphogenesis. Perturbation of the IRE1 arm of the UPR pathway causes loss of dendritic branches, a phenotype that can be rescued by overexpression of the ER chaperone HSP-4 (a homolog of mammalian BiP/ grp78). Surprisingly, a single transmembrane leucine-rich repeat protein, DMA-1, plays a major role in the induction of the UPR and the dendritic phenotype in the UPR mutants. These findings reveal a significant role for the physiological UPR in the maintenance of ER homeostasis during morphogenesis of large dendritic arbors. DOI: http://dx.doi.org/10.7554/eLife.06963.001 PMID:26052671

  13. Dendritic cells recognize tumor-specific glycosylation of carcinoembryonic antigen on colorectal cancer cells through dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin

    NARCIS (Netherlands)

    van Gisbergen, Klaas P. J. M.; Aarnoudse, Corlien A.; Meijer, Gerrit A.; Geijtenbeek, Teunis B. H.; van Kooyk, Yvette

    2005-01-01

    Dendritic cells play a pivotal role in the induction of antitumor immune responses. Immature dendritic cells are located intratumorally within colorectal cancer and intimately interact with tumor cells, whereas mature dendritic cells are present peripheral to the tumor. The majority of colorectal

  14. Probiotics, dendritic cells and bladder cancer.

    Science.gov (United States)

    Feyisetan, Oladapo; Tracey, Christopher; Hellawell, Giles O

    2012-06-01

    What's known on the subject? and What does the study add? The suppressor effect of probiotics on superficial bladder cancer is an observed phenomenon but the specific mechanism is poorly understood. The evidence strongly suggests natural killer (NK) cells are the anti-tumour effector cells involved and NK cell activity correlates with the observed anti-tumour effect in mice. It is also known that dendritic cells (DC) cells are responsible for the recruitment and mobilization of NK cells so therefore it may be inferred that DC cells are most likely to be the interphase point at which probiotics act. In support of this, purification of NK cells was associated with a decrease in NK cells activity. The current use of intravesical bacille Calmette-Guérin in the management of superficial bladder cancer is based on the effect of a localised immune response. In the same way, understanding the mechanism of action of probiotics and the role of DC may potentially offer another avenue via which the immune system may be manipulated to resist bladder cancer. Probiotic foods have been available in the UK since 1996 with the arrival of the fermented milk drink (Yakult) from Japan. The presence of live bacterial ingredients (usually lactobacilli species) may confer health benefits when present in sufficient numbers. The role of probiotics in colo-rectal cancer may be related in part to the suppression of harmful colonic bacteria but other immune mechanisms are involved. Anti-cancer effects outside the colon were suggested by a Japanese report of altered rates of bladder tumour recurrence after ingestion of a particular probiotic. Dendritic cells play a central role to the general regulation of the immune response that may be modified by probiotics. The addition of probiotics to the diet may confer benefit by altering rates of bladder tumour recurrence and also alter the response to immune mechanisms involved with the application of intravesical treatments (bacille Calmette

  15. Sequential Retraction Segregates SGN Processes during Target Selection in the Cochlea

    Science.gov (United States)

    Druckenbrod, Noah R.

    2015-01-01

    A hallmark of the nervous system is the presence of precise patterns of connections between different types of neurons. Many mechanisms can be used to establish specificity, including homophilic adhesion and synaptic refinement, but the range of strategies used across the nervous system remains unclear. To broaden the understanding of how neurons find their targets, we studied the developing murine cochlea, where two classes of spiral ganglion neurons (SGNs), type I and type II, navigate together to the sensory epithelium and then diverge to contact inner hair cells (IHCs) or outer hair cells (OHCs), respectively. Neurons with type I and type II morphologies are apparent before birth, suggesting that target selection might be accomplished by excluding type I processes from the OHC region. However, because type I processes appear to overshoot into type II territory postnatally, specificity may also depend on elimination of inappropriate synapses. To resolve these differences, we analyzed the morphology and dynamic behaviors of individual fibers and their branches as they interact with potential partners. We found that SGN processes continue to be segregated anatomically in the postnatal cochlea. Although type I-like fibers branched locally, few branches contacted OHCs, arguing against synaptic elimination. Instead, time-lapse imaging studies suggest a prominent role for retraction, first positioning processes to the appropriate region and then corralling branches during a subsequent period of exuberant growth and refinement. Thus, sequential stages of retraction can help to achieve target specificity, adding to the list of mechanisms available for sculpting neural circuits. SIGNIFICANCE STATEMENT During development, different types of neurons must form connections with specific synaptic targets, thereby creating the precise wiring diagram necessary for adult function. Although studies have revealed multiple mechanisms for target selection, we still know little about

  16. Ten-year results of cartilage palisades versus fascia in eardrum reconstruction after surgery for sinus or tensa retraction cholesteatoma in children

    DEFF Research Database (Denmark)

    Cayé-Thomasen, Per; Andersen, Janne; Uzun, Cem

    2009-01-01

    OBJECTIVES/HYPOTHESIS: To compare cartilage palisades with fascia grafting in reconstruction of the eardrum after surgery for sinus or tensa retraction cholesteatoma in children, with respect to long-term postoperative eardrum retraction and perforation, cholesteatoma recurrence, and hearing acuity....... METHODS: A total of 64 children underwent surgery for either sinus or tensa retraction cholesteatoma during the period 1995 to 2000 (mean age 9 years, range 5-15). The eardrum was reconstructed using cartilage palisades in 32 children (32 ears) and fascia or perichondrium in 32 children (33 ears...... threshold, and pure tone air-bone gap). RESULTS: All but two patients in both groups attended the 10-year follow-up examination (94% attendance). The mean overall follow-up period was 119 months (115 months in the palisade and 125 months in the fascia group). Total number of retractions during follow...

  17. Retraction: 'Effect of blonanserin on cognitive function in antipsychotic-naïve first-episode schizophrenia'.

    Science.gov (United States)

    Tenjin, Tomomi; Miyamoto, Seiya; Miyake, Nobumi; Ogino, Shin; Kitajima, Rei; Ojima, Kazuaki; Arai, Jun; Teramoto, Haruki; Tsukahara, Sachiko; Ito, Yukie; Tadokoro, Masanori; Anai, Kiriko; Funamoto, Yasuyuki; Kaneda, Yasuhiro; Sumiyoshi, Tomiki; Yamaguchi, Noboru

    2017-05-01

    The above article from Human Psychopharmacology, first published on 25 January 2012 in Wiley OnlineLibrary (onlinelibrary.wiley.com), and in Volume 90, pp. 90-100, has been retracted by agreement between the authors, the journal Editor in Chief, David Baldwin, and John Wiley & Sons Ltd. The retraction has been agreed following an investigation by the St Marianna University Ethics Committee which determined that the paper was not as originally designed and approved. Tenjin, T., Miyamoto, S., Miyake, N., Ogino, S., Kitajima, R., Ojima, K., … Yamaguchi, N. (2012). Effect of blonanserin on cognitive function in antipsychotic-naïve first-episode schizophrenia. Hum. Psychopharmacol Clin Exp, 27, 90-100. https://doi.org/10.1002/hup.1276. Copyright © 2017 John Wiley & Sons, Ltd.

  18. RETRACTED: Development of a cryogenic test bed for high amperage critical current measurement on high temperature superconductor wire

    Science.gov (United States)

    Wang, Qiuliang; Dai, Yinming; Zhao, Baozhi; Song, Souseng; Chen, Shunzhong; Yan, Luguang

    2009-06-01

    This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editors. The article duplicates significant parts of a paper that had already appeared in IEEE TASC, VOL. 18 (2008) 548-551. 10.1109/TASC.2008.921295. One of the conditions of submission of a paper for publication is that authors declare explicitly that the paper is not under consideration for publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

  19. RETRACTED: Green synthesis of zinc oxide nanoparticles using Moringa oleifera leaf extract and evaluation of its antimicrobial activity

    Science.gov (United States)

    Elumalai, K.; Velmurugan, S.; Ravi, S.; Kathiravan, V.; Ashokkumar, S.

    2015-05-01

    This article has been retracted: please see Elsevier Policy on Article Withdrawal. This article has been retracted at the request of the Editor. The article contains the same image in two panels (Fig. 8A and B) which was previously published in "Facile, eco-friendly and template free photosynthesis of cauliflower like ZnO nanoparticles using leaf extract of Tamarindus indica (L.) and its biological evolution of antibacterial and antifungal activities" by K. Elumalai et al. in Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 136 (2015) 1052-1057, http://dx.doi.org/10.1016/j.saa.2014.09.129 despite being attributed to different nanoparticles. Furthermore, Figures 9C, D and E are the same, despite being indicated as analysis of different microorganisms. The scientific community takes a very strong view on this scientific misbehavior and apologies are offered to readers of the journal that this was not detected during the submission process.

  20. State Administrative Legal Review on the Bill of Retraction Law of Corrupted Assets in Eradication Effort of Corruption in Indonesia

    Directory of Open Access Journals (Sweden)

    Dian Puji Simatupang

    2011-09-01

    Full Text Available Since eradicating corruption having been continously encouraged by late governments – and until now – , there would not be less important as to retracting the corrupted assets. There are many aspects to be considered in doing such action, such as manifesting the legal aspects of administrative law, and so other applied national regulations. By these regulations, such as Law No. 7 of 2006 on Ratification of United Nations Convention against Corruption, 2003 (Konvensi Perserikatan Bangsa Bangsa Anti-Korupsi, 2003, Law Number 25 of 2003 On Amendment to Law Number 15 of 2002 on Money Laundering, Act 30 of 2002 on Corruption Eradication Commission, Law Number 20 Year 2001 regarding Amendment to Law Number 31 Year 1999 on the Eradication of Corruption, and Government Regulation Number 65 of 1999 on Implementation Procedures for Examination of State Property, retraction the corrupted assets should be define in order to get known about eradicating corruption.