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Sample records for laktierenden ratten vpt

  1. Systematic Comparison of Brain Imaging Meta-Analyses of ToM with vPT

    PubMed Central

    Schurz, Matthias; Perner, Josef

    2017-01-01

    In visual perspective taking (vPT) one has to concern oneself with what other people see and how they see it. Since seeing is a mental state, developmental studies have discussed vPT within the domain of “theory of mind (ToM)” but imaging studies have not treated it as such. Based on earlier results from several meta-analyses, we tested for the overlap of visual perspective taking studies with 6 different kinds of ToM studies: false belief, trait judgments, strategic games, social animations, mind in the eyes, and rational actions. Joint activation was observed between the vPT task and some kinds of ToM tasks in regions involving the left temporoparietal junction (TPJ), anterior precuneus, left middle occipital gyrus/extrastriate body area (EBA), and the left inferior frontal and precentral gyrus. Importantly, no overlap activation was found for the vPT tasks with the joint core of all six kinds of ToM tasks. This raises the important question of what the common denominator of all tasks that fall under the label of “theory of mind” is supposed to be if visual perspective taking is not one of them. PMID:28367446

  2. Systematic Comparison of Brain Imaging Meta-Analyses of ToM with vPT.

    PubMed

    Arora, Aditi; Schurz, Matthias; Perner, Josef

    2017-01-01

    In visual perspective taking (vPT) one has to concern oneself with what other people see and how they see it. Since seeing is a mental state, developmental studies have discussed vPT within the domain of "theory of mind (ToM)" but imaging studies have not treated it as such. Based on earlier results from several meta-analyses, we tested for the overlap of visual perspective taking studies with 6 different kinds of ToM studies: false belief, trait judgments, strategic games, social animations, mind in the eyes, and rational actions. Joint activation was observed between the vPT task and some kinds of ToM tasks in regions involving the left temporoparietal junction (TPJ), anterior precuneus, left middle occipital gyrus/extrastriate body area (EBA), and the left inferior frontal and precentral gyrus. Importantly, no overlap activation was found for the vPT tasks with the joint core of all six kinds of ToM tasks. This raises the important question of what the common denominator of all tasks that fall under the label of "theory of mind" is supposed to be if visual perspective taking is not one of them.

  3. Mercaptursäure und Nukleosidaddukt im Harn als Biomarker in 1-Hydroxymethylpyren-exponierten Ratten

    NASA Astrophysics Data System (ADS)

    Ma, Lan

    2002-01-01

    1-Methylpyren (MP) ist hepatokanzerogen in neugeborenen männlichen Mäusen. Durch Hydroxylierung an der benzylischen Stelle und anschließende Sulfonierung wird MP zu DNA-reaktivem 1-Sulfooxymethylpyren (SMP) aktiviert. In der Ratte führt die Exposition des benzylischen Alkohols, 1-Hydroxymethylpyren (HMP), zur DNA-Adduktbildung in verschiedenen Geweben. Eventuelle Konsequenz der Toxifizierung ist die Ausscheidung entsprechender Mercaptursäure und Nukleosidaddukt im Harn, welche aufgrund ihrer Herkunft als Biomarker eignen könnten. In dieser Arbeit wird die Ausscheidung der Mercaptursäure und des N2-Desoxyguanosinadduktes in HMP-exponierten Ratten untersucht. Nach der Applikation von HMP bzw. MP wurden weniger als 1 % der Dosis als MPMA über Urin und Faeces ausgeschieden (0 - 48 h). Die Ausscheidung erfolgt hauptsächlich in den ersten 24 h nach der Applikation. MPdG konnte weder in Urin noch in Faeces der HMP-behandelten Tieren identifiziert werden. Nach direkter SMP-Applikation wurde MPdG nur in sehr geringe Menge (weniger als 0,9 ppm in 12 h) im Urin gefunden. Aufgrund der geringen Menge eignet sich MPdG nicht als Biomarker. MPMA dagegen, lässt sich analytisch gut erfassen. Es sollte daher untersucht werden, ob MPMA die Toxifizierung des HMP wiederspiegelt. Die Voraussetzung dafür ist die Kenntnisse über das Metabolismusmuster von HMP. Es wurde daher umfassende Untersuchungen zum Metabolismus des HMP durchgeführt. Die Ergebnisse zeigten, dass mehr als 80 % der Metaboiten in ihrer oxidierten Form (PCS, deren Glucuronsäure-Konjugate sowie phenolische Sulfatester der PCS) ausgeschieden wurden. Demnach spielt die Oxidation des HMP zu PCS eine sehr wichtige Rolle bei der Detoxifizierung und Ausscheidung von HMP. Ferne konnte nachgewiesen werden, dass die Enzyme Alkohol- und Aldehyd-Dehydrogenase an der Oxidation von HMP beteiligt waren. Die Inhibitoren Disulfiram und Ethanol der o. g. Enzyme wurde daher zur Modulation der Detoxifizierung in vivo eingesetzt

  4. Transition metal complexes of Vanillin- 4N-(2-pyridyl) thiosemicarbazone (H 2VPT); thermal, structural and spectroscopic studies

    NASA Astrophysics Data System (ADS)

    El-Reash, Gaber Abu; El-Ayaan, Usama; Gabr, I. M.; El-Rachawy, El-Bastawesy

    2010-04-01

    The present work carried out a study on the ligational behavior of the new ligand, Vanillin- 4N-(2-pyridyl) thiosemicarbazone (H 2VPT) 1 towards some transition metal ions namely, Mn 2+, Co 2+, Ni 2+, Cu 2+, Zn 2+,Cd 2+, Hg 2+ and U 6+. These complexes namely [Mn(HVPT)Cl] 2, [Co(VPT)(H 2O)] 2H 2O 3, [Ni(HVPT)Cl(H 2O)] 4, [Cu(HVPT)Cl(H 2O)] 5, [Zn(VPT)(H 2O)]H 2O 6, [Cd(HVPT)Cl(H 2O)] 7, [Hg(VPT)(H 2O)]H 2O 8 and [UO 2(H 2VPT)(OAc) 2]H 2O 9, were characterized by elemental analysis, spectral (IR, 1H NMR and UV-vis) and magnetic moment measurements. The suggested structures were confirmed by applying geometry optimization and conformational analysis. Thermal properties and decomposition kinetics of all compounds are investigated. The interpretation, mathematical analysis and evaluation of kinetic parameters ( E, A, Δ H, Δ S and Δ G) of all thermal decomposition stages have been evaluated using Coats-Redfern equation. ESR spectra of [Cu(HVPT)Cl]H 2O at room temperature show broad signal, indicating spin-exchange interactions between copper(II) ions.

  5. Doppler-limited high-resolution spectrum and VPT2 assisted assignment of the C-H stretch of CH2Br2

    NASA Astrophysics Data System (ADS)

    Sadiek, Ibrahim; Friedrichs, Gernot

    2017-06-01

    The Doppler limited non-saturated rotationally resolved infrared spectra of the symmetric and asymmetric CH-stretch bands of CH2Br2 have been measured. A continuous wave cavity ringdown setup with a widely tunable Mid-IR-OPO laser light source yielded a single-shot minimum absorption of 4.9 × 10-8 cm-1. In contrast to the heavily congested ν1 band, the ν6 band showed partially resolved rotational features that may serve as suitable absorption targets in future environmental detection schemes for CH2Br2. A straightforward, VPT2 (second-order vibrational perturbation theory) assisted quantum-chemical approach for assigning the rotational structure has been tested using different model chemistries. The molecular structures, anharmonic frequencies and the structural changes upon vibrational excitation of CH2Br2 have been investigated. The predicted changes of the anharmonic rotational constants have been used together with available spectroscopic ground state constants to simulate the rovibrational structures of the ν1 and ν6 bands of CH2Br2. A refined analysis of the ν6 band is presented yielding accurate values for the band origin and the rotational constants. A fit of the line positions of 312 prominent transitions of the three isotopologues revealed a low standard error of 0.00056 cm-1, hence within the absolute 0.0009 cm-1 wavelength accuracy of the used spectrometer setup. A combined analysis of the predicted line strengths and positions of the strong Q sub-branches of the ν6 band has been performed to test the ability of the different density functionals for VPT2 prediction of anharmonic molecular constants. The M06/6-311++G(d,p) model chemistry turned out to yield reliable state-dependent rotational constants that are accurate enough to reproduce the overall rotational structure even without fitting.

  6. The theoretical-cum-statistical approach for the investigation of reaction NO2 + O(3P) → NO + O2 using SCTST and a full anharmonic VPT2 model

    NASA Astrophysics Data System (ADS)

    Shiekh, Bilal Ahmad; Kaur, Damanjit; Seth, Bharti; Mahajan, Shalagha

    2016-10-01

    The study of the titled reaction has been carried out using high-level quantum mechanics in conjugation with SCTST and VPT2 model. The many quantum mechanical methods have been employed in combinatory approach to find out the various properties such as energy, anharmonic vibrational coefficients and ro-vibrational parameters for the stationary points including the transition state of the reaction. Then the thermal rate coefficients were computed over a temperature regime of 150-1500 K and the corresponding results were compared with the available literature. In this temperature regime, our computed results are in excellent contrast with the experiment.

  7. Toward feasible and comprehensive computational protocol for simulation of the spectroscopic properties of large molecular systems: the anharmonic infrared spectrum of uracil in the solid state by the reduced dimensionality/hybrid VPT2 approach.

    PubMed

    Fornaro, Teresa; Carnimeo, Ivan; Biczysko, Malgorzata

    2015-05-28

    Feasible and comprehensive computational protocols for simulating the spectroscopic properties of large and complex molecular systems are very sought after. Indeed, due to the great variety of intra- and intermolecular interactions that may take place, the interpretation of experimental data becomes more and more difficult as the system under study increases in size or is placed in a complex environment, such as condensed phases. In this framework, we are actively developing a comprehensive and robust computational protocol aimed at quantitative reproduction of the spectra of nucleic acid base complexes, with increasing complexity toward condensed phases and monolayers of biomolecules on solid supports. We have resorted to fully anharmonic quantum mechanical computations within the generalized second-order vibrational perturbation theory (GVPT2) approach, combined with the cost-effective B3LYP-D3 method, in conjunction with basis sets of double-ζ plus polarization quality. Such an approach has been validated in a previous work ( Phys. Chem. Chem. Phys. 2014 , 16 , 10112 - 10128 ) for simulating the IR spectra of the monomers of nucleobases and some of their dimers. In the present contribution we have extended such computational protocol to simulate spectroscopic properties of a molecular solid, namely polycrystalline uracil. First we have selected a realistic molecular model for representing the spectroscopic properties of uracil in the solid state, the uracil heptamer, and then we have computed the relative anharmonic frequencies combining less demanding approaches such as the hybrid B3LYP-D3/DFTBA one, in which the harmonic frequencies are computed at a higher level of theory (B3LYP-D3/N07D) whereas the anharmonic shifts are evaluated at a lower level of theory (DFTBA), and the reduced dimensionality VPT2 (RD-VPT2) approach, where only selected vibrational modes are computed anharmonically along with the couplings with other modes. The good agreement between the

  8. Materials Data on VPt (SG:123) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-23

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  9. Materials Data on AlVPt (SG:216) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-11

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  10. Growth of 18O isotopically enriched ZnO nanorods by two novel VPT methods

    NASA Astrophysics Data System (ADS)

    Gray, Ciarán; Trefflich, Lukas; Röder, Robert; Ronning, Carsten; Henry, Martin O.; McGlynn, Enda

    2017-02-01

    We have developed two novel vapour phase transport methods to grow ZnO nanorod arrays isotopically enriched with 18O. Firstly, a three-step process used to grow natural and Zn-enriched ZnO nanorods has been further modified, by replacing the atmospheric O2 with enriched 18O2, in order to grow 18O-enriched ZnO nanorods using this vapour-solid method on chemical bath deposited buffer layers. In addition, 18O-enriched ZnO nanorods were successfully grown using 18O isotopically enriched ZnO source powders in a vapour-liquid-solid growth method. Scanning electron microscopy studies confirmed the success of both growth methods in terms of nanorod morphology, although in the case of the vapour-liquid-solid samples, the nanorods' c-axes were not vertically aligned due to the use of a non-epitaxial substrate. Raman and PL studies indicated clearly that O-enrichment was successful in both cases, although the results indicate that the enrichment is at a lower level in our samples compared to previous reports with the same nominal enrichment levels. The results of our studies also allow us to comment on both levels of enrichment achieved and on novel effects of the high temperature growth environment on the nanorod growth, as well as suggesting possible mechanisms for such effects. Very narrow photoluminescence line widths, far narrower than those reported previously in the literature for isotopically enriched bulk ZnO, are seen in both the vapour-solid and vapour-liquid-solid nanorod samples demonstrating their excellent optical quality and their potential for use in detailed optical studies of defects and impurities using low temperature photoluminescence.

  11. Elevated Vibration Perception Thresholds in CIDP Patients Indicate More Severe Neuropathy and Lower Treatment Response Rates.

    PubMed

    Abraham, Alon; Albulaihe, Hana; Alabdali, Majed; Qrimli, Mohammad; Breiner, Ari; Barnett, Carolina; Katzberg, Hans D; Lovblom, Leif E; Perkins, Bruce A; Bril, Vera

    2015-01-01

    Vibration perception threshold (VPT) examination using a neurothesiometer provides objective, sensitive and specific information, and has been utilized mainly in patients with diabetic polyneropathy. Explore the utility of VPT examination in CIDP patients. CIDP subjects attending the Neuromuscular clinic between 01/2013 and 12/2014 were evaluated. Demographic data, clinical history, physical examination, VPT values, and electrophysiologic data from their charts were extracted. 70 charts were reviewed. 55 CIDP patients had elevated VPT, associated with higher frequency of abnormal sensory testing for various modalities (92.7% vs. 46.7%, p<0.0001), lower sensory and motor amplitudes and reduced conduction velocities on nerve conduction studies, and lower treatment response rates (54% vs. 93%, p = 0.01). VPT examination is a simple tool, which is a reliable and sensitive measure not only for diabetic neuropathy, but also for CIDP. Moreover, in CIDP, elevated VPT values are also associated with lower treatment response rates.

  12. Fourth-Order Vibrational Transition State Theory and Chemical Kinetics

    NASA Astrophysics Data System (ADS)

    Stanton, John F.; Matthews, Devin A.; Gong, Justin Z.

    2015-06-01

    Second-order vibrational perturbation theory (VPT2) is an enormously successful and well-established theory for treating anharmonic effects on the vibrational levels of semi-rigid molecules. Partially as a consequence of the fact that the theory is exact for the Morse potential (which provides an appropriate qualitative model for stretching anharmonicity), VPT2 calculations for such systems with appropriate ab initio potential functions tend to give fundamental and overtone levels that fall within a handful of wavenumbers of experimentally measured positions. As a consequence, the next non-vanishing level of perturbation theory -- VPT4 -- offers only slight improvements over VPT2 and is not practical for most calculations since it requires information about force constants up through sextic. However, VPT4 (as well as VPT2) can be used for other applications such as the next vibrational correction to rotational constants (the ``gammas'') and other spectroscopic parameters. In addition, the marriage of VPT with the semi-classical transition state theory of Miller (SCTST) has recently proven to be a powerful and accurate treatment for chemical kinetics. In this talk, VPT4-based SCTST tunneling probabilities and cumulative reaction probabilities are give for the first time for selected low-dimensional model systems. The prospects for VPT4, both practical and intrinsic, will also be discussed.

  13. Network interdependency between social media and stock trading activities: Evidence from China

    NASA Astrophysics Data System (ADS)

    Lin, Shen; Ren, Da; Zhang, Wei; Zhang, Yongjie; Shen, Dehua

    2016-06-01

    The emergence of social media accelerates the research on information dissemination and its corresponding influence on trading tendency. Based on empirical study of the dynamic relationship between the ratio of re-post microblog and original microblog (RRO) and average volume per transaction (VPT), we find the following results: (1) In microblog network, stocks with high RRO are often accompanied with low statistical VPT; (2) When the discussion about one stock is quite lively in microblog network (such as the blog postings reach a summit), it does not statistically cause the fluctuations of VPT of the stock; (3) Overall speaking, RRO plays a significant role in inverting u-shaped relationship with VPT.

  14. Association of SUDOSCAN Values with Vibration Perception Threshold in Chinese Patients with Type 2 Diabetes Mellitus

    PubMed Central

    Zhu, Xiaoming; Liu, Siying; Zheng, Hangping

    2017-01-01

    Aims/Introduction SUDOSCAN has been proved to be an efficient method in detecting diabetic microvascular complications. In this study, we determine to detect the possible relationship between vibration perception threshold (VPT) and cardiac autonomic neuropathy (CAN) values produced by SUDOSCAN. Materials and Methods A total of 920 Chinese patients with T2DM were enrolled in the study. Spearman correlation analysis and multivariate regression analysis were performed to determine the relation between CAN and VPT values. Mean VPT values across the CAN value tertiles were analyzed stratified by HbA1c status. Results In the study, we discovered a relatively high correlation between CAN value and both VPT values from dorsal feet and toes. Multivariate regression analyses also showed a significant relation between VPT and CAN values after adjusting all covariates. The mean value of VPT decreased across the SUDOSCAN-CAN value quartiles in both groups, and it was higher in patients with HbA1C > 9% than in patients with HbA1C < 9% across all quartiles of the SUDOSCAN-CAN except for the VPT mean in the low quartile of the SUDOSCAN-CAN value. Conclusions All these results suggested that SUDOSCAN-CAN result was associated with VPT value which indicated a probable link between VPT value and cardiovascular autonomic dysfunction. PMID:28808444

  15. Visual to Print Transfer: A Literacy Strategy for Theme Analysis of Text

    ERIC Educational Resources Information Center

    Buelow, Stephanie

    2015-01-01

    This article shares a literacy strategy to support students' analysis of the theme of text and provide evidence to support their assertion. The strategy is called Visual to Print Transfer (VPT). The VPT strategy leverages students' out-of-school literacy practices involving media images of Hollywood icons as a way to support their understanding of…

  16. Parenting Behavior at 2 Years Predicts School-age Performance at 7 Years in Very Preterm Children

    ERIC Educational Resources Information Center

    Treyvaud, Karli; Doyle, Lex W.; Lee, Katherine J.; Ure, Alexandra; Inder, Terrie E.; Hunt, Rod W.; Anderson, Peter J.

    2016-01-01

    Parenting influences child development, but it is unclear whether early parenting behavior can influence school-age outcomes in very preterm (VPT) children, and/or if certain groups of VPT children may be more affected by early parenting behavior. These research questions were examined. Participants were 147 children born <30 weeks' gestation…

  17. Visual to Print Transfer: A Literacy Strategy for Theme Analysis of Text

    ERIC Educational Resources Information Center

    Buelow, Stephanie

    2015-01-01

    This article shares a literacy strategy to support students' analysis of the theme of text and provide evidence to support their assertion. The strategy is called Visual to Print Transfer (VPT). The VPT strategy leverages students' out-of-school literacy practices involving media images of Hollywood icons as a way to support their understanding of…

  18. Psychiatric Outcomes at Age Seven for Very Preterm Children: Rates and Predictors

    ERIC Educational Resources Information Center

    Treyvaud, Karli; Ure, Alexandra; Doyle, Lex W.; Lee, Katherine J.; Rogers, Cynthia E.; Kidokoro, Hiroyuki; Inder, Terrie E.; Anderson, Peter J.

    2013-01-01

    Background: Uncertainty remains about the rate of specific psychiatric disorders and associated predictive factors for very preterm (VPT) children. The aims of this study were to document rates of psychiatric disorders in VPT children aged 7 years compared with term born children, and to examine potential predictive factors for psychiatric…

  19. Corpus Callosum and Prefrontal Functions in Adolescents with History of Very Preterm Birth

    ERIC Educational Resources Information Center

    Narberhaus, Ana; Segarra, Dolors; Caldu, Xavier; Gimenez, Monica; Pueyo, Roser; Botet, Francesc; Junque, Carme

    2008-01-01

    Very preterm (VPT) birth can account for thinning of the corpus callosum and poorer cognitive performance. Research findings about preterm and VPT adolescents usually describe a small posterior corpus callosum, although our research group has also found reductions of the anterior part, specifically the genu. The aim of the present study was to…

  20. Very Preterm Adolescents Show Gender-Dependent Alteration of the Structural Brain Correlates of Spelling Abilities

    ERIC Educational Resources Information Center

    Scott, Fiona E.; Mechelli, Andrea; Allin, Matthew P.; Walshe, Muriel; Rifkin, Larry; Murray, Robin M.; Nosarti, Chiara

    2011-01-01

    Individuals born very preterm (VPT) are at risk of neurodevelopmental damage and of adverse educational outcomes in childhood and adolescence. The present study used voxel-based morphometry to investigate the association between grey matter and white matter volume and measures of language and executive functioning in VPT born adolescents and…

  1. Neonatal Cerebral Morphometry and Later Risk of Persistent Inattention/Hyperactivity in Children Born Very Preterm

    ERIC Educational Resources Information Center

    Bora, Samudragupta; Pritchard, Verena E.; Chen, Zhe; Inder, Terrie E.; Woodward, Lianne J.

    2014-01-01

    Background: Attention problems are among the most prevalent neurobehavioral morbidities affecting very preterm (VPT) born children. The first study aim was to document rates of persistent attention/hyperactivity problems from ages 4 to 9 years in a regional cohort of VPT born children. The second aim was to examine the extent to which persistent…

  2. A pilot study of reference vibrotactile perception thresholds on the fingertip obtained with Malaysian healthy people using ISO 13091-1 equipment.

    PubMed

    Daud, Roshada; Maeda, Setsuo; Kameel, Nur Nazmin Mustafa; Ripin, Muhamad Yunus; Bakrun, Norazman; Md Zein, Raemy; Kido, Masaharu; Higuchi, Kiyotaka

    2004-04-01

    The purpose of this paper is to clarify the reference vibrotactile perception thresholds (VPT) for healthy people in Malaysia. The measurement equipment standard, ISO 13091-1, of the vibrotactile perception thresholds for the assessment of nerve dysfunction and the analysis and interpretation of measurements at the fingertips standard, ISO 13091-2, were published in ISO/TC108/SC4/WG8 on 2001 and 2003 individually. In the ISO 13091-2 standard, the reference VPT data were obtained from few research papers. Malaysian people's VPT data don't include to this standard. In Malaysia, when the VPT is using to diagnose of the hand-arm vibration syndrome, the reference VPT data need to compare with the worker's ones. But, Malaysia does not have the reference VPT data yet. So, in this paper, the VPT was measured by using ISO 13091-1 standard equipment to obtain the reference data for Malaysian people. And these data were compared with the ISO reference data on the ISO 13091-2 standard. From the comparison of these data, it was clear that the Malaysian healthy people's VPT data were consistent with the reference data of the ISO 13091-2 standard.

  3. Corpus Callosum and Prefrontal Functions in Adolescents with History of Very Preterm Birth

    ERIC Educational Resources Information Center

    Narberhaus, Ana; Segarra, Dolors; Caldu, Xavier; Gimenez, Monica; Pueyo, Roser; Botet, Francesc; Junque, Carme

    2008-01-01

    Very preterm (VPT) birth can account for thinning of the corpus callosum and poorer cognitive performance. Research findings about preterm and VPT adolescents usually describe a small posterior corpus callosum, although our research group has also found reductions of the anterior part, specifically the genu. The aim of the present study was to…

  4. Neonatal Cerebral Morphometry and Later Risk of Persistent Inattention/Hyperactivity in Children Born Very Preterm

    ERIC Educational Resources Information Center

    Bora, Samudragupta; Pritchard, Verena E.; Chen, Zhe; Inder, Terrie E.; Woodward, Lianne J.

    2014-01-01

    Background: Attention problems are among the most prevalent neurobehavioral morbidities affecting very preterm (VPT) born children. The first study aim was to document rates of persistent attention/hyperactivity problems from ages 4 to 9 years in a regional cohort of VPT born children. The second aim was to examine the extent to which persistent…

  5. Very Preterm Adolescents Show Gender-Dependent Alteration of the Structural Brain Correlates of Spelling Abilities

    ERIC Educational Resources Information Center

    Scott, Fiona E.; Mechelli, Andrea; Allin, Matthew P.; Walshe, Muriel; Rifkin, Larry; Murray, Robin M.; Nosarti, Chiara

    2011-01-01

    Individuals born very preterm (VPT) are at risk of neurodevelopmental damage and of adverse educational outcomes in childhood and adolescence. The present study used voxel-based morphometry to investigate the association between grey matter and white matter volume and measures of language and executive functioning in VPT born adolescents and…

  6. Psychiatric Outcomes at Age Seven for Very Preterm Children: Rates and Predictors

    ERIC Educational Resources Information Center

    Treyvaud, Karli; Ure, Alexandra; Doyle, Lex W.; Lee, Katherine J.; Rogers, Cynthia E.; Kidokoro, Hiroyuki; Inder, Terrie E.; Anderson, Peter J.

    2013-01-01

    Background: Uncertainty remains about the rate of specific psychiatric disorders and associated predictive factors for very preterm (VPT) children. The aims of this study were to document rates of psychiatric disorders in VPT children aged 7 years compared with term born children, and to examine potential predictive factors for psychiatric…

  7. Socio-Economic Achievements of Individuals Born Very Preterm at the Age of 27 to 29 Years: A Nationwide Cohort Study

    ERIC Educational Resources Information Center

    Mathiasen, Rene; Hansen, Bo M.; Anderson, Anne-Marie Nybo; Greisen, Gorm

    2009-01-01

    Aim: To describe the socio economic achievement of individuals born very preterm (VPT) at the age of 27 to 29 years. Method: Demographic and social data were extracted from national registers for all individuals born between 1974 and 1976 in Denmark (n = 208 656). Of these, 203 283 individuals were alive in 2006. We compared VPT individuals…

  8. Parenting Behavior at 2 Years Predicts School-age Performance at 7 Years in Very Preterm Children

    ERIC Educational Resources Information Center

    Treyvaud, Karli; Doyle, Lex W.; Lee, Katherine J.; Ure, Alexandra; Inder, Terrie E.; Hunt, Rod W.; Anderson, Peter J.

    2016-01-01

    Parenting influences child development, but it is unclear whether early parenting behavior can influence school-age outcomes in very preterm (VPT) children, and/or if certain groups of VPT children may be more affected by early parenting behavior. These research questions were examined. Participants were 147 children born <30 weeks' gestation…

  9. Identification of volume phase transition of a single microgel particle using optical tweezers

    NASA Astrophysics Data System (ADS)

    Karthickeyan, D.; Gupta, Deepak K.; Tata, B. V. R.

    2016-10-01

    Poly (N-isopropyl acrylamide-co-acrylic acid) (PNIPAM-co-Aac) microgel particles are pH responsive and exhibit volume phase transition (VPT) upon variation of pH. Dynamic light scattering (DLS) is used conventionally to identify VPT and requires a dilute suspension with particle concentration ˜107 particles cm-3 and if particles are polydisperse in nature, DLS data interpretation is relatively difficult. Here we show that optical tweezers allow one to measure the VPT of a single microgel particle by measuring the optical trap stiffness, κ of trapped particle as a function of pH. We report here a sudden change in κ at VPT, which is shown to arise from a sudden decrease in particle diameter with a concomitant increase in the refractive index of the particle at VPT.

  10. Evaluating venous pool technique for blood sampling in neonatal ICU.

    PubMed

    Hatler, Carol; Dalton, Beverly; Day, Susan; Sharfner, Andrea; Hauffe, Rhonda

    2013-01-01

    To evaluate venous pool technique (VPT) for obtaining neonatal blood samples as compared with the needlestick technique. An experimental design was used with subjects enrolled in two phases: an equivalence phase (N = 10) and a comparison phase (N = 64). In the equivalence phase, subjects weighing 1,500 g or more had two needlesticks. In the comparison phase, subjects weighing 800 g or more were randomized to receive blood drawn by either needlestick method or VPT. Comparative results suggest that infant and maternal demographic factors, sampling attempts, and sampling failures were similar. However, for the outcome of hematoma development, the standard technique was significantly worse (t = 2.25 ; p = .029). Results suggest that the VPT method is safe and accurate for use in critically ill neonates. This study demonstrated that the VPT process is easily learned and may provide advantages over standard blood sampling methods. Nurses can use this information to evaluate this VPT technique in their institutions.

  11. A vacuolar phosphate transporter essential for phosphate homeostasis in Arabidopsis.

    PubMed

    Liu, Jinlong; Yang, Lei; Luan, Mingda; Wang, Yuan; Zhang, Chi; Zhang, Bin; Shi, Jisen; Zhao, Fu-Geng; Lan, Wenzhi; Luan, Sheng

    2015-11-24

    Inorganic phosphate (Pi) is stored in the vacuole, allowing plants to adapt to variable Pi availability in the soil. The transporters that mediate Pi sequestration into vacuole remain unknown, however. Here we report the functional characterization of Vacuolar Phosphate Transporter 1 (VPT1), an SPX domain protein that transports Pi into the vacuole in Arabidopsis. The vpt1 mutant plants were stunted and consistently retained less Pi than wild type plants, especially when grown in medium containing high levels of Pi. In seedlings, VPT1 was expressed primarily in younger tissues under normal conditions, but was strongly induced by high-Pi conditions in older tissues, suggesting that VPT1 functions in Pi storage in young tissues and in detoxification of high Pi in older tissues. As a result, disruption of VPT1 rendered plants hypersensitive to both low-Pi and high-Pi conditions, reducing the adaptability of plants to changing Pi availability. Patch-clamp analysis of isolated vacuoles showed that the Pi influx current was severely reduced in vpt1 compared with wild type plants. When ectopically expressed in Nicotiana benthamiana mesophyll cells, VPT1 mediates vacuolar influx of anions, including Pi, SO4(2-), NO3(-), Cl(-), and malate with Pi as that preferred anion. The VPT1-mediated Pi current amplitude was dependent on cytosolic phosphate concentration. Single-channel analysis showed that the open probability of VPT1 was increased with the increase in transtonoplast potential. We conclude that VPT1 is a transporter responsible for vacuolar Pi storage and is essential for Pi adaptation in Arabidopsis.

  12. A vacuolar phosphate transporter essential for phosphate homeostasis in Arabidopsis

    PubMed Central

    Liu, Jinlong; Yang, Lei; Luan, Mingda; Wang, Yuan; Zhang, Chi; Zhang, Bin; Shi, Jisen; Zhao, Fu-Geng; Lan, Wenzhi; Luan, Sheng

    2015-01-01

    Inorganic phosphate (Pi) is stored in the vacuole, allowing plants to adapt to variable Pi availability in the soil. The transporters that mediate Pi sequestration into vacuole remain unknown, however. Here we report the functional characterization of Vacuolar Phosphate Transporter 1 (VPT1), an SPX domain protein that transports Pi into the vacuole in Arabidopsis. The vpt1 mutant plants were stunted and consistently retained less Pi than wild type plants, especially when grown in medium containing high levels of Pi. In seedlings, VPT1 was expressed primarily in younger tissues under normal conditions, but was strongly induced by high-Pi conditions in older tissues, suggesting that VPT1 functions in Pi storage in young tissues and in detoxification of high Pi in older tissues. As a result, disruption of VPT1 rendered plants hypersensitive to both low-Pi and high-Pi conditions, reducing the adaptability of plants to changing Pi availability. Patch-clamp analysis of isolated vacuoles showed that the Pi influx current was severely reduced in vpt1 compared with wild type plants. When ectopically expressed in Nicotiana benthamiana mesophyll cells, VPT1 mediates vacuolar influx of anions, including Pi, SO42−, NO3−, Cl−, and malate with Pi as that preferred anion. The VPT1-mediated Pi current amplitude was dependent on cytosolic phosphate concentration. Single-channel analysis showed that the open probability of VPT1 was increased with the increase in transtonoplast potential. We conclude that VPT1 is a transporter responsible for vacuolar Pi storage and is essential for Pi adaptation in Arabidopsis. PMID:26554016

  13. Cortical Gray and Adjacent White Matter Demonstrate Synchronous Maturation in Very Preterm Infants

    PubMed Central

    Smyser, Tara A.; Smyser, Christopher D.; Rogers, Cynthia E.; Gillespie, Sarah K.; Inder, Terrie E.; Neil, Jeffrey J.

    2016-01-01

    Spatial and functional gradients of development have been described for the maturation of cerebral gray and white matter using histological and radiological approaches. We evaluated these patterns in very preterm (VPT) infants using diffusion tensor imaging. Data were obtained from 3 groups: 1) 22 VPT infants without white matter injury (WMI), of whom all had serial MRI studies during the neonatal period, 2) 19 VPT infants with WMI, of whom 3 had serial MRI studies and 3) 12 healthy, term-born infants. Regions of interest were placed in the cortical gray and adjacent white matter in primary motor, primary visual, visual association, and prefrontal regions. From the MRI data at term-equivalent postmenstrual age, differences in mean diffusivity were found in all areas between VPT infants with WMI and the other 2 groups. In contrast, minimal differences in fractional anisotropy were found between the 3 groups. These findings suggest that cortical maturation is delayed in VPT infants with WMI when compared with term control infants and VPT infants without WMI. From the serial MRI data from VPT infants, synchronous development between gray and white matter was evident in all areas and all groups, with maturation in primary motor and sensory regions preceding that of association areas. This finding highlights the regionally varying but locally synchronous nature of the development of cortical gray matter and its adjacent white matter. PMID:26209848

  14. Cortical Gray and Adjacent White Matter Demonstrate Synchronous Maturation in Very Preterm Infants.

    PubMed

    Smyser, Tara A; Smyser, Christopher D; Rogers, Cynthia E; Gillespie, Sarah K; Inder, Terrie E; Neil, Jeffrey J

    2016-08-01

    Spatial and functional gradients of development have been described for the maturation of cerebral gray and white matter using histological and radiological approaches. We evaluated these patterns in very preterm (VPT) infants using diffusion tensor imaging. Data were obtained from 3 groups: 1) 22 VPT infants without white matter injury (WMI), of whom all had serial MRI studies during the neonatal period, 2) 19 VPT infants with WMI, of whom 3 had serial MRI studies and 3) 12 healthy, term-born infants. Regions of interest were placed in the cortical gray and adjacent white matter in primary motor, primary visual, visual association, and prefrontal regions. From the MRI data at term-equivalent postmenstrual age, differences in mean diffusivity were found in all areas between VPT infants with WMI and the other 2 groups. In contrast, minimal differences in fractional anisotropy were found between the 3 groups. These findings suggest that cortical maturation is delayed in VPT infants with WMI when compared with term control infants and VPT infants without WMI. From the serial MRI data from VPT infants, synchronous development between gray and white matter was evident in all areas and all groups, with maturation in primary motor and sensory regions preceding that of association areas. This finding highlights the regionally varying but locally synchronous nature of the development of cortical gray matter and its adjacent white matter.

  15. White Matter and Cognition in Adults Who Were Born Preterm

    PubMed Central

    Allin, Matthew P. G.; Kontis, Dimitris; Walshe, Muriel; Wyatt, John; Barker, Gareth J.; Kanaan, Richard A. A.; McGuire, Philip; Rifkin, Larry; Murray, Robin M.; Nosarti, Chiara

    2011-01-01

    Background and Purpose Individuals born very preterm (before 33 weeks of gestation, VPT) are at risk of damage to developing white matter, which may affect later cognition and behaviour. Methods We used diffusion tensor MRI (DT-MRI) to assess white matter microstructure (fractional anisotropy; FA) in 80 VPT and 41 term-born individuals (mean age 19.1 years, range 17–22, and 18.5 years, range17–22 years, respectively). VPT individuals were part of a 1982–1984 birth cohort which had been followed up since birth; term individuals were recruited by local press advertisement. General intellectual function, executive function and memory were assessed. Results The VPT group had reduced FA in four clusters, and increased FA in four clusters relative to the Term group, involving several association tracts of both hemispheres. Clusters of increased FA were associated with more severe neonatal brain injury in the VPT group. Clusters of reduced FA were associated with lower birth weight and perinatal hypoxia, and with reduced adult cognitive performance in the VPT group only. Conclusions Alterations of white matter microstructure persist into adulthood in VPT individuals and are associated with cognitive function. PMID:22022357

  16. Ventricular pacing threshold after transthoracic external defibrillation with two different waveforms: an experimental study.

    PubMed

    Assumpção, Antonio Carlos; de Oliveira, Pedro Paulo Martins; Vilarinho, Karlos Alexandre de Souza; Eghtesady, Pirooz; Silveira Filho, Lindemberg Mota; Lavagnoli, Carlos Fernando Ramos; Severino, Elaine Soraya Barbosa de Oliveira; Petrucci, Orlando

    2013-02-01

    Although an increase in the ventricular pacing threshold (VPT) has been observed after administration of transthoracic shock for ventricular defibrillation, few studies have evaluated the phenomenon with respect to the defibrillation waveform energy. Therefore, this study examined the VPT behaviour after transthoracic shock with a monophasic or biphasic energy waveform. Domestic Landrace male piglets implanted with a permanent pacemaker stimulation system were divided into three groups: no ventricular fibrillation (VF) induction and transthoracic shock with monophasic or biphasic energy (group I); VF induction, 1 min of observation without intervention, 2 min of external cardiac massage, and transthoracic shock with monophasic or biphasic energy (group II); and VF induction, 2 min of observation without intervention, 4 min of external cardiac massage, and transthoracic shock with monophasic or biphasic energy (group III). After external shock, the VPT was evaluated every minute for 10 min. A total of 143 experiments were performed. At the end of the observation period, groups I and II showed steady VPT values. Group III showed an increase in VPT with monophasic or biphasic external energy, with no difference between the external energy sources. The monophasic but not the biphasic waveform was associated with higher VPT values when the VF was longer. Defibrillation does not have a significant impact on pacing threshold, but a longer VF period is related to a higher VPT after defibrillation with monophasic waveform.

  17. Health Technology Assessment of CEM Pulpotomy in Permanent Molars with Irreversible Pulpitis

    PubMed Central

    Yazdani, Shahram; Jadidfard, Mohammad-Pooyan; Tahani, Bahareh; Kazemian, Ali; Dianat, Omid; Alim Marvasti, Laleh

    2014-01-01

    Introduction: Teeth with irreversible pulpitis usually undergo root canal therapy (RCT). This treatment modality is often considered disadvantageous as it removes vital pulp tissue and weakens the tooth structure. A relatively new concept has risen which suggests vital pulp therapy (VPT) for irreversible pulpitis. VPT with calcium enriched mixture (VPT/CEM) has demonstrated favorable treatment outcomes when treating permanent molars with irreversible pulpitis. This study aims to compare patient related factors, safety and organizational consideration as parts of health technology assessment (HTA) of the new VPT/CEM biotechnology when compared with RCT. Materials and Methods: Patient related factors were assessed by looking at short- and long-term clinical success; safety related factors were evaluated by a specialist committee and discussion board involved in formulating healthcare policies. Organizational evaluation was performed and the social implications were assessed by estimating the costs, availability, accessibility and acceptability. The impact of VPT/CEM biotechnology was assessed by investigating the incidence of irreversible pulpitis and the effect of this treatment on reducing the burden of disease. Results: VPT/CEM biotechnology was deemed feasible and acceptable like RCT; however, it was more successful, accessible, affordable, available and also safer than RCT. Conclusion: When considering socioeconomic implications on oral health status and oral health-related quality of life of VPT/CEM, the novel biotechnology can be more effective and more efficient than RCT in mature permanent molars with irreversible pulpitis. PMID:24396372

  18. Axon density and axon orientation dispersion in children born preterm.

    PubMed

    Kelly, Claire E; Thompson, Deanne K; Chen, Jian; Leemans, Alexander; Adamson, Christopher L; Inder, Terrie E; Cheong, Jeanie L Y; Doyle, Lex W; Anderson, Peter J

    2016-09-01

    Very preterm birth (VPT, <32 weeks' gestation) is associated with altered white matter fractional anisotropy (FA), the biological basis of which is uncertain but may relate to changes in axon density and/or dispersion, which can be measured using Neurite Orientation Dispersion and Density Imaging (NODDI). This study aimed to compare whole brain white matter FA, axon dispersion, and axon density between VPT children and controls (born ≥37 weeks' gestation), and to investigate associations with perinatal factors and neurodevelopmental outcomes. FA, neurite dispersion, and neurite density were estimated from multishell diffusion magnetic resonance images for 145 VPT and 33 control 7-year-olds. Diffusion values were compared between groups and correlated with perinatal factors (gestational age, birthweight, and neonatal brain abnormalities) and neurodevelopmental outcomes (IQ, motor, academic, and behavioral outcomes) using Tract-Based Spatial Statistics. Compared with controls, VPT children had lower FA and higher axon dispersion within many major white matter fiber tracts. Neonatal brain abnormalities predicted lower FA and higher axon dispersion in many major tracts in VPT children. Lower FA, higher axon dispersion, and lower axon density in various tracts correlated with poorer neurodevelopmental outcomes in VPT children. FA and NODDI measures distinguished VPT children from controls and were associated with neonatal brain abnormalities and neurodevelopmental outcomes. This study provides a more detailed and biologically meaningful interpretation of white matter microstructure changes associated with prematurity. Hum Brain Mapp 37:3080-3102, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. Pain-related stress during the Neonatal Intensive Care Unit stay and SLC6A4 methylation in very preterm infants

    PubMed Central

    Provenzi, Livio; Fumagalli, Monica; Sirgiovanni, Ida; Giorda, Roberto; Pozzoli, Uberto; Morandi, Francesco; Beri, Silvana; Menozzi, Giorgia; Mosca, Fabio; Borgatti, Renato; Montirosso, Rosario

    2015-01-01

    Very preterm (VPT) infants need long-lasting hospitalization in the Neonatal Intensive Care Unit (NICU) during which they are daily exposed to pain-related stress. Alterations of DNA methylation at the promoter region of the SLC6A4 have been associated with early adverse experiences in infants. The main aim of the present work was to investigate the association between level of exposure to pain-related stress during hospitalization and changes in SLC6A4 DNA methylation at NICU discharge in VPT infants. In order to exclude the potential effect of birth status (i.e., preterm vs. full-term birth) on SLC6A4 methylation, we preliminarily assessed SLC6A4 epigenetic differences between VPT and full-term (FT) infants at birth. Fifty-six VPT and thirty-two FT infants participated in the study. The level of exposure to pain-related stress was quantified on the basis of the amount of skin-breaking procedures to which they were exposed. VPT infants were divided in two sub-groups: low-pain exposure (LPE, N = 25) and high-pain exposure (HPE, N = 31). DNA methylation was evaluated at birth for both VPT and FT infants, assessing 20 CpG sites within the SLC6A4 promoter region. The same CpG sites were re-evaluated for variations in DNA methylation at NICU discharge in LPE and HPE VPT infants. No differences in SLC6A4 CpG sites' methylation emerged between FT and VPT infants at birth. Methylation at CpG sites 5 and 6 significantly increased from birth to NICU discharge only for HPE VPT infants. Findings show that preterm birth per se is not associated with epigenetic alterations of the SLC6A4, whereas higher levels of pain-related stress exposure during NICU stay might alter the transcriptional functionality of the serotonin transporter gene. PMID:25941480

  20. Comparison of electrochemical skin conductance and vibration perception threshold measurement in the detection of early diabetic neuropathy.

    PubMed

    Goel, Amit; Shivaprasad, Channabasappa; Kolly, Anish; Sarathi H A, Vijaya; Atluri, Sridevi

    2017-01-01

    The early diagnosis of diabetic peripheral neuropathy (DPN) is challenging. Sudomotor dysfunction is one of the earliest detectable abnormalities in DPN. The present study aimed to determine the diagnostic performance of the electrochemical skin conductance (ESC) test in detecting early DPN, compared with the vibration perception threshold (VPT) test and diabetic neuropathy symptom (DNS) score, using the modified neuropathy disability score (NDS) as the reference standard. Five hundred and twenty-three patients with type 2 diabetes underwent an NDS-based clinical assessment for neuropathy. Participants were classified into the DPN and non-DPN groups based on the NDS (≥ 6). Both groups were evaluated further using the DNS, and VPT and ESC testing. A receiver-operator characteristic (ROC) curve analysis was performed to compare the efficacy of ESC measurements with those of DNS and VPT testing in detecting DPN. The DPN group (n = 110, 21%) had significantly higher HbA1c levels and longer diabetes durations compared with the non-DPN group (n = 413). The sensitivity of feet ESC < 60 μS, VPT testing, and DNS in detecting DPN were 85%, 72%, and 52%, respectively. The specificity of feet ESC, VPT, and DNS in detecting DPN were 85%, 90% and 60% respectively. The areas under the curves of the ROC plots for feet ESC, VPT testing, and DNS were 0.88, 0.84, and 0.6, respectively. A significant inverse linear relationship was noted between VPT and feet ESC (r = -0.45, p = <0.0001). The odds ratios for having DPN, based on the mean feet ESC testing < 60 μS, VPT testing > 15 V, and DNS ≥ 1, were 16.4, 10.9 and 1.8, respectively. ESC measurement is an objective and sensitive technique for the early detection of DPN. Feet ESC measurement was superior to VPT testing for identifying patients with early DPN.

  1. Comparison of electrochemical skin conductance and vibration perception threshold measurement in the detection of early diabetic neuropathy

    PubMed Central

    Kolly, Anish; Sarathi H. A., Vijaya; Atluri, Sridevi

    2017-01-01

    The early diagnosis of diabetic peripheral neuropathy (DPN) is challenging. Sudomotor dysfunction is one of the earliest detectable abnormalities in DPN. The present study aimed to determine the diagnostic performance of the electrochemical skin conductance (ESC) test in detecting early DPN, compared with the vibration perception threshold (VPT) test and diabetic neuropathy symptom (DNS) score, using the modified neuropathy disability score (NDS) as the reference standard. Five hundred and twenty-three patients with type 2 diabetes underwent an NDS-based clinical assessment for neuropathy. Participants were classified into the DPN and non-DPN groups based on the NDS (≥ 6). Both groups were evaluated further using the DNS, and VPT and ESC testing. A receiver-operator characteristic (ROC) curve analysis was performed to compare the efficacy of ESC measurements with those of DNS and VPT testing in detecting DPN. The DPN group (n = 110, 21%) had significantly higher HbA1c levels and longer diabetes durations compared with the non-DPN group (n = 413). The sensitivity of feet ESC < 60 μS, VPT testing, and DNS in detecting DPN were 85%, 72%, and 52%, respectively. The specificity of feet ESC, VPT, and DNS in detecting DPN were 85%, 90% and 60% respectively. The areas under the curves of the ROC plots for feet ESC, VPT testing, and DNS were 0.88, 0.84, and 0.6, respectively. A significant inverse linear relationship was noted between VPT and feet ESC (r = -0.45, p = <0.0001). The odds ratios for having DPN, based on the mean feet ESC testing < 60 μS, VPT testing > 15 V, and DNS ≥ 1, were 16.4, 10.9 and 1.8, respectively. ESC measurement is an objective and sensitive technique for the early detection of DPN. Feet ESC measurement was superior to VPT testing for identifying patients with early DPN. PMID:28880907

  2. Neurodevelopmental outcomes and neural mechanisms associated with non-right handedness in children born very preterm

    PubMed Central

    Pascoe, L; Scratch, SE; Burnett, AC; Thompson, DK; Lee, KJ; Doyle, LW; Cheong, JLY; Inder, TE; Anderson, PJ

    2016-01-01

    Objective Non-right handedness (NRH) is reportedly more common in very preterm (VPT; <32 weeks’ gestation) children compared with term-born peers, but it is unclear whether neonatal brain injury or altered brain morphology and microstructure underpins NRH in this population. Given that NRH has been inconsistently reported to be associated with cognitive and motor difficulties, this study aimed to examine associations between handedness and neurodevelopmental outcomes in VPT 7 year-olds. Further, the relationship between neonatal brain injury and integrity of motor tracts (corpus callosum and corticospinal tract) with handedness at age 7 years in VPT children was explored. Method One hundred and seventy-five VPT and 69 term-born children completed neuropsychological and motor assessments and a measure of handedness at 7 years’ corrected age. At term-equivalent age, brain injury on MRI was assessed and diffusion tensor measures were obtained for the corpus callosum and posterior limb of the internal capsule. Results There was little evidence of stronger NRH in the VPT group compared with term controls (regression coefficient [b] −1.95, 95% confidence interval [CI] −5.67 to 1.77). Poorer academic and working memory outcomes were associated with stronger NRH in the VPT group. While there was little evidence that neonatal unilateral brain injury was associated with stronger NRH, increased area and fractional anisotropy of the corpus callosum splenium were predictive of stronger NRH in the VPT group. Conclusions VPT birth may alter the relationship between handedness and academic outcomes, and neonatal corpus callosum integrity predicts hand preference in VPT children at school age. PMID:26328609

  3. Language outcomes at 36 months in prematurely born children is associated with the quality of developmental care in NICUs.

    PubMed

    Montirosso, R; Giusti, L; Del Prete, A; Zanini, R; Bellù, R; Borgatti, R

    2016-09-01

    The aim of this study was to examine the relationship between the quality levels of NICU developmental care (DC) and language skills at 36 months in very preterm (VPT) children. Language skills of 78 VPT children from 19 NICUs and 90 full-term controls was assessed using a standardized language test. We compared children' language task performance by splitting NICUs into units with high- and low-quality of DC according to two main factors: (1) infant centered care (ICC), and (2) infant pain management (IPM). VPT children from low-care units with respect to ICC obtained lower scores in sentence comprehension, compared to children from high-care units. No differences were found between preterm children from high-quality ICC NICUs and full-term children. Findings suggest that higher quality of DC related to infant centered care can mitigate delays in language skills at 36 months in children born VPT.

  4. Making sense of an unexpected detrimental effect of sign language use in a visual task.

    PubMed

    Romero Lauro, Leonor J; Crespi, Marta; Papagno, Costanza; Cecchetto, Carlo

    2014-07-01

    What supports deaf signers advantage over nonsigners on visuospatial short-term memory (STM) tasks is still a matter of debate. We compared the performance of 18 deaf Italian Sign Language (LIS) users with that of a matched group of Italian hearing nonsigners in three different tasks: two versions of the Corsi Block test, namely span forward and span backward, and the Visual Pattern Test (VPT). Although the Corsi forward and backward are dynamic and mainly involve a spatial component, the VPT is static and taps primarily the visual component of STM. Signers significantly outperformed nonsigners on both versions of the Corsi Block test, whereas they performed significantly worse on the VPT. We suggest that the source of the different pattern lies in the static nature of the VPT versus the dynamic nature of the Corsi spans. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. High prevalence/low severity language delay in preschool children born very preterm.

    PubMed

    Foster-Cohen, Susan H; Friesen, Myron D; Champion, Patricia R; Woodward, Lianne J

    2010-10-01

    To examine the language development at corrected age 4 years of a regionally representative cohort of children born very preterm (VPT). Of particular interest was the identification of biological and socioenvironmental risk and protective factors that influence VPT children's early language development. Data were collected as part of a prospective longitudinal study of 110 VPT (VPT: ≤ 33 weeks gestation) and 113 full-term children (full term: 37-41 weeks gestation) born in Canterbury, New Zealand from 1998 to 2000. At corrected age 4 years, all children were assessed with the preschool version of the Clinical Evaluation of Language Fundamentals. Extensive information was also collected about children's family social background, perinatal health, childrearing environment, education/intervention exposures, and neurodevelopmental progress from birth to age 4. At the age of 4 years, VPT children were characterized by poorer receptive and expressive language development than full-term children. These differences persisted after exclusion of children with neurosensory impairment as well as statistical adjustment for the effects of social risk. Within the VPT group, the key predictors of children's overall language development were family social risk at birth (p =.05), severity of white matter abnormalities on neonatal magnetic resonance imaging (p =.49), observed parent-child synchrony (p =.001), and concurrent child cognitive ability (p =.001). Together, these factors accounted for 45% of the variance in children's total Clinical Evaluation of Language Fundamentals-Preschool scores. By preschool age, children born VPT show early emerging mild to moderate language delays that are likely to affect their school success and longer-term developmental progress. Findings highlight the importance of potentially modifiable factors such as early brain injury and parenting quality in predicting the language outcomes of children born VPT.

  6. Cognitive Development Trajectories of Very Preterm and Typically Developing Children

    ERIC Educational Resources Information Center

    Mangin, Kathryn S.; Horwood, L. J.; Woodward, Lianne J.

    2017-01-01

    Cognitive impairment is common among children born very preterm (VPT), yet little is known about how this risk changes over time. To examine this issue, a regional cohort of 110 VPT (= 32 weeks gestation) and 113 full-term (FT) born children was prospectively assessed at ages 4, 6, 9, and 12 years using the Wechsler Preschool and Primary Scale of…

  7. Bioceramic Materials and the Changing Concepts in Vital Pulp Therapy.

    PubMed

    Cao, Yangpei; Bogen, George; Lim, Jung; Shon, Won-Jun; Kang, Mo K

    2016-05-01

    Vital pulp therapy (VPT) is devised to preserve and maintain vitality of pulpally involved teeth challenged by a variety of intraoral conditions. Notable progress has been made in this field due to a better understanding of pulp physiology, improved clinical protocols and advanced bioceramic materials paired with adhesive technology. With focused case selection, conservative VPT can provide reliable treatment options for permanent teeth diagnosed with normal pulps or reversible pulpitis.

  8. Cognitive Development Trajectories of Very Preterm and Typically Developing Children

    ERIC Educational Resources Information Center

    Mangin, Kathryn S.; Horwood, L. J.; Woodward, Lianne J.

    2017-01-01

    Cognitive impairment is common among children born very preterm (VPT), yet little is known about how this risk changes over time. To examine this issue, a regional cohort of 110 VPT (= 32 weeks gestation) and 113 full-term (FT) born children was prospectively assessed at ages 4, 6, 9, and 12 years using the Wechsler Preschool and Primary Scale of…

  9. Transmastoid reshaping of the sigmoid sinus: preliminary study of a novel surgical method to quiet pulsatile tinnitus of an unrecognized vascular origin.

    PubMed

    Kim, Chong Sun; Kim, So Young; Choi, Hyunseok; Koo, Ja-Won; Yoo, Shin-Young; An, Gwang Seok; Lee, Kyogu; Choi, Inyong; Song, Jae-Jin

    2016-08-01

    OBJECTIVE A dominant sigmoid sinus with focal dehiscence or thinning (DSSD/T) of the overlying bony wall is a commonly encountered, but frequently overlooked, cause of vascular pulsatile tinnitus (VPT). Also, the pathophysiological mechanism of sound perception in patients with VPT remains poorly understood. In the present study, a novel surgical method, termed transmastoid SS-reshaping surgery, was introduced to ameliorate VPT in patients with DSSD/T. The authors reviewed a case series, analyzed the surgical outcomes, and suggested the pathophysiological mechanism of sound perception. The theoretical background underlying VPT improvement after transmastoid SS-reshaping surgery was also explored. METHODS Eight patients with VPT that was considered attributable to DSSD/T underwent transmastoid SS-reshaping surgery between February 2010 and February 2015. The mean postoperative follow-up period was 9.5 months (range 4-13 months). Transmastoid SS-reshaping surgery featured simple mastoidectomy, partial compression of the SS using harvested cortical bone chips, and reinforcement of the bony SS wall with bone cement. Perioperative medical records, imaging results, and audiological findings were comprehensively reviewed. RESULTS In 7 of the 8 patients (87.5%), the VPT abated immediately after surgery. Statistically significant improvements in tinnitus loudness and distress were evident on numeric rating scales. Three patients with preoperative ipsilesional low-frequency hearing loss exhibited postoperative improvements in their low-frequency hearing thresholds. No major postoperative complications were encountered except in the first subject, who experienced increased intracranial pressure postoperatively. This subsided after a revision operation for partial decompression of the SS. CONCLUSIONS Transmastoid SS-reshaping surgery may be a good surgical option in patients with DSSD/T, a previously unrecognized cause of VPT. Redistribution of severely asymmetrical blood flow

  10. Developmental changes in mental rotation ability and visual perspective-taking in children and adults with Williams syndrome

    PubMed Central

    Hirai, Masahiro; Muramatsu, Yukako; Mizuno, Seiji; Kurahashi, Naoko; Kurahashi, Hirokazu; Nakamura, Miho

    2013-01-01

    Williams syndrome (WS) is a genetic disorder caused by the partial deletion of chromosome 7. Individuals with WS have atypical cognitive abilities, such as hypersociability and compromised visuospatial cognition, although the mechanisms underlying these deficits, as well as the relationship between them, remain unclear. Here, we assessed performance in mental rotation (MR) and level 2 visual perspective taking (VPT2) tasks in individuals with and without WS. Individuals with WS obtained lower scores in the VPT2 task than in the MR task. These individuals also performed poorly on both the MR and VPT2 tasks compared with members of a control group. For the individuals in the control group, performance scores improved during development for both tasks, while the scores of those in the WS group improved only in the MR task, and not the VPT2 task. Therefore, we conducted a second experiment to explore the specific cognitive challenges faced by people with WS in the VPT2 task. In addition to asking participants to change their physical location (self-motion), we also asked them to adopt a third-person perspective by imagining that they had moved to a specified location (self-motion imagery). This enabled us to assess their ability to simulate the movement of their own bodies. The performance in the control group improved in both the self-motion and self-motion imagery tasks and both performances were correlated with verbal mental age. However, we did not find any developmental changes in performance for either task in the WS group. Performance scores for the self-motion imagery task in the WS group were low, similar to the scores observed for the VPT2 in this population. These results suggest that MR and VPT2 tasks involve different processes, and that these processes develop differently in people with WS. Moreover, difficulty completing VPT2 tasks may be partly because of an inability of people with WS to accurately simulate mental body motion. PMID:24376412

  11. Neurological abnormalities in young adults born preterm

    PubMed Central

    Allin, M; Rooney, M; Griffiths, T; Cuddy, M; Wyatt, J; Rifkin, L; Murray, R

    2006-01-01

    Objective Individuals born before 33 weeks' gestation (very preterm, VPT) have an increased likelihood of neurological abnormality, impaired cognitive function, and reduced academic performance in childhood. It is currently not known whether neurological signs detected in VPT children persist into adulthood or become attenuated by maturation of the CNS. Method We assessed 153 VPT individuals and 71 term‐born controls at 17–18 years old, using a comprehensive neurological examination. This examination divides neurological signs into primary and integrative domains, the former representing the localising signs of classical neurology, and the latter representing signs requiring integration between different neural networks or systems. Integrative signs are sub‐divided into three groups: sensory integration, motor confusion, and sequencing. The VPT individuals have been followed up since birth, and neonatal information is available on them, along with the results of neurological assessment at 4 and 8 years of age and neuropsychological assessment at 18 years of age. Results The total neurology score and primary and integrative scores were significantly increased in VPT young adults compared to term‐born controls. Within the integrative domain, sensory integration and motor confusion scores were significantly increased in the VPT group, but sequencing was not significantly different between the VPT and term groups. Integrative neurological abnormalities at 18 were strongly associated with reduced IQ but primary abnormalities were not. Conclusions Neurological signs are increased in VPT adults compared to term‐born controls, and are strongly associated with reduced neuropsychological function. PMID:16543529

  12. A comparison of the new indicator test for sudomotor function (Neuropad) with the vibration perception threshold and the clinical examination in the diagnosis of peripheral neuropathy in subjects with type 2 diabetes.

    PubMed

    Papanas, N; Papatheodorou, K; Papazoglou, D; Monastiriotis, C; Christakidis, D; Maltezos, E

    2008-02-01

    Peripheral neuropathy remains a major cause of morbidity and is a cardinal factor in the pathogenesis of diabetic foot ulceration. The aim of the present study was to compare the new indicator test for sudomotor function (Neuropad) with the vibration perception threshold (VPT) and the clinical examination in the diagnosis of peripheral neuropathy in subjects with type 2 diabetes. This study included 154 type 2 diabetic patients (76 men) with a mean age of 64.3+/-7.3 years and a mean diabetes duration of 12.8+/-4.3 years. Neuropathy was diagnosed clinically using the Neuropathy Disability Score (NDS). The VPT was measured with a neurothesiometer, values > 25Volts being classified as abnormal. Sudomotor function was evaluated by the indicator test. Sensitivity of the indicator test for neuropathy was 97.8% and specificity was 67.2%. Sensitivity and specificity of VPT for neuropathy were 78.9% and 85.9% respectively. A significant correlation was shown between time to colour change of the indicator test and VPT (rs=0.889, p<0.001). Both the indicator test and the VPT have a high sensitivity for neuropathy. Sensitivity is higher with the indicator test, but specificity is higher with VPT. Time until complete colour change of the indicator test shows a positive correlation with VPT. Thus, the indicator test appears to be a useful additional diagnostic tool of neuropathy, particularly suitable for screening and self-examination, in type 2 diabetes. The correlation between time to colour change of the indicator test and VPT is interesting and merits investigation in a prospective study.

  13. Vibration Perception Threshold as a Measure of Distal Symmetrical Peripheral Neuropathy in Type 1 Diabetes

    PubMed Central

    Martin, Catherine L.; Waberski, Barbara H.; Pop-Busui, Rodica; Cleary, Patricia A.; Catton, Sarah; Albers, James W.; Feldman, Eva L.; Herman, William H.

    2010-01-01

    OBJECTIVE To describe the sensitivity, specificity, positive predictive value, and negative predictive value of vibration perception threshold (VPT) testing in subjects with type 1 diabetes relative to gold standard assessments of peripheral neuropathy. RESEARCH DESIGN AND METHODS VPT was determined in 1,177 adults with type 1 diabetes 13–14 years after participating in a study of intensive (INT) versus conventional (CONV) diabetes treatment. Abnormal VPT was defined by values exceeding 2.5 SD above age-specific normal values. Signs and symptoms of peripheral neuropathy were assessed and electrodiagnostic studies were performed to establish definite clinical neuropathy, abnormal nerve conduction, and confirmed clinical neuropathy (the presence of both definite clinical neuropathy and abnormal nerve conduction). RESULTS Thirty-seven percent of subjects had definite clinical neuropathy, 61% had abnormal nerve conduction, and 30% had confirmed clinical neuropathy. Abnormal VPT was more common among former CONV than among INT subjects (64 vs. 57%, P < 0.05) and was associated with older age. VPT was a sensitive measure of confirmed clinical neuropathy (87%) and of definite clinical neuropathy (80%) and a specific measure of abnormal nerve conduction (62%). Higher VPT cut points improved test sensitivity and lower cut points improved specificity. Areas under the receiver operating characteristic curves ranged from 0.71–0.83 and were higher for older than for younger subjects and highest for those with confirmed clinical neuropathy. CONCLUSIONS VPT was a sensitive measure of peripheral neuropathy. Future researchers may choose to select VPT cut points for defining abnormality based on the population studied and clinical outcome of interest. PMID:20833868

  14. Screening patients at risk for diabetic foot ulceration: a comparison between measurement of vibration perception threshold and 10-g monofilament test.

    PubMed

    Richard, Jean-Louis; Reilhes, Lise; Buvry, Stéphanie; Goletto, Monique; Faillie, Jean-Luc

    2014-04-01

    The aim is to compare the frequency of increased vibration perception threshold (VPT) with abnormal 10-g Semmes-Weinstein monofilament (SWF) testing in a non-selected diabetic population, and to assess the agreement between these two screening methods. VPT was measured using a neurothesiometer at the pulp of the hallux and 10-g SWF was applied on three plantar sites on each foot according to the guidelines of the International Working Group on the Diabetic Foot, in 400 consecutive diabetic patients. VPT was considered as abnormal if ≥25 V and SWF was considered as abnormal if the patient was unable to feel ≥2 applications at a single site. Both tests were normal in 240 patients (60%) and both abnormal in 78. In 21 patients, only SWF was abnormal whereas only VPT was abnormal in 61. As a whole, 160 patients (40%) were considered at risk for foot ulceration by VPT and/or SWF. Agreement between the two screening methods was only moderate with a kappa coefficient of 0·52 (95% CI: 0·43-0·60). Using VPT as a predictor for foot ulceration, the number of patients at risk is much higher than identified by SWF. This discrepancy might have potential effects on costs and prevention policies. © 2012 The Authors. International Wound Journal © 2012 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  15. Elevated Vibration Perception Thresholds in CIDP Patients Indicate More Severe Neuropathy and Lower Treatment Response Rates

    PubMed Central

    Abraham, Alon; Albulaihe, Hana; Alabdali, Majed; Qrimli, Mohammad; Breiner, Ari; Barnett, Carolina; Katzberg, Hans D.; Lovblom, Leif E.; Perkins, Bruce A.; Bril, Vera

    2015-01-01

    Introduction Vibration perception threshold (VPT) examination using a neurothesiometer provides objective, sensitive and specific information, and has been utilized mainly in patients with diabetic polyneropathy. Objectives Explore the utility of VPT examination in CIDP patients. Methods CIDP subjects attending the Neuromuscular clinic between 01/2013 and 12/2014 were evaluated. Demographic data, clinical history, physical examination, VPT values, and electrophysiologic data from their charts were extracted. Results 70 charts were reviewed. 55 CIDP patients had elevated VPT, associated with higher frequency of abnormal sensory testing for various modalities (92.7% vs. 46.7%, p<0.0001), lower sensory and motor amplitudes and reduced conduction velocities on nerve conduction studies, and lower treatment response rates (54% vs. 93%, p = 0.01). Conclusion VPT examination is a simple tool, which is a reliable and sensitive measure not only for diabetic neuropathy, but also for CIDP. Moreover, in CIDP, elevated VPT values are also associated with lower treatment response rates. PMID:26545096

  16. Implicit and explicit motor sequence learning in children born very preterm.

    PubMed

    Jongbloed-Pereboom, Marjolein; Janssen, Anjo J W M; Steiner, K; Steenbergen, Bert; Nijhuis-van der Sanden, Maria W G

    2017-01-01

    Motor skills can be learned explicitly (dependent on working memory (WM)) or implicitly (relatively independent of WM). Children born very preterm (VPT) often have working memory deficits. Explicit learning may be compromised in these children. This study investigated implicit and explicit motor learning and the role of working memory in VPT children and controls. Three groups (6-9 years) participated: 20 VPT children with motor problems, 20 VPT children without motor problems, and 20 controls. A nine button sequence was learned implicitly (pressing the lighted button as quickly as possible) and explicitly (discovering the sequence via trial-and-error). Children learned implicitly and explicitly, evidenced by decreased movement duration of the sequence over time. In the explicit condition, children also reduced the number of errors over time. Controls made more errors than VPT children without motor problems. Visual WM had positive effects on both explicit and implicit performance. VPT birth and low motor proficiency did not negatively affect implicit or explicit learning. Visual WM was positively related to both implicit and explicit performance, but did not influence learning curves. These findings question the theoretical difference between implicit and explicit learning and the proposed role of visual WM therein. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Maternal Sensitivity Buffers the Association between SLC6A4 Methylation and Socio-Emotional Stress Response in 3-Month-Old Full Term, but not very Preterm Infants.

    PubMed

    Provenzi, Livio; Fumagalli, Monica; Giorda, Roberto; Morandi, Francesco; Sirgiovanni, Ida; Pozzoli, Uberto; Mosca, Fabio; Borgatti, Renato; Montirosso, Rosario

    2017-01-01

    Very preterm (VPT) infants are hospitalized in Neonatal Intensive Care Units (NICUs) and are exposed to life-saving procedures eliciting pain-related stress. Recent research documented that pain-related stress might result in birth-to-discharge increased methylation of serotonin transporter gene (SLC6A4) in VPT infants, leading to poorer stress regulation at 3 months of age in VPT infants compared to their full-term (FT) counterparts. Maternal sensitivity is thought to support infants' stress response, but its role in moderating the effects of altered SLC6A4 methylation is unknown. To assess the role of maternal sensitivity in moderating the association between altered SLC6A4 methylation and stress response in 3-month-old VPT and FT infants. 53 infants (27 VPTs, 26 FTs) and their mothers were enrolled. SLC6A4 methylation was obtained from peripheral blood samples at NICU discharge for VPT infants and from cord blood at birth for FT infants. At 3 months (age corrected for prematurity), both groups participated to the face-to-face still-face (FFSF) paradigm to measure both infants' stress response (i.e., negative emotionality) and maternal sensitivity. Maternal sensitivity did not significantly differ between VPT and FT infants' mothers. In VPT infants, higher SLC6A4 methylation at hospital discharge associates with higher negative emotionality during the FFSF. In FT infants, SLC6A4 methylation and maternal sensitivity significantly interacted to predict stress response: a positive significant association between SLC6A4 methylation and negative emotionality emerged only in FT infants of less-sensitive mothers. Although no differences emerged in caregiving behavior in the two groups of mothers, maternal sensitivity was effective in moderating the effects of SLC6A4 methylation in FT infants, but not in VPT infants at 3 months. Speculatively, the buffering effect of maternal sensitivity observed in FT infants was disrupted by the altered early mother

  18. Vibratory sense deficits in patients with symptomatic femoroacetabular impingement

    PubMed Central

    Farkas, G.J.; Shakoor, N.; Cvetanovich, G.L.; Fogg, L.F.; Orías, A.A. Espinoza; Nho, S.J.

    2016-01-01

    Objective: Sensory deficits, measured through vibratory perception threshold (VPT), have been recognized in hip and knee osteoarthritis (OA), but have not been evaluated in femoroacetabular impingement (FAI), thought to be a pre-OA condition. This study aimed to assess VPT in symptomatic FAI pre- and 6-months post-arthroscopy vs. controls. Methods: FAI patients and controls were assessed for VPT at the first metatarsophalangeal joint. Pain was assessed using a visual analog pain scale. FAI participants were evaluated again 6-months after surgery for FAI. Differences between groups and pre- and post- surgery were evaluated with independent and paired sample t-tests, respectively. Secondary analysis was performed using repeated-measures ANOVA to evaluate the effect of pain and time since surgery on VPT pre- and post-operatively. Results: No differences in age and BMI were seen between groups (p>0.05). Reduced VPT (higher value is worse) was evident in the pre- (8.0±3.9V, t=2.81, p=0.009) and post-operative (6.8±2.8V, t=2.34, p=0.027) patients compared to controls (4.7±1.3V). After hip arthroscopy, there was a trend toward improved VPT (t=1.97, p=0.068). Preoperative and 6-months postoperative pain and time since surgery were not found to influence VPT (F-ratio≥0.00, p≥0.427). Conclusion: Sensory deficits were observed in FAI patients both before and 6-months after hip arthroscopy. PMID:26944822

  19. A simple screen performed at school entry can predict academic under-achievement at age seven in children born very preterm.

    PubMed

    Taylor, Rebecca; Pascoe, Leona; Scratch, Shannon; Doyle, Lex W; Anderson, Peter; Roberts, Gehan

    2016-07-01

    We aimed to compare the academic outcomes of a cohort of children born very preterm (VPT, <32 weeks of gestation) and children born at term at age 7 years and assess the ability of a pre-academic skill screen at age five to predict later academic impairment in children born VPT at age seven. One hundred ninety-four children born VPT (born with either gestational age <30 weeks or birthweight <1250 g) and 70 controls born at term from a prospective birth cohort were compared on academic outcomes (Wide Range Achievement Test, WRAT4) at age seven using regression analyses. Receiver-operating characteristic curves were used to determine whether pre-academic skills (Kaufman Survey of Early Academic and Language Skills, K-SEALS) at age five predicted academic impairment at age seven in 174 of the VPT cohort. At the age of 7 years, children born VPT had lower mean word reading (-9.7, 95% CI: -14.7 to -4.6), spelling (-8.3, 95% CI: -13.3 to -3.3) and math computation (-10.9, 95% CI: -15.3 to -6.5) scores (all P-values ≤0.001) compared with controls born at term, even after adjusting for social risk and time since school commencement. In terms of pre-academic screening, the Numbers, Letters and Words subtest of the K-SEALS had adequate sensitivity and specificity (70-80%) for predicting children with academic impairment at age seven. Children born VPT underperformed in academic outcomes at age seven compared with controls born at term. A pre-academic screening tool used at school entry can predict children born VPT at risk of academic impairment at age seven who could benefit from targeted early intervention. © 2016 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).

  20. Processing speed mediates executive function difficulties in very preterm children in middle childhood.

    PubMed

    Mulder, Hanna; Pitchford, Nicola J; Marlow, Neil

    2011-05-01

    Executive function and attention difficulties are reported in very preterm (VPT) children at school entry, but it is unclear if these remain at later ages and/or if these difficulties are mediated by more basic functions, such as processing speed. Processing speed has been shown to underlie academic and behavioral problems in VPT children in middle childhood (Mulder, Pitchford, & Marlow, 2010, 2011), so may also underpin executive function and attention difficulties. We investigated this by comparing VPT (gestational age <31 weeks; N = 56) to term children (N = 22) aged 9-10 years on a comprehensive battery of executive function and attention tasks from the Test of Everyday Attention for Children (Manly, Robertson, Anderson, & Nimmo-Smith, 1999) and NEPSY (Korkman, Kirk, & Kemp, 1998). Selective and sustained attention, inhibition, working memory, shifting, verbal fluency, planning, and processing speed were examined. Group differences favoring term children were shown on most executive function tasks (i.e., inhibition, working memory, verbal fluency, and shifting), all of which were mediated by slow processing speed in the VPT group, except response inhibition. Seemingly, processing speed is an important determinant underpinning many neuropsychological deficits seen in VPT children in middle childhood.

  1. Eating disorder psychopathology, brain structure, neuropsychological correlates and risk mechanisms in very preterm young adults.

    PubMed

    Micali, Nadia; Kothari, Radha; Nam, Kie Woo; Gioroukou, Elena; Walshe, Muriel; Allin, Matthew; Rifkin, Larry; Murray, Robin M; Nosarti, Chiara

    2015-03-01

    This study investigates the prevalence of eating disorder (ED) psychopathology, neuropsychological function, structural brain correlates and risk mechanisms in a prospective cohort of very preterm (VPT) young adults. We assessed ED psychopathology and neuropsychological correlates in 143 cohort individuals born at <33 weeks of gestation. Structural brain correlates and risk factors at birth, in childhood and adolescence, were investigated using prospectively collected data throughout childhood/adolescence. VPT-born individuals had high levels of ED psychopathology at age 21 years. Executive function did not correlate with ED symptomatology. VPT adults presenting with ED psychopathology had smaller grey matter volume at age 14/15 years in the left posterior cerebellum and smaller white matter volume in the fusiform gyrus bilaterally, compared with VPT adults with no ED psychopathology. Caesarean delivery predicted engaging in compensatory behaviours, and severe eating difficulty at age 14 years predicted ED symptomatology in young adulthood. VPT individuals are at risk for ED symptomatology, with evidence of associated structural alterations in posterior brain regions. Further prospective studies are needed to clarify the pathways that lead from perinatal/obstetric complications to ED and relevant neurobiological mechanisms. © 2015 The Authors. European Eating Disorders Review published by John Wiley &Sons, Ltd.

  2. Socio-Emotional Development Following Very Preterm Birth: Pathways to Psychopathology

    PubMed Central

    Montagna, Anita; Nosarti, Chiara

    2016-01-01

    Very preterm birth (VPT; < 32 weeks of gestation) has been associated with an increased risk to develop cognitive and socio-emotional problems, as well as with increased vulnerability to psychiatric disorder, both with childhood and adult onset. Socio-emotional impairments that have been described in VPT individuals include diminished social competence and self-esteem, emotional dysregulation, shyness and timidity. However, the etiology of socio-emotional problems in VPT samples and their underlying mechanisms are far from understood. To date, research has focused on the investigation of both biological and environmental risk factors associated with socio-emotional problems, including structural and functional alterations in brain areas involved in processing emotions and social stimuli, perinatal stress and pain and parenting strategies. Considering the complex interplay of the aforementioned variables, the review attempts to elucidate the mechanisms underlying the association between very preterm birth, socio-emotional vulnerability and psychopathology. After a comprehensive overview of the socio-emotional impairments associated with VPT birth, three main models of socio-emotional development are presented and discussed. These focus on biological vulnerability, early life adversities and parenting, respectively. To conclude, a developmental framework is used to consider different pathways linking VPT birth to psychopathology, taking into account the interaction between medical, biological, and psychosocial factors. PMID:26903895

  3. Social development of children born very preterm: a systematic review.

    PubMed

    Ritchie, Kirsten; Bora, Samudragupta; Woodward, Lianne J

    2015-10-01

    To review systematically studies examining the development of social competence in children born very preterm (VPT) (gestation <33 wks) and identify neonatal and family predictors. Peer-reviewed original articles were extracted from PubMed and PsycINFO following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Selection criteria included children born VPT and comparison children born at term, sample born after 1990, and children assessed between 0 and 17 years on at least one measure of social competence spanning social adjustment, performance, and/or social skills. Twenty-three studies were included. Seven focused on social competence and another 16 examined social competence within a range of outcomes. Study quality was low. Limitations included reliance on single informant data, cross-sectional measurement, use of brief screening tools, absence of child or peer report, and no conceptual model. In terms of social adjustment, 16 out of 21 studies found children born VPT had more peer problems and social withdrawal. Findings of social performance were mixed, with some studies suggesting differences in prosocial behavior (4/14) and others not. Social skills were assessed in four studies and showed children born VPT had poorer skills than children born at term. Predictors of social competence included gestational age, neonatal brain abnormalities, and family socio-economic status. Children born VPT have poorer social competence. These difficulties emerge early and persist throughout childhood. © 2015 Mac Keith Press.

  4. Level-Set-Segmentierung von Rattenhirn MRTs

    NASA Astrophysics Data System (ADS)

    Eiben, Björn; Kunz, Dietmar; Pietrzyk, Uwe; Palm, Christoph

    In dieser Arbeit wird die Segmentierung von Gehirngewebe aus Kopfaufnahmen von Ratten mittels Level-Set-Methoden vorgeschlagen. Dazu wird ein zweidimensionaler, kontrastbasierter Ansatz zu einem dreidimensionalen, lokal an die Bildintensität adaptierten Segmentierer erweitert. Es wird gezeigt, dass mit diesem echten 3D-Ansatz die lokalen Bildstrukturen besser berücksichtigt werden können. Insbesondere Magnet-Resonanz-Tomographien (MRTs) mit globalen Helligkeitsgradienten, beispielsweise bedingt durch Oberfiächenspulen, können auf diese Weise zuverlässiger und ohne weitere Vorverarbeitungsschritte segmentiert werden. Die Leistungsfähigkeit des Algorithmus wird experimentell an Hand dreier Rattenhirn-MRTs demonstriert.

  5. Peripheral neuropathy in military aircraft maintenance workers in Australia.

    PubMed

    Guest, Maya; Attia, John R; D'este, Catherine A; Boggess, May M; Brown, Anthony M; Gibson, Richard E; Tavener, Meredith A; Ross, James; Gardner, Ian; Harrex, Warren

    2011-04-01

    This study aimed to examine possible persisting peripheral neuropathy in a group who undertook fuel tank repairs on F-111 aircraft, relative to two contemporaneous comparison groups. Vibration perception threshold (VPT) was tested using biothesiometry in 614 exposed personnel, compared with two unexposed groups (513 technical trades and 403 nontrades). Regression modeling was used to examine associations, adjusting for possible confounders. We observed that 26% of participants had chronic persistent increased VPT in the great toe. In contrast, statistically significant higher VPT of the great toe was observed in the comparison groups; however, the effect was small, about 1/4 the magnitude of diabetes. Age, height, and diabetes were all significant and strong predictors in most models. This study highlights chronic persisting peripheral neuropathy in a population of aircraft maintainers.

  6. Vital Pulp Therapy of a Mature Molar with Concurrent Hyperplastic Pulpitis, Internal Root Resorption and Periradicular Periodontitis: A Case Report

    PubMed Central

    Asgary, Saeed; Kemal Çalışkan, Mehmet

    2015-01-01

    Vital pulp therapy (VPT) of permanent mature teeth is continuously ascertaining to be a more reliable endodontic treatment. The purpose of this case report was to describe successful VPT of a mature mandibular left first molar with concurrent hyperplastic pulpitis, internal root resorption and periradicular periodontitis in a 35-year-old male patient. After complete caries removal and access cavity preparation, the dental pulp was removed from the coronal third of the roots. To protect the remaining pulp, calcium-enriched mixture (CEM) cement was placed and adapted into the cavities; the tooth was then restored with amalgam. Six months after VPT, radiographic examination showed evidence of periradicular healing. Clinically, the tooth was functional without signs and symptoms of infection/inflammation. The successful outcome of this case suggests that diseased dental pulp (i.e. irreversible pulpitis) has the potential to heal after pulp protection with CEM biocement. PMID:26523145

  7. Vital Pulp Therapy of a Symptomatic Immature Permanent Molar with Long-Term Success

    PubMed Central

    Sabbagh, Sedigheh; Sarraf Shirazi, Alireza; Eghbal, Mohammad Jafar

    2016-01-01

    Vital pulp therapy (VPT) is the preferred conservative treatment for preservation of symptomatic pulps in immature permanent teeth. The present case report summarizes VPT of an immature permanent molar with irreversible pulpitis associated with apical periodontitis in a 9-year-old boy. Cervical pulpotomy was performed and radicular pulp stumps were covered with calcium-enriched mixture (CEM) cement; the tooth was then restored with stainless steel crown. After a 50-month follow-up period, the pulpotomized molar was clinically functional and asymptomatic. Moreover, radiographic evaluation revealed evidence of complete root development as well as normal periodontal ligament around the roots. The successful outcome achieved through VPT using CEM biomaterial in the reported case suggests that this method may produce favorable outcome for vital immature permanent teeth with irreversible pulpitis and periapical disease. PMID:27790270

  8. Vital pulp therapy using calcium-enriched mixture: An evidence-based review

    PubMed Central

    Asgary, Saeed; Ahmadyar, Maryam

    2013-01-01

    Worldwide, casecontrol studies have revealed that the treatment outcomes of root canal therapy (RCT) are generally favorable; however, the overall epidemiological success rate of RCT in the general population is relatively low. On the other hand, vitality of dental pulp is a key factor in the long-term prognosis of permanent teeth; in recent years, vital pulp therapy (VPT) has received significant consideration as it has been revealed that the inflamed pulp has the potential to heal. In this review article, the current best evidence with regard to VPT using calcium-enriched mixture (CEM) cement in human permanent/primary teeth is discussed. A strategy based on a search using keywords for CEM cement as well as VPT was applied. PMID:23716958

  9. Effectiveness and feasibility of nailfold microcirculation test to screen for diabetic peripheral neuropathy.

    PubMed

    Hu, Guotao; Zhai, Fanglong; Mo, Feifei; He, Li; Shen, Weiya; Wang, Hailan

    2017-09-01

    The nailfold microcirculation index (MI) is a non-invasive, objective, and highly sensitive blood capillary detection method. This study evaluated the diagnostic efficiency of the nailfold MI relative to the more subjective vibration perception threshold (VPT) examination for early diagnostic screening of diabetic peripheral neuropathy (DPN). From February 2015 to February 2016, 227 diabetes mellitus patients and 39 healthy individuals were enrolled. Each subject underwent the MI test and the VPT examination. MI was more closely associated with DPN than age, diabetic duration, smoking, drinking, systolic pressure, serum creatinine, 24-h urinary protein, hypoxia-inducible factor-1α (HIF1A), vascular endothelial growth factor (VEGF), the VEGF receptors Flt-1 and Flt-4, ankle branchial index (ABI), DPN, or DPN stage (OR=11.819). Both the MI and VPT closely correlated with age, diabetic duration, serum creatinine, 24-h urinary protein, HIF1A, VEGF, Flt-1, Flt-4, ABI, DPN, and DPN stage. By the receiver operating characteristic (ROC) curve, the MI diagnostic cutoff point was 2.56, where the corresponding Youden's index was maximum and the area under ROC curve was 0.943. The diagnostic efficiency of MI and VPT were similar. MI and VPT indicated similar percentages of diabetic patients with DPN at the most severe stage, while MI achieved a higher diagnostic rate for the earliest stages. The nailfold MI is a feasible method for clinical early diagnostic screening of DPN in diabetic patients, and is more objective and reliable than VPT. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Validation of bedside methods in evaluation of diabetic peripheral neuropathy.

    PubMed

    Jayaprakash, P; Bhansali, Anil; Bhansali, Shobhit; Dutta, Pinaki; Anantharaman, R; Shanmugasundar, G; Ravikiran, M

    2011-06-01

    Vibration perception threshold (VPT) is considered as a gold standard for diagnosis of diabetic peripheral neuropathy. However, the data are sparse comparing the VPT with commonly used bedside modalities. This study was carried out to evaluate the usefulness of simple bed side screening modalities for peripheral neuropathy in patients with diabetes mellitus. A total of 1044 patients with diabetes mellitus attending the Diabetes clinic from January 2007 to May 2008, were included in this study. All subjects had a detailed clinical assessment including Diabetic Neuropathy Symptom (DNS) score, Diabetic Neuropathy Examination (DNE) score, ankle reflex, vibration sensation with a 128 Hz tuning fork, 10 g Semmes-Weinstein monofilament and vibration perception threshold (VPT). The prevalence of peripheral neuropathy was 34.9 per cent with VPT. Foot care practices were followed by only 214 (20.5%) of the study population. When compared with VPT, ankle reflex was the most sensitive (90.7%) but least specific (37.3%). The tuning fork and monofilament tests respectively had lower sensitivity (62.5 and 62.8%) but better specificity (95.3 and 92.9%) and accuracy (78.9 and 77.9%). Significant correlations were observed between the VPT score and the DNE (r = 0.532, P<0.001) and DNS (r = 0.546, P<0.001) scores and absent tuning fork sensation (r = 0.590; P<0.001), monofilament sensation (r = 0.573; P<0.001) and ankle reflex (r = 0.377, P = 0.01). The present findings show that simple bed side tests are useful for assessing peripheral diabetic neuropathy, even in those subjects in whom foot care practices are not followed.

  11. Comparison of Gait Speed and Peripheral Nerve Function Between Chronic Kidney Disease Patients With and Without Diabetes

    PubMed Central

    2017-01-01

    Objective To compare overall physical function, including gait speed and peripheral nerve function, between diabetic chronic kidney disease (CKD) patients and nondiabetic CKD patients and to investigate the association between gait speed and peripheral nerve function in CKD patients. Methods Sixty adult CKD patients (35 with and 25 without diabetes), who received maintenance hemodialysis (HD), were included in this study. Demographic data, past medical history, current medical condition and functional data—usual gait speed, vibration perception threshold for the index finger (VPT-F) and the great toe (VPT-T), activity of daily living (ADL) difficulty, and peripheral neuropathy (PN) along with the degree of its severity—were collected and compared between the two groups. Correlations between the severity of PN and the impairment of other functions were identified. Results Diabetic CKD patients showed significantly slower gait speed (p=0.029), impaired sensory function (VPT-F, p=0.011; VPT-T, p=0.023), and more frequent and severe PN (number of PN, p<0.001; severity of PN, p<0.001) as compared to those without diabetes. Usual gait speed had a significant negative correlation with the severity of PN (rho=−0.249, p=0.013). By contrast, VPT-F (rho=0.286, p=0.014) and VPT-T (rho=0.332, p=0.035) were positively correlated with the severity of PN. ADL difficulty was comparatively more frequent in the patients with more severe PN (p=0.031). Conclusion In CKD patients with maintenance HD, their gait speed, sensory functions, and peripheral nerve functions were all significantly impaired when they have diabetes, and the severity of PN was negatively correlated with their gait speed, sensory function, and ADL function. Adverse effects of diabetes impacted physical performance of CKD patients. The physical disability of those patients might be attributable to PN and its severity. PMID:28289638

  12. Identifying very preterm children at educational risk using a school readiness framework.

    PubMed

    Pritchard, Verena E; Bora, Samudragupta; Austin, Nicola C; Levin, Karelia J; Woodward, Lianne J

    2014-09-01

    Children born very preterm (VPT) are at high risk of educational delay, yet few guidelines exist for the early identification of those at greatest risk. Using a school readiness framework, this study examined relations between preschool neurodevelopmental functioning and educational outcomes to age 9 years. The sample consisted of a regional cohort of 110 VPT (≤ 32 weeks' gestation) and 113 full-term children born during 1998-2000. At corrected age 4 years, children completed a multidisciplinary assessment of their health/motor development, socioemotional adjustment, core learning skills, language, and general cognition. At ages 6 and 9, children's literacy and numeracy skills were assessed using the Woodcock-Johnson III Tests of Achievement. Across all readiness domains, VPT children were at high risk of delay/impairment (odds ratios 2.5-3.5). Multiple problems were also more common (47% vs 16%). At follow-up, almost two-thirds of VPT children were subject to significant educational delay in either literacy, numeracy or both compared with 29% to 31% of full-term children (odds ratios 3.4-4.4). The number of readiness domains affected at age 4 strongly predicted later educational risk, especially when multiple problems were present. Receiver operating characteristic analysis confirmed ≥ 2 readiness problems as the optimal threshold for identifying VPT children at educational risk. School readiness offers a promising framework for the early identification of VPT children at high educational risk. Findings support the utility of ≥ 2 affected readiness domains as an effective criterion for referral for educational surveillance and/or additional support during the transition to school. Copyright © 2014 by the American Academy of Pediatrics.

  13. Application of Fourth Order Vibrational Perturbation Theory with Analytic Hartree-Fock Force Fields

    NASA Astrophysics Data System (ADS)

    Gong, Justin Z.; Matthews, Devin A.; Stanton, John F.

    2014-06-01

    Fourth-Order Rayleigh-Schrodinger Perturbation Theory (VPT4) is applied to a series of small molecules. The quality of results have been shown to be heavily dependent on the quality of the quintic and sextic force constants used and that numerical sextic force constants converge poorly and are unreliable for VPT4. Using analytic Hartree-Fock force constants, it is shown that these analytic higher-order force constants are comparable to corresponding force constants from numerical calculations at a higher level of theory. Calculations show that analytic Hartree-Fock sextic force constants are reliable and can provide good results with Fourth-Order Rayleigh-Schrodinger Perturbation Theory.

  14. Comparison of static and dynamic methods of treatment of anharmonicity for the vibrational study of isolated and aqueous forms of guanine

    NASA Astrophysics Data System (ADS)

    Thicoipe, Sandrine; Carbonniere, Philippe; Pouchan, Claude

    2014-01-01

    This theoretical study provides the anharmonic vibrational wavenumbers of isolated and aqueous guanine. They were performed at the DFT B3LYP/6-31+G(d,p) level of theory using two different ways for the treatment of anharmonicity: time-independent (VPT2) and time-dependent (molecular dynamics) approaches. The wavenumbers obtained are compared to experimental data for isolated and aqueous forms: the VPT2 approach is slightly better than MD, especially for the determination of stretching and wagging (NH) motions. Finally, the structural model of solvatation used for aqueous guanine which combines an explicit solvent model with a polarizable continuum model (PCM) was validated.

  15. Vibrational Constants for Triatomic Molecules from Fourth-Order Perturbation Theory

    NASA Astrophysics Data System (ADS)

    Matthews, Devin A.; Gong, Justin Z.; Stanton, John F.

    2013-06-01

    The second vibrational anharmonicity constants (y_{ijk}) for general non-linear triatomic molecules as derived from fourth-order Rayleigh-Schrödinger perturbation theory (VPT4) are presented. The derived constants include all force field and Coriolis terms from the Watson Hamiltonian except for the pseudopotential. The basic theory of VPT4 is discussed, particularly with application to molecular constants, as well as the computational methods used to derive the specific constants. Finally, the constants are analyzed in the context of model systems such as Morse and double-well potentials.

  16. Object-based mental rotation and visual perspective-taking in typical development and Williams syndrome.

    PubMed

    Broadbent, Hannah J; Farran, Emily K; Tolmie, Andrew

    2014-01-01

    This study examined Object-based (OB) rotation and Visual Perspective-Taking (VPT) abilities in Williams syndrome (WS) compared to typically developing (TD) 5-10-year-olds. Extensive difficulties with both types of imagined rotation were observed in WS; WS performance was in line with the level of ability observed in TD 5-year-olds. However, an atypical pattern of errors on OB and VPT tasks was observed in WS compared to TD groups. Deficits in imagined rotations are consistent with known atypical cortical development in WS. Such difficulties in updating the position of the self following movement in WS may have implications for large-scale spatial navigation.

  17. Vitrectomy for vitreopapillary traction in a nondiabetic 16-year-old girl

    PubMed Central

    Nagesha, C. K.; Rishi, Pukhraj; Rishi, Ekta

    2017-01-01

    Vitreopapillary traction (VPT) is an unusual clinical entity and its management and prognosis have been sparsely studied. It has been described in adults with various vitreomacular pathologies and the possible effects on visual functions. However, the role of surgical intervention in altering the course of the disease is not well understood. Hereby, we describe a case of idiopathic VPT in a 16-year-old girl who presented with decreased vision and visual field changes corresponding to the area of retinal traction. This case was managed with pars plana vitrectomy and epiretinal membrane removal that resulted in improved visual field sensitivity; thus, emphasizing the role of surgical intervention in such eyes. PMID:28298864

  18. Vibration perception thresholds in workers with long term exposure to lead.

    PubMed

    Chuang, H Y; Schwartz, J; Tsai, S Y; Lee, M L; Wang, J D; Hu, H

    2000-09-01

    To evaluate the impact of long term occupational exposure to lead on function of the peripheral nervous system as reflected by vibration perception threshold (VPT), measured with a portable vibrameter. 217 Workers in a lead battery factory were required to have an annual blood lead measurement during each of the 5 years preceding this study. All were invited to take the VPT test. A total of 206 workers were studied. The associations were analysed between VPTs and current blood lead concentration, mean concentration of blood lead over the past 5 years, maximum blood lead concentration during the past 5 years, index of cumulative blood lead (ICL), time weighted index of cumulative blood lead (TWICL), and percentage of lifespan spent at work in the plant, as well as the other potential confounders. Ordinary multiple regressions, generalised additive models, and hockey stick regression analyses were used to explore the potential existence of a threshold effect of blood lead variables on VPT. VPT at a frequency of 220 Hz ranged from 6 to 100 (10(-2) g, or 0.098 m/s(2)) with a mean (SD) of 19.8 (14.2) for the feet and from 4 to 43 with a mean (SD) of 10.2 (6.1) for the hands. The five variables of exposure to lead were all significantly correlated with VPT of the feet but not the hands. In multiple linear regression analyses, the mean of the blood lead concentrations and the TWICL were significantly associated with VPT of the feet. The relation between VPT of the feet and mean blood lead was shown to be a J shaped curve with a generalised additive model and local smoothing technique. In the hockey stick regression, evidence was found of a threshold effect at a mean blood lead concentration of 31 microgram/dl. Above this threshold it was estimated that each increase of 1 microgram/dl mean blood lead over 5 years would increase VPT of the feet by 0.29 (10(-2) g) or 0.028 m/s(2) (at a frequency of 220 Hz) with other potential confounders held constant. This study suggests

  19. Anharmonic rovibrational calculations of singlet cyclic C{sub 4} using a new ab initio potential and a quartic force field

    SciTech Connect

    Wang, Xiaohong; Bowman, Joel M.; Huang, Xinchuan; Lee, Timothy J.

    2013-12-14

    We report a CCSD(T)/cc-pCV5Z quartic force field (QFF) and a semi-global CCSD(T)-F12b/aug-cc-pVTZ potential energy surface (PES) for singlet, cyclic C{sub 4}. Vibrational fundamentals, combinations, and overtones are obtained using vibrational second-order perturbation theory (VPT2) and the vibrational configuration-interaction (VCI) approach. Agreement is within 10 cm{sup −1} between the VCI calculated fundamentals on the QFF and PES using the MULTIMODE (MM) program, and VPT2 and VCI results agree for the fundamentals. The agreement between VPT2-QFF and MM-QFF results is also good for the C{sub 4} combinations and overtones. The J = 1 and J = 2 rovibrational energies are reported from both VCI (MM) on the PES and VPT2 on the QFF calculations. The spectroscopic constants of {sup 12}C{sub 4} and two C{sub 2v}-symmetry, single {sup 13}C-substituted isotopologues are presented, which may help identification of cyclic C{sub 4} in future experimental analyses or astronomical observations.

  20. Inflammatory Response in Preterm and Very Preterm Newborns with Sepsis

    PubMed Central

    Segura-Cervantes, Enrique; Mancilla-Ramírez, Javier; González-Canudas, Jorge; Alba, Erika; Santillán-Ballesteros, René; Morales-Barquet, Deneb; Sandoval-Plata, Gabriela

    2016-01-01

    The response of the adaptive immune system is usually less intense in premature neonates than term neonates. The primary objective of this study was to determine whether immunological parameters vary between preterm (PT) neonates (≥32 weeks of gestational age) and very preterm (VPT) neonates (<32 weeks of gestational age). A cross-sectional study was designed to prospectively follow PT and VPT neonates at risk of developing sepsis. Plasma concentrations of IFN-γ, TNF-α, IL-6, IL-4, and IL-10 were detected using flow cytometry. C-reactive protein (C-RP) and the complex SC5b-9 were detected in the plasma using commercial kits. A total of 83 patients were included. The laboratory results and clinical histories showed that 26 patients had sepsis; 14 were VPT, and 12 were PT. The levels of C-RP, SC5b-9 (innate immune response mediators), and IL-10 or IL-4 (anti-inflammatory cytokines) were elevated during sepsis in both groups. IFN-γ, TNF-α, and IL-6 (proinflammatory cytokines) were differentially elevated only in PT neonates. The VPT neonates with sepsis presented increases in C-RP, SC5b-9, and anti-inflammatory cytokines but not in proinflammatory cytokines, whereas PT neonates showed increases in all studied mediators of inflammation. PMID:27293317

  1. A Study of Quenching Cooling in Gaseous Atmospheres

    NASA Astrophysics Data System (ADS)

    Shevchenko, S. Yu.; Smirnov, A. E.; Kirillov, I. V.; Kurpyakova, N. A.

    2016-11-01

    Prismatic sensors of two standard sizes are used to determine the heat-transfer coefficients of high-pressure nitrogen at different turbine rotor speeds of a SECO/WARWICK 10.0VPT-4020/24N vacuum furnace. The adequacy of the values obtained is estimated.

  2. Hippocampal shape variations at term equivalent age in very preterm infants compared with term controls: perinatal predictors and functional significance at age 7

    PubMed Central

    Thompson, Deanne K.; Adamson, Christopher; Roberts, Gehan; Faggian, Nathan; Wood, Stephen J.; Warfield, Simon K.; Doyle, Lex W.; Anderson, Peter J.; Egan, Gary F.; Inder, Terrie E.

    2013-01-01

    The hippocampus undergoes rapid growth and development in the perinatal months. Infants born very preterm (VPT) are vulnerable to hippocampal alterations, and can provide a model of disturbed early hippocampal development. Hippocampal shape alterations have previously been associated with memory impairment, but have never been investigated in infants. The aims of this study were to determine hippocampal shape differences between 184 VPT infants (<30 weeks’ gestation or <1250 g at birth) and 32 full-term infants, effects of perinatal factors, and associations between infant hippocampal shape and volume, and 7 year verbal and visual memory (California Verbal Learning Test- Children’s Version and Dot Locations). Infants underwent 1.5T magnetic resonance imaging at term equivalent age. Hippocampi were segmented, and spherical harmonics-point distribution model shape analysis was undertaken. VPT infants’ hippocampi were less infolded than full-term infants, being less curved toward the midline and less arched superior-inferiorly. Straighter hippocampi were associated with white matter injury and postnatal corticosteroid exposure. There were no significant associations between infant hippocampal shape and 7 year memory measures. However, larger infant hippocampal volumes were associated with better verbal memory scores. Altered hippocampal shape in VPT infants at term equivalent age may reflect delayed or disrupted development. This study provides further insight into early hippocampal development and the nature of hippocampal abnormalities in prematurity. PMID:23296179

  3. Language abilities in children who were very preterm and/or very low birth weight: a meta-analysis.

    PubMed

    Barre, Natalie; Morgan, Angela; Doyle, Lex W; Anderson, Peter J

    2011-05-01

    To conduct a meta-analysis to characterize differences in language ability between children born very preterm (VPT, <32 weeks' gestational age), with a very low birth weight (VLBW, <1500 g), or both and in term-born control children. Electronic databases were systematically searched, and 12 studies met the inclusion criteria. Effect sizes were calculated to compare VPT/VLBW children and control children. VPT/VLBW children performed between 0.38 and 0.77 SD below control subjects in the areas of expressive and receptive language overall and expressive and receptive semantics. Results for expressive and receptive grammar were equivocal. Subgroup analysis of school-aged children revealed similar results. No studies assessing phonological awareness, discourse, or pragmatics were identified. Language ability is reduced in VPT/VLBW children. When considering only school-aged children, this reduction is still present, suggesting that their difficulty appears to be ongoing. Rigorous studies examining a range of language subdomains are needed to fully understand the specific nature of language difficulties in this population. Copyright © 2011 Mosby, Inc. All rights reserved.

  4. Power Converters Secure Electronics in Harsh Environments

    NASA Technical Reports Server (NTRS)

    2013-01-01

    In order to harden power converters for the rigors of space, NASA awarded multiple SBIR contracts to Blacksburg, Virginia-based VPT Inc. The resulting hybrid DC-DC converters have proven valuable in aerospace applications, and as a result the company has generated millions in revenue from the product line and created four high-tech jobs to handle production.

  5. Anharmonic Rovibrational Calculations of Singlet Cyclic C4 Using a New Ab Initio Potential and a Quartic Force

    NASA Technical Reports Server (NTRS)

    Wang, Xiaohong; Huang, Xinchuan; Bowman, Joel M.; Lee, Timothy J.

    2013-01-01

    We report a CCSD(T)/cc-pCV5Z quartic force field (QFF) and a semi-global CCSD(T)-F12b/aug-cc-pVTZ potential energy surface (PES) for singlet, cyclic C4. Vibrational fundamentals, combinations and overtones are obtained using vibrational second-order perturbation theory (VPT2) and the vibrational configurationinteraction (VCI) approach. Agreement is within 10 cm(exp -1) between the VCI calculated fundamentals on the QFF and PES using the MULTIMODE (MM) program, and VPT2 and VCI results agree for the fundamentals. The agreement between VPT2- QFF and MM-QFF results is also good for the C4 combinations and overtones. The J = 1 and J = 2 rovibrational energies are reported from both VCI (MM) on the PES and VPT2 on the QFF calculations. The spectroscopic constants of (12)C4 and two C(sub 2v)-symmetry, single (13)C-substituted isotopologues are presented, which may help identification of cyclic C4 in future experimental analyses or astronomical observations.

  6. Aviation Safety in the Rapid Onset, High-G Environment

    DTIC Science & Technology

    2006-01-01

    performance tests (VPT, visual acuity and refraction) and corneal measurements ( topography and keratometry) were performed on all subjects before and...MED ............. ................................................................. 2 Effects of Acceleration on Corneal Stability in Post-Refractive...The results were presented at the 2003 2 Aerospace Medical Association meeting (4). Effects of Acceleration on Corneal Stability in Postrefractive

  7. Evaluating vacuum phototriodes designed for the PANDA electromagnetic calorimeter

    NASA Astrophysics Data System (ADS)

    Makónyi, K.; Marcks von Würtemberg, K.; Tegnér, P.-E.; Hansen, K.; Isaksson, L.; Lundin, M.; Schröder, B.; Balkeståhl, L.; Fransson, K.; Johansson, T.; Rosenbaum, C.; Wolke, M.; Erni, W.; Keshelashvili, I.; Krushe, B.

    2014-11-01

    In this work properties of a vacuum phototriode (VPT) and preamplifier unit designed for the electromagnetic calorimeter of the PANDA experiment being built at FAIR are investigated. With the use of lead tungstate and lanthanium bromide scintillators the VPT properties are studied at low photon energies, from tens of keV in the lanthanium bromide measurements and between 10 MeV and 60 MeV in the lead tungstate measurements. At these energies the noise of the VPT unit can be expected to influence its performance significantly. It is shown that the noise contribution to the measured energy resolution, under optimal conditions, is consistent with a fluctuation of (one standard deviation) approximately 200 electrons at the VPT anode. For a lead tungstate crystal this is equivalent to a noise of 1.2 MeV. For lanthanium bromide this makes it possible to use VPTs for gamma ray spectroscopy above a few hundreds of keV without noticeable effects on the energy resolution compared to measurements with a standard photomultiplier.

  8. Prognostic factors for cerebral palsy and motor impairment in children born very preterm or very low birthweight: a systematic review

    PubMed Central

    Linsell, Louise; Malouf, Reem; Morris, Joan; Kurinczuk, Jennifer J; Marlow, Neil

    2017-01-01

    Aim There is a large literature reporting risk factor analyses for poor neurodevelopment in children born very preterm (VPT: ≤32wks) or very low birthweight (VLBW: ≤1250g), which to date has not been formally summarized. The aim of this paper was to identify prognostic factors for cerebral palsy (CP) and motor impairment in children born VPT/VLBW. Method A systematic review was conducted using Medline, Embase, and Pyscinfo databases to identify studies published between 1 January 1990 and 1 June 2014 reporting multivariable prediction models for poor neurodevelopment in VPT/VLBW children (registration number CRD42014006943). Twenty-eight studies for motor outcomes were identified. Results There was strong evidence that intraventricular haemorrhage and periventricular leukomalacia, and some evidence that the use of postnatal steroids and non-use of antenatal steroids, were prognostic factors for CP. Male sex and gestational age were of limited use as prognostic factors for CP in cohorts restricted to ≤32 weeks gestation; however, in children older than 5 years with no major disability, there was evidence that male sex was a predictive factor for motor impairment. Interpretation This review has identified factors which may be of prognostic value for CP and motor impairment in VPT/VLBW children and will help to form the basis of future prognostic research. PMID:26862030

  9. Does lower limb revascularization result in an improvement in sensory perception thresholds?

    PubMed

    Toursarkissian, Boulos; Connaughton, James C; D'Ayala, Marcus; Shireman, Paula K; Harrison, Amy; Schoolfield, John; Sykes, Mellick T

    2002-05-01

    Patients with peripheral vascular disease are susceptible to neuropathy from chronic hypoxia. We wished to determine whether revascularization of chronically ischemic limbs results in any clinical changes in peripheral sensory thresholds. We prospectively measured quantitative vibration perception thresholds (VPT) using a Horwell neurothesiometer (in volts) in patients undergoing infrainguinal bypass, preoperatively and up to 6 month postoperatively. The bypassed limbs' preoperative VPT values were higher (lesser sensory perception) than the contralateral control limbs' preoperative values (mean score differences: 6 +/- 2 and 4 +/- 10 at toe and foot levels respectively; p ? 0.004). Preoperative VPT values were not different from the 6-month postoperative values for the revascularized legs at toe and foot levels for all 55 patients (mean score change of ?0.84 and ?1.32, p > 0.5). The contralateral limbs' VPT values did not change significantly over the 6-month period (mean change scores of 2.9, p > 0.15, and 2, p > 0.30, for toe and foot, respectively). A comparison of preoperative values between limbs that were eventually amputated and saved revealed no statistically significant differences. This study suggests that revascularization does not result in a clinically detectable improvement in sensory neuropathy. It may, however, prevent further degradation. The degree of preoperative neuropathy does not affect outcome in terms of limb salvage.

  10. Novel synthesis of FAU-type zeolite membrane with high performance.

    PubMed

    Cheng, Zhilin; Gao, Enqing; Wan, Huilin

    2004-08-07

    FAU-type zeolite membranes were synthesized by the vapor phase transformation (VPT) methods with or without prior seeding on the substrate, and it was revealed that the CO(2)/N(2) selectivity of the seeded membrane is greater than that of the unseeded membrane.

  11. Maternal intelligence quotient (IQ) predicts IQ and language in very preterm children at age 5 years.

    PubMed

    Lean, Rachel E; Paul, Rachel A; Smyser, Christopher D; Rogers, Cynthia E

    2017-09-19

    Sociodemographic factors are linked to cognitive outcomes in children born very preterm (VPT; ≤30 weeks gestation). The influence of maternal intellectual ability, a heritable trait, is unknown. Also undetermined is the extent to which associations between maternal and child intellectual ability vary according to parenting behaviors that target cognitive stimulation in the home. At age 5 years, 84 VPT and 38 demographically matched full-term (FT) children underwent neurodevelopmental assessment. Children's intellectual ability was assessed using The Wechsler Preschool Primary Scale of Intelligence-III, and language was assessed with the Clinical Evaluation of Language Fundamentals Preschool-2. The Wechsler Test of Adult Reading estimated maternal intellectual ability. The StimQ-Preschool questionnaire provided a measure of cognitive stimulation in the home. Linear mixed-effects models examined independent effects and interactions between maternal intellectual ability and cognitive stimulation on children's outcomes. After covariate adjustment, maternal intellectual ability was associated with child intellectual (p < .001) and language (p = .002) abilities. Stronger associations were observed in FT mother-child dyads (B = .63, p = .04) than VPT dyads (B = .42, p = .01). Mothers of VPT children reported lower levels of Parental Involvement in Developmental Advance (p = .007) and Parental Verbal Responsiveness (p = .04). Group differences in Parental Involvement in Developmental Advance, but not Parental Verbal Responsivity, persisted after adjusting for social background (p = .03). There was no evidence of an interaction between maternal intellectual ability and Parental Involvement in Developmental Advance (p = .34). Instead, maternal intellectual ability (p < .001) and Parental Involvement in Developmental Advance (p = .05) independently predicted VPT children's outcomes. Maternal intellectual ability is an important trait linked to VPT

  12. [Intracranial Pressure Evaluation by Ophthalmologist].

    PubMed

    Čmelo, J; Illéš, R; Šteňo, J

    2017-01-01

    The value of ICT is important in diagnosis of the diseases of the eye and orbit Methods for direct measurement of intracranial pressure (ICT) are exact, but they are invasive and there is some risk of infection and damage of the tissue. Currently there are 2 valid indirect methods of mesurement of IKT. Digital Ophthalmodynamometry (D-ODM) and Transcranial Doppler ultrasonography (TDU). D-ODM is a non-invasive method for measuring of the Pulsating Venous Pressure (VPT). We can measure VPT by the pulse phenomena. Physiologically (to be maintained blood flow) VPT not be less than the ICT and intraorbital pressure (IorbitT). If we raise the VPT to compensate the current IKT (or IorbitT) - there is a pulsation VCR. We can calculate aproxymative IKT with the formula: IKT = 0.903 - (VPT) - 8.87, or IKT = 0.29 + 0.74 (VOT / PI (AO)). [VOT = intraocular pressure. PI - pulsatility index arteriae ophthalmic from Color Doppler ultrasonography.] IKT can be approximate calculate with mathematical formulas: IKT = 0:55 × BMI (kg / m2) + 0.16 × KTD (mmHg) - 0:18 x age (years) - 1.91. [KTD - diastolic blood pressure, BMI - Body master index] or: IKT = 16.95 x 0.39 x OSASW09 + BMI + 0.14 + TKS - 20.90. [OSASW095: width of the orbital arachnoid space at a distance of 9 mm behind the eyeball (nuclear magnetic resonance). BMI: Body Mass Index. TKS: mean arterial pressure]. Normal values of VPT are under 15 torr. The risk of increased intracranial pressure is above 20 torr. Under physiological conditions, there is intraocular pressure lower in about 5 torr than VPT. D-ODM is a useful screening method in the evaluation of IKT for hydrocephalus, brain tumors, cerebral hemorrhage after brain trauma and also in ocular diseases: Glaucoma, Ocular hypertension, orbitopathy (endocrine orbitopathy), ischemic / non-ischemic occlusion of blood vessels of the eye, indirect detection ICT carotid artery-cavernous fistula, amaurosis fugax, optic neuropathy. D-ODM is suitable for immediate evaluation

  13. Examination of the Pattern of Growth of Cerebral Tissue Volumes From Hospital Discharge to Early Childhood in Very Preterm Infants.

    PubMed

    Monson, Brian B; Anderson, Peter J; Matthews, Lillian G; Neil, Jeffrey J; Kapur, Kush; Cheong, Jeanie L Y; Doyle, Lex W; Thompson, Deanne K; Inder, Terrie E

    2016-08-01

    Smaller cerebral volumes at hospital discharge in very preterm (VPT) infants are associated with poor neurobehavioral outcomes. Brain growth from the newborn period to middle childhood has not been explored because longitudinal data have been lacking. To examine the pattern of growth of cerebral tissue volumes from hospital discharge to childhood in VPT infants and to determine perinatal risk factors for impaired brain growth and associations with neurobehavioral outcomes at 7 years. Prospective cohort study of VPT infants (<30 weeks' gestation or <1250 g) born between April 11, 2001, and April 26, 2004, and followed up at 7 years' corrected age. The setting was The Royal Women's Hospital and The Royal Children's Hospital, Melbourne, Australia. Of 224 VPT infants and 46 full-term (FT) infants, usable magnetic resonance imaging data at either infancy or 7 years were collected for 214 VPT children (95.5%) and 46 FT children (100%), while 126 VPT children (56.3%) and 31 FT children (67.4%) had usable magnetic resonance imaging data at both time points. Follow-up was conducted from April 28, 2008, to August 9, 2011. Our final analysis was on March 3, 2016. Prematurity. Absolute tissue growth, defined as change in absolute tissue volume, between infancy and 7 years was calculated for cortical gray matter volume (GMV), white matter volume (WMV), and subcortical GMV. IQ, language, and motor function were measured at 7 years. The study cohort comprised 260 participants. Their mean (SD) age was 7.5 (0.2) years, and 49.2% (128 of 260) were female. Early GMV deficits in VPT infants were magnified by 7 years, with less growth than FT controls. Growth differences were 31.4 (95% CI, 14.8-48.1) cm3 for cortical GMV and 1.7 (95% CI, 0.5-2.8) cm3 for subcortical GMV. Within the VPT group, greater growth was observed in boys for cortical GMV (31.9; 95% CI, 16.8-46.9 cm3), WMV (31.7; 95% CI, 19.7-43.7 cm3), and subcortical GMV (1.8; 95% CI, 0.8-2.8 cm3). After controlling for sex and

  14. Attention and Regional Gray Matter Development in Very Preterm Children at Age 12 Years.

    PubMed

    Lean, Rachel E; Melzer, Tracy R; Bora, Samudragupta; Watts, Richard; Woodward, Lianne J

    2017-08-01

    This study examines the selective, sustained, and executive attention abilities of very preterm (VPT) born children in relation to concurrent structural magnetic resonance imaging (MRI) measures of regional gray matter development at age 12 years. A regional cohort of 110 VPT (≤32 weeks gestation) and 113 full term (FT) born children were assessed at corrected age 12 years on the Test of Everyday Attention-Children. They also had a structural MRI scan that was subsequently analyzed using voxel-based morphometry to quantify regional between-group differences in cerebral gray matter development, which were then related to attention measures using multivariate methods. VPT children obtained similar selective (p=.85), but poorer sustained (p=.02) and executive attention (p=.01) scores than FT children. VPT children were also characterized by reduced gray matter in the bilateral parietal, temporal, prefrontal and posterior cingulate cortices, bilateral thalami, and left hippocampus; and increased gray matter in the occipital and anterior cingulate cortices (family-wise error-corrected p<.05). Poorer sustained auditory attention was associated with increased gray matter in the anterior cingulate cortex (p=.04). Poor executive shifting attention was associated with reduced gray matter in the right superior temporal cortex (p=.04) and bilateral thalami (p=.05). Poorer executive divided attention was associated with reduced gray matter in the occipital (p=.001), posterior cingulate (p=.02), and left temporal (p=.01) cortices; and increased gray matter in the anterior cingulate cortex (p=.001). Disturbances in regional gray matter development appear to contribute, at least in part, to the poorer attentional performance of VPT children at school age. (JINS, 2017, 23, 539-550).

  15. Inattentive behaviour is associated with poor working memory and slow processing speed in very pre-term children in middle childhood.

    PubMed

    Mulder, Hanna; Pitchford, Nicola J; Marlow, Neil

    2011-03-01

    BACKGROUND. Problem behaviour is common following pre-term birth, but the underlying nature of these difficulties is not well known. AIMS. We sought to establish the mechanisms underpinning behavioural difficulties in very pre-term (VPT) children in middle childhood by comparing their performance to that of term born peers on tasks of working memory, inhibition, and processing speed, and relating these to parent and teacher assessments of their behaviour. Particular focus was given to inattention and overactive/impulsive behaviour, as these behaviours have been associated with different neuropsychological problems in term children. SAMPLES. A group of VPT children (gestational age < 31 weeks, N= 56) aged 9-10 years and term controls (N= 22) participated in the study. METHOD. Children were assessed with measures of working memory, inhibition, and processing speed. Parents and teachers reported behavioural problems using the Strengths and Difficulties Questionnaire and two additional scales measuring overactive/impulsive behaviour and inattention. RESULTS. Results revealed increased rates of problem behaviour in VPT compared to term children for parent-rated total difficulties, hyperactivity, emotional problems, peer problems, prosocial behaviour, overactive/impulsive behaviour, and parent- and teacher-rated inattention. Processing speed and working memory, but not inhibition, were significantly related to inattentive and overactive/impulsive behaviour. CONCLUSIONS. The increased rates of inattention and overactive/impulsive behaviour in VPT children may be explained by impairment in processing speed and working memory. Expected links between overactive/impulsive behaviour and inhibitory control were not identified, suggesting the nature of such difficulties may be different in VPT compared to term children. © 2010 The British Psychological Society.

  16. The value of the Rydel-Seiffer tuning fork as a predictor of diabetic polyneuropathy compared with a neurothesiometer.

    PubMed

    Kästenbauer, T; Sauseng, S; Brath, H; Abrahamian, H; Irsigler, K

    2004-06-01

    The aim of the study was to investigate the predictive value of the Rydel-Seiffer tuning fork for detecting diabetic neuropathy and to compare it with an electronic neurothesiometer. In 2022 consecutive diabetic subjects, peripheral polyneuropathy was diagnosed by vibration perception threshold (VPT) at the tip of both great toes using a 128-Hz tuning fork and a neurothesiometer, by simple bedside tests and by the presence of neuropathic symptoms. These evaluations were further combined to diagnose peripheral nerve dysfunction (abnormal bedside tests) and symptomatic neuropathy. VPT was also measured in 175 non-diabetic control subjects to define normal values. VPT was normal in 1917 subjects and abnormal in 105 (5.2%) patients when measured by the tuning fork. Patients with an abnormal vibration test were significantly (P < 0.0001) older than subjects with a normal vibration sense, while diabetes duration and HbA(1c) of the former were also significantly elevated. The same was true for the percentages of an abnormal 10-g monofilament test (66.7% vs. 7.2%, P < 0.0001) and a missing Achilles' tendon reflex (68.6% vs. 24.8%, P < 0.0001). Finally, the VPT measured by the neurothesiometer was 2.5 times higher in patients with an abnormal tuning fork test (32.0 +/- 9.8 vs. 12.5 +/- 6.4 V, P < 0.0001). The plot of the difference of both methods against their mean yielded a good agreement of the two VPT measurements, and the tuning fork had a high sensitivity and positive predictive value for the diagnosis of abnormal bedside tests and for symptomatic neuropathy. The tuning fork reliably detected peripheral neuropathy in comparison with the neurothesiometer. A tuning fork is a useful screening test for diabetic neuropathy.

  17. Predictors of vibration perception threshold in type 2 diabetic patients with proliferative retinopathy.

    PubMed

    Magri, Caroline Jane; Calleja, Neville; Buhagiar, Gerald; Fava, Stephen; Vassallo, Josanne

    2011-10-01

    Distal peripheral neuropathy (DPN) is a troublesome complication of diabetes mellitus (DM). The factors associated with the disease are still incompletely understood. The purpose of this study was to investigate factors associated with vibration perception threshold (VPT) as a marker of DPN in a type 2 diabetic population with advanced microvascular disease. The study included 203 diabetic patients (117 male, 86 female) with proliferative diabetic retinopathy. Subjects were investigated by questionnaires, clinical examinations, blood and urine sampling, and review of medical records in the period from November 2008 through April 2009. Presence of DPN was defined as VPT ≥25 V. The mean (±SD) age was 65.2 (±9.9) years and median (IQR) diabetes duration was 18 (10-25) years. Forty-six per cent of subjects were found to have DPN, defined as a VPT ≥25 V by neurothesiometer testing. Prevalence of DPN was found to be associated with age (p=0.038), male gender (p=0.046), low haemoglobin (p<0.001), high erythrocyte sedimentation rate (p=0.03), uric acid values (p=0.034), and peripheral vascular disease (PVD) (p=0.003) in univariate analysis. Multivariate logistic regression analysis revealed male gender (OR 5.52; p<0.001) and low haemoglobin values (B=-0.58; p<0.001) to be independent predictors of VPT ≥25 V in subjects with proliferative retinopathy, while linear regression analysis revealed male gender (p<0.001), haemoglobin (p=0.001), age (p=0.04), and PVD (p=0.001) to be significant predictors of VPT. This study reports a novel independent association of DPN with low haemoglobin values. In the study population with type 2 DM and proliferative retinopathy, DPN was also independently associated with male gender, age, and PVD. Further studies are needed to confirm the association with low haemoglobin and identify the underlying mechanism.

  18. Cognitive and behavioral aspects of executive functions in children born very preterm.

    PubMed

    Ritter, Barbara Catherine; Perrig, Walter; Steinlin, Maja; Everts, Regula

    2014-03-01

    This study investigated whether children aged between 8 and 12 years born very preterm (VPT) and/or at very low birth weight (VLBW) performed lower than same-aged term-born controls in cognitive and behavioral aspects of three executive functions: inhibition, working memory, and shifting. Special attention was given to sex differences. Fifty-two VPT/VLBW children (26 girls, 50%) born in the cohort of 1998-2003 and 36 same-aged term-born children (18 girls, 50%) were recruited. As cognitive measures, children completed tasks of inhibition (Color-Word Interference Test, D-KEFS; Delis, Kaplan, & Kramer, 2001), working memory (digit span backwards, HAWIK-IV; Petermann & Petermann, 2008), and shifting (Trail Making Test, number-letter-switching, D-KEFS; Delis et al., 2001). As behavioral measures, mothers completed the Behavior Rating Inventory of Executive Function (BRIEF; Gioia, Isquith, Guy, & Kenworthy, 2000). Scales of interest were inhibit, working memory, and shift. Analyses of the cognitive aspects of executive functions revealed that VPT/VLBW children performed significantly lower than controls in the shifting task but not in the working memory and inhibition tasks. Analyses of behavioral aspects of executive functions revealed that VPT/VLBW children displayed more problems than the controls in working memory in everyday life but not in inhibition and shifting. No sex differences could be detected either in cognitive or behavioral aspects of executive functions. To conclude, cognitive and behavioral measures of executive functions were not congruent in VPT/VLBW children. In clinical practice, the combination of cognitive and behavioral instruments is required to disclose children's executive difficulties.

  19. Vibrating perception threshold and body mass index are associated with abnormal foot plantar pressure in type 2 diabetes outpatients.

    PubMed

    Shen, Jing; Liu, Fang; Zeng, Hui; Wang, Jue; Zhao, Jun-Gong; Zhao, Jun; Lu, Feng-Di; Jia, Wei-Ping

    2012-11-01

    This study investigated the influencing factors of foot plantar pressure and attempted to find practical indicators to predict abnormal foot pressure in patients with type 2 diabetes mellitus (T2DM). Vibration perception threshold (VPT) and foot plantar pressure in 1,126 T2DM outpatients were examined. Patients were assigned to Group A (n=599), Group B (n=312), and Group C (n=215) according to VPT values and to Group I (n=555), Group II (n=436), and Group III (n=135) based on body mass index (BMI). The clinical characteristics and pressure-time integral (PTI) were compared among the three groups, and the associated factors of the total PTI in the entire foot (T-PTI) were analyzed. PTI of Group C in heel medial and heel lateral was significantly higher than that of Group A (all P<0.01). PTI of Group B in the right fifth metatarsal and heel medial was significantly higher than that of Group A (all P<0.05). T-PTI of Group C was significantly higher than those of Groups A and B, and that of Group B was higher than that of Group A (all P<0.01). PTI of Groups II and III in the second, third, and fourth metatarsal, midfoot, heel medial, and heel lateral was significantly higher than that of Group I (all P<0.05). T-PTI of Groups II and III was significantly higher than that of Group I (all P<0.01). Pearson correlation analysis showed that T-PTI was positively associated with age, VPT, waist circumference, waist-to-hip ratio, and BMI (P<0.05). In multiple stepwise regression analysis, VPT (P=0.004) and BMI (P=0.000) were independent risk factors of T-PTI, and each 1 unit increase in BMI increased the T-PTI by 5.962 kPa•s. Receiver operator characteristic curve analysis further revealed that the optimal cutpoint of VPT and BMI to predict the abnormal PTI was 21 V (odds ratio=2.33, 95% confidence interval 1.67-3.25) and 24.9 kg/m(2) (odds ratio=2.12, 95% confidence interval 1.55-2.90), respectively. Having a VPT higher than 21 V and a BMI above 24.9 kg/m(2) increases

  20. Outcomes of Different Vital Pulp Therapy Techniques on Symptomatic Permanent Teeth: A Case Series

    PubMed Central

    Asgary, Saeed; Fazlyab, Mahta; Sabbagh, Sedigheh; Eghbal, Mohammad Jafar

    2014-01-01

    In modern endodontics, vital pulp therapy (VPT) has been considered an ultra-conservative treatment modality. Based on the level of pulp preservation, VPT includes stepwise excavation, indirect pulp capping (IDPC), direct pulp capping (DPC), miniature pulpotomy (MP), partial/Cvek pulpotomy and coronal/complete pulpotomy (CP). The present article reviews the treatment outcomes of 94 permanent teeth with irreversible pulpitis treated with either IDPC (n=28), DPC (n=28), MP (n=29) or CP (n=9) using calcium-enriched mixture (CEM) cement. After a mean follow-up time of 12.3 months, 93 treated teeth were radiographic/clinically successful; only one radiographic failure was observed in the DPC group. PMID:25386213

  1. A Review on Vital Pulp Therapy in Primary Teeth

    PubMed Central

    Parisay, Iman; Ghoddusi, Jamileh; Forghani, Maryam

    2015-01-01

    Maintaining deciduous teeth in function until their natural exfoliation is absolutely necessary. Vital pulp therapy (VPT) is a way of saving deciduous teeth. The most important factors in success of VPT are the early diagnosis of pulp and periradicular status, preservation of the pulp vitality and proper vascularization of the pulp. Development of new biomaterials with suitable biocompatibility and seal has changed the attitudes towards preserving the reversible pulp in cariously exposed teeth. Before exposure and irreversible involvement of the pulp, indirect pulp capping (IPC) is the treatment of choice, but after the spread of inflammation within the pulp chamber and establishment of irreversible pulpitis, removal of inflamed pulp tissue is recommended. In this review, new concepts in preservation of the healthy pulp tissue in deciduous teeth and induction of the reparative dentin formation with new biomaterials instead of devitalization and the consequent destruction of vital tissues are discussed. PMID:25598803

  2. Automatic Generation of Analytic Equations for Vibrational and Rovibrational Constants from Fourth-Order Vibrational Perturbation Theory

    NASA Astrophysics Data System (ADS)

    Matthews, Devin A.; Gong, Justin Z.; Stanton, John F.

    2014-06-01

    The derivation of analytic expressions for vibrational and rovibrational constants, for example the anharmonicity constants χij and the vibration-rotation interaction constants α^B_r, from second-order vibrational perturbation theory (VPT2) can be accomplished with pen and paper and some practice. However, the corresponding quantities from fourth-order perturbation theory (VPT4) are considerably more complex, with the only known derivations by hand extensively using many layers of complicated intermediates and for rotational quantities requiring specialization to orthorhombic cases or the form of Watson's reduced Hamiltonian. We present an automatic computer program for generating these expressions with full generality based on the adaptation of an existing numerical program based on the sum-over-states representation of the energy to a computer algebra context. The measures taken to produce well-simplified and factored expressions in an efficient manner are discussed, as well as the framework for automatically checking the correctness of the generated equations.

  3. Selective weighting of cutaneous receptor feedback and associated balance impairments following short duration space flight.

    PubMed

    Strzalkowski, Nicholas D J; Lowrey, Catherine R; Perry, Stephen D; Williams, David R; Wood, Scott J; Bent, Leah R

    2015-04-10

    The present study investigated the perception of low frequency (3 Hz) vibration on the foot sole and its relationship to standing balance following short duration space flight in nine astronauts. Both 3 Hz vibration perception threshold (VPT) and standing balance measures increased on landing day compared to pre-flight. Contrary to our hypothesis, a positive linear relationship between these measures was not observed; however astronauts with the most sensitive skin (lowest 3 Hz VPT) were found to have the largest sway on landing day. While the change in foot sole sensitivity does not appear to directly relate to standing balance control, an exploratory strategy may be employed by astronauts whose threshold to pressure information is lower. Understanding sensory adaptations and balance control has implications to improve balance control strategies following space flight and in sensory impaired populations on earth.

  4. A review on vital pulp therapy in primary teeth.

    PubMed

    Parisay, Iman; Ghoddusi, Jamileh; Forghani, Maryam

    2015-01-01

    Maintaining deciduous teeth in function until their natural exfoliation is absolutely necessary. Vital pulp therapy (VPT) is a way of saving deciduous teeth. The most important factors in success of VPT are the early diagnosis of pulp and periradicular status, preservation of the pulp vitality and proper vascularization of the pulp. Development of new biomaterials with suitable biocompatibility and seal has changed the attitudes towards preserving the reversible pulp in cariously exposed teeth. Before exposure and irreversible involvement of the pulp, indirect pulp capping (IPC) is the treatment of choice, but after the spread of inflammation within the pulp chamber and establishment of irreversible pulpitis, removal of inflamed pulp tissue is recommended. In this review, new concepts in preservation of the healthy pulp tissue in deciduous teeth and induction of the reparative dentin formation with new biomaterials instead of devitalization and the consequent destruction of vital tissues are discussed.

  5. Cortical Structural Abnormalities in Very Preterm Children at 7 Years of Age

    PubMed Central

    Zhang, Yuning; Inder, Terrie E; Neil, Jeffrey J; Dierker, Donna L; Alexopoulos, Dimitrios; Anderson, Peter J; Van Essen, David C

    2015-01-01

    We analyzed long-lasting alterations in brain morphometry associated with preterm birth using volumetric and surface-based analyses applied to children at age 7 years. Comparison of 24 children born very preterm (VPT) to 24 healthy term-born children revealed reductions in total cortical grey matter volume, white matter volume, cortical surface area and gyrification index. Regional cortical shape abnormalities in VPT children included the following: shallower anterior superior temporal sulci, smaller relative surface area in the inferior sensori-motor cortex and posterior superior temporal cortex, larger relative surface area and a cingulate sulcus that was shorter or more interrupted in medial frontoparietal cortex. These findings indicate a complex pattern of regional vulnerabilities in brain development that may contribute to the diverse and long-lasting neurobehavioral consequences that can occur after very premature birth. PMID:25614973

  6. Vibration perception thresholds in workers with long term exposure to lead

    PubMed Central

    Chuang, H.; Schwartz, J.; Tsai, S.; Lee, M.; Wang, J.; Hu, H.

    2000-01-01

    OBJECTIVES—To evaluate the impact of long term occupational exposure to lead on function of the peripheral nervous system as reflected by vibration perception threshold (VPT), measured with a portable vibrameter.
METHODS—217 Workers in a lead battery factory were required to have an annual blood lead measurement during each of the 5 years preceding this study. All were invited to take the VPT test. A total of 206 workers were studied. The associations were analysed between VPTs and current blood lead concentration, mean concentration of blood lead over the past 5 years, maximum blood lead concentration during the past 5 years, index of cumulative blood lead (ICL), time weighted index of cumulative blood lead (TWICL), and percentage of lifespan spent at work in the plant, as well as the other potential confounders. Ordinary multiple regressions, generalised additive models, and hockey stick regression analyses were used to explore the potential existence of a threshold effect of blood lead variables on VPT.
RESULTS—VPT at a frequency of 220 Hz ranged from 6 to 100 (10-2 g, or 0.098 m/s2) with a mean (SD) of 19.8 (14.2) for the feet and from 4 to 43 with a mean (SD) of 10.2 (6.1) for the hands. The five variables of exposure to lead were all significantly correlated with VPT of the feet but not the hands. In multiple linear regression analyses, the mean of the blood lead concentrations and the TWICL were significantly associated with VPT of the feet. The relation between VPT of the feet and mean blood lead was shown to be a J shaped curve with a generalised additive model and local smoothing technique. In the hockey stick regression, evidence was found of a threshold effect at a mean blood lead concentration of 31 µg/dl. Above this threshold it was estimated that each increase of 1 µg/dl mean blood lead over 5 years would increase VPT of the feet by 0.29 (10-2 g) or 0.028 m/s2 (at a frequency of 220 Hz) with other potential confounders

  7. Isolated use of vibration perception thresholds and semmes-weinstein monofilament in diagnosing diabetic polyneuropathy: "the North Catalonia diabetes study".

    PubMed

    Jurado, Jeroni; Ybarra, Juan; Pou, Josep Maria

    2007-03-01

    Several systems are used for the diagnosis of diabeticpolyneuropathy (DPN). We analyzed the isolated use of vibration perception thresholds (VPTs) or monofilament (MF) for the diagnosis of DPN. A group of 400 patients who had type 2 diabetes was selected from the North Catalonia Study Group. A clinical neurologic evaluation was performed based on three categories of the San Antonio Consensus. Neurothesiometer and quantitative tuning fork explored VPT, and MF was assessed by Olmos and Michigan Diabetic Neuropathy Score (MDNS) criteria. The use of VPT and MF showed a high specificity and low sensitivity. MF, by MDNS criteria, was more sensitive and specific, and showed more accurate positive and negative predictive values. The predicted probability of DPN diagnosis was higher with a tuning fork evaluation.

  8. [Study of peripheral sensorineural function in a cohort of dental hygienists].

    PubMed

    Ronchese, F; Bovenzi, M

    2011-01-01

    The aim of this study was to investigate over time the changes in thermotactile and vibrotactile sensitivity in a cohort of dental hygiene students exposed to high-frequency vibration from dental tools. Thermal perception thresholds for warmth and cold (TPT in degrees C) and vibrotactile perception thresholds (VPT in ms-2 r.m.s) at 31.5 Hz and 125 Hz were measured at the fingertips of the 2nd digit and 5th digit of both hands in 52 controls and 30 dental hygiene students. At baseline, there were no significant differences in either TPT or VPT between the two groups. No significant changes in tactile sensitivity were observed in the dental hygienists over 1-year follow-up period. In conclusion, shortterm exposure to high-frequency vibration from dental tools did not affect tactile sensitivity in a cohort of young dental hygienists.

  9. Home care practices for preterm and term infants after hospital discharge in Massachusetts, 2007 to 2010.

    PubMed

    Hwang, S S; Lu, E; Cui, X; Diop, H; Barfield, W D; Manning, S E

    2015-10-01

    The objective of this study was to compare the prevalence of home care practices in very to moderately preterm (VPT), late preterm (LPT) and term infants born in Massachusetts. Using 2007 to 2010 Massachusetts Pregnancy Risk Assessment Monitoring System data, births were categorized by gestational age (VPT: 23 to 33 weeks; LPT: 34 to 36 weeks; term: 37 to 42 weeks). Home care practices included breastfeeding initiation and continuation, and infant sleep practices (supine sleep position, sleeping in a crib, cosleeping in an adult bed). We developed multivariate models to examine the association of infant sleep practices and breastfeeding with preterm status, controlling for maternal sociodemographic characteristics. Supine sleep position was more prevalent among term infants compared with VPT and LPT infants (77.1%, 71.5%, 64.4%; P=0.02). In the adjusted model, LPT infants were less likely to be placed in supine sleep position compared with term infants (adjusted prevalence ratio=0.86; 95% confidence interval: 0.75 to 0.97). Breastfeeding initiation and continuation did not differ among preterm and term groups. Nearly 16% of VPT and 18% of LPT and term infants were not sleeping in cribs and 14% of LPT and term infants were cosleeping on an adult bed. Compared with term infants, LPT infants were less likely to be placed in supine sleep position after hospital discharge. A significant percent of preterm and term infants were cosleeping on an adult bed. Hospitals may consider improving their safe sleep education, particularly to mothers of LPT infants.

  10. Associations between anthropometric factors and peripheral neuropathy defined by vibrotactile perception threshold among industrial vibrating tool operators in Japan

    PubMed Central

    Takemura, Shigeki; Yoshimasu, Kouichi; Tsuno, Kanami; Fukumoto, Jin; Kuroda, Mototsugu; Miyashita, Kazuhisa

    2016-01-01

    Objectives: The effect of anthropometric factors on the fingertip vibrotactile perception threshold (VPT) of industrial vibrating tool operators (IVTOs) is not well known. The purpose of this study was to investigate the associations between anthropometric factors and fingertip VPT. Methods: We included for analysis two groups of IVTOs: Group 1, predominantly forestry workers (n=325); and Group 2, public servants (n=68). These IVTOs regularly received medical examinations to evaluate hand-arm vibration syndrome. In the examination, measurements of their fingertip VPTs were taken before and after cold-water immersion (10 minutes at 10°C for Group 1 and 5 minutes at 12°C for Group 2). Their body height and weight were measured to calculate the body mass index (BMI). The presence of peripheral neuropathy (PN) was defined as a VPT ≥17.5 dB at 10 minutes after finishing immersion. Results: In the univariate analysis, weight and BMI were associated with a decreased risk of PN in both Groups 1 and 2. The negative association between BMI and PN remained in the multivariate analysis consistently, but weight reached marginal significance only in the multivariate analysis without BMI in both the groups. Age was positively associated with PN consistently in Group 1 but not in Group 2. Years exposed to vibration showed positive association with PN only in the univariate analysis of Group 1. Conclusions: Among IVTOs, factors reflecting body heat production, such as weight and BMI, were associated with a decreased risk of VPT-defined PN, regardless of the task engaged. PMID:27010084

  11. Use of Mass-Flux Measurement and Vapor-Phase Tomography to Quantify Vadose-Zone Source Strength and Distribution

    DTIC Science & Technology

    2016-01-01

    anticipated that these technologies will improve evaluation of vadose zone source impacts on groundwater and vapor intrusion. Multi-stage vapor-phase...contaminant mass discharge (MS-CMD), vapor-phase tomography (VPT), volatile organic compound (VOC), groundwater , vapor intrusion, chlorinated solvents...evaluation of vadose zone source impacts on groundwater and vapor intrusion. The specific performance objectives for this demonstration were as follows

  12. Gestational and postnatal modulation of esophageal sphincter reflexes in human premature neonates.

    PubMed

    Jadcherla, Sudarshan R; Shubert, Theresa R; Malkar, Manish B; Sitaram, Swetha; Moore, Rebecca K; Wei, Lai; Fernandez, Soledad; Castile, Robert G

    2015-11-01

    Effects of gestational age (GA) and postnatal maturation on upper and lower esophageal sphincter (UES and LES) reflex development remain unclear. We hypothesized very-preterm (VPT) born neonates (< 32 wk GA) have delayed maturation of UES contractile reflex (UESCR) and LES relaxation reflex (LESRR) vs. preterm (PT) born (32-37 wk GA) neonates. Using provocative manometry, effects of 1,263 graded mid-esophageal stimuli (air, liquid) on sensory-motor characteristics of UESCR and LESRR were investigated in 24 VPT-born and 12 PT-born neonates (37.8 ± 0.6 vs. 38.9 ± 0.4 wk postmenstrual age respectively, P = 0.14). In response to liquid stimuli (vs. air), VPT-born neonates displayed prolonged UESCR and LESRR response latencies (P < 0.001) and prolonged UESCR and LESRR durations (P < 0.01); unlike PT-born neonates, who exhibit prolonged LESRR response latency (P < 0.01), but similar UESCR and LESRR durations (P = 0.2). Differences were noted in LESRR duration in VPT vs. PT neonates for air stimuli (P = 0.04). With liquid stimuli, increasing GA was associated with decreasing response onset latencies to UESCR and LESRR (P < 0.05), and increasing LESRR duration (P = 0.02). Using GA as categorical or continuous variable, vagus-mediated mechano-sensitive and liquid-sensitive reflex characteristics of UESCR and LESRR are distinct; LESRR differs with varying intrauterine maturation suggesting inhibitory modulation progresses with advancing maturation.

  13. Prognostic Factors for Behavioral Problems and Psychiatric Disorders in Children Born Very Preterm or Very Low Birth Weight: A Systematic Review

    PubMed Central

    Linsell, Louise; Malouf, Reem; Johnson, Samantha; Morris, Joan; Kurinczuk, Jennifer J.; Marlow, Neil

    2017-01-01

    Objective Risk factors associated with adverse behavioral outcomes in very preterm (VPT) or very low birth weight (VLBW) infants are poorly understood. The aim of this article is to identify prognostic factors for behavioral problems and psychiatric disorders in children born ≤32 weeks gestational age or with birth weight ≤1250 g. Method A systematic review was conducted using MEDLINE, Embase, and Pyscinfo databases to identify studies published between January 1, 1990 and June 1, 2014 reporting multivariable prediction models for behavioral problems or psychiatric disorders in VPT/VLBW children. Fifteen studies were identified and 2 independent reviewers extracted key information on study design, outcome definition, risk factor selection, model development, reporting, and conducted a risk of bias assessment. Results The 15 studies included reported risk factor analyses for the following domains: general behavioral problems (n = 8), any psychiatric disorder (n = 2), autism spectrum symptoms/disorders (n = 5), and attention deficit/hyperactivity disorder (n = 1). Findings were inconclusive because of the following: small number of studies in each domain, heterogeneity in outcome measures, lack of overlap in the risk factors examined, and differences in strategies for dealing with children with neurological impairments. Conclusion There is a lack of evidence concerning risk factors for behavior problems and psychiatric disorders among VPT/VLBW survivors. This review has identified the need for further research examining the etiology of disorders of psychological development in the VPT/VLBW population to refine risk prediction and identify targets for intervention. Large well-conducted studies that use standard diagnostic evaluations to assess psychiatric disorders throughout childhood and adolescence are required. PMID:26703327

  14. Association between sensory function and medio-lateral knee position during functional tasks in patients with anterior cruciate ligament injury.

    PubMed

    Cronström, Anna; Ageberg, Eva

    2014-12-13

    Patients with anterior cruciate ligament (ACL) injury often exhibit reduced movement quality during functional tasks in the form of a knee-medial-to-foot position (KMFP). This movement pattern is suggested to be more common in women than in men, but the possible contributing sensorimotor factors for this altered knee position are poorly studied in these patients. The aim of this study was to evaluate the association between sensory function and medio-lateral knee position during functional tasks in men and women with ACL injury. Fifty-one patients (23 women) aged 18-40 years with ACL injury were included in this cross-sectional study. Measures of sensory function were assessed by the threshold to detection of passive motion (TDPM) for knee kinesthesia and by the vibration perception threshold (VPT) for vibration sense. Movement quality was assessed by visual observation of the position of the knee relative to the foot during the following four functional tasks with different degrees of difficulty: the single-limb mini-squat, stair descending, the forward lunge, and the drop-jump. Spearman's rank correlation coefficient was used to determine the relationship between the sensory measures and the medio-lateral knee position during the functional tasks. Differences in TDPM and/or VPT between subjects with good and poor movement quality were evaluated using the independent t-test. Separate gender analyses were performed. Worse TDPM was associated with a KMFP during the drop jump in men. Worse VPT at the toe and ankle was associated with a KMFP during stair descending and the forward lunge in women, but no associations were found in men. Worse kinesthesia, measured by TDPM, might be associated with KMFP during the drop jump in men with ACL injury while worse vibration sense, measured by the VPT, at the foot and ankle might be related to KMFP in women. Further studies are needed to confirm these results.

  15. Human serum amyloid A (SAA) and high sensitive C-reactive protein (hsCRP) in preterm newborn infants with nosocomial infections.

    PubMed

    Lannergård, A; Larsson, A; Friman, G; Ewald, U

    2008-08-01

    Human serum amyloid A (SAA) and high sensitive C-reactive protein (hsCRP) and their relation to suggestive nosocomial infections (NIs) were investigated in very preterm (VPT) newborn infants. In a retrospective analysis, information of suggestive NI was matched to levels of SAA and hsCRP in 224 serum samples from 72 VPT newborn infants. As a control group, 35 healthy-term newborn infants were chosen. Of the 224 serum samples, 145 samples were not associated with nosocomial infections. However, 79 were associated with NI: of these 79, 42 were found to be culture-proven NI. Trimmed mean (alpha= 0.05) levels for SAA and hsCRP in VPT newborn infants were higher than in control term newborn infants (1.74, 2.67 mg/L vs. 0.78, 0.16 mg/L; p = 0.01 and <0.0001, respectively), and higher in the NI group than in the non-NI group (5.14, 5.74 mg/L vs. 1.03, 1.18; p < 0.01 and <0.0001; respectively). The areas under the curve (AUC) for hsCRP, calculated from the receiver-operator characteristic (ROC) curves, was greater (0.816; 95% CI 0.759-0.864) than for SAA (0.610; 95% CI 0.543-0.675). Identifying and monitoring of bacterial and fungal infections in VPT might be further improved by the use of SAA and hsCRP.

  16. Parenting behavior at 2 years predicts school-age performance at 7 years in very preterm children.

    PubMed

    Treyvaud, Karli; Doyle, Lex W; Lee, Katherine J; Ure, Alexandra; Inder, Terrie E; Hunt, Rod W; Anderson, Peter J

    2016-07-01

    Parenting influences child development, but it is unclear whether early parenting behavior can influence school-age outcomes in very preterm (VPT) children, and/or if certain groups of VPT children may be more affected by early parenting behavior. These research questions were examined. Participants were 147 children born <30 weeks' gestation or birth weight <1250 g and their primary caregiver. At term corrected age (CA), magnetic resonance imaging (MRI) was used to determine presence and severity of brain abnormality and medical data collected. High medical risk was defined as the presence of at least one of sepsis, necrotizing enterocolitis, bronchopulmonary dysplasia, moderate to severe white matter abnormality on MRI, or postnatal corticosteroids. At 2 years CA, parent-child interaction was assessed, and at 7 years CA, general intelligence (IQ), language, executive function, academic skills, and social-emotional functioning were assessed. Higher levels of parent-child synchrony, and parent facilitation, sensitivity and positive affect at 2 years were associated with better child outcomes at 7 years, while higher levels of intrusiveness and negative affect were associated with poorer outcomes. Many of these relationships remained after controlling for early child cognitive development. Interactions between child medical risk (higher/lower) and parenting were limited to child reading, math, and executive functioning outcomes, with stronger relationships for lower medical risk children. The contribution of early parenting to VPT children's school-age performance is significant, with stronger effects for lower medical risk children in some outcomes. These findings support the premise that parenting strategies should be included in the NICU and early interventions programs for VPT infants. © 2015 Association for Child and Adolescent Mental Health.

  17. Relations between language and cognition in native-signing children with autism spectrum disorder.

    PubMed

    Shield, Aaron; Pyers, Jennie; Martin, Amber; Tager-Flusberg, Helen

    2016-12-01

    Two populations have been found to exhibit delays in theory of mind (ToM): deaf children of hearing parents and children with autism spectrum disorder (ASD). Deaf children exposed to sign from birth by their deaf parents, however, show no such delay, suggesting that early language exposure is key to ToM development. Sign languages also present frequent opportunities with visual perspective-taking (VPT), leading to the question of whether sign exposure could benefit children with ASD. We present the first study of children with ASD exposed to sign from birth by their deaf parents. Seventeen native-signing children with a confirmed ASD diagnosis and a chronological- and mental age-matched control group of 18 typically developing (TD) native-signing deaf children were tested on American Sign Language (ASL) comprehension, two minimally verbal social cognition tasks (ToM and VPT), and one spatial cognition task (mental rotation). The TD children outperformed the children with ASD on ASL comprehension (p < 0.0001), ToM (p = 0.02), and VPT (p < 0.01), but not mental rotation (p = 0.12). Language strongly correlated with ToM (p < 0.01) and VPT (p < 0.001), but not mental rotation (p = ns). Native exposure to sign is thus insufficient to overcome the language and social impairments implicated in ASD. Contrary to the hypothesis that sign could provide a scaffold for ToM skills, we find that signing children with ASD are unable to access language so as to gain any potential benefit sign might confer. Our results support a strong link between the development of social cognition and language, regardless of modality, for TD and ASD children. Autism Res 2016, 9: 1304-1315. © 2016 International Society for Autism Research, Wiley Periodicals, Inc. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

  18. Prognostic Factors for Poor Cognitive Development in Children Born Very Preterm or With Very Low Birth Weight: A Systematic Review

    PubMed Central

    Linsell, Louise; Malouf, Reem; Morris, Joan; Kurinczuk, Jennifer J.; Marlow, Neil

    2016-01-01

    Importance Cognitive delay is the most common form of impairment among children born very preterm (VPT) at 32 weeks or less or with very low birth weight (VLBW) of 1250 g or less. It is important to identify factors that are robust predictors of long-term outcome because the ability to predict future prognosis will assist in health care and educational service planning and provision. Objective To identify prognostic factors for poor cognitive development in children born VPT or with VLBW. Evidence Review A systematic review was conducted using MEDLINE, EMBASE, and PyscINFO databases to identify studies published between January 1, 1990, and June 1, 2014, reporting multivariable prediction models for neurodevelopment in VPT or VLBW children. Thirty-one studies comprising 98 risk factor models for cognitive outcome were identified. Two independent reviewers extracted key information on study design, outcome definition, risk factor selection, model development, and reporting and conducted a risk-of-bias assessment. Findings There was evidence that male sex, nonwhite race/ethnicity, lower level of parental education, and lower birth weight were predictive of global cognitive impairment in children younger than 5 years. In older children, only the influence of parental education was sustained. Male sex was also predictive of language impairment in early infancy, but not in middle childhood. Gestational age was a poor predictor of cognitive outcome, probably because of a reduced discriminatory power in cohorts restricted to a narrow gestational age range. The prognostic value of neonatal brain injury was unclear; however, studies adopted mixed strategies for managing children with physical or neurosensory disability. Conclusions and Relevance The influence of perinatal risk factors on cognitive development of VPT or VLBW children appears to diminish over time as environmental factors become more important. It is difficult to isolate cognitive outcomes from motor and

  19. User’s Guide: Vapor Intrusion Estimation Tool for Unsaturated Zone Contaminant Sources

    DTIC Science & Technology

    2016-08-30

    PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 6. AUTHOR(S) 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION ...and application of the technology. Vapor Intrusion, VI, Volatile Organic Compound, VOC, VPT, Vapor Phase Tomography U U U UU Mark Brusseau 520-621...11 3 Categorization of pairs of VZT and STR values to assist in data organization

  20. Gestational Age and Kindergarten School Readiness in a National Sample of Preterm Infants.

    PubMed

    Shah, Prachi E; Kaciroti, Niko; Richards, Blair; Lumeng, Julie C

    2016-11-01

    To examine the association of gestational age with school readiness in kindergarten reading and math skills. We hypothesized that compared with infants born at 39-41 weeks, infants born at lower gestational ages would have poorer school readiness. The study sample comprised 5250 children from the Early Childhood Longitudinal Study, Birth Cohort, assessed with specialized reading and math assessments at kindergarten. Poor school readiness was characterized by reading and math theta scores ≥1.5 SD below the sample mean. The aOR and 95% CI of poor school readiness were estimated using multivariate logistic regression, examining gestational age continuously and categorically (very preterm [VPT], moderate/late preterm [M/LPT], early term [ET], and term). Pairwise comparisons were performed to test for differences by gestational age category. There was an association between gestational age and poor school readiness for reading and math, with the suggestion of a threshold effect in children born at ≥32 weeks gestation. In adjusted models, in VPT infants, the aORs of poor school readiness in reading and math were 2.58 (95% CI, 1.29-5.15) and 3.38 (95% CI, 1.66-6.91), respectively. For infants born M/LPT and ET, the odds of poor school readiness in reading did not differ from those of children born full-term, however. Compared with term infants, the highest odds of poor school readiness in reading and math were seen in VPT infants, with lower odds of poor school readiness in children born at ≥32 weeks gestation. Ongoing developmental surveillance before kindergarten is indicated for VPT infants. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. A Cross Sectional Study on Hand-arm Vibration Syndrome among a Group of Tree Fellers in a Tropical Environment

    PubMed Central

    SU, Anselm Ting; MAEDA, Setsuo; FUKUMOTO, Jin; MIYAI, Nobuyuki; ISAHAK, Marzuki; YOSHIOKA, Atsushi; NAKAJIMA, Ryuichi; BULGIBA, Awang; MIYASHITA, Kazuhisa

    2014-01-01

    This study aimed to explore the clinical characteristics of hand arm vibration syndrome (HAVS) in a group of tree fellers in a tropical environment. We examined all tree fellers and selected control subjects in a logging camp of central Sarawak for vibration exposure and presence of HAVS symptoms utilizing vibrotactile perception threshold test (VPT) and cold water provocation test (CWP). None of the subjects reported white finger. The tree fellers reported significantly higher prevalence of finger coldness as compared to the control subjects (OR=10.32, 95%CI=1.21–87.94). A lower finger skin temperature, longer fingernail capillary return time and higher VPT were observed among the tree fellers as compared to the control subjects in all fingers (effect size >0.5). The VPT following CWP of the tree fellers was significantly higher (repeated measures ANOVA p=0.002, partial η2=0.196) than the control subject. The A (8) level was associated with finger tingling, numbness and dullness (effect size=0.983) and finger coldness (effect size=0.524) among the tree fellers. Finger coldness and finger tingling, numbness and dullness are important symptoms for HAVS in tropical environment that may indicate vascular and neurological damage due to hand-transmitted vibration exposure. PMID:24739764

  2. Rovibrational spectroscopic constants and fundamental vibrational frequencies for isotopologues of cyclic and bent singlet HC{sub 2}N isomers

    SciTech Connect

    Inostroza, Natalia; Fortenberry, Ryan C.; Lee, Timothy J.; Huang, Xinchuan

    2013-12-01

    Through established, highly accurate ab initio quartic force fields, a complete set of fundamental vibrational frequencies, rotational constants, and rovibrational coupling and centrifugal distortion constants have been determined for both the cyclic 1 {sup 1} A' and bent 2 {sup 1} A' DCCN, H{sup 13}CCN, HC{sup 13}CN, and HCC{sup 15}N isotopologues of HCCN. Spectroscopic constants are computed for all isotopologues using second-order vibrational perturbation theory (VPT2), and the fundamental vibrational frequencies are computed with VPT2 and vibrational configuration interaction (VCI) theory. Agreement between VPT2 and VCI results is quite good, with the fundamental vibrational frequencies of the bent isomer isotopologues in accord to within a 0.1-3.2 cm{sup –1} range. Similar accuracies are present for the cyclic isomer isotopologues. The data generated here serve as a reference for astronomical observations of these closed-shell, highly dipolar molecules using new, high-resolution telescopes and as reference for laboratory studies where isotopic labeling may lead to elucidation of the formation mechanism for the known interstellar molecule: X {sup 3} A' HCCN.

  3. Mentalizing Another's Visual World-A Novel Exploration via Motion Aftereffect.

    PubMed

    Yuan, Xuefei; Wang, Nanbo; Geng, Haiyan; Zhang, Shen

    2017-01-01

    Past research on level 2 visual perspective-taking (VPT) has mostly focused on understanding the mental rotation involved when one adopts others' perspective; the mechanisms underlying how the visual world of others is mentally represented remain unclear. In three studies, we addressed this question by adopting a novel VPT task with motion stimuli and exploring the aftereffect on motion discrimination from the self-perspective. Overall the results showed a facilitation aftereffect when participants were instructed to take the avatar's perspective. Meanwhile, participants' self-reported perspective-taking tendencies correlated with the aftereffect for both instructed and spontaneous VPT tasks, when the "to-be-adopted" perspective required the participants to mentally transform their self-body clockwise. Specifically, while facilitation was induced for participants with low self-reported perspective-taking tendencies (e.g., viewing a leftward motion stimulus under another's perspective enhanced subsequent perception of leftward motion from the self-perspective), those with high self-reported perspective-taking tendencies showed an adaptation aftereffect (e.g., viewing a leftward motion stimulus under another's perspective weakened subsequent perception of leftward motion from the self-perspective). For these individuals, the adaptation effect indicated the engagement of direction-selective neurons in processing of the subsequent congruent-direction motion from self's perspective. These findings suggest that motion perception from different perspectives (self vs. another) may share the same direction-selective neural circuitry, and this possibility depends on observers' general perspective-taking tendencies.

  4. Outcomes of vital pulp therapy in permanent teeth with different medicaments based on review of the literature

    PubMed Central

    Akhlaghi, Najmeh; Khademi, Abbasali

    2015-01-01

    Vital pulp therapy (VPT) is a biologic and conservative treatment modality to preserve the vitality and function of the coronal or remaining radicular pulp tissue in vital permanent teeth. A search was conducted via the Cochrane database, PubMed, MEDLINE, and Ovid for any articles with the criteria for “pulp-capping,” or “pulp-capping materials” and “VPT outcomes” from 1978 to mid 2014. All articles were evaluated and the valid papers were selected. The outcomes of various VPT techniques, including indirect pulp treatment, direct pulp treatment, partial pulpotomy, and complete pulpotomy in vital permanent teeth were extracted. Although various studies have different research approach, most studies noted a favorable treatment outcome. Mineral trioxide aggregate (MTA) appears to be more effective than calcium hydroxide (Ca(OH)2) for maintaining long-term pulp vitality after indirect and direct pulp-capping. However, it seems that the success rate for partial pulpotomy and pulpotomy with Ca(OH)2 is similar to MTA. PMID:26604953

  5. Rovibrational Spectroscopic Constants and Fundamental Vibrational Frequencies for Isotopologues of Cyclic and Bent Singlet HC2N isomers

    NASA Technical Reports Server (NTRS)

    Inostroza, Natalia; Fortenberry, Ryan C.; Huang, Xinchuan; Lee, Timothy J.

    2013-01-01

    Through established, highly-accurate ab initio quartic force fields (QFFs), a complete set of fundamental vibrational frequencies, rotational constants, and rovibrational coupling and centrifugal distortion constants have been determined for both the cyclic 1(sup 1) 1A' and bent 2(sup 1)A' DCCN, H(C13)CCN, HC(C-13)N, and HCC(N-15) isotopologues of HCCN. Spectroscopic constants are computed for all isotopologues using second-order vibrational perturbation theory (VPT2), and the fundamental vibrational frequencies are computed with VPT2 and vibrational configuration interaction (VCI) theory. Agreement between VPT2 and VCI results is quite good with the fundamental vibrational frequencies of the bent isomer isotopologues in accord to within a 0.1 to 3.2 / cm range. Similar accuracies are present for the cyclic isomer isotopologues. The data generated here serve as a reference for astronomical observations of these closed-shell, highly-dipolar molecules using new, high-resolution telescopes and as reference for laboratory studies where isotopic labeling may lead to elucidation of the formation mechanism for the known interstellar molecule: X 3A0 HCCN.

  6. Impaired language abilities and white matter abnormalities in children born very preterm and/or very low birth weight

    PubMed Central

    Reidy, Natalie; Morgan, Angela; Thompson, Deanne K; Inder, Terrie E.; Doyle, Lex W; Anderson, Peter J

    2012-01-01

    Objectives To investigate language abilities in children born very preterm (VPT; <32 weeks’ gestational age (GA)) or very low birth weight (VLBW; <1500 g) at 7 years of age and compare their performances with children born at term, and to determine whether group differences could be explained by cerebral white matter abnormality on neonatal MRI. Study design A cohort of 198 children born <30 weeks’ GA and/or <1250 g, and 70 term controls were examined. White matter abnormalities were rated quantitatively on brain MRI at term-equivalent age. Language was assessed at age 7 years using standardized language tests. Differences between groups were tested in the five language sub-domains of phonological awareness, semantics, grammar, discourse, and pragmatics. A mediation effect was tested between birth group, white matter abnormality, and language sub-domains. Results The VPT/VLBW group performed significantly worse than controls on all language sub-domains (all p <.001). White matter abnormality mediated the effect of group differences on phonological awareness, and partly mediated this effect for semantics, grammar and discourse. White matter abnormality was not significantly associated with pragmatics (p = .13). Conclusions Language is an important area of concern in children born VPT/VLBW. Neonatal white matter abnormality is an important predictor of outcome; however, different language abilities are differentially associated with neonatal white matter abnormality. PMID:23158026

  7. Impaired language abilities and white matter abnormalities in children born very preterm and/or very low birth weight.

    PubMed

    Reidy, Natalie; Morgan, Angela; Thompson, Deanne K; Inder, Terrie E; Doyle, Lex W; Anderson, Peter J

    2013-04-01

    To investigate language abilities in children born very preterm (VPT; <32 weeks' gestational age) or very low birth weight (VLBW; <1500 g) at 7 years of age and compare their performances with children born at term, and to determine whether group differences could be explained by cerebral white matter abnormality on neonatal magnetic resonance imaging. A cohort of 198 children born <30 weeks' gestational age and/or <1250 g, and 70 term controls were examined. White matter abnormalities were rated quantitatively on brain magnetic resonance imaging at term-equivalent age. Language was assessed at age 7 years using standardized language tests. Differences between groups were tested in the 5 language subdomains of phonological awareness, semantics, grammar, discourse, and pragmatics. A mediation effect was tested between birth group, white matter abnormality, and language subdomains. The VPT/VLBW group performed significantly worse than controls on all language subdomains (all P < .001). White matter abnormality mediated the effect of group differences on phonological awareness, and partly mediated this effect for semantics, grammar, and discourse. White matter abnormality was not significantly associated with pragmatics (P = .13). Language is an important area of concern in children born VPT/VLBW. Neonatal white matter abnormality is an important predictor of outcome; however, different language abilities are differentially associated with neonatal white matter abnormality. Copyright © 2013 Mosby, Inc. All rights reserved.

  8. A novel, non-invasive method of respiratory monitoring for use with stereotactic procedures

    PubMed Central

    Cleary, Daniel R.; Phillips, Ryan S.; Wallisch, Michael; Heinricher, Mary M.

    2012-01-01

    Accurate monitoring of respiration is often needed for neurophysiological studies, as either a dependent experimental variable or an indicator of physiological state. Current options for respiratory monitoring of animals held in a stereotaxic frame include EMG recordings, pneumotachograph measurements, inductance-plethysmography, whole-body plethysmography (WBP), and visual monitoring. While powerful, many of these methods prevent access to the animal’s body, interfere with experimental manipulations, or require deep anesthesia and additional surgery. For experiments where these issues may be problematic, we developed a non-invasive method of recording respiratory parameters specifically for use with animals held in a stereotaxic frame. This system, ventilation pressure transduction (VPT), measures variations in pressure at the animal’s nostril from inward and outward airflow during breathing. These pressure changes are detected by a sensitive pressure transducer, then filtered and amplified. The output is an analog signal representing each breath. VPT was validated against WBP using 10% carbon dioxide and systemic morphine (4 mg/kg) challenges in lightly anesthetized animals. VPT accurately represented breathing rate and tidal volume changes under both baseline and challenge conditions. This novel technique can therefore be used to measure respiratory rate and relative tidal volume when stereotaxic procedures are needed for neuronal manipulations and recording. PMID:22771713

  9. Does anodyne light therapy improve peripheral neuropathy in diabetes? A double-blind, sham-controlled, randomized trial to evaluate monochromatic infrared photoenergy.

    PubMed

    Lavery, Lawrence A; Murdoch, Douglas P; Williams, Jayme; Lavery, David C

    2008-02-01

    The purpose of this study was to determine the efficacy of anodyne monochromatic infrared photo energy (MIRE) in-home treatments over a 90-day period to improve peripheral sensation and self-reported quality of life in individuals with diabetes. This was a double-blind, randomized, sham-controlled clinical trail. We randomly assigned 69 individuals with diabetes and a vibration perception threshold (VPT) between 20 and 45 V to two treatment groups: active or sham treatment. Sixty patients (120 limbs) completed the study. Anodyne units were used at home every day for 40 min for 90 days. We evaluated nerve conduction velocities, VPT, Semmes-Weinstein monofilaments (SWM) (4-, 10-, 26-, and 60-g monofilaments), the Michigan Neuropathy Screening Instrument (MNSI), a 10-cm visual analog pain scale, and a neuropathy-specific quality of life instrument. We used a nested repeated-measures multiple ANOVA design. Two sites (great toe and fifth metatarsal) were tested on both the left and right feet of each patient, so two feet were nested within each patient and two sites were nested within each foot. To analyze the ordinal SWM scores, we used a nonparametric factorial analysis for longitudinal data. There were no significant differences in measures for quality of life, MNSI, VPT, SWM, or nerve conduction velocities in active or sham treatment groups (P > 0.05). Anodyne MIRE therapy was no more effective than sham therapy in the treatment of sensory neuropathy in individuals with diabetes.

  10. Role of pars plana vitrectomy and membrane peel in vitreomacular traction associated with retinal vasoproliferative tumors

    PubMed Central

    Castro-Navarro, Verónica; Saktanasate, Jarin; Say, Emil Anthony T.; Chiang, Allen; Shields, Carol Lally

    2016-01-01

    To report a case of retinal vasoproliferative tumor (VPT) with secondary epiretinal membrane (ERM) formation and vitreo-macular traction managed by pars plana vitrectomy (PPV) and membrane peel. A 29-year-old male was referred for management of decreased vision in the right eye (OD) for 1 week. Presenting visual acuity was 20/50 Snellen feet (ft) OD, and fundus examination showed an ERM associated with a reddish-yellow mass in the inferotemporal quadrant with overlying exudation, hemorrhage, and subretinal fluid consistent with VPT, and cryotherapy was recommended. Two months later, there was complete tumor regression, but there was decreased vision from progressive vitreomacular traction to 20/400 ft. PPV with combined ERM and internal limiting membrane (ILM) peel were performed with resolution of vitreomacular traction and improvement of visual acuity to 20/50 ft at 6 months. PPV with combined ERM and ILM peel is effective for vision loss secondary to ERM and vitreomacular traction associated with retinal VPT. PMID:27843233

  11. Early Electrographic Seizures, Brain Injury an Neurodevelopmental Risk in the Very Preterm Infant

    PubMed Central

    Vesoulis, Zachary A.; Inder, Terrie E.; Woodward, Lianne J.; Buse, Bradley; Vavasseur, Claudine; Mathur, Amit M.

    2014-01-01

    Background Previous studies of very preterm (VPT) infants have shown a wide range of seizure prevalence and association with intraventricular hemorrhage (IVH), white matter injury (WMI) and death. However, the impact of seizures on neurodevelopment is not well known. We hypothesized that seizures in the first three days after VPT birth would be associated with increased radiographic brain injury and later neurodevelopmental risk. Methods For 72 hours after birth 95 VPT infants underwent aEEG monitoring. High and low seizure burdens were related to radiographic brain injury, death in the neonatal period and children’s Bayley III performance at 2 years corrected age in a subgroup of 59 infants. Results The overall incidence of seizures in this sample was 48%. High seizure burden was associated with increased risk of IVH on day 1; IVH, WMI and death on day 2 and high grade IVH on day 3. The presence of seizures on any day was associated with decreased language performance at age 2, even after controlling for family social risk. Conclusions Seizures during the first three days after birth are common and are associated with an increased risk of IVH, WMI and death. They were also associated with poorer early language development. PMID:24366515

  12. Method and mechanism of vapor phase treatment-total reflection X-ray fluorescence for trace element analysis on silicon wafer surface

    NASA Astrophysics Data System (ADS)

    Takahara, Hikari; Mori, Yoshihiro; Shimazaki, Ayako; Gohshi, Yohichi

    2010-12-01

    Vapor phase treatment (VPT) is a pretreatment with hydrofluoric acid vapor to raise the sensitivity of total reflection X-ray fluorescence spectroscopy (TXRF) for trace metal analysis on silicon wafers. The International Organization for Standardization/Technical Committee 201/Working Group 2 (ISO/TC201/WG2) has been investigating the method to analyze 10 9 atoms/cm 2 level of metallic contamination on the silicon wafer surface. Though VPT can enhance the TXRF signal intensity from the metallic contamination, it has turned out that the magnitude of the enhancement varies with the type of methods and the process conditions. In this study, approaches to increase TXRF intensity by VPT are investigated using a fuming chamber in an automated VPD instrument. Higher signal intensity can be obtained when condensation is formed on the sample surface in a humidifying atmosphere and with a decreasing stage temperature. Surface observations with SEM and AFM show that particles with ~ 4 μm in diameter are formed and unexpectedly they are dented from the top surface level.

  13. A cross sectional study on hand-arm vibration syndrome among a group of tree fellers in a tropical environment.

    PubMed

    Su, Anselm Ting; Maeda, Setsuo; Fukumoto, Jin; Miyai, Nobuyuki; Isahak, Marzuki; Yoshioka, Atsushi; Nakajima, Ryuichi; Bulgiba, Awang; Miyashita, Kazuhisa

    2014-01-01

    This study aimed to explore the clinical characteristics of hand arm vibration syndrome (HAVS) in a group of tree fellers in a tropical environment. We examined all tree fellers and selected control subjects in a logging camp of central Sarawak for vibration exposure and presence of HAVS symptoms utilizing vibrotactile perception threshold test (VPT) and cold water provocation test (CWP). None of the subjects reported white finger. The tree fellers reported significantly higher prevalence of finger coldness as compared to the control subjects (OR=10.32, 95%CI=1.21-87.94). A lower finger skin temperature, longer fingernail capillary return time and higher VPT were observed among the tree fellers as compared to the control subjects in all fingers (effect size >0.5). The VPT following CWP of the tree fellers was significantly higher (repeated measures ANOVA p=0.002, partial η(2)=0.196) than the control subject. The A (8) level was associated with finger tingling, numbness and dullness (effect size=0.983) and finger coldness (effect size=0.524) among the tree fellers. Finger coldness and finger tingling, numbness and dullness are important symptoms for HAVS in tropical environment that may indicate vascular and neurological damage due to hand-transmitted vibration exposure.

  14. Comparison of a neurothesiometer and vibration in measuring vibration perception thresholds and relationship to nerve conduction studies.

    PubMed

    Bril, V; Kojic, J; Ngo, M; Clark, K

    1997-09-01

    To compare vibration perception thresholds (VPTs) obtained with two different instruments, a neurothesiometer and a vibratron, and to characterize variability of repeat measures and correlation with sural nerve conduction parameters. A total of 152 patients with diabetic peripheral neuropathy received electrodiagnostic evaluation and quantitative VPT testing with the Vibratron II and the Horwell Neurothesiometer. Of the patients, 42 returned for repeat nerve conduction studies and VPT testing with both types of equipment on three separate occasions. The variability of repeat testing for the vibratron was 34 and 31% in the right and left first toes, respectively. Variability for neurothesiometer was 8 and 6% for the right and left toes. This variability compares with that of sural nerve conduction velocity of 2% and that of sural nerve amplitude of 8% in this series of patients. We conclude that VPT determined with the neurothesiometer is less variable than with the vibratron and more reflective of peripheral nerve function. Our results indicate that the neurothesiometer can be used reliably in clinical research trials.

  15. A comparison of the neurothesiometer and biothesiometer for measuring vibration perception in diabetic patients.

    PubMed

    Young, M J; Every, N; Boulton, A J

    1993-05-01

    The Neurothesiometer is a new device designed to replace the Biothesiometer in screening for diabetic peripheral neuropathy by measuring vibration perception threshold (VPT). It was compared with the Biothesiometer in 85 diabetic patients, mean age 61 (range 21-82) years and mean duration of diabetes 12 (1-26) years, attending routine diabetes and foot screening clinics. VPT correlated with age and duration of diabetes (r = 0.46 and r = 0.42, respectively P < 0.01), with both devices. The Biothesiometer VPT was 29.9 +/- 15.2 V (mean +/- S.D.) compared with 26.2 +/- 13.4 V with the Neurothesiometer (P = NS) and there was a close correlation between the two devices r = 0.93 P < 0.001. The within patient coefficient of variation was 8.6% for the Biothesiometer and 8.1% for the Neurothesiometer. The Neurothesiometer gives results that are in close agreement with the Biothesiometer and has a good coefficient of variation in routine clinical use. It is a self contained, battery operated device, which, although more expensive than its predecessor, is well suited to diabetes screening programmes and would be particularly useful to epidemiological surveys in the community.

  16. Neurosensory sequelae assessed by thermal and vibrotactile perception thresholds after local cold injury.

    PubMed

    Carlsson, Daniel; Burström, Lage; Lilliesköld, Victoria Heldestad; Nilsson, Tohr; Nordh, Erik; Wahlström, Jens

    2014-01-01

    Local freezing cold injuries are common in the north and sequelae to cold injury can persist many years. Quantitative sensory testing (QST) can be used to assess neurosensory symptoms but has previously not been used on cold injury patients. To evaluate neurosensory sequelae after local freezing cold injury by thermal and vibrotactile perception thresholds and by symptom descriptions. Fifteen patients with a local freezing cold injury in the hands or feet, acquired during military training, were studied with QST by assessment of vibrotactile (VPT), warmth (WPT) and cold (CPT) perception thresholds 4 months post-injury. In addition, a follow-up questionnaire, focusing on neurovascular symptoms, was completed 4 months and 4 years post-injury. QST demonstrated abnormal findings in one or both affected hands for VPT in 6 patients, for WPT in 4 patients and for CPT in 1 patient. In the feet, QST was abnormal for VPT in one or both affected feet in 8 patients, for WPT in 6 patients and for CPT in 4 patients. Freezing cold injury related symptoms, e.g. pain/discomfort when exposed to cold, cold sensation and white fingers were common at 4 months and persisted 4 years after the initial injury. Neurosensory sequelae after local freezing cold injury, in terms of abnormal thermal and/or vibration perception thresholds, may last at least 4 months after the initial injury. Symptoms such as pain/discomfort at cold exposure, cold sensations and white fingers may persist at least 4 years after the initial injury.

  17. Road work on memory lane--functional and structural alterations to the learning and memory circuit in adults born very preterm.

    PubMed

    Salvan, Piergiorgio; Froudist Walsh, Seán; Allin, Matthew P G; Walshe, Muriel; Murray, Robin M; Bhattacharyya, Sagnik; McGuire, Philip K; Williams, Steven C R; Nosarti, Chiara

    2014-11-15

    Very preterm (VPT) birth is considered a risk factor not only for neurological impairment, but also for reduced function in several cognitive domains in childhood and later in life. Individuals who were born VPT are more likely to demonstrate learning and memory difficulties compared to term-born controls. These problems contribute to more VPT-born children repeating grades and underachieving in school. This, in turn, affects their prospects in adult life. Here we aimed to 1) study how the VPT-born adult brain functionally recruited specific areas during learning, i.e. encoding and recall across four repeated blocks of verbal stimuli, and to investigate how these patterns of activation differed from term-born subjects; and 2) probe the microstructural differences of white-matter tracts connecting these areas to other parts of the learning and memory network. To investigate these functional-structural relationships we analyzed functional and diffusion-weighted MRI. Functional-MRI and a verbal paired associate learning (VPAL) task were used to extract Blood Oxygenation Level Dependent (BOLD) activity in 21 VPT-born adults (<33 weeks of gestation) (mean age: 19.68 years ± 0.85; IQ: 99.86 ± 11.20) and 10 term-born controls (mean age: 19.87 years ± 2.04; IQ: 108.9 ± 13.18). Areas in which differences in functional activation were observed between groups were used as seed regions for tractography. Fractional anisotropy (FA) of the tract-skeleton was then compared between groups on a voxel-wise basis. Results of functional MRI analysis showed a significantly different pattern of activation between groups during encoding in right anterior cingulate-caudate body, and during retrieval in left thalamus, hippocampus and parts of left posterior parahippocampal gyrus. The number of correctly recalled word pairs did not statistically differ between individuals who were born VPT and controls. The VPT-born group was found to have reduced FA in tracts passing through the

  18. Evolution of Depression and Anxiety Symptoms in Parents of Very Preterm Infants During the Newborn Period.

    PubMed

    Pace, Carmen C; Spittle, Alicia J; Molesworth, Charlotte M-L; Lee, Katherine J; Northam, Elisabeth A; Cheong, Jeanie L Y; Davis, Peter G; Doyle, Lex W; Treyvaud, Karli; Anderson, Peter J

    2016-09-01

    Mothers experience heightened depression and anxiety following very preterm (VPT) birth, but how these symptoms evolve during the first months after birth is unknown. Research on the psychological adjustment of fathers following VPT birth is limited. To describe the trajectory and predictors of distress in parents of VPT infants during the first 12 weeks after birth, and to compare rates of depression and anxiety in parents of VPT infants with those in parents of healthy full-term (FT) infants shortly after birth and at 6 months' postnatal age. Longitudinal, prospective, follow-up cohort study of depression and anxiety symptoms in parents of VPT infants (<30 weeks' gestational age; admitted to the neonatal intensive care unit at the Royal Women's Hospital, Melbourne, Australia, between January 21, 2011, and December 23, 2013), documented every 2 weeks until age 12 weeks and at age 6 months, as well as in parents of healthy FT infants (≥37 weeks' gestational age; birth weight >2499 g; born at the Royal Women's Hospital between August 15, 2012, and March 26, 2014; not admitted to the neonatal nursery) shortly after birth and at age 6 months. Birth of a VPT infant. Symptoms of depression (Center for Epidemiological Studies Depression Scale) and anxiety (Hospital Anxiety and Depression Scale). The study included 113 mothers (mean [SD] age at birth, 32.7 [5.3] years) and 101 fathers (mean [SD] age at birth, 34.7 [6.4] years) of 149 VPT infants (49% male; 84 singletons, 65 multiples; mean [SD] birth weight, 1021 [261] g) as well as 117 mothers (mean [SD] age at birth, 32.9 [4.8] years) and 110 fathers (mean [SD] age at birth, 35.9 [5.3] years) of 151 healthy FT infants (50% male; 149 singletons, 2 multiples; mean [SD] birth weight, 3503 [438] g). Mean scores and rates of depression and anxiety reduced over time for parents of VPT infants in the 12 weeks after birth: the mean (95% CI) change in depression score per week was -0.52 (-0.73 to -0.31; P < .001) for

  19. Impact of high dose n-3 polyunsaturated fatty acid treatment on measures of microvascular function and vibration perception in non-alcoholic fatty liver disease: results from the randomised WELCOME trial.

    PubMed

    McCormick, Keith G; Scorletti, Eleonora; Bhatia, Lokpal; Calder, Philip C; Griffin, Michael J; Clough, Geraldine F; Byrne, Christopher D

    2015-08-01

    The effect of n-3 fatty acid treatment on vibration perception thresholds (VPTs) and cutaneous microvascular reactivity is not known. We tested whether: (1) a 15-18 month treatment with high dose (4 g/day) docosahexaenoic (DHA) plus eicosapentaenoic (EPA) acid improved VPT and microvascular reactivity in patients with non-alcoholic fatty liver disease; and (2) there are associations between VPT, microvascular reactivity and metabolic variables. In the completed single centre, randomised, parallel group, placebo controlled Wessex Evaluation of fatty Liver and Cardiovascular markers in non-alcoholic fatty liver disease with OMacor thErapy (WELCOME) trial, we tested the effect of DHA+EPA on VPT at 125 Hz (big toe) and the cutaneous hyperaemic response (forearm) to arterial occlusion (ratio of maximum to resting blood flux [MF/RF]). Allocation and dispensing was carried out by an independent research pharmacist; all participants and research team members were blinded to group assignment. In all, 51 and 49 patients were randomised to placebo and DHA+EPA, respectively (mean age 51.4 years). Of these, 32 had type 2 diabetes. Forty-six (placebo) and 47 (DHA+EPA) patients completed the study; there were no important adverse (or unexpected) effects or side effects. In multivariable-adjusted regression models (intention-to-treat analyses), DHA+EPA treatment was associated with an increase in VPT (β coefficient 1.49 [95% CI 0.04, 2.94], p = 0.04). For VPT, the adjusted mean differences (95% CIs) in the placebo and DHA+EPA treatment groups were -0.725 (-1.71, 0.25) and 0.767 (-0.21, 1.75) m/s(2), respectively. With DHA+EPA treatment, there was no change in MF/RF (β coefficient 0.07 [95% CI -0.56, 0.70], p = 0.84), the adjusted mean differences (95% CIs) in the placebo and DHA+EPA treatment groups were -0.549 (-1.03, -0.07) and -0.295 (-0.77, 0.18) respectively. VPT was independently associated with age (β coefficient 0.019 [95% CI 0.010, 0.029], p < 0.0001) and MF/RF (

  20. Brain injury and altered brain growth in preterm infants: predictors and prognosis.

    PubMed

    Kidokoro, Hiroyuki; Anderson, Peter J; Doyle, Lex W; Woodward, Lianne J; Neil, Jeffrey J; Inder, Terrie E

    2014-08-01

    To define the nature and frequency of brain injury and brain growth impairment in very preterm (VPT) infants by using MRI at term-equivalent age and to relate these findings to perinatal risk factors and 2-year neurodevelopmental outcomes. MRI scans at term-equivalent age from 3 VPT cohorts (n = 325) were reviewed. The severity of brain injury, including periventricular leukomalacia and intraventricular and cerebellar hemorrhage, was graded. Brain growth was assessed by using measures of biparietal width (BPW) and interhemispheric distance. Neurodevelopmental outcome at age 2 years was assessed across all cohorts (n = 297) by using the Bayley Scales of Infant Development, Second Edition (BSID-II) or Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III), and evaluation for cerebral palsy. Of 325 infants, 107 (33%) had some grade of brain injury and 33 (10%) had severe injury. Severe brain injury was more common in infants with lower Apgar scores, necrotizing enterocolitis, inotropic support, and patent ductus arteriosus. Severe brain injury was associated with delayed cognitive and motor development and cerebral palsy. Decreased BPW was related to lower gestational age, inotropic support, patent ductus arteriosus, necrotizing enterocolitis, prolonged parenteral nutrition, and oxygen at 36 weeks and was associated with delayed cognitive development. In contrast, increased interhemispheric distance was related to male gender, dexamethasone use, and severe brain injury. It was also associated with reduced cognitive development, independent of BPW. At term-equivalent age, VPT infants showed both brain injury and impaired brain growth on MRI. Severe brain injury and impaired brain growth patterns were independently associated with perinatal risk factors and delayed cognitive development. Copyright © 2014 by the American Academy of Pediatrics.

  1. Footwear and foot care knowledge as risk factors for foot problems in Indian diabetics.

    PubMed

    Chandalia, H B; Singh, D; Kapoor, V; Chandalia, S H; Lamba, P S

    2008-10-01

    We assessed 300 diabetic and 100 age- and sex-matched controls for correlating foot wear practices and foot care knowledge and the presence of foot complications. A structured questionnaire evaluated the knowledge about foot care, type of footwear used, education level, association of tobacco abuse, and any associated symptoms of foot disease. Clinical evaluation was done by inspection of feet for presence of any external deformities, assessment of sensory function (vibration perception threshold, VPT), vascular status (foot pulses and ankle brachial ratio) and presence of any infection.In the diabetes category, 44.7% patients had not received previous foot care education. 0.6% walked barefoot outdoors and 45% walked barefoot indoors. Fourteen (4.7%) patients gave history of foot ulceration in the past and comprised the high risk group; only 2 out of 14 had received foot care education, 6 gave history of tobacco abuse, 8 had symptoms of claudication, 9 had paresthesias, 2 walked barefoot indoors. Average duration of diabetes in the high-risk and low-risk diabetes group was 10.85 +/- 6.53 and 9.83 +/- 7.99 years, respectively. In the high- and low-risk diabetic groups, VPT was 19.57 +/- 11.26 and 15.20 +/- 10.21V (P < 0.02), ankle brachial ratio was 1.05 +/- 0.19 and 1.14 +/- 0.18 (P < 0.05), and the questionnaire scores was 40.8% and 57%, respectively.In the diabetic and the control group, VPT was 15.62 +/- 10.39 and 8.36 +/- 3.61 V (P < 0.01), ankle brachial ratio was 1.14 +/- 0.18 and 1.15 +/- 0.12, and the questionnaire scores were 57% and 40.3%, respectively.In conclusion, poor knowledge of foot care and poor footwear practices were important risk factors for foot problems in diabetes.

  2. Development of calcium phosphate/sulfate biphasic cement for vital pulp therapy.

    PubMed

    Chang, Kai-Chun; Chang, Chia-Chieh; Chen, Wei-Tang; Hsu, Chung-King; Lin, Feng-Huei; Lin, Chun-Pin

    2014-12-01

    Bioactive calcium phosphate cement (CPC) has been used widely to repair bone defects because of its excellent biocompatibility and bioactivity. However, the poor handling properties, low initial mechanical strength, and long setting time of CPC limit its application in vital pulp therapy (VPT). The aim of this study was to synthesize biphasic calcium phosphate/sulfate cements and evaluate the feasibility of applying these cements in VPT. The physical, chemical, and mechanical properties of CPC were improved by mixing the cement with various amounts of α-calcium sulfate hemihydrate (CSH). The hydration products and crystalline phases of the materials were characterized using scanning electron microscopy and X-ray diffraction analysis. In addition, the physical properties, such as the setting time, compressive strength, viscosity, and pH were determined. Water-soluble tetrazolium salt-1 and lactase dehydrogenase were used to evaluate cell viability and cytotoxicity. The developed CPC (CPC/CSH cement), which contains 50wt% CSH cement, exhibited no obvious temperature increase or pH change during setting when it was used as a paste. The initial setting time of the CPC/CSH biphasic cement was substantially shorter than that of CPC, and the initial mechanical strength was 23.7±5.6MPa. The CPC/CSH cement exhibited higher viscosity than CPC and, thus, featured acceptable handling properties. X-ray diffraction analysis revealed that the relative peak intensity for hydroxyapatite increased, and the intensity for calcium sulfate dehydrate decreased as the amount of CPC was increased. The cell viability and cytotoxicity test results indicated that the CPC/CSH cement did not harm dental pulp cells. The developed CPC/CSH biphasic cement exhibits substantial potential for application in VPT. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  3. Neurosensory sequelae assessed by thermal and vibrotactile perception thresholds after local cold injury

    PubMed Central

    Carlsson, Daniel; Burström, Lage; Lilliesköld, Victoria Heldestad; Nilsson, Tohr; Nordh, Erik; Wahlström, Jens

    2014-01-01

    Background Local freezing cold injuries are common in the north and sequelae to cold injury can persist many years. Quantitative sensory testing (QST) can be used to assess neurosensory symptoms but has previously not been used on cold injury patients. Objective To evaluate neurosensory sequelae after local freezing cold injury by thermal and vibrotactile perception thresholds and by symptom descriptions. Design Fifteen patients with a local freezing cold injury in the hands or feet, acquired during military training, were studied with QST by assessment of vibrotactile (VPT), warmth (WPT) and cold (CPT) perception thresholds 4 months post-injury. In addition, a follow-up questionnaire, focusing on neurovascular symptoms, was completed 4 months and 4 years post-injury. Results QST demonstrated abnormal findings in one or both affected hands for VPT in 6 patients, for WPT in 4 patients and for CPT in 1 patient. In the feet, QST was abnormal for VPT in one or both affected feet in 8 patients, for WPT in 6 patients and for CPT in 4 patients. Freezing cold injury related symptoms, e.g. pain/discomfort when exposed to cold, cold sensation and white fingers were common at 4 months and persisted 4 years after the initial injury. Conclusions Neurosensory sequelae after local freezing cold injury, in terms of abnormal thermal and/or vibration perception thresholds, may last at least 4 months after the initial injury. Symptoms such as pain/discomfort at cold exposure, cold sensations and white fingers may persist at least 4 years after the initial injury. PMID:24624368

  4. Linguistic features in children born very preterm at preschool age.

    PubMed

    Guarini, Annalisa; Marini, Andrea; Savini, Silvia; Alessandroni, Rosina; Faldella, Giacomo; Sansavini, Alessandra

    2016-09-01

    This cross-sectional study focused on the effect of very preterm (VPT) birth on language development by analysing phonological, lexical, grammatical, and pragmatic skills and assessing the role of cognitive and memory skills. Sixty children (29 males, 31 females) born VPT (<32wks) aged 5 years were compared with 60 children with typical development. The linguistic assessment was performed by administering a battery of Italian tests for the evaluation of language; cognitive and memory skills were assessed by Raven's coloured progressive matrices and digit span subtest (Wechsler Intelligence Scale for Children [WISC-III]). Children born VPT showed delays in lexical (comprehension: z-score difference -1.18; 95% confidence interval [CI] -1.60 to -0.77; naming: -0.88; 95% CI -1.19 to -0.58) and pragmatic skills (comprehension: -0.76; 95% CI -1.02 to -0.49; narrative production: -0.47; 95% CI -0.72 to -0.23). Delays in phonology and grammar were less diffuse, involving productive skills (-1.09; 95% CI -1.64 to -0.54; -0.48; 95% CI -0.85 to -0.12, respectively), and were dependent by cognitive and memory skills. Lexical delays were more specific. The linguistic profile of children born preterm is characterized by some abilities more impaired than others. This highlights the need of a linguistic assessment at the end of preschool age in order to plan a focused intervention aimed at improving lexical and pragmatic skills. © 2016 Mac Keith Press.

  5. Static balance function in children with a history of preterm birth

    PubMed Central

    Eshaghi, Zahra; Jafari, Zahra; Jalaie, Shohreh

    2015-01-01

    Background: The incomplete maturation of brain in preterm children results in long-term neurodevelopmental impairment. This study aimed to investigate the static balance function in children with a history of preterm birth. Methods: Participants were 31 preterm children including 21 moderately preterm (MPT), 10 very preterm (VPT), and 20 term children aged 5.5 and 6.5 years. The cervical vestibular-evoked myogenic potential (cVEMP) test and four static balance subscales of BOT-2 were performed. Results: The VPT children showed a significant increase in P1 and N1 wave latencies in cVEMP test compared to those in the term children (p= 0.041). Mean scores in the four static balance subscales of BOT-2 were significantly lower in the preterm children compared to those in the term children (p= 0.025). The P1 wave latency (p= 0.003) and mean score of standing on a balance beam with open eyes (p= 0.039) were significantly lower in the VPT children compared to those in the MPT children. A significant correlation was observed between the mean score in exercise 4 (standing on one leg on a balance beam with closed eyes) of static balance subscales of BOT-2 and P1 (r= -0.267, p= 0.036) and N1 (r= -0.304, p= 0.016) wave latencies of cVEMP. Conclusion: The longer latency of cVEMP waves along with a poor performance of children with a history of preterm birth suggests a possible defect in central vestibular pathway. PMID:26913273

  6. Comparison of vibration perception thresholds obtained with the Neurothesiometer and the CASE IV and relationship to nerve conduction studies.

    PubMed

    Bril, Vera; Perkins, B A

    2002-08-01

    Vibration perception thresholds (VPTs) are used frequently to assess somatosensory pathways in clinical trials. Different equipment, testing paradigms, and stimulation sites produce varying results which make comparisons between trials and patient populations challenging. Information comparing the VPT obtained with the Neurothesiometer with that with the Vibratron is available, but not for a similar comparison with the CASE IV (computer-assisted sensory examination device). Subjects (n = 478) including reference, non-neuropathic subjects with diabetes mellitus (DM), and diabetic patients with mild, moderate and severe diabetic sensorimotor polyneuropathy (DSP) had VPTs measured with the CASE IV and Neurothesiometer, as well as standard sural nerve conduction studies (NCS), all performed during the same half-day. The dorsum of the foot was used as the site of stimulation for the CASE IV VPT determination and the distal phalanx of the first toe for the Neurothesiometer. VPTs by the CASE IV and the Neurothesiometer compared moderately by linear regression analyses (R2 = 0.547, P < 0.0001), and by 95% confidence intervals. Sensitivity for the diagnosis of mild DSP was 70% with the Neurothesiometer and 49% with the CASE IV. VPTs determined by either the Neurothesiometer or the CASE IV correlated with similar agreement to the sural nerve action potential amplitude as determined by nerve conduction studies (NCS) (R2 = 0.456 and 0.461, respectively, P < 0.0001). The results demonstrated a significant correlation of VPT values in different stages of DSP obtained by the two methods. The Neurothesiometer was more sensitive for the diagnosis of DSP, particularly in those with mild neuropathy. Similar correlations between VPTs and electrophysiological parameters were observed, indicating that both methods are valid, and thus the Neurothesiometer may be preferable due to the ease and rapidity of testing by this method.

  7. Association between Hemoglobin Levels and Diabetic Peripheral Neuropathy in Patients with Type 2 Diabetes: A Cross-Sectional Study Using Electronic Health Records

    PubMed Central

    Wan, Qin; Li, Hua

    2017-01-01

    Objective To investigate the relationship between hemoglobin levels and diabetic peripheral neuropathy (DPN) in type 2 diabetes mellitus (T2DM). Methods 1511 patients with T2DM were included in the study. DPN was diagnosed based on symptoms, signs, and laboratory tests. Hemoglobin was defined as both a continuous variable and a quartile category variable. We compared patient characteristics between the no diabetic peripheral neuropathy (NDPN) and DPN groups. Logistic regression was conducted to investigate the association of DPN with hemoglobin in all T2DM patients. Linear regression was also performed to investigate the impact of hemoglobin on the vibrating perception threshold (VPT). Results Compared with the NDPN group, hemoglobin level in the DPN group was significantly lower (118.54 ± 16.91 versus 131.62 ± 18.32 g/L, P < 0.01). The prevalence of DPN increased by 50.1% (95% CI: 42.2–57.0%; P < 0.001) per standard deviation decrease in hemoglobin. Compared to the highest quartile of hemoglobin, the lower quartiles were associated with a significantly increased risk of DPN in the entire T2DM population (all P < 0.01). A per unit decrease in hemoglobin leads to a 0.12 (95% CI: 0.07–0.168) unit increase in VPT after adjustment for possible confounders (P < 0.001). Conclusions Lower hemoglobin levels were associated with increased prevalence of DPN and higher VPT. PMID:28713833

  8. Anharmonic zero point vibrational energies: Tipping the scales in accurate thermochemistry calculations?

    NASA Astrophysics Data System (ADS)

    Pfeiffer, Florian; Rauhut, Guntram; Feller, David; Peterson, Kirk A.

    2013-01-01

    Anharmonic zero point vibrational energies (ZPVEs) calculated using both conventional CCSD(T) and MP2 in combination with vibrational second-order perturbation theory (VPT2) are compared to explicitly correlated CCSD(T)-F12 and MP2-F12 results that utilize vibrational configuration interaction (VCI) theory for 26 molecules of varying size. Sequences of correlation consistent basis sets are used throughout. It is found that the explicitly correlated methods yield results close to the basis set limit even with double-zeta quality basis sets. In particular, the anharmonic contributions to the ZPVE are accurately recovered at just the MP2 (or MP2-F12) level of theory. Somewhat surprisingly, the best vibrational CI results agreed with the VPT2 values with a mean unsigned deviation of just 0.09 kJ/mol and a standard deviation of just 0.11 kJ/mol. The largest difference was observed for C4H4O (0.34 kJ/mol). A simplified version of the vibrational CI procedure that limited the modal expansion to at most 2-mode coupling yielded anharmonic corrections generally within about 0.1 kJ/mol of the full 3- or 4-mode results, except in the cases of C3H8 and C4H4O where the contributions were underestimated by 1.3 and 0.8 kJ/mol, respectively (34% and 40%, respectively). For the molecules considered in this work, accurate anharmonic ZPVEs are most economically obtained by combining CCSD(T)-F12a/cc-pVDZ-F12 harmonic frequencies with either MP2/aug-cc-pVTZ/VPT2 or MP2-F12/cc-pVDZ-F12/VCI anharmonic corrections.

  9. Evaluation of children's dental anxiety levels at a kindergarten and at a dental clinic.

    PubMed

    Kilinç, Gulser; Akay, Aynur; Eden, Ece; Sevinç, Nilgün; Ellidokuz, Hülya

    2016-08-18

    This study evaluated the dental anxiety levels of preschool children at a kindergarten and at a dental clinic. The anxiety levels of ninety 4-6-year-old (4.99 ± 0.81) preschool children were evaluated according to pulse rates, the facial image scale (FIS), the Venham picture test (VPT), and the Frankl behavior rating scale. The children's mothers were asked to complete the state-trait anxiety inventory (STAI) forms 1 and 2 (STAI 2 and STAI 2). The sample t-test, Mann-Whitney U test, and Pearson's correlation test were used. A statistically significant difference was observed between the children's pulse rates when measured at the dental clinic and those when measured at the kindergarten (p < 0.001). Although the results were not statistically significant, more negative facial expressions were observed in the children at the dental clinic than in those at the kindergarten when assessed using FIS and VPT (p = 0.090 and p = 0.108, respectively). There was a statistically significant correlation between the transient anxiety levels (STAI 1) of mothers and the VPT scores of their children evaluated at the dental clinic (r = 0.506, p < 0.001). The continuous anxiety level of the mothers of males was found to be significantly higher (p = 0.033) than that of the mothers of females (STAI 2). Although the children had been informed about dentistry and were introduced to a dentist at the kindergarten, their anxiety levels seemingly increased as they arrived at the dental clinic. The significant increase observed in the children's pulse rates was a physical indicator that their anxiety levels had increased. It can be concluded that the children felt more anxious at the dental clinic that at the kindergarten.

  10. A comparison of ZnO films deposited on indium tin oxide and soda lime glass under identical conditions

    SciTech Connect

    Deka, Angshuman; Nanda, Karuna Kar

    2013-06-15

    ZnO films have been grown via a vapour phase transport (VPT) on soda lime glass (SLG) and indium-tin oxide (ITO) coated glass. ZnO film on ITO had traces of Zn and C which gives them a dark appearance while that appears yellowish-white on SLG. X-ray photoelectron spectroscopy studies confirm the traces of C in the form of C-O. The photoluminescence studies reveal a prominent green luminescence band for ZnO film on ITO.

  11. Implementation of Process Management for a Secure Archival Storage System.

    DTIC Science & Technology

    1981-03-01

    V.DT.MSGQ.NEXTP_’SG(R2), UNI e iB2 FFFF 0134 5E08 EXIT FROM MSG- LS TINIT 01B6 01CZ’ v~ibe 5Eee ELSiE (diBA 01CkO’ 013C 6F21 LD VPT.MSG-Q.Ni;XTMSG(R~e...RET V 28 2 hEND RUNNING_.P 220 £282 SPIN LOCK PROCEDUPE * USLS SPIN LOCK MiCh. * LOCLS UNLOCKID DATA ’ STRUCTURE (POINTED TO * BY INPUT PARAMETER

  12. Comparative roles of microvascular and nerve function in foot ulceration in type 2 diabetes.

    PubMed

    Krishnan, Singhan T M; Baker, Neil R; Carrington, Anne L; Rayman, Gerry

    2004-06-01

    To determine the relative roles of different modalities of sensory nerve function (large and small fiber) and the role of microvascular dysfunction in foot ulceration in type 2 diabetic subjects. A total of 20 control subjects and 18 type 2 diabetic subjects with foot ulceration and 20 without were studied. None of the subjects had clinical features of peripheral vascular disease. The Computer-Aided Sensory Evaluator IV (CASE IV) was used to determine vibration detection threshold (VDT), cold detection threshold (CDT), warm detection threshold (WDT), and heat pain onset threshold (HPO). Vibration perception threshold (VPT) was also assessed by a neurothesiometer. Microvascular function (maximum hyperemia to skin heating to 44 degrees C) was assessed using laser Doppler flowmetry (mean maximum hyperemia using laser Doppler flowmeter [LDF(max)]), laser Doppler imaging (mean maximum hyperemia using laser Doppler imager [LDI(max)]), and skin oxygenation with transcutaneous oxygen tension (TcpO(2)). VPT, VDT, CDT, and HPO were all significantly higher in individuals with ulceration than in those without (VPT and VDT: P < 0.0001) (CDT and HPO: P = 0.01). LDF(max), LDI(max), and TcpO(2) were significantly lower in the two diabetic groups than in the control subjects, but there was no difference between individuals with and without ulceration. Univariate logistic regression analysis revealed similar odds ratios for foot ulceration for VDT, CDT, HPO, and VPT (OR 1.97 [95% CI 1.30-2.98], 1.58 [1.20-2.08], 2.30 [1.21-4.37], and 1.24 [1.08-1.42], respectively). None of the microvascular parameters yielded significant odds ratios for ulceration. This study found that there was no additional value in measuring small-fiber function with the CASE IV over measuring vibration by either CASE IV or the inexpensive neurothesiometer in discriminating between individuals with and without ulceration. Furthermore, none of the tests of microvascular function including the TcpO(2) were able

  13. Predicting the structure and vibrational frequencies of ethylene using harmonic and anharmonic approaches at the Kohn-Sham complete basis set limit.

    PubMed

    Buczek, Aneta; Kupka, Teobald; Broda, Małgorzata A; Żyła, Adriana

    2016-01-01

    In this work, regular convergence patterns of the structural, harmonic, and VPT2-calculated anharmonic vibrational parameters of ethylene towards the Kohn-Sham complete basis set (KS CBS) limit are demonstrated for the first time. The performance of the VPT2 scheme implemented using density functional theory (DFT-BLYP and DFT-B3LYP) in combination with two Pople basis sets (6-311++G** and 6-311++G(3df,2pd)), the polarization-consistent basis sets pc-n, aug-pc-n, and pcseg-n (n = 0, 1, 2, 3, 4), and the correlation-consistent basis sets cc-pVXZ and aug-cc-pVXZ (X = D, T, Q, 5, 6) was tested.The BLYP-calculated harmonic frequencies were found to be markedly closer than the B3LYP-calculated harmonic frequencies to the experimentally derived values, while the calculated anharmonic frequencies consistently underestimated the observed wavenumbers. The different basis set families gave very similar estimated values for the CBS parameters. The anharmonic frequencies calculated with B3LYP/aug-pc-3 were consistently significantly higher than those obtained with the pc-3 basis set; applying the aug-pcseg-n basis set family alleviated this problem. Utilization of B3LYP/aug-pcseg-n basis sets instead of B3LYP/aug-cc-pVXZ, which is computationally less expensive, is suggested for medium-sized molecules. Harmonic BLYP/pc-2 calculations produced fairly accurate ethylene frequencies. Graphical Abstract In this study, the performance of the VPT2 scheme implemented using density functional theory (DFT-BLYP and DFT-B3LYP) in combination with the polarization-consistent basis sets pc-n, aug-pc-n, and pcseg-n (n = 0, 1, 2, 3, 4), and the correlation-consistent basis sets cc-pVXZ and aug-cc-pVXZ (X = D, T, Q, 5, and 6) was tested. For the first time, we demonstrated regular convergence patterns of the structural, harmonic, and VPT2-calculated anharmonic vibrational parameters of ethylene towards the Kohn-Sham complete basis set (KS CBS) limit.

  14. Efficacy of Enamel Matrix Derivative in Vital Pulp Therapy: A Review of Literature

    PubMed Central

    Najeeb, Shariq; Khurshid, Zohaib; Sohail Zafar, Muhammad; Zohaib, Sana; Siddiqui, Fahad

    2017-01-01

    Introduction: Vital pulp therapy (VPT) aims to preserve the health and maintain life of the tooth pulp which has been compromised by caries, trauma or restorative procedures. Recently, enamel matrix derivative (EMD) has been introduced as a material for vital pulp therapy. The aim of this review is to critically analyze and summarize the available literature on EMD for VPT. Methods and Materials: Online databases (PubMED/MEDLINE, Google Scholar, ISI Web of Science, and Wiley-Online) were searched by using the following keywords in various combinations: Enamel Matrix Derivative, Emdogain, ‘Vital Pulp Therapy, ‘Apexogenisis’, Apexification, Pulp Capping, Endodontics, Dentine and Pulpotomy for studies indexed from January 1949 to April 2016. We used an English-limited search in Google.co.uk for the missing grey literature. All studies fulfilling the selection criteria were carefully reviewed for the focused question: “Does using EMD in VPT, compared with other materials, result in better clinical, radiographic and histological outcomes?”. Results: The primary search resulted in 18 articles of which, 14 articles (including 6 animal studies and 6 clinical trials and 2 case reports) met the inclusion criteria for this review and hence were included. The number of teeth tested in the animal studies ranged from 8 to 144 including pigs, rats and dogs teeth. A number of studies used EMD in the experimental group in comparison with calcium hydroxide, propylene glycol alginate (PGA) and MTA as a control. The observation period ranged from 1 to 2 months and 4 out of 6 animal trials reported more favorable outcomes with EMD while two studies reported comparable outcomes. Conclusion: Although EMD has potential for various applications in endodontics, studies conducted to date have failed to demonstrate any significant advantage of EMD over conventional VPT materials. Additionally, the 5-year and 10-year survival rate of EMD-treated teeth is not yet known. Hence, studies

  15. A model for the computation of thermal expansivity at high compression and high temperatures - MGO as an example

    NASA Astrophysics Data System (ADS)

    Anderson, Orson L.; Oda, Hitoshi; Isaak, Donald

    1992-10-01

    The value of the thermal expansivity, alpha, over a wide range of compression, eta, and temperature is computed. Values of alpha for MgO over V,P,T conditions including those of the earth's lower mantle are suggested using a simple equation relating alpha to eta along isochores. The ab initio database is used to evaluate the parameters in the equation. The thermal expansivity is found to vary from about 1.40 alpha(a) to 0.40 alpha(a) along a geotherm through the upper and lower mantle, where alpha(a) is alpha at ambient conditions.

  16. Brain systems for visual perspective taking and action perception.

    PubMed

    Mazzarella, Elisabetta; Ramsey, Richard; Conson, Massimiliano; Hamilton, Antonia

    2013-01-01

    Taking another person's viewpoint and making sense of their actions are key processes that guide social behavior. Previous neuroimaging investigations have largely studied these processes separately. The current study used functional magnetic resonance imaging to examine how the brain incorporates another person's viewpoint and actions into visual perspective judgments. Participants made a left-right judgment about the location of a target object from their own (egocentric) or an actor's visual perspective (altercentric). Actor location varied around a table and the actor was either reaching or not reaching for the target object. Analyses examined brain regions engaged in the egocentric and altercentric tasks, brain regions where response magnitude tracked the orientation of the actor in the scene and brain regions sensitive to the action performed by the actor. The blood oxygen level-dependent (BOLD) response in dorsomedial prefrontal cortex (dmPFC) was sensitive to actor orientation in the altercentric task, whereas the response in right inferior frontal gyrus (IFG) was sensitive to actor orientation in the egocentric task. Thus, dmPFC and right IFG may play distinct but complementary roles in visual perspective taking (VPT). Observation of a reaching actor compared to a non-reaching actor yielded activation in lateral occipitotemporal cortex, regardless of task, showing that these regions are sensitive to body posture independent of social context. By considering how an observed actor's location and action influence the neural bases of visual perspective judgments, the current study supports the view that multiple neurocognitive "routes" operate during VPT.

  17. NerveCheck for the Detection of Sensory Loss and Neuropathic Pain in Diabetes

    PubMed Central

    Ponirakis, Georgios; Odriozola, Maria N.; Odriozola, Samantha; Petropoulos, Ioannis N.; Azmi, Shazli; Ferdousi, Maryam; Fadavi, Hassan; Alam, Uazman; Marshall, Andrew; Jeziorska, Maria; Miro, Anthony; Kheyami, Ahmad; Tavakoli, Mitra; Al-Ahmar, Ahmed; Odriozola, Maria B.; Odriozola, Ariel

    2016-01-01

    Abstract Background: Accurate and economic detection of nerve damage in diabetes is key to more widespread diagnosis of patients with diabetic peripheral neuropathy (DPN) and painful diabetic neuropathy. This study examined the diagnostic performance of NerveCheck, an inexpensive ($500) quantitative sensory testing (QST) device. Methods: One hundred forty-four subjects (74 with and 70 without diabetes) underwent assessment with NerveCheck, neuropathy disability score (NDS), nerve conduction studies (NCS), intraepidermal and corneal nerve fiber density (IENFD and CNFD), and McGill questionnaire for neuropathic pain. Results: Of the 74 subjects with diabetes, 41 were diagnosed with DPN based on the NDS. The NerveCheck scores for vibration perception threshold (VPT), cold perception threshold (CPT), and warm perception threshold (WPT) were significantly lower (P ≤ 0.0001) in diabetic patients with DPN compared to patients without DPN. The diagnostic accuracy of VPT was high with reference to NCS (area under the curve [AUC]: 82%–84%) and moderate for IENFD, CNFD, and neuropathic pain (AUC: 60%–76%). The diagnostic accuracy of CPT and WPT was moderate with reference to NCS, IENFD, and CNFD (AUC: 69%–78%) and low for neuropathic pain (AUC: 63%–65%). Conclusions: NerveCheck is a low-cost QST device with good diagnostic utility for identifying sensory deficits, comparable to established tests of large and small fiber neuropathy and for the severity of neuropathic pain. PMID:27922760

  18. Peripheral tactile sensory perception of older adults improved using subsensory electrical noise stimulation.

    PubMed

    Breen, Paul P; Serrador, Jorge M; O'Tuathail, Claire; Quinlan, Leo R; McIntosh, Caroline; ÓLaighin, Gearóid

    2016-08-01

    Loss of tactile sensory function is common with aging and can lead to numbness and difficulty with balance and gait. In previous work we found that subsensory electrical noise stimulation (SENS) applied to the tibial nerve improved tactile perception in the soles of the feet of healthy adults. In this work we aimed to determine if SENS remained effective in an older adult population with significant levels of sensory loss. Older adult subjects (N=8, female = 4, aged 65-80) had SENS applied via surface electrodes placed proximally to the medial and lateral malleoli. Vibration perception thresholds (VPTs) were assessed in six conditions, two control conditions (no SENS) and four SENS conditions (zero mean ±15µA, 30µA, 45µA and 60µA SD). VPT was assessed at three sites on the plantar aspect of the foot. Vibration perception was significantly improved in the presence of ±30µA SENS and by 16.2±2.4% (mean ± s.e.m.) when optimised for each subject. The improvement in perception was similar across all VPT test sites. Copyright © 2016 IPEM. All rights reserved.

  19. Sensory nerve action potentials and sensory perception in women with arthritis of the hand

    PubMed Central

    2012-01-01

    Background Arthritis of the hand can limit a person’s ability to perform daily activities. Whether or not sensory deficits contribute to the disability in this population remains unknown. The primary purpose of this study was to determine if women with osteoarthritis (OA) or rheumatoid arthritis (RA) of the hand have sensory impairments. Methods Sensory function in the dominant hand of women with hand OA or RA and healthy women was evaluated by measuring sensory nerve action potentials (SNAPs) from the median, ulnar and radial nerves, sensory mapping (SM), and vibratory and current perception thresholds (VPT and CPT, respectively) of the second and fifth digits. Results All SNAP amplitudes were significantly lower for the hand OA and hand RA groups compared with the healthy group (p < 0.05). No group differences were found for SNAP conduction velocities, SM, VPT, and CPT. Discussion We propose, based on these findings, that women with hand OA or RA may have axonal loss of sensory fibers in the median, ulnar and radial nerves. Less apparent were losses in conduction speed or sensory perception. PMID:22575001

  20. Sensory nerve action potentials and sensory perception in women with arthritis of the hand.

    PubMed

    Calder, Kristina M; Martin, Alison; Lydiate, Jessica; MacDermid, Joy C; Galea, Victoria; MacIntyre, Norma J

    2012-05-10

    Arthritis of the hand can limit a person's ability to perform daily activities. Whether or not sensory deficits contribute to the disability in this population remains unknown. The primary purpose of this study was to determine if women with osteoarthritis (OA) or rheumatoid arthritis (RA) of the hand have sensory impairments. Sensory function in the dominant hand of women with hand OA or RA and healthy women was evaluated by measuring sensory nerve action potentials (SNAPs) from the median, ulnar and radial nerves, sensory mapping (SM), and vibratory and current perception thresholds (VPT and CPT, respectively) of the second and fifth digits. All SNAP amplitudes were significantly lower for the hand OA and hand RA groups compared with the healthy group (p < 0.05). No group differences were found for SNAP conduction velocities, SM, VPT, and CPT. We propose, based on these findings, that women with hand OA or RA may have axonal loss of sensory fibers in the median, ulnar and radial nerves. Less apparent were losses in conduction speed or sensory perception.

  1. ZnO nanorod growth by plasma-enhanced vapor phase transport with different growth durations

    SciTech Connect

    Kim, Chang-Yong; Oh, Hee-bong; Ryu, Hyukhyun; Yun, Jondo; Lee, Won-Jae

    2014-09-01

    In this study, the structural properties of ZnO nanostructures grown by plasma-enhanced vapor phase transport (PEVPT) were investigated. Plasma-treated oxygen gas was used as the oxygen source for the ZnO growth. The structural properties of ZnO nanostructures grown for different durations were measured by scanning electron microscopy, x-ray diffraction, and transmission electron microscopy. The authors comprehensively analyzed the growth of the ZnO nanostructures with different growth durations both with and without the use of plasma-treated oxygen gas. It was found that PEVPT has a significant influence on the growth of the ZnO nanorods. PEVPT with plasma-treated oxygen gas facilitated the generation of nucleation sites, and the resulting ZnO nanorod structures were more vertical than those prepared by conventional VPT without plasma-treated oxygen gas. As a result, the ZnO nanostructures grown using PEVPT showed improved structural properties compared to those prepared by the conventional VPT method.

  2. Quantum chemical calculations and analysis of FTIR, FT-Raman and UV-Vis spectra of temozolomide molecule

    NASA Astrophysics Data System (ADS)

    Bhat, Sheeraz Ahmad; Ahmad, Shabbir

    2015-11-01

    A combined experimental and theoretical study of the structure, vibrational and electronic spectra of temozolomide molecule, which is largely used in the treatment of brain tumours, is presented. FTIR (4000-400 cm-1) and FT-Raman spectra (4000‒50 cm-1) have been recorded and analysed using anharmonic frequency calculations using VPT2, VSCF and CC-VSCF levels of theory within B3LYP/6-311++G(d,p) framework. Anharmonic methods give accurate frequencies of fundamental modes, overtones as well as Fermi resonances and account for coupling of different modes. The anharmonic frequencies calculated using VPT2 and CC-VSCF methods show better agreement with the experimental data. Harmonic frequencies including solvent effects are also computed using IEF-PCM model. The magnitudes of coupling between pair of modes have been calculated using coupling integral based on 2MR-QFF approximation. Intermolecular interactions are discussed for three possible dimers of temozolomide. UV-Vis spectrum, examined in ethanol solvent, is compared with the calculated spectrum at TD-DFT/6-311++G(d,p) level of theory. The electronic properties, such as excitation energy, frontier molecular orbital energies and the assignments of the absorption bands are also discussed.

  3. Near-infrared spectroscopy and anharmonic theory of the H2O(+)Ar1,2 cation complexes.

    PubMed

    Wagner, J Philipp; McDonald, David C; Duncan, Michael A

    2017-09-14

    Weakly bound complexes of the water radical cation with argon (H2O(+)Arn, n = 1,2) were generated by an electrical discharge/supersonic expansion and probed with mid- and near-infrared photodissociation spectroscopy in the 2050-4550 and 4850-7350 cm(-1) regions. To elucidate these spectra, these complexes were studied computationally at the CCSD(T) level including anharmonicity with the VPT2 method. The comparison between experiment and predicted spectra demonstrates that the VPT2 method is adequate to capture most of the vibrational band positions and their intensities. In addition to the fundamentals, overtones of the symmetric and the asymmetric water stretches and their combination were detected. Additional bands were assigned to combinations of the overtone of the bound O-H stretch with multiple excitation levels of the intermolecular Ar-H stretch. H2O(+)Ar2 could not be dissociated in the higher frequency region (4850-7350 cm(-1)).

  4. A new paradigm of electrical stimulation to enhance sensory neural function.

    PubMed

    Breen, Paul P; ÓLaighin, Gearóid; McIntosh, Caroline; Dinneen, Sean F; Quinlan, Leo R; Serrador, Jorge M

    2014-08-01

    The ability to improve peripheral neural transmission would have significant therapeutic potential in medicine. A technology of this kind could be used to restore and/or enhance sensory function in individuals with depressed sensory function, such as older adults or patients with peripheral neuropathies. The goal of this study was to investigate if a new paradigm of subsensory electrical noise stimulation enhances somatosensory function. Vibration (50Hz) was applied with a Neurothesiometer to the plantar aspect of the foot in the presence or absence of subsensory electrical noise (1/f type). The noise was applied at a proximal site, on a defined region of the tibial nerve path above the ankle. Vibration perception thresholds (VPT) of younger adults were measured in control and experimental conditions, in the absence or presence of noise respectively. An improvement of ∼16% in VPT was found in the presence of noise. These are the first data to demonstrate that modulation of axonal transmission with externally applied electrical noise improves perception of tactile stimuli in humans.

  5. Comparison between Positive Dental Images and Neutral Images in Managing Anticipatory Anxiety of Children.

    PubMed

    Kamel, Dalia O; Wahba, Nadia A; Talaat, Dalia M

    To evaluate the impact of positive images versus neutral images on child behavior during dental treatment and their dental anxiety after dental treatment. Sixty, 4 to 6 year old healthy pediatric dental patients, indicated for pulpotomy and stainless steel crown restorations, were divided randomly into two equal groups. Group I (experimental group viewed positive dental images and group II (control group) viewed neutral cartoon images prior to treatment. Behavior was assessed using Frankl rating scale in all four treatment phases: seating, local anesthesia administration, pulpotomy and overall rating. Patient's anxiety was determined according to Venham Picture Test (VPT) before and after dental procedure. Behavior rating using the Frankl scale showed a statistically significant difference in the two groups in the overall rating (P= 0.003, 0.001 respectively). No statistically significant difference was found between both groups in any of the treatment phases (P= 0.288, 0.060, 0.719 respectively) and between the mean VPT scores before and after procedures (P=0.95, 0.93 respectively. Viewing neutral or positive dental images did not have an effect on child's anticipatory anxiety level. However, it is an effective method of improving the behavior in children.

  6. Impact of exposure to positive images on dental anxiety among children: a controlled trial.

    PubMed

    Ramos-Jorge, M L; Ramos-Jorge, J; Vieira de Andrade, R G; Marques, L S

    2011-08-01

    To determine whether exposing children to images of positive dental care would have an effect on their degree of anxiety, assessing anxiety three separate times. Controlled trial. The 70 participants from 4-11 years of age were randomly assigned to one of two conditions. The intervention consisted of viewing positive images of dentistry and dental treatment (n=35). The control condition consisted of dentally neutral images (n=35). Anxiety was assessed using the Venham Picture Test (VPT) prior to the intervention, immediately following the intervention and following the dental appointment. Statistical analysis (chisquare and Mann-Whitney tests) was conducted blind to group allocation. No significant difference was detected between the scores of the VPT in the two groups at any evaluation time (p>0.05). Dental anxiety at the three evaluation times was not correlated to age. There was no difference in level of anxiety between male and female participants (p>0.05). Viewing positive images of dentistry and dentists did not have a greater effect on child anxiety in the dental setting than viewing neutral images, however, showed lower rates of anxiety for all children although this was not significant.

  7. Semi-quartic force fields retrieved from multi-mode expansions: Accuracy, scaling behavior, and approximations

    SciTech Connect

    Ramakrishnan, Raghunathan; Rauhut, Guntram

    2015-04-21

    Semi-quartic force fields (QFF) rely on a Taylor-expansion of the multi-dimensional Born-Oppenheimer potential energy surface (PES) and are frequently used within the calculation of anharmonic vibrational frequencies based on 2nd order vibrational perturbation theory (VPT2). As such they are usually determined by differentiation of the electronic energy with respect to the nuclear coordinates. Alternatively, potential energy surfaces can be expanded in terms of multi-mode expansions, which typically do not require any derivative techniques. The computational effort to retrieve QFF from size-reduced multi-mode expansions has been studied and has been compared with standard Taylor-expansions. As multi-mode expansions allow for the convenient introduction of subtle approximations, these will be discussed in some detail. In addition, a preliminary study about the applicability of a generalized Duschinsky transformation to QFFs is provided. This transformation allows for the efficient evaluation of VPT2 frequencies of isotopologues from the PES of the parent compound and thus avoids the recalculation of PESs in different axes systems.

  8. Quick and Simple Evaluation of Sudomotor Function for Screening of Diabetic Neuropathy

    PubMed Central

    Yajnik, Chittaranjan S.; Kantikar, Vaishali V.; Pande, Amol J.; Deslypere, Jean P.

    2012-01-01

    Objective. The aim of this study was to compare SUDOSCAN, a new device to evaluate sweat function (reflecting peripheral small C-fiber status), with conventional measures of peripheral and cardiac neuropathy in patients with type 2 diabetes. Methods. 265 diabetic patients were tested for symptoms and clinical signs of neuropathy using Michigan Neuropathy Screening Instrument (MNSI), vibration perception threshold (VPT) using biothesiometer, and cardiac autonomic neuropathy (CAN) using Ewing's protocol. Sudomotor function was investigated with SUDOSCAN through measurement of electrochemical skin conductance (ESC) of hands and feet. Lower ESC is suggestive of sudomotor dysfunction. Results. Lower ESC at feet was significantly associated both with increasing symptoms (MNSI A) and increasing score on physical abnormalities (MNSI B). Lower ESC at feet was also significantly associated with increasing VPT by biothesiometry (P < 0.01), and with higher number of abnormal CAN results (P < 0.05). ESC was associated with postural fall in blood pressure (sympathetic abnormality) (P < 0.05), but not with heart rate variability (HRV) tests (parasympathetic abnormalities). Conclusions. Sudomotor dysfunction testing may be a simple test to alert physicians to peripheral nerve and cardiac sympathetic dysfunction. Ease of performance could make it useful in a busy diabetic clinic. Further studies with hard clinical outcomes are indicated. PMID:22830040

  9. Non-contact measurement technique of the vapor pressure of liquid and high temperature solid materials

    NASA Astrophysics Data System (ADS)

    Paradis, P.-F.; Ishikawa, T.; Yoda, S.

    2003-05-01

    Here is reported a new scheme to accurately determine the vapor pressure of undercooled, liquid, and high temperature solid materials. The method relies on an imaging technique that measures the time variation of the radius of an electrostatically levitated sample. This scheme, compared to other techniques, offers unique opportunity to explore not only the liquid above the melting point but also the undercooled states of highly reactive materials in a contamination free environment. This was exemplified in this paper with titanium. For the first time, we report the vapor pressure (V_p) of its liquid phase over a large temperature range, covering the undercooled region. Over the 1700 to 2050 K temperature range, it was measured as Log V_p(T) = 9.154 - 17978 T^{-1} (3%). Similarly, for high temperature solid titanium, the vapor pressure could be expressed as Log V_p(T) = 16.634 - 32960 T^{-1} (6%) over the 1770 to 1940 K temperature interval. From these data, the average latent heats of vaporization and sublimation were calculated respectively as 344.8 kJ/kg (8%) and 632.1 kJ/kg (6%) respectively.

  10. The Effect of Pulse Rate on Vacuum Phototriodes Response and the Use of AN LED Pulser to Improve Stability

    NASA Astrophysics Data System (ADS)

    Leslie, Dawn E.

    2010-04-01

    The Endcap Electromagnetic Calorimeter of the Compact Muon Solenoid detector (CMS) at the Large Hadron Collider (LHC) uses vacuum phototriodes (VPTs), which operate in the full 3.8T magnetic field of the experiment, to detect the scintillation light from the lead tungstate crystals. Initial measurements of the variation in response of VPTs, induced by sudden changes in the illuminating light pulse rate, prompted the inclusion of a dedicated stability pulser based on light emitting diodes (LEOs). The response of production VPTs, under simulated LHC operating conditions, has been investigated in three independent studies: in-situ tests with the installed endcaps at CERN, and separate VPT studies by groups at the University of Virginia, USA and Brunel University, UK. In this work, results are presented which illustrate the magnitude of the effect to demonstrate the expected stability of the VPTs during normal LHC operation, with a proposed regime for operating the stability pulser to minimise variations in response. It is demonstrated that a continuous signal at a rate of 100Hz is sufficient to reduce the change in the VPT response to <0.2%.

  11. Visuospatial working memory in children with autism: the effect of a semantic global organization.

    PubMed

    Mammarella, Irene C; Giofrè, David; Caviola, Sara; Cornoldi, Cesare; Hamilton, Colin

    2014-06-01

    It has been reported that individuals with Autism Spectrum Disorders (ASD) perceive visual scenes as a sparse set of details rather than as a congruent and meaningful unit, failing in the extraction of the global configuration of the scene. In the present study, children with ASD were compared with typically developing (TD) children, in a visuospatial working memory task, the Visual Patterns Test (VPT). The VPT array was manipulated to vary the semantic affordance of the pattern, high semantic (global) vs. low semantic; temporal parameters were also manipulated within the change detection protocol. Overall, there was no main effect associated with Group, however there was a significant effect associated with Semantics, which was further qualified by an interaction between the Group and Semantic factors; there was only a significant effect of semantics in the TD group. The findings are discussed in light of the weak central coherence theory where the ASD group are unable to make use of long term memory semantics in order to construct global representations of the array. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. The effects of cilostazol on peripheral neuropathy in diabetic patients with peripheral arterial disease.

    PubMed

    O'Donnell, Mark E; Badger, Stephen A; Sharif, Muhammed Anees; Makar, Ragai R; Young, Ian S; Lee, Bernard; Soong, Chee V

    Evidence from diabetic animal models suggests that cilostazol, a cyclic AMP phosphodiesterase inhibitor used in the treatment of claudication, is efficacious in the treatment of peripheral neuropathy, although this is unproven in humans. The main aim of this study was to assess the effects of cilostazol on neuropathic symptomatology in diabetic patients with peripheral arterial disease (PAD). Diabetic patients with PAD were prospectively recruited to a randomized double-blinded placebo-controlled trial. Baseline clinical data were recorded prior to trial commencement following medical optimization. Neurological assessment included the Toronto Clinical Neuropathy Scoring system (TCNS) and vibration perception thresholds (VPT) with a neurothesiometer at baseline, 6 weeks, and 24 weeks. Twenty-six patients were recruited from December 2004 to January 2006, which included 20 males. Baseline patient allocation to treatment arms was matched for age, sex, and medical comorbidities. There was no significant difference in neurological assessment between the treatment groups using the TCNS and VPT at 6 and 24 weeks. Despite extensive animal-based evidence that cilostazol attenuates neuropathic symptomatology, our results do not support this effect in human diabetic PAD patients.

  13. [Feeding habits of immature individuals of Ephemeroptera, Plecoptera, and Trichoptera from middle reaches of a tropical mountain stream].

    PubMed

    Guzmán-Soto, Cristian José; Tamarís-Turizo, Cesar Enrique

    2014-04-01

    Morphological and behavioral aspects of insects allow their grouping in trophic guilds and represent their dependence on food resources. We determined the feeding habits of immature organisms of Ephemeroptera, Plecoptera, and Trichoptera (EPT) from the middle reaches of Gaira stream (Sierra Nevada de Santa Marta, Colombia), using gut content analysis. We identified 13 EPT genera, but only ten were analyzed for a total of 100 organisms. We describe six food items: animal parts (AP), vascular plant tissue (VPT), microalgae (M), fungi (F), coarse particulate organic matter (CPOM) and fine particulate organic matter (FPOM). Baetodes was determined to be a collector-scraper, since FPOM represented 46.6% of food content, followed by F (38.4%). Chimarra, Leptohyphes, Lachlania, and Thraulodes were categorized as collectors with average proportions of FPOM 86.8%, 93.1%, 93.1% and 93.7%, respectively. Phylloicus, Smicridea and Leptonema were main consumers of VPT and CPOM with proportions of 76.3%, 54.6%, and 62.4%, respectively; while ratios of FPOM were 22.3%, 38.8%, and 32.9%, respectively. While all are detritivores, Phylloicus is functionally classified as shredders and Smicridea and Leptonema as collectors. Atopsyche and Anacroneuria were the only taxa in which AP were observed in high proportions, 57.9% and 58.2%, respectively, for that reason they were classified as predators. The organisms examined consume a wide variability of resources.

  14. VERY PRETERM BIRTH: MATERNAL EXPERIENCES OF THE NEONATAL INTENSIVE CARE ENVIRONMENT

    PubMed Central

    Woodward, Lianne J.; Bora, Samudragupta; Clark, Caron A. C.; Montgomery-Hönger, Argène; Pritchard, Verena E.; Spencer, Carole; Austin, Nicola C.

    2014-01-01

    Objective Examine sources, predictors, and child outcomes associated with NICU-related stress for mothers of infants born very preterm (VPT). Study Design Participants were 133 mothers of VPT infants admitted to a regional level-III NICU. At term equivalent, mothers completed the Parental Stressor Scale: NICU and were interviewed about their psychological wellbeing and family circumstances. Infant clinical data were also collected. At corrected age 4, 49 children were assessed for cognition, language, and socio-emotional development. Result Mothers reported moderate to low stress, with parental role alteration considered most stressful and parent-staff communications least stressful. Predictors of overall stress included maternal educational underachievement, stressful life events, postnatal depression, and infant unsettled-irregular behavior. NICU-related stress was associated with child anxiety and poorer language development. Conclusion Parental wellbeing is an important focus of care in the neonatal setting. Strategies are needed to optimize early engagement and reduce stress levels to assist improved child outcomes. PMID:24651730

  15. Using Vapor Phase Tomography to Measure the Spatial Distribution of Vapor Concentrations and Flux for Vadose-zone VOC Sources

    PubMed Central

    Mainhagu, J.; Morrison, C.; Brusseau, M.L.

    2015-01-01

    A test was conducted at a chlorinated-solvent contaminated site in Tucson, AZ, to evaluate the effectiveness of vapor-phase tomography (VPT) for characterizing the distribution of volatile organic contaminants (VOC) in the vadose zone. A soil vapor extraction (SVE) system has been in operation at the site since 2007. Vapor concentration and vacuum pressure were measured at four different depths in each of four monitoring wells surrounding the extraction well. The test provided a 3D characterization of local vapor concentrations under induced-gradient conditions. Permeability data obtained from analysis of borehole logs were combined with the vapor-concentration data to determine VOC mass flux within the test domain. A region of higher mass flux was identified in the deepest interval of the S-SW section of the domain, indicating the possible location of a zone with greater contaminant mass. These results are consistent with the TCE-concentration distribution obtained from sediment coring conducted at the site. In contrast, the results of a standard soil gas survey did not indicate the presence of a zone with greater contaminant mass. These results indicate that the VPT test provided a robust characterization of VOC concentration and flux distribution at the site. PMID:25835545

  16. Correlation between plantar foot temperature and diabetic neuropathy: a case study by using an infrared thermal imaging technique.

    PubMed

    Bagavathiappan, Subramnaiam; Philip, John; Jayakumar, Tammana; Raj, Baldev; Rao, Pallela Narayana Someshwar; Varalakshmi, Muthukrishnan; Mohan, Viswanathan

    2010-11-01

    Diabetic neuropathy consists of multiple clinical manifestations of which loss of sensation is most prominent. High temperatures under the foot coupled with reduced or complete loss of sensation can predispose the patient to foot ulceration. The aim of this study was to look at the correlation between plantar foot temperature and diabetic neuropathy using a noninvasive infrared thermal imaging technique. Infrared thermal imaging, a remote and noncontact experimental tool, was used to study the plantar foot temperatures of 112 subjects with type 2 diabetes selected from a tertiary diabetes centre in South India. Patients with diabetic neuropathy (defined as vibration perception threshold (VPT) values on biothesiometry greater than 20 V) had a higher foot temperature (32-35 °C) compared to patients without neuropathy (27-30 °C). Diabetic subjects with neuropathy also had higher mean foot temperature (MFT) (p=.001) compared to non-neuropathic subjects. MFT also showed a positive correlation with right great toe (r=0.301, p=.001) and left great toe VPT values (r=0.292, p=.002). However, there was no correlation between glycated hemoglobin and MFT. Infrared thermal imaging may be used as an additional tool for evaluation of high risk diabetic feet. © 2010 Diabetes Technology Society.

  17. Minocycline improves peripheral and autonomic neuropathy in type 2 diabetes: MIND study.

    PubMed

    Syngle, Ashit; Verma, Inderjeet; Krishan, Pawan; Garg, Nidhi; Syngle, Vijaita

    2014-07-01

    Diabetic peripheral neuropathy and diabetic autonomic neuropathy are serious and common complications of diabetes associated with increased risk of mortality and cardiovascular disease. We sought to evaluate the safety and efficacy of minocycline in type 2 diabetic patients with diabetic peripheral and autonomic neuropathy. In a randomized placebo controlled study, 50 outpatients were randomly assigned to receive 100 mg minocycline or placebo. Outcome measures included the vibration perception threshold (VPT), Leeds assessment of neuropathic symptoms and signs (LANSS), Pain Disability Index (PDI), Visual Analog Scale (VAS), beck depression inventory (BDI), health assessment questionnaire (HAQ) and autonomic neuropathy, assessed by cardiovascular reflex tests according to Ewing and peripheral sympathetic autonomic function was assessed by FDA approved Sudoscan. At baseline there were no significant differences between demographic variables and the neuropathy variables in the minocycline and placebo groups. After treatment, VPT significantly improved in the minocycline group as compared to the placebo group. Mean posttreatment scores on the LANSS, PDI and HAQ were significantly lower in the minocycline group compared with the placebo group. However, BDI and VAS significantly (p = 0.01) improved in both minocycline and placebo groups (Table 2). After treatment with minocycline, heart rate (HR) response to standing significantly improved, while there was a borderline significance toward a reduction in HR response to deep breath. These finding indicate that 6-week oral treatment with minocycline is safe, well tolerated and significantly improves peripheral and autonomic neuropathy in type 2 diabetic patients.

  18. Dysconnectivity of neurocognitive networks at rest in very-preterm born adults☆

    PubMed Central

    White, Thomas P.; Symington, Iona; Castellanos, Nazareth P.; Brittain, Philip J.; Froudist Walsh, Seán; Nam, Kie-Woo; Sato, João R.; Allin, Matthew P.G.; Shergill, Sukhi S.; Murray, Robin M.; Williams, Steve C.R.; Nosarti, Chiara

    2014-01-01

    Advances in neonatal medicine have resulted in a larger proportion of preterm-born individuals reaching adulthood. Their increased liability to psychiatric illness and impairments of cognition and behaviour intimate lasting cerebral consequences; however, the central physiological disturbances remain unclear. Of fundamental importance to efficient brain function is the coordination and contextually-relevant recruitment of neural networks. Large-scale distributed networks emerge perinatally and increase in hierarchical complexity through development. Preterm-born individuals exhibit systematic reductions in correlation strength within these networks during infancy. Here, we investigate resting-state functional connectivity in functional magnetic resonance imaging data from 29 very-preterm (VPT)-born adults and 23 term-born controls. Neurocognitive networks were identified with spatial independent component analysis conducted using the Infomax algorithm and employing Icasso procedures to enhance component robustness. Network spatial focus and spectral power were not generally significantly affected by preterm birth. By contrast, Granger-causality analysis of the time courses of network activity revealed widespread reductions in between-network connectivity in the preterm group, particularly along paths including salience-network features. The potential clinical relevance of these Granger-causal measurements was suggested by linear discriminant analysis of topological representations of connection strength, which classified individuals by group with a maximal accuracy of 86%. Functional connections from the striatal salience network to the posterior default mode network informed this classification most powerfully. In the VPT-born group it was additionally found that perinatal factors significantly moderated the relationship between executive function (which was reduced in the VPT-born as compared with the term-born group) and generalised partial directed coherence

  19. Footwear and foot care knowledge as risk factors for foot problems in Indian diabetics

    PubMed Central

    Chandalia, H. B.; Singh, D.; Kapoor, V.; Chandalia, S. H.; Lamba, P. S.

    2008-01-01

    We assessed 300 diabetic and 100 age- and sex-matched controls for correlating foot wear practices and foot care knowledge and the presence of foot complications. A structured questionnaire evaluated the knowledge about foot care, type of footwear used, education level, association of tobacco abuse, and any associated symptoms of foot disease. Clinical evaluation was done by inspection of feet for presence of any external deformities, assessment of sensory function (vibration perception threshold, VPT), vascular status (foot pulses and ankle brachial ratio) and presence of any infection. In the diabetes category, 44.7% patients had not received previous foot care education. 0.6% walked barefoot outdoors and 45% walked barefoot indoors. Fourteen (4.7%) patients gave history of foot ulceration in the past and comprised the high risk group; only 2 out of 14 had received foot care education, 6 gave history of tobacco abuse, 8 had symptoms of claudication, 9 had paresthesias, 2 walked barefoot indoors. Average duration of diabetes in the high-risk and low-risk diabetes group was 10.85 ± 6.53 and 9.83 ± 7.99 years, respectively. In the high- and low-risk diabetic groups, VPT was 19.57 ± 11.26 and 15.20 ± 10.21V (P < 0.02), ankle brachial ratio was 1.05 ± 0.19 and 1.14 ± 0.18 (P < 0.05), and the questionnaire scores was 40.8% and 57%, respectively. In the diabetic and the control group, VPT was 15.62 ± 10.39 and 8.36 ± 3.61 V (P < 0.01), ankle brachial ratio was 1.14 ± 0.18 and 1.15 ± 0.12, and the questionnaire scores were 57% and 40.3%, respectively. In conclusion, poor knowledge of foot care and poor footwear practices were important risk factors for foot problems in diabetes. PMID:20165597

  20. Long-Acting C-Peptide and Neuropathy in Type 1 Diabetes: A 12-Month Clinical Trial.

    PubMed

    Wahren, John; Foyt, Howard; Daniels, Mark; Arezzo, Joseph C

    2016-04-01

    Lack of C-peptide in type 1 diabetes may be an important contributing factor in the development of microvascular complications. Replacement of native C-peptide has been shown to exert a beneficial influence on peripheral nerve function in type 1 diabetes. The aim of this study was to evaluate the efficacy and safety of a long-acting C-peptide in subjects with type 1 diabetes and mild to moderate peripheral neuropathy. A total of 250 patients with type 1 diabetes and peripheral neuropathy received long-acting (pegylated) C-peptide in weekly dosages of 0.8 mg (n = 71) or 2.4 mg (n = 73) or placebo (n = 106) for 52 weeks. Bilateral sural nerve conduction velocity (SNCV) and vibration perception threshold (VPT) on the great toe were measured on two occasions at baseline, at 26 weeks, and at 52 weeks. The modified Toronto Clinical Neuropathy Score (mTCNS) was used to grade the peripheral neuropathy. Plasma C-peptide rose during the study to 1.8-2.2 nmol/L (low dose) and to 5.6-6.8 nmol/L (high dose). After 52 weeks, SNCV had increased by 1.0 ± 0.24 m/s (P < 0.001 within group) in patients receiving C-peptide (combined groups), but the corresponding value for the placebo group was 1.2 ± 0.29 m/s. Compared with basal, VPT had improved by 25% after 52 weeks of C-peptide therapy (Δ for combined C-peptide groups: -4.5 ± 1.0 μm, placebo group: -0.1 ± 0.9 μm; P < 0.001). mTCNS was unchanged during the study. Once-weekly subcutaneous administration of long-acting C-peptide for 52 weeks did not improve SNCV, other electrophysiological variables, or mTCNS but resulted in marked improvement of VPT compared with placebo. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  1. Exhaust Fan Temperature Switch

    SciTech Connect

    Ball, G.S.; /Fermilab

    1989-05-11

    The 13000 cfm 'emergency' vent fan must be protected from over cooling which would result in a mechanical failure. Over cooling could result from a catastrophic cryogen release from the cryostat(s) or Argon Storage Dewar. In order to protect the fan, a VPT has been calibrated for -31 C to open a switch which sends a signal to allow warm gas to enter the sump by means of a motor controlled louver installed at 'sidewalk level' in the ductwork between the assembly hall and the Argon Dewar Enclosure. The bulb of the VPT is enclosed in a thermal well and will be placed in the gas stream directly above the fan. The switching unit will be mounted nearby on the wall in order to isolate it from vibrational effects. Should the fan be activated due to a cryogen release, it should not experience any problems when operating above -40 C. The switch was set and checked in a saturated calcium chloride solution cooled to -31 C by running cold gaseous Nitrogen through a copper tube coiled in a dewar. Switching temperature was measured by a thermocouple tied to the VPT bulb. The thermocouple was checked in LN2, in an ice water bath, and against an ordinary thermometer (which was assumed to be accurate to plus or minus 0.3 C) at room temperature. The results are shown below in 'Table 1' By interpolation of the data, thermocouple error at -31.0 C was found to be 0.43 C on the warm side. Since this error was small, it was ignored. 'Table 2' shows the results of the tests. Ten readings were taken with the switch wired in the 'normally open' mode. This results in a signal at room temperature. The worst deviation was 2.5 C. Three readings were then taken from the 'normally closed' wiring arrangement (the way it will be wired for installation). The greatest deviation was 1.2 C. The next day, the switch was checked five times wired in the 'normally open' configuration. The greatest error was 1.1 C. A graph has been prepared showing the switching and resetting temperatures. The errors these

  2. Optical sensor based on a single CdS nanobelt.

    PubMed

    Li, Lei; Yang, Shuming; Han, Feng; Wang, Liangjun; Zhang, Xiaotong; Jiang, Zhuangde; Pan, Anlian

    2014-04-23

    In this paper, an optical sensor based on a cadmium sulfide (CdS) nanobelt has been developed. The CdS nanobelt was synthesized by the vapor phase transportation (VPT) method. X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) results revealed that the nanobelt had a hexagonal wurtzite structure of CdS and presented good crystal quality. A single nanobelt Schottky contact optical sensor was fabricated by the electron beam lithography (EBL) technique, and the device current-voltage results showed back-to-back Schottky diode characteristics. The photosensitivity, dark current and the decay time of the sensor were 4 × 10⁴, 31 ms and 0.2 pA, respectively. The high photosensitivity and the short decay time were because of the exponential dependence of photocurrent on the number of the surface charges and the configuration of the back to back Schottky junctions.

  3. A new Gaussian MCTDH program : implementation and validation on the levels of the water and glycine molecules

    PubMed Central

    Skouteris, D.; Barone, V.

    2015-01-01

    We report the main features of a new general implementation of the Gaussian Multi-Configuration Time-Dependent Hartree (G-MCTDH) model. The code allows effective computations of time-dependent phenomena, including calculation of vibronic spectra (in one or more electronic states), relative state populations etc. Moreover, by expressing the Dirac-Frenkel variational principle in terms of an effective Hamiltonian we are able to provide a new reliable estimate of the representation error. After validating the code on simple one-dimensional systems, we analyze the harmonic and anharmonic vibrational spectra of water and glycine showing that reliable and converged energy levels can be obtained with reasonable computing resources. The data obtained on water and glycine are compared with results of previous calculations using the vibrational second-order perturbation theory (VPT2) method. Additional features and perspectives are also shortly discussed. PMID:24985615

  4. Optical Properties of ZnO Soccer-Ball Structures Grown by Vapor Phase Transport

    NASA Astrophysics Data System (ADS)

    Nam, Giwoong; Lee, Sang-heon; Kim, Soaram; Kim, Min Su; Kim, Do Yeob; Gug Yim, Kwang; Lee, Dong-Yul; Kim, Jin Soo; Kim, Jong Su; Son, Jeong-Sik; Kim, Sung-O.; Jung, Jae Hak; Leem, Jae-Young

    2012-02-01

    ZnO soccer balls were grown on an Au-catalyzed Si(100) substrate by vapor phase transport (VPT) with a mixture of zinc oxide and graphite powders. Temperature-dependent PL was carried out to investigate the mechanism governing the quenching behavior of the PL spectra. From the PL spectra of the ZnO soccer balls at 10 K, several PL peaks were observed at 3.365, 3.318, 3.249, and 3.183 eV corresponding to excitons bound to neutral donors (DoX), a donor-acceptor pair (DAP), first-order longitudinal optical phonon replica of donor-acceptor pair (DAP-1LO), and DAP-2LO, respectively. The mixed system composed of the free exciton (FX) and DoX and the DAP radiative lifetimes were estimated with a theoretical relation between the lifetime and the spectral width. The exciton radiative lifetimes were observed to increase linearly with temperature.

  5. UV light sensing properties of Sm doped vertically aligned ZnO nanorod arrays

    SciTech Connect

    Kumar, D. Ranjith; Ranjith, K. S.; Rajendrakumar, R. T.

    2015-06-24

    Samarium doped ZnO nanorods were grown on silicon substrate by using vapor phase transport method (VPT) with the growth temperature of 950°C. The synthesized nanorods were characterized by XRD, field emission scanning electron microscopy, Raman spectra, and photocurrent measurements. The XRD result revealed that Sm was successfully doped into lattice plane of hexagonal ZnO nanorods. The FESEM result confirms the pure ZnO has nanorod like morphology with an average diameter and length of 130nm and 10µm respectively. The above observation is supported by the Micro-Raman spectroscopy result. The photocurrent in the visible region has been significantly enhanced due to deposition of Sm on the surface of the ZnO nanorods. Sm acts as a visible sensitizer because of its lower band gap compared to ZnO.

  6. Molecular structure and vibrational analysis of 5-nitro-6-methyluracil molecule based on monomer, dimer and trimer calculations

    NASA Astrophysics Data System (ADS)

    Alam, M. J.; Bhat, S. A.; Ahmad, S.

    2016-05-01

    Molecular structure and vibrational spectra of 5-nitro-6-methyluracil molecule have been studied by the simulation of its monomer, dimer and trimer forms using DFT and MP2 methods with 6-311G(d,p) basis set. Anharmonic force field calculations have been carried out for the isolated monomer, while the calculations on dimer and trimer have been done in the harmonic approximation. An accurate numerical integration grid has been used for geometry optimization as well as frequency calculation. Anharmonic vibrational frequencies have been computed using VPT2 algorithm (Barone's method) as well as VSCF and VSCF-PT2 approaches. These methods yield results that are in remarkable agreement with the experiment. The coupling strengths between pair of modes have been also calculated using coupling integral based on 2MR-QFF approximation. The vibrational assignments have been made with the help of potential energy distribution values and animated modes.

  7. Editorial Conference Comments by the General Chair

    NASA Astrophysics Data System (ADS)

    Reed, Robert A.

    2017-01-01

    The 53rd IEEE Nuclear and Space Radiation Effects Conference (NSREC) was held July 11-15, 2016, at the Oregon Convention Center in Portland; the conference hotel was the Portland Doubletree. The NSREC is recognized as one of the premier international conferences on radiation effects in electronic materials, devices, and systems. The 2016 conference continued this tradition with a strong technical program, a one-day tutorial short course, radiation effects data workshop, industrial exhibit, and meetings for the IEEE Women in Engineering and Young Professionals organizations. The conference was sponsored by the Radiation Effects Committee of the IEEE Nuclear and Plasma Sciences Society (NPSS), and supported by Atmel, BAE Systems, Boeing, Cobham Semiconductor Solutions, Freebird Semiconductor, Honeywell, International Rectifier, Intersil Corporation, Jet Propulsion Laboratory, Northrop Grumman, Southwest Research Institute, and VPT Rad.

  8. Phosgene at the complete basis set limit of CCSDT(Q): Molecular structure and rovibrational analysis

    NASA Astrophysics Data System (ADS)

    Murphy, Kevin V.; Schaefer, Henry F.; Agarwal, Jay

    2017-09-01

    The ground-state (X∼1A″) equilibrium geometry of phosgene is examined with coupled-cluster theory, using derivatives extrapolated to the complete basis set (CBS) limit of CCSDT(Q). The C-O and C-Cl bond lengths are predicted to be 1.1768 Å and 1.7374 Å, respectively; the Cl-C-Cl bond angle is 124.03° and the O-C-Cl bond angle is 111.93°. Anharmonic frequencies are determined with VPT2, using CCSD(T)/cc-pCVQZ cubic and quartic force-fields and a CCSDT(Q)/CBS quadratic force field: ν1 = 1832.9 ; ν2 = 570.5 ; ν3 = 301.2 ; ν4 = 576.3 ; ν5 = 849.4 ; and ν6 = 438.9 cm-1.

  9. Fully anharmonic IR and Raman spectra of medium-size molecular systems: accuracy and interpretation†

    PubMed Central

    Barone, Vincenzo; Biczysko, Malgorzata; Bloino, Julien

    2015-01-01

    Computation of full infrared (IR) and Raman spectra (including absolute intensities and transition energies) for medium- and large-sized molecular systems beyond the harmonic approximation is one of the most interesting challenges of contemporary computational chemistry. Contrary to common beliefs, low-order perturbation theory is able to deliver results of high accuracy (actually often better than those issuing from current direct dynamics approaches) provided that anharmonic resonances are properly managed. This perspective sketches the recent developments in our research group toward the development a robust and user-friendly virtual spectrometer rooted into the second-order vibrational perturbation theory (VPT2) and usable also by non-specialists essentially as a black-box procedure. Several examples are explicitly worked out in order to illustrate the features of our computational tool together with the most important ongoing developments. PMID:24346191

  10. Ab Initio Effective Rovibrational Hamiltonians for Non-Rigid Molecules via Curvilinear VMP2

    NASA Astrophysics Data System (ADS)

    Changala, Bryan; Baraban, Joshua H.

    2017-06-01

    Accurate predictions of spectroscopic constants for non-rigid molecules are particularly challenging for ab initio theory. For all but the smallest systems, ``brute force'' diagonalization of the full rovibrational Hamiltonian is computationally prohibitive, leaving us at the mercy of perturbative approaches. However, standard perturbative techniques, such as second order vibrational perturbation theory (VPT2), are based on the approximation that a molecule makes small amplitude vibrations about a well defined equilibrium structure. Such assumptions are physically inappropriate for non-rigid systems. In this talk, we will describe extensions to curvilinear vibrational Møller-Plesset perturbation theory (VMP2) that account for rotational and rovibrational effects in the molecular Hamiltonian. Through several examples, we will show that this approach provides predictions to nearly microwave accuracy of molecular constants including rotational and centrifugal distortion parameters, Coriolis coupling constants, and anharmonic vibrational and tunneling frequencies.

  11. Optical Sensor Based on a Single CdS Nanobelt

    PubMed Central

    Li, Lei; Yang, Shuming; Han, Feng; Wang, Liangjun; Zhang, Xiaotong; Jiang, Zhuangde; Pan, Anlian

    2014-01-01

    In this paper, an optical sensor based on a cadmium sulfide (CdS) nanobelt has been developed. The CdS nanobelt was synthesized by the vapor phase transportation (VPT) method. X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) results revealed that the nanobelt had a hexagonal wurtzite structure of CdS and presented good crystal quality. A single nanobelt Schottky contact optical sensor was fabricated by the electron beam lithography (EBL) technique, and the device current-voltage results showed back-to-back Schottky diode characteristics. The photosensitivity, dark current and the decay time of the sensor were 4 × 104, 31 ms and 0.2 pA, respectively. The high photosensitivity and the short decay time were because of the exponential dependence of photocurrent on the number of the surface charges and the configuration of the back to back Schottky junctions. PMID:24763211

  12. Genetic regulation of human immunodeficiency virus.

    PubMed Central

    Steffy, K; Wong-Staal, F

    1991-01-01

    Human immunodeficiency virus (HIV) has a complex life cycle in which both cellular and virus-encoded factors participate to determine the level of virus production. Two of the viral genes, tat and rev, are essential for virus replication and encode novel trans-activators that interact specifically with their cognate RNA target elements. Elucidation of their mechanisms of action is likely to expand our knowledge of gene regulation at transcriptional and posttranscriptional levels in the eukaryotic cell. Several viral genes (vif, vpu, and vpr) facilitate virus infection and/or release and may play a role in target cell tropism and infection in vivo. The functions of yet other viral genes (nef, vpt) remain unclear. Recent data also suggest that the tat gene product may have a role in HIV pathogenesis that goes beyond trans-activating virus expression. It can potentially impact on uninfected cells as a diffusible molecule and alter the growth of different cell types. PMID:1886517

  13. Structural investigation of thermo-responsive poly(2-isopropyl-2-oxazoline) hydrogel across the volume phase transition.

    PubMed

    Li, Tianjiao; Tang, Hui; Wu, Peiyi

    2015-03-14

    The deswelling and swelling behaviors of poly(2-isopropyl-2-oxazoline)-based hydrogel synthesized by a one-pot microwave-assisted solvent-free reaction were investigated. A distinct hydrophobic collapse of the hydrogel compared with the corresponding aqueous solution was observed by FT-IR spectroscopy combined with two-dimensional correlation spectroscopy (2DCOS) and perturbation-correlation moving-window (PCMW) analyses. The volume phase transition (VPT) temperature of 35 °C during heating and the transition temperature range of 41-30 °C during cooling were determined, indicating different dynamic transition mechanisms during heating and cooling. Water expulsion starting from the benzene ring-centered hydrophobic spots to the surroundings was revealed during deswelling. However, during swelling, although the rebuilding of cross-linking hydrogen bond bridges provided a channel-like microstructure to reswell the hydrogel gradually, a slow, unusual recovery of the amide hydrogen bonds to water molecules was observed.

  14. Phosphate Uptake and Allocation – A Closer Look at Arabidopsis thaliana L. and Oryza sativa L.

    PubMed Central

    Młodzińska, Ewa; Zboińska, Magdalena

    2016-01-01

    This year marks the 20th anniversary of the discovery and characterization of the two Arabidopsis PHT1 genes encoding the phosphate transporter in Arabidopsis thaliana. So far, multiple inorganic phosphate (Pi) transporters have been described, and the molecular basis of Pi acquisition by plants has been well-characterized. These genes are involved in Pi acquisition, allocation, and/or signal transduction. This review summarizes how Pi is taken up by the roots and further distributed within two plants: A. thaliana and Oryza sativa L. by plasma membrane phosphate transporters PHT1 and PHO1 as well as by intracellular transporters: PHO1, PHT2, PHT3, PHT4, PHT5 (VPT1), SPX-MFS and phosphate translocators family. We also describe the role of the PHT1 transporters in mycorrhizal roots of rice as an adaptive strategy to cope with limited phosphate availability in soil. PMID:27574525

  15. Chronic pain has a small influence and mood has no influence on vibrotactile perception thresholds among working women

    PubMed Central

    Sandén, Helena; Wallin, B Gunnar; Hagberg, Mats

    2010-01-01

    In chronic diffuse upper limb pain physical abnormalities are usually absent. The aims of our study were to investigate: (1) the function of somatosensory pathways and (2) the influence of mood on vibration perception. Measurements were made of: (i) vibrotactile perception thresholds (VPTs) and nerve conduction in working women with (n = 35) and without (n = 65) chronic diffuse upper limb pain, and (ii) perceived stress and energy using a two-dimensional mood adjective checklist. The groups did not differ in any nerve conduction measurements. Women with chronic pain had raised VPTs in the radial and ulnar nerve areas, but not in the median nerve area. Neither perceived stress nor energy appeared to influence the VPT. Increases of VPTs in chronic diffuse upper limb pain may be due to peripheral nerve affliction, but our findings support the idea that they may also be secondary to pain and may be related to a central nervous mechanism. Muscle Nerve, 2010 PMID:20564595

  16. Realizations of the ITS-90 below 24.5561 K at NMIJ/AIST

    SciTech Connect

    Tamura, O.; Nakano, T.; Shimazaki, T.; Takasu, S.

    2013-09-11

    The International Temperature Scale of 1990 (ITS-90) down to its defined minimum temperature of 0.65 K has been realized at the National Metrology Institute of Japan (NMIJ), using a {sup 3}He vapor pressure thermometer (VPT) from 0.65 K to 3.2 K, a {sup 4}He VPT from 2.2 K to 4.2 K, an interpolating constant-volume gas thermometer (ICVGT) from 3 K to 24.5561 K and standard platinum resistance thermometers (SPRTs) above 13.8803 K. The scales realized by these different thermometers in the overlapped temperature ranges differ among each other. These differences, also known as the non-uniqueness of the ITS-90, are estimated and reported in this paper. The difference between the scales of the SPRTs and ICVGT has a maximum of about 0.6 mK at temperatures close to 15 K, though it is about half of the propagation of the calibration uncertainties of the SPRT at the fixed points. The difference between the vapor pressure scales of {sup 4}He and {sup 3}He shows temperature dependence, which is consistent with that reported previously and has a maximum of about 0.2 mK at temperatures close to 3.1 K. The differences between the ICVGT scales with different lowest calibration temperatures are also estimated. The difference between the ICVGT scales with or without corrections for the aerostatic pressure head, the dead-space volume effect and the thermomolecular pressure difference has a maximum of about 0.17 mK.

  17. The utility of affinity-tags for detection of a streptococcal protein from a variety of streptococcal species

    PubMed Central

    Zhou, Meixian; Fives-Taylor, Paula; Wu, Hui

    2008-01-01

    There is no systematic examination of affinity tag utility in Gram-positive bacteria, which limits the investigation of protein function in this important group of bacteria as specific antibodies for many of native proteins are generally not available. In this study, we utilized an E. coli-streptococcal shuttle vector pVT1666 and constructed two sets of expression plasmids pVPT-CTag and pVPT-NTag, with each set containing five affinity tags (GST, GFP, HSV, T7 and Nano) that can be fused to either the C- or N-terminus of a target protein. A putative glycosyltransferase (Gtf2) essential for Fap1 glycosylation was used to demonstrate the utility of the cassettes in detection of Gtf2 fusion proteins, and the biological relevance of the proteins in our working strain Streptococcus parasanguinis. GFP and T7 tags were readily expressed in S. parasanguinis as either an N- or C-terminal fusion to Gtf2. Only the C- terminal fusion of GST and HSV were able to be identified in S. parasanguinis. The Nano tag was not detected in either E. coli or S. parasanguinis. Genetic complementation experiments indicated that all the tagged Gtf2 fusion proteins could restore the Gtf2 function in the null mutant except for the Nano-tagged Gtf2 at its N-terminal fusion. Using a T7-tagged Gtf2 fusion construct, we demonstrated that the fusion cassette is also useful in detection of the fusion tag expression in other streptococci including S. mutans, S. pneumoniae and S. sanguinis. Therefore, the expression cassettes we constructed will be a useful tool not only to investigate protein-protein interactions in Fap1 biogenesis in S. parasanguinis, but also to study protein functions in other gram-positive bacteria in which pVT1666 replicates. PMID:18201786

  18. Preschool self regulation predicts later mental health and educational achievement in very preterm and typically developing children.

    PubMed

    Woodward, Lianne J; Lu, Zhigang; Morris, Alyssa R; Healey, Dione M

    2017-02-01

    To examine the extent to which preschool emotional and behavioral regulatory difficulties were associated with an increased risk of later mental health and educational problems. Of particular interest was whether early regulatory abilities contributed to later risk once baseline child behavioral adjustment and cognitive function were taken into account. Data were drawn from a prospective longitudinal study of 223 children born very preterm (VPT; <32 weeks gestation, n = 110) and full term (37-40 weeks gestation). At corrected ages 2 and 4 years, children's regulatory abilities were assessed using (1) direct observation of child behavior, (2) a modified version of the Emotion Regulation Checklist, and (3) tester ratings of child behavior during neuropsychological testing. At age 9 years, mental health and educational achievement were assessed using the Development and Well-being Assessment interview and the Woodcock Johnson-III Tests of Achievement. VPT-born children had poorer emotional and behavioral regulation across all measures and time points. They also had higher rates of DSM-IV mental health disorder and educational delay at age 9. Across both study groups, poorer self regulation was associated with an increased risk of ADHD, conduct disorder, anxiety disorders and any disorder net of preschool child behavior problems and social risk. In contrast, only associations between early regulation and later language and any educational delay remained significant after adjustment for preschool cognitive functioning and family social risk. Early assessment of regulation in addition to behavioral screening may improve the early identification of preschool children at mental health risk.

  19. Validation of the nerve axon reflex for the assessment of small nerve fibre dysfunction

    PubMed Central

    Caselli, A; Spallone, V; Marfia, G A; Battista, C; Pachatz, C; Veves, A; Uccioli, L

    2006-01-01

    Objective To validate nerve–axon reflex‐related vasodilatation as an objective method to evaluate C‐nociceptive fibre function by comparing it with the standard diagnostic criteria. Methods Neuropathy was evaluated in 41 patients with diabetes (26 men and 15 women) without peripheral vascular disease by assessing the Neuropathy Symptom Score, the Neuropathy Disability Score (NDS), the vibration perception threshold (VPT), the heat detection threshold (HDT), nerve conduction parameters and standard cardiovascular tests. The neurovascular response to 1% acetylcholine (Ach) iontophoresis was measured at the forearm and at both feet by laser flowmetry. An age‐matched and sex‐matched control group of 10 healthy people was also included. Results Significant correlations were observed between the neurovascular response at the foot and HDT (rs = −0.658; p<0.0001), NDS (rs = −0.665; p<0.0001), VPT (rs = −0.548; p = 0.0005), tibial nerve conduction velocity (rs = 0.631; p = 0.0002), sural nerve amplitude (rs = 0.581; p = 0.0002) and autonomic function tests. According to the NDS, in patients with diabetes who had mild, moderate or severe neuropathy, a significantly lower neurovascular response was seen at the foot than in patients without neuropathy and controls. A neurovascular response <50% was found to be highly sensitive (90%), with a good specificity (74%), in identifying patients with diabetic neuropathy. Conclusion Small‐fibre dysfunction can be diagnosed reliably with neurovascular response assessment. This response is already reduced in the early stages of peripheral neuropathy, supporting the hypothesis that small‐fibre impairment is an early event in the natural history of diabetic neuropathy. PMID:16624842

  20. Premature delivery influences the immunological composition of colostrum and transitional and mature human milk.

    PubMed

    Castellote, Cristina; Casillas, Rosario; Ramírez-Santana, Carolina; Pérez-Cano, Francisco J; Castell, Margarida; Moretones, M Glòria; López-Sabater, M Carmen; Franch, Angels

    2011-06-01

    Human breast milk is the ideal nutrition for the newborn, and in addition to its nutritional contribution, necessary for infant growth and development, it contains various immune bioactive factors that confer some of the numerous beneficial effects of breastfeeding. The current study analyzed the concentrations of IgA, growth factors such as epidermal growth factor (EGF), TGFβ1, and TGFβ2, cytokines IL-6, IL-8, IL-10, IL-13, and TNFα, and TNF-receptor I (TNF-RI) in colostrum and transitional and mature milk from mothers with mature, premature, and very premature infants. Human milk samples were collected from mothers delivering at term (T), preterm (PT), and very preterm (VPT). Milk from all the mothers was collected at 3 different time points after delivery corresponding to colostrum and transitional and mature milk. After obtaining milk whey, IgA, EGF, TGFβ1, and TGFβ2 were determined by ELISA and IL-6, IL-8, IL-10, IL-13, TNFα and TNF-RI by cytometric bead array immunoassay. The colostrum of the PT group was extremely rich in most of the factors studied, but higher concentrations than in the T group were only found for IL-6 (P = 0.051), TGFβ1, and TGFβ2 (P < 0.05). Conversely, the colostrum of the VPT group had lower concentrations of IgA, IL-8, IL-10, and TNFα than those in the T group (P < 0.05). Results suggest that maternal lactogenic compensatory mechanisms accelerating the development of immature breast-fed preterm infants may take effect only after wk 30 of gestation.

  1. Comparison of the effects of cognitive behavioural therapy and inhalation sedation on child dental anxiety.

    PubMed

    Kebriaee, F; Sarraf Shirazi, A; Fani, K; Moharreri, F; Soltanifar, A; Khaksar, Y; Mazhari, F

    2015-04-01

    To compare the effectiveness of inhalation sedation with nitrous oxide/oxygen (N2O/O2) and cognitive behavioural therapy (CBT) in reducing dental anxiety in preschool children. Randomised controlled clinical trial. This study was conducted on 45 preschoolers with moderate to severe dental anxiety (determined by the Children's Fear Survey Schedule Dental Subscale), who required pulp treatment of at least one primary mandibular molar. Baseline anxiety and cooperation levels were determined using Venham Clinical Anxiety and Cooperation Scales (VCAS and VCCS) and Venham Picture Test (VPT) at the first dental visit (dental prophylaxis and fluoride treatment). Before the second dental visit (pulp treatment), the children were randomly assigned to one of three groups--1: control, 2: N(2)O/O(2) and 3: CBT. In group 1, the usual behaviour management techniques were used, in group 2, nitrous oxide/oxygen gas was used and in group 3, unrelated play, Benson's breathing and positive self-talk and modelling were used. Anxiety and cooperation levels were determined at three periods: injection, rubber dam placement and the application of a high-speed handpiece with VCAS and VCCS and VPT. Finally, anxiety and cooperation differences between the two dental visits were compared within the three groups. Chi square, ANOVA and Kruskal-Wallis and Mann-Whitney U tests were used. N(2)O/O(2) and CBT significantly resulted in lower anxiety and higher cooperation in the second visit (at all three periods) compared to the control, although there was no significant difference between these two treatment methods. Both test methods were effective in reducing dental anxiety in preschoolers. Considering the adverse effects and necessity of equipment and trained personnel when using nitrous oxide and oxygen inhalation sedation, cognitive behavioural therapy is preferable because of its better applicability.

  2. Effect of Exposure to Positive Images of Dentistry on Dental Anxiety among 7 to 12 Years Old Children.

    PubMed

    Gangwal, Rini Rajendra; Rameshchandra Badjatia, Sourabh; Harish Dave, Bhavna

    2014-01-01

    To evaluate the effect of exposure to positive images of dentistry on dental anxiety among 7 to 12 years old children. Controlled trial. Assessment of anxiety and analysis of data were conducted blind to experimental condition. Assessment of anxiety was carried out in the waiting room prior intervention, postintervention into the operatory during the treatment and again after the completion of treatment. Anticipatory anxiety was recorded by Venham's picture test (VPT). Sixty children of 7 to 12 years age group. PARTICIPANTS were randomly assigned to one of two conditions. In both conditions the participant was asked to look at photographs for 2 minutes in the waiting area prior to their appointment. The intervention consisted of viewing positive images of dentistry and dental treatment (study group), the (control group) consisted of neutral images. The assessment of anticipatory dental anxiety was made blind to experimental condition and statistical analysis was conducted blind to group membership. Anticipatory anxiety assessed by the VP T. A total of 60 subjects participated in the study and were equally and randomly allotted to study group (positive image) and control group (neutral image). The mean anxiety score found at waiting area before intervention, after intervention (OPD) and postoperative was statistically significant in study group. Post hoc comparison of anxiety score in study group showed high statistical significance. Positive dental images have an effect on reducing anxiety as compared to neutral images when measured by the VPT. How to cite this article: Gangwal RR, Badjatia SR, Dave BH. Effect of Exposure to Positive Images of Dentistry on Dental Anxiety among 7 to 12 Years Old Children. Int J Clin Pediatr Dent 2014;7(3):176 -179.

  3. Contrast sensitivity and its determinants in people with diabetes: SN-DREAMS-II, Report No 6.

    PubMed

    Gella, L; Raman, R; Pal, S S; Ganesan, S; Sharma, T

    2017-03-01

    PurposeTo assess contrast sensitivity (CS) and to elucidate the factors associated with CS among subjects with type 2 diabetes in a cross-sectional population-based study.Patients and methodsSubjects were recruited from a follow-up cohort, Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular genetics Study (SN-DREAMS II). Of 958 subjects who were followed up in SN-DREAMS II, a subset of 653 subjects was included in the analysis. All subjects underwent a comprehensive eye examination, which included CS assessment using the Pelli-Robson chart. The cross-sectional association between CS and independent variables was assessed using stepwise linear regression analysis. A P-value of <0.05 was considered statistically significant.ResultsThe mean age of the study sample was 58.7±9.41 (44-87) years. Mean CS of the study sample was 1.32±0.20 (range: 0-1.65) log units. CS was negatively and significantly correlated with age, duration of diabetes, hemoglobin level, vibration perception threshold (VPT) value, albuminuria, best corrected visual acuity (BCVA), refractive error, total error score (TEM) of FM 100 hue test, and mean retinal sensitivity. In multiple regression analysis, after adjusting for all the related factors, CS was significantly associated with BCVA (β=-0.575; P<0.001), VPT (β=-0.003; P=0.010), severity of cataract (β=-0.018; P=0.032), diabetic retinopathy (β=-0.016; P=0.019), and age (β=-0.002; P=0.029). These factors explained about 29.3% of the variation in CS.ConclusionAmong the factors evaluated, differences in BCVA were associated with the largest predicted differences in CS. This association of CS with visual acuity highlights the important role of visual assessment in type 2 diabetes.

  4. D0 Silicon Upgrade: Vapor Pressure Thermometry System Near LN2 Subcooler

    SciTech Connect

    Kuwazaki, Andrew; /Fermilab

    1996-07-01

    Fermi National Accelerator Laboratory (Fermilab) is in the process of upgrading its detectors. Among these upgrades is the need for more transfer lines containing both liquid nitrogen and helium gas. These two fluids are used to provide the necessary operating cryogenic temperatures for the various detectors, such as the Visible Light Photon Counter (VLPC) and the solenoid inside the detector's calorimeter. With additional piping, it is important to monitor the temperatures to assure that the detectors can operate correctly. This can be done two ways. The first method is to use a Resistance Temperature Device, called a RTD, which is made using either a carbon resistor or a platinum resistor and measures the temperature based on resistance. The second method is to use a vapor-pressure thermometry system. This design will focus on the second method. A nitrogen Vapor Pressure Thermometer (VPT) system is designed to determine the temperature of the liquid nitrogen (LN{sub 2}) supply line, after exiting the LN{sub 2} subcooler, inside the D-Zero Assembly Hall. The operating temperature range is designed from 77 to 300 Kelvin with an initial charge pressure of 100 psia. A cylindrical bulb with a 0.1875-inch diameter and 0.625-inch length allows for minimum cold and warm 1/4-inch O.D. SS 304L tubing lengths, 12-inch and 18-inch respectively, and maintains a liquid level of 50% inside the bulb during cold operation. The amount of nitrogen needed to fill the cylindrical bulb approximately half full is 0.149 grams. In order to conform to the conventional cold volume and warm volume VPT systems, we need to enlarge the existing 1/2-inch x 2-inch SCH. 10 LN{sub 2} supply line over a one foot section to 1-inch x 3-inch SCH. 10 piping.

  5. Thresholds of skin sensitivity are partially influenced by mechanical properties of the skin on the foot sole

    PubMed Central

    Strzalkowski, Nicholas D J; Triano, John J; Lam, Chris K; Templeton, Cale A; Bent, Leah R

    2015-01-01

    Across the foot sole, there are vibration and monofilament sensory differences despite an alleged even distribution of cutaneous afferents. Mechanical property differences across foot sole sites have been proposed to account for these differences. Vibration (VPT; 3 Hz, 40 Hz, 250 Hz), and monofilament (MF) perception threshold measurements were compared with skin hardness, epidermal thickness, and stretch response across five foot sole locations in young healthy adults (n = 22). Perceptual thresholds were expected to correlate with all mechanical property measurements to help address sensitivity differences between sites. Following this hypothesis, the MedArch was consistently found to be the thinnest and softest site and demonstrated the greatest sensitivity. Conversely, the Heel was found to be the thickest and hardest site, and was relatively insensitive across perceptual tests. Site differences were not observed for epidermal stretch response measures. Despite an apparent trend of elevated sensory threshold at harder and thicker sites, significant correlations between sensitivity measures and skin mechanical properties were not observed. Skin hardness and epidermal thickness appeared to have a negligible influence on VPT and minor influence on MF within this young healthy population. When normalized (% greater or smaller than subject mean) to the subject mean for each variable, significant positive correlations were observed between MF and skin hardness (R2 = 0.422, P < 0.0001) and epidermal thickness (R2 = 0.433, P < 0.0001) providing evidence that skin mechanics can influence MF threshold. In young healthy adults, differences in sensitivity are present across the foot sole, but cannot solely be accounted for by differences in the mechanical properties of the skin. PMID:26059035

  6. Realizations of the ITS-90 below 24.5561 K at NMIJ/AIST

    NASA Astrophysics Data System (ADS)

    Tamura, O.; Nakano, T.; Shimazaki, T.; Takasu, S.

    2013-09-01

    The International Temperature Scale of 1990 (ITS-90) down to its defined minimum temperature of 0.65 K has been realized at the National Metrology Institute of Japan (NMIJ), using a 3He vapor pressure thermometer (VPT) from 0.65 K to 3.2 K, a 4He VPT from 2.2 K to 4.2 K, an interpolating constant-volume gas thermometer (ICVGT) from 3 K to 24.5561 K and standard platinum resistance thermometers (SPRTs) above 13.8803 K. The scales realized by these different thermometers in the overlapped temperature ranges differ among each other. These differences, also known as the non-uniqueness of the ITS-90, are estimated and reported in this paper. The difference between the scales of the SPRTs and ICVGT has a maximum of about 0.6 mK at temperatures close to 15 K, though it is about half of the propagation of the calibration uncertainties of the SPRT at the fixed points. The difference between the vapor pressure scales of 4He and 3He shows temperature dependence, which is consistent with that reported previously and has a maximum of about 0.2 mK at temperatures close to 3.1 K. The differences between the ICVGT scales with different lowest calibration temperatures are also estimated. The difference between the ICVGT scales with or without corrections for the aerostatic pressure head, the dead-space volume effect and the thermomolecular pressure difference has a maximum of about 0.17 mK.

  7. Spontaneous Reinnervation of Deep Inferior Epigastric Perforator Flaps after Delayed Breast Reconstruction.

    PubMed

    Stromps, Jan-Philipp; Bozkurt, Ahmet; Grieb, Gerrit; Kim, Bong-Sung; Wiezik, Martyna; Pallua, Norbert

    2016-03-01

    The spontaneous reinnervation of free flaps, such as deep inferior epigastric perforator (DIEP) flaps, is not fully understood, and few publications have investigated this issue. The aim of this study was to examine spontaneous reinnervation following breast reconstruction with autologous DIEP flaps without an additional nerve transfer. In a retrospective clinical study, 18 female patients were investigated for a mean of 49.59 months (range, 12-88 months) following breast reconstruction with a unilateral DIEP flap. Five sensory modalities were tested: pressure perception, dynamic two-point discrimination, sharp-blunt discrimination, hot and cold discrimination, and vibration perception threshold (VPT). The measurements were performed on the reconstructed breast, flap surrounding transition zone, healthy contralateral breast, and the donor site. For a more precise analysis all breasts have been divided into five different segments (mediocranial, laterocranial, mediocaudal, laterocaudal, and reconstructed nipple-areola complex, if present). Additionally, tissue oxygen saturation and tissue hemoglobin were measured by laser Doppler spectroscopy. Spontaneous reinnervation of at least one modality tested was observed in all DIEP flaps (n = 18). This sensitive recovery increases over the postoperative period. The maximum difference between the controls and DIEP flaps was observed in cold perception, whereas the least difference was observed in the VPT. Regarding the different segments, we observed better sensitive recovery in the cranial parts of the DIEP flaps and the transition zone. This study provides certain predictions for patients and surgeons, when and to which extent spontaneous reinnervation can be expected. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  8. Effectiveness and Comparison of Various Audio Distraction Aids in Management of Anxious Dental Paediatric Patients.

    PubMed

    Navit, Saumya; Johri, Nikita; Khan, Suleman Abbas; Singh, Rahul Kumar; Chadha, Dheera; Navit, Pragati; Sharma, Anshul; Bahuguna, Rachana

    2015-12-01

    Dental anxiety is a widespread phenomenon and a concern for paediatric dentistry. The inability of children to deal with threatening dental stimuli often manifests as behaviour management problems. Nowadays, the use of non-aversive behaviour management techniques is more advocated, which are more acceptable to parents, patients and practitioners. Therefore, this present study was conducted to find out which audio aid was the most effective in the managing anxious children. The aim of the present study was to compare the efficacy of audio-distraction aids in reducing the anxiety of paediatric patients while undergoing various stressful and invasive dental procedures. The objectives were to ascertain whether audio distraction is an effective means of anxiety management and which type of audio aid is the most effective. A total number of 150 children, aged between 6 to 12 years, randomly selected amongst the patients who came for their first dental check-up, were placed in five groups of 30 each. These groups were the control group, the instrumental music group, the musical nursery rhymes group, the movie songs group and the audio stories group. The control group was treated under normal set-up & audio group listened to various audio presentations during treatment. Each child had four visits. In each visit, after the procedures was completed, the anxiety levels of the children were measured by the Venham's Picture Test (VPT), Venham's Clinical Rating Scale (VCRS) and pulse rate measurement with the help of pulse oximeter. A significant difference was seen between all the groups for the mean pulse rate, with an increase in subsequent visit. However, no significant difference was seen in the VPT & VCRS scores between all the groups. Audio aids in general reduced anxiety in comparison to the control group, and the most significant reduction in anxiety level was observed in the audio stories group. The conclusion derived from the present study was that audio distraction

  9. New Methods for Quantification of Visual Photosensitivity Threshold and Symptoms

    PubMed Central

    Verriotto, Jennifer D.; Gonzalez, Alex; Aguilar, Mariela C.; Parel, Jean-Marie A.; Feuer, William J.; Smith, Andrew R.; Lam, Byron L.

    2017-01-01

    Purpose Visual photosensitivity is a common symptom difficult to measure and diagnose, and is found in many ocular and neurological disorders. We developed two novel reproducible quantitative assessments of visual photosensitivity. Methods We designed and built the ocular photosensitivity analyzer (OPA), an automated instrument to determine light intensity visual photosensitivity threshold (VPT), and developed the Visual Light Sensitivity Questionnaire-8 (VLSQ-8), an eight-question survey to assess the presence and severity of photosensitivity symptoms. We evaluated the test–retest variability and obtained normative values of these two approaches in 35 healthy normal subjects, distributed evenly over five age groups from eight to 60 years. Each subject underwent two test sessions, each with VLSQ-8, eye examination, and OPA, four weeks apart, between April 2015 and June 2016. Results Log-transformed VPTs (log10lux) and VLSQ-8 results were highly reproducible between the two sessions (VPT intraclass correlation coefficient [ICC] = 0.86; 95% confidence interval [CI] = 0.71–0.93; binocular testing, VLSQ-items ICC range = 0.53–0.87). No consistent significant differences in VPTs were found with monocular (P = 0.053, session 1) or binocular (P = 0.26) testing. Subjects in age group >30 to 40 years had significantly higher VPTs than those in other age groups (P ≤ 0.011) except the >40 to 50 years age group (P = 0.11). Photosensitivity symptoms assessed by the VLSQ-8 generally were low and highly reproducible with ≥88% of responses between the 2 sessions being within one category of each other. Conclusions Our results provide reliability data and normative results toward validation of two novel approaches to quantify visual photosensitivity and provide support for their potential use in ocular and neurologic conditions as well as in clinical trials. Translational Relevance The new quantitative photosensitivity approaches are potential measures to characterize

  10. New Methods for Quantification of Visual Photosensitivity Threshold and Symptoms.

    PubMed

    Verriotto, Jennifer D; Gonzalez, Alex; Aguilar, Mariela C; Parel, Jean-Marie A; Feuer, William J; Smith, Andrew R; Lam, Byron L

    2017-07-01

    Visual photosensitivity is a common symptom difficult to measure and diagnose, and is found in many ocular and neurological disorders. We developed two novel reproducible quantitative assessments of visual photosensitivity. We designed and built the ocular photosensitivity analyzer (OPA), an automated instrument to determine light intensity visual photosensitivity threshold (VPT), and developed the Visual Light Sensitivity Questionnaire-8 (VLSQ-8), an eight-question survey to assess the presence and severity of photosensitivity symptoms. We evaluated the test-retest variability and obtained normative values of these two approaches in 35 healthy normal subjects, distributed evenly over five age groups from eight to 60 years. Each subject underwent two test sessions, each with VLSQ-8, eye examination, and OPA, four weeks apart, between April 2015 and June 2016. Log-transformed VPTs (log10lux) and VLSQ-8 results were highly reproducible between the two sessions (VPT intraclass correlation coefficient [ICC] = 0.86; 95% confidence interval [CI] = 0.71-0.93; binocular testing, VLSQ-items ICC range = 0.53-0.87). No consistent significant differences in VPTs were found with monocular (P = 0.053, session 1) or binocular (P = 0.26) testing. Subjects in age group >30 to 40 years had significantly higher VPTs than those in other age groups (P ≤ 0.011) except the >40 to 50 years age group (P = 0.11). Photosensitivity symptoms assessed by the VLSQ-8 generally were low and highly reproducible with ≥88% of responses between the 2 sessions being within one category of each other. Our results provide reliability data and normative results toward validation of two novel approaches to quantify visual photosensitivity and provide support for their potential use in ocular and neurologic conditions as well as in clinical trials. The new quantitative photosensitivity approaches are potential measures to characterize disease severity, monitor disease progression, and evaluate treatment

  11. Interactive Sensor-Based Balance Training in Older Cancer Patients with Chemotherapy-Induced Peripheral Neuropathy: A Randomized Controlled Trial.

    PubMed

    Schwenk, Michael; Grewal, Gurtej S; Holloway, Dustin; Muchna, Amy; Garland, Linda; Najafi, Bijan

    2016-01-01

    Cancer patients with chemotherapy-induced peripheral neuropathy (CIPN) have deficits in sensory and motor skills leading to inappropriate proprioceptive feedback, impaired postural control, and fall risk. Balance training programs specifically developed for CIPN patients are lacking. This pilot study investigated the effect of an interactive motor adaptation balance training program based on wearable sensors for improving balance in older cancer patients with CIPN. Twenty-two patients (age: 70.3 ± 8.7 years) with objectively confirmed CIPN [vibration perception threshold (VPT) >25 V] were randomized to either an intervention (IG) or a control (CG) group. The IG received interactive game-based balance training including repetitive weight shifting and virtual obstacle crossing tasks. Wearable sensors provided real-time visual/auditory feedback from the lower limb trajectory and allowed the perception of motor errors during each motor action. The CG received no exercise intervention and continued their normal activity. Outcome measures were changes in sway of ankle, hip, and center of mass (CoM) in both mediolateral and anteroposterior (AP) directions during 30-second balance tests with increasing task difficulty [i.e. standing in feet-closed position with eyes open (EO) and eyes closed (EC), and in semi-tandem position with EO] at baseline and after the intervention. Additionally, gait performance (speed, variability) and fear of falling [Falls Efficacy Scale-International (FES-I)] were measured. Training was safe despite the participants' impaired health status, great severity of CIPN (VPT 49.6 ± 26.7 V), and great fear of falling (FES-I score 31.37 ± 11.20). After the intervention, sway of hip, ankle, and CoM was significantly reduced in the IG compared to the CG while standing in feet-closed position with EO (p = 0.010-0.022, except AP CoM sway) and in semi-tandem position (p = 0.008-0.035, except ankle sway). No significant effects were found for balance with

  12. Effectiveness and Comparison of Various Audio Distraction Aids in Management of Anxious Dental Paediatric Patients

    PubMed Central

    Johri, Nikita; Khan, Suleman Abbas; Singh, Rahul Kumar; Chadha, Dheera; Navit, Pragati; Sharma, Anshul; Bahuguna, Rachana

    2015-01-01

    Background Dental anxiety is a widespread phenomenon and a concern for paediatric dentistry. The inability of children to deal with threatening dental stimuli often manifests as behaviour management problems. Nowadays, the use of non-aversive behaviour management techniques is more advocated, which are more acceptable to parents, patients and practitioners. Therefore, this present study was conducted to find out which audio aid was the most effective in the managing anxious children. Aims and Objectives The aim of the present study was to compare the efficacy of audio-distraction aids in reducing the anxiety of paediatric patients while undergoing various stressful and invasive dental procedures. The objectives were to ascertain whether audio distraction is an effective means of anxiety management and which type of audio aid is the most effective. Materials and Methods A total number of 150 children, aged between 6 to 12 years, randomly selected amongst the patients who came for their first dental check-up, were placed in five groups of 30 each. These groups were the control group, the instrumental music group, the musical nursery rhymes group, the movie songs group and the audio stories group. The control group was treated under normal set-up & audio group listened to various audio presentations during treatment. Each child had four visits. In each visit, after the procedures was completed, the anxiety levels of the children were measured by the Venham’s Picture Test (VPT), Venham’s Clinical Rating Scale (VCRS) and pulse rate measurement with the help of pulse oximeter. Results A significant difference was seen between all the groups for the mean pulse rate, with an increase in subsequent visit. However, no significant difference was seen in the VPT & VCRS scores between all the groups. Audio aids in general reduced anxiety in comparison to the control group, and the most significant reduction in anxiety level was observed in the audio stories group

  13. Primary Tooth Vital Pulp Therapy: A Systematic Review and Meta-analysis.

    PubMed

    Coll, James A; Seale, N Sue; Vargas, Kaaren; Marghalani, Abdullah A; Al Shamali, Shahad; Graham, Laurel

    2017-01-15

    This systematic review and meta-analysis assessed outcomes in primary teeth for the vital pulp therapy (VPT) options of indirect pulp therapy (IPT), direct pulp capping (DPC), and pulpotomy after a minimum of 12 months to determine whether one VPT was superior. The following databases were searched from 1960 to September 2016: MEDLINE, EMBASE, CENTRAL, EBSCO, ICTRP, Dissertation abstracts, and grey literature for parallel and split-mouth randomized controlled trials of at least 12 months duration comparing the success of IPT, DPC, and pulpotomy in children with deep caries in primary teeth. Our primary outcome measure was overall success (combined clinical and radiographic). Three authors determined the included RCTs, performed data extraction, and assessed the risk of bias (ROB). Meta-analysis and assignment of quality of evidence by Grading of Recommendations Assessment, Development and Evaluation approach were done. Forty-one articles qualified for meta-analysis (six IPT, four DPC, and 31 pulpotomy) from 322 screened articles. The 24-month success rates were: IPT=94.4 percent, and the liner material (calcium hydroxide [CH]/bonding agents) had no effect on success (P=0.88), based on a moderate quality of evidence; DP =88.8 percent, and the capping agent (CH/alternate agent) did not affect success (P=0.56), based on a low quality of evidence. The combined success rate for all pulpotomies was 82.6 percent based on 1,022 teeth. Mineral trioxide aggregate (MTA) (89.6 percent) and formocresol (FC) (85.0 percent) success rates were the highest of all pulpotomy types and were not significantly different (P=0.15), with a high quality of evidence. MTA's success rate (92.2 percent) was higher than ferric sulfate (FS) (79.3 percent) and approached significance (P=0.06), while FS's success rate (84.8 percent) was not significantly different from FC (87.1 percent), both with a moderate quality of evidence. MTA and FC success rates were significantly better than CH (P=0

  14. Random hcp and fcc structures in thermoresponsive microgel crystals.

    PubMed

    Brijitta, J; Tata, B V R; Joshi, R G; Kaliyappan, T

    2009-08-21

    Monodisperse thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) microgel particles having a diameter of 520 nm were synthesized by free-radical precipitation polymerization and centrifuged to obtain a concentrated suspension. The centrifuged mother suspension was made to self-order into a crystalline state by repeated annealing beyond the volume phase transition (VPT) of the particles. We report here the three-dimensional (3D) real space structure, determined using a confocal laser scanning microscope, of PNIPAM microgel crystal samples prepared by two different recrystallized routes: (1) solidifying a shear melted colloidal liquid (referred as as-prepared sample) and (2) slow cooling of a colloidal liquid (referred as recrystallized sample). We have recorded images of several regions of the crystal with each region containing 15 horizontal crystal planes for determining the in-plane [two-dimensional (2D)] and 3D pair-correlation functions. The 2D pair-correlation function g(r) revealed hexagonal long-range order of particles in the layers with a lattice constant of 620 nm. The analysis of stacking sequence of layers recorded on as-prepared sample has revealed the existence of stacking disorder with an average stacking probability alpha approximately 0.42. This value of alpha together with the analysis of 3D pair-correlation function determined from particle positions revealed the structure of microgel crystals in the as-prepared sample to be random hexagonal close packing. We report the first observation of a split second peak in the 3D g(r) of the microgel crystals obtained from a shear melted liquid. Upon melting the sample above VPT and recrystallizing it the split second peak disappeared and the crystals are found to have a face centered cubic (fcc) structure with alpha approximately 0.95. From simulations, the split second peak is shown to arise from the displacement of some of the B-planes from the ideal hcp positions. The present results are discussed in

  15. Intraligamental analgesia for post-operative pain control in children having dental extractions under general anaesthesia.

    PubMed

    Anand, P; Wilson, R; Sheehy, E C

    2005-03-01

    This was to assess the effectiveness and safety of intraligamental local analgesia (ILA) for postoperative pain control in children having dental extractions under general anaesthesia (GA). The variables affecting the effectiveness of ILA were also investigated. Data were collected from children having permanent molars extracted under GA using a randomised half mouth study design. ILA (bupivicaine 0.5% with 1:200,000 adrenaline) was used on the randomly assigned experimental side prior to extraction of the teeth, and the contralateral control side received no ILA. Children were interviewed pre- and post-operatively by the principal investigator (PA) who was blind to the side of ILA. Pre- and post-operative anxiety levels of each child were measured using the Venham Picture Test (VPT). Patients were asked to rate which side was better in terms of pain control, whether they felt numbness and whether they preferred the numbness. Their post-operative pain levels were also measured using the visual analogue scale (VAS). Self-inflicted trauma following ILA was noted. Thirty children, with a mean age of 11.3 years (SD+/-1.7) completed the study. None of the patients had self-inflicted soft tissue trauma following ILA. Nineteen children (63%) found that pain control was better post-operatively on the side with ILA. Twenty-one children (70%) reported numbness following ILA of whom 14 (67%) said that they preferred this. VAS scores were not significantly different between the experimental and control sides. A higher percentage of boys (85%) than girls (47%) rated the ILA side "better" (p = 0.034). VPT scores were significantly higher for girls postoperatively (p = 0.048). ILA was a useful and safe adjunct for postoperative pain control in children having permanent teeth extracted under GA. The technique was found to be more effective in boys than girls. However, less than half the children in this study preferred the side with numbness. Further research is needed to

  16. Mineral trioxide aggregate and other bioactive endodontic cements: An updated overview- Part II: Other clinical applications and complications.

    PubMed

    Torabinejad, M; Parirokh, M; Dummer, P M H

    2017-08-28

    Mineral trioxide aggregate (MTA) is a dental material used extensively for vital pulp therapy (VPT), scaffold cover during regenerative endodontic procedures, apical barrier in teeth with necrotic pulps and open apices, perforation repair, and root canal filling and root-end filling during surgical endodontics. A number of bioactive endodontic cements (BECs) have recently been introduced to the market. Most of these materials had calcium and silicate in their compositions; however, the bioactivity is the common property of these cements. These materials include: BioAggregate, Biodentine, BioRoot RCS, calcium enriched mixture (CEM) cement, Endo-CPM, Endocem, EndoSequence, EndoBinder, EndoSeal MTA, iRoot, MicroMega MTA,, MTA Bio, MTA Fillapex, MTA Plus, Neo MTA Plus, Ortho MTA, Quick-Set, Retro MTA, Tech Biosealer, and TheraCal. It has been claimed that these materials have properties similar to those of MTA but without the drawbacks. In Part I of this discussion we extensively reviewed available information on the chemical composition of the materials listed above and reported their applications for VPT. In this article the clinical applications of MTA and other BECs will be reviewed for apexification, regenerative endodontics, perforation repair, root canal filling, root-end filling, restorative procedures, periodontal defects and treatment of vertical and horizontal root fractures. In addition, the literature regarding the possible drawbacks of these materials after their clinical applications is reviewed. These drawbacks are including the materials' discoloration potential, systemic effects, and retreatability following use as a root canal filling. Furthermore, the current levels of evidence of these materials are also reported. Based on selected keywords, all publications were searched regarding the use of MTA as well as BECs for the rest of clinical applications. Additionally, the levels of evidence for MTA's clinical applications and the newly introduced

  17. Anharmonic Vibrational Analysis for the Propadienylidene Molecule (H2C═C═C:).

    PubMed

    Wu, Qunyan; Hao, Qiang; Wilke, Jeremiah J; Simmonett, Andrew C; Yamaguchi, Yukio; Li, Qianshu; Fang, De-Cai; Schaefer, Henry F

    2010-10-12

    Maier et al. found that photolysis of singlet cyclopropenylidene (1S) in a matrix yields triplet propargylene (2T), which upon further irradiation is converted to singlet propadienylidene (vinylidenecarbene, 3S). Their discovery was followed by interstellar identification of 3S by Cernicharo et al. An accurate quartic force field for propadienylidene (3S) has been determined employing the ab initio coupled-cluster (CC) with single and double excitations and perturbative triple excitations [CCSD(T)] method and the correlation-consistent core-valence quadruple-ζ (cc-pCVQZ) basis set. Utilizing vibrational second-order perturbation theory (VPT2), vibration-rotation coupling constants, rotational constants, centrifugal distortion constants, vibrational anharmonic constants, and fundamental vibrational frequencies are determined. The predicted fundamental frequencies for 3S as well as its (13)C and deuterium isotopologues are in good agreement with experimental values. The theoretical zero-point vibration corrected rotational constants B0 are consistent with experimental values within 0.3% of errors. The isotopic shifts of B0 are in close to exact agreement with experimental observations. The mean absolute deviation between theoretical anharmonic and experimental fundamental vibrational frequencies for 24 modes (excluding CH2 s-str.) is only 2.6 cm(-1). The isotopic shifts of the vibrational frequencies are also in excellent agreement with the available experimental values. However, a large discrepancy is observed for the CH2 symmetric stretch, casting doubt on the experimental assignment for this mode.

  18. The O_2 + Ethyl Reaction in Helium Nanodroplets: Infrared Spectroscopy of the Ethylperoxy Radical

    NASA Astrophysics Data System (ADS)

    Franke, Peter R.; Douberly, Gary E.

    2017-06-01

    Helium-solvated ethylperoxy radicals (CH_3CH_2OO) are formed via the in situ reaction between ethyl radicals and ˜{X}^{3}Σ_{g}^{-} O_2. The reactants are captured sequentially through the droplet pick-up technique. Helium droplets are doped with ethyl radical via pyrolysis of di-tert-amyl peroxide or n-propylnitrite in an effusive, low-pressure source. A mid-infrared spectrum of ethylperoxy is recorded with species-selective droplet beam depletion spectroscopy. Spectral assignments in the CH stretching region are made via comparisons to second-order vibrational perturbation theory with resonances (VPT2+K) based on coupled-cluster quartic force fields. Gauche and trans conformers are predicted to be nearly isoenergetic; however, the spectrum indicates that one dominant conformer is present. Indeed, in several previous studies in our group, where chemical reactions were conducted inside droplets, only a single conformer of the product was observed. Exploration of the ethylperoxy potential energy surface, particularly along the CCOO torsional and CO stretching coordinates, motivates an explanation that is based upon an adiabatic funneling mechanism that leads to the exclusive production of one conformer. The slower torsional degree of freedom is cooled more rapidly than the higher frequency stretching and bending coordinates owing to the stronger coupling between the torsional modes and the collective modes of the helium droplet. The reactants are cooled into the torsional well that stabilizes first during their approach on the PES.

  19. Generalized Vibrational Perturbation Theory for Rotovibrational Energies of Linear, Symmetric and Asymmetric Tops: Theory, Approximations, and Automated Approaches to Deal with Medium-to-Large Molecular Systems.

    PubMed

    Piccardo, Matteo; Bloino, Julien; Barone, Vincenzo

    2015-08-05

    Models going beyond the rigid-rotor and the harmonic oscillator levels are mandatory for providing accurate theoretical predictions for several spectroscopic properties. Different strategies have been devised for this purpose. Among them, the treatment by perturbation theory of the molecular Hamiltonian after its expansion in power series of products of vibrational and rotational operators, also referred to as vibrational perturbation theory (VPT), is particularly appealing for its computational efficiency to treat medium-to-large systems. Moreover, generalized (GVPT) strategies combining the use of perturbative and variational formalisms can be adopted to further improve the accuracy of the results, with the first approach used for weakly coupled terms, and the second one to handle tightly coupled ones. In this context, the GVPT formulation for asymmetric, symmetric, and linear tops is revisited and fully generalized to both minima and first-order saddle points of the molecular potential energy surface. The computational strategies and approximations that can be adopted in dealing with GVPT computations are pointed out, with a particular attention devoted to the treatment of symmetry and degeneracies. A number of tests and applications are discussed, to show the possibilities of the developments, as regards both the variety of treatable systems and eligible methods.

  20. The Role of Anharmonicity in Hydrogen-Bonded Systems: The Case of Water Clusters.

    PubMed

    Temelso, Berhane; Shields, George C

    2011-09-13

    The nature of vibrational anharmonicity has been examined for the case of small water clusters using second-order vibrational perturbation theory (VPT2) applied on second-order Møller-Plesset perturbation theory (MP2) potential energy surfaces. Using a training set of 16 water clusters (H2O)n=2-6,8,9 with a total of 723 vibrational modes, we determined scaling factors that map the harmonic frequencies onto anharmonic ones. The intermolecular modes were found to be substantially more anharmonic than intramolecular bending and stretching modes. Due to the varying levels of anharmonicity of the intermolecular and intramolecular modes, different frequency scaling factors for each region were necessary to achieve the highest accuracy. Furthermore, new scaling factors for zero-point vibrational energies (ZPVE) and vibrational corrections to the enthalpy (ΔHvib) and the entropy (Svib) have been determined. All the scaling factors reported in this study are different from previous works in that they are intended for hydrogen-bonded systems, while others were built using experimental frequencies of covalently bonded systems. An application of our scaling factors to the vibrational frequencies of water dimer and thermodynamic functions of 11 larger water clusters highlights the importance of anharmonic effects in hydrogen-bonded systems.

  1. Infrared Spectrum of the Cyclobutyl Radical in he Droplets

    NASA Astrophysics Data System (ADS)

    Brown, Alaina R.; Franke, Peter R.; Douberly, Gary E.

    2017-06-01

    Gas phase cyclobutyl radical (C_{4}H_{7}) is produced via pyrolysis of cyclobutyl methyl nitrite (C_{4}H_{7}(CH_{2})ONO). The nascent radicals are promptly solvated in liquid He droplets, allowing for the acquisition of the infrared spectrum in the CH stretching region. Anharmonic frequencies are predicted by VPT2+K simulations based upon a CCSD(T)/ANO0 force field. Several resonance polyads emerge in the 2800-3000 \\wn region as a result of anharmonic coupling between the CH stretching fundamentals and CH_{2} bend overtones and combinations. Evidence of rotational fine structure is observed for two bands. The vibrationally averaged cyclobutyl radical geometry and the C_4H_7 potential energy surface will be discussed. In agreement with the findings by Schultz^{1} and coworkers, 1,3-butadiene is formed from cyclobutyl ring opening and H atom loss, given a sufficiently high pyrolysis temperature. However, signatures of 1-methylallyl and allylcarbinyl radicals, proposed^{1} as intermediates along the above mentioned reaction path, are yet to be seen. 1. Schultz, J.C., Houle, F.A., Beauchamp, J.L. J. Am. Chem. Soc. 1984, 106, 7336-7347.

  2. Vibrational-Torsional Coupling Revealed in the Infrared Spectrum of He-Solvated n-PROPYL Radical

    NASA Astrophysics Data System (ADS)

    Moradi, Christopher P.; Broderick, Bernadette M.; Agarwal, Jay; Schaefer, Henry F., III.; Douberly, Gary E.

    2015-06-01

    The n-propyl and i-propyl radicals were generated in the gas phase via pyrolysis of n-butyl nitrite (CH3(CH2)3ONO) and i-butyl nitrite (CH3CH(CH3)CH2ONO) precursors, respectively. Nascent radicals were promptly solvated by a beam of He nanodroplets, and the infrared spectra of the radicals were recorded in the C-H stretching region. In addition to three vibrations of n-propyl previously measured in an Ar matrix, we observe many unreported bands between 2800 and 3150 wn, which we attribute to propyl radicals. The C-H stretching modes observed above 2960 wn for both radicals are in excellent agreement with anharmonic frequencies computed using VPT2. Between 2800 and 2960 wn, however, the spectra of n-propyl and i-propyl radicals become quite congested and difficult to assign due to the presence of multiple anharmonic resonances. Computations reveal the likely origin of the spectral congestion to be strong coupling between the high frequency C-H stretching modes and a lower frequency torsional motion, which modulates quite substantially a through-space hyperconjugation interaction. Pacansky, et. al., J. Phys. Chem. 1977, 81, 2149.

  3. Infrared Laser Spectroscopy of the n-PROPYL and i-PROPYL Radicals in Helium Droplets: Significant Bend-Stretch Coupling Revealed in the CH Stretch Region

    NASA Astrophysics Data System (ADS)

    Moradi, Christopher P.; Douberly, Gary E.; Tabor, Daniel P.; Sibert, Edwin

    2016-06-01

    The n-propyl and i-propyl radicals were generated in the gas phase via pyrolysis of n-butyl nitrite (CH3(CH2)3ONO) and i-butyl nitrite (CH3CH(CH3)CH2ONO) precursors, respectively. Nascent radicals were promptly solvated by a beam of He nanodroplets, and the infrared spectra of the radicals were recorded in the C-H stretching region. In addition to three vibrations of n-propyl previously measured in an Ar matrix, we observe many unreported bands between 2800 and 3150 wn, which we attribute to propyl radicals. The C-H stretching modes observed above 2960 wn for both radicals are in excellent agreement with anharmonic frequencies computed using VPT2. Between 2800 and 2960 wn, however, the spectra of n-propyl and i-propyl radicals become quite congested and difficult to assign due to the presence of multiple anharmonic resonances. Computations employing a local mode Hamiltonian reveal the origin of the spectral congestion to be strong coupling between the high frequency C-H stretching modes and the lower frequency bending/scissoring motions. The only significant local coupling is between stretches and bends on the same CH2/CH3 group.

  4. The effect of hydrogen bonding on torsional dynamics: A combined far-infrared jet and matrix isolation study of methanol dimer

    SciTech Connect

    Kollipost, F.; Heger, M.; Suhm, M. A.; Andersen, J.; Mahler, D. W.; Wugt Larsen, R.; Heimdal, J.

    2014-11-07

    The effect of strong intermolecular hydrogen bonding on torsional degrees of freedom is investigated by far-infrared absorption spectroscopy for different methanol dimer isotopologues isolated in supersonic jet expansions or embedded in inert neon matrices at low temperatures. For the vacuum-isolated and Ne-embedded methanol dimer, the hydrogen bond OH librational mode of the donor subunit is finally observed at ∼560 cm{sup −1}, blue-shifted by more than 300 cm{sup −1} relative to the OH torsional fundamental of the free methanol monomer. The OH torsional mode of the acceptor embedded in neon is observed at ∼286 cm{sup −1}. The experimental findings are held against harmonic predictions from local coupled-cluster methods with single and double excitations and a perturbative treatment of triple excitations [LCCSD(T)] and anharmonic. VPT2 corrections at canonical MP2 and density functional theory (DFT) levels in order to quantify the contribution of vibrational anharmonicity for this important class of intermolecular hydrogen bond vibrational motion.

  5. Structural and biological evaluation of some metal complexes of vanillin-4N-(2-pyridyl) thiosemicarbazone

    NASA Astrophysics Data System (ADS)

    Yousef, T. A.; Abu El-Reash, G. M.; Al-Jahdali, M.; El-Rakhawy, El-Bastawesy R.

    2013-12-01

    The synthesis and characterization of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II) and U(VI)O2 complexes of vanillin-4N-(2-pyridyl) thiosemicarbazone (H2PVT) are reported. Theoretical calculations have been performed to obtain IR spectra of ligand and its complexes using AM1, Zindo/1, MM+ and PM3, methods. The Schiff base and its metal complexes have been screened for antibacterial Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Staphylococcus saprophyticus. H2VPT shows no apparent digestion effect on the egg albumin while Mn(II), Hg(II) and Cu(II) complexes exhibited a considerable digestion effect following the order Cu(II) > Mn(II) > Hg(II). Moreover, Ni(II) and Co(II) complexes revealed strong digestion effect. Fe(II), Mn(II), Cu(II), Zn(II) and Ni(II) acted as metal co- SOD enzyme factors, which are located in different compartments of the cell.

  6. Microstructure of Hydrophobically Modified Alkyl Acrylamide Hydrogels

    NASA Astrophysics Data System (ADS)

    Tian, Jun; Seery, Thomas A. P.; Ho, Derek L.; Weiss, R. A.

    2004-03-01

    Hydrophobically modified water-soluble acrylamide polymers have a variety of applications, including viscosity thickeners, microencapsulation, biosensors and controlled drug delivery systems. The microstructure of copolymer hydrogels of N,N-dimethylacrylamide (DMA) or N-isopropylacrylamide(NIPA) modified with 2-(N-ethylfluorooctanesulfonamido)ethyl acrylate, FOSA, was studied by small angle x-ray (SAXS) and neutron scattering (SANS). Swelling and DSC measurements showed that FOSA/NIPA gels exhibited a volume phase transition (VPT), but that FOSA/DMA gels did not. A modified interacting core-shell model was used to explain the SAXS and SANS data for both gels. The crosslink junctions of the gel consisted of nanophase-separated FOSA domains as the core surrounded by a water-poor layer of the alkyl acrylamide. These nanodomains were dispersed in a matrix of water-swollen alkyl acrylamide that had large scale heterogeneities. The average spherical core radius ranged from 1 to 3 nm and the average shell thickness ranged from 1 to 1.5 nm; the aggregation number ranged from 10 to 200.

  7. Degree of dental anxiety in children with and without toothache: prospective assessment.

    PubMed

    Ramos-Jorge, Joana; Marques, Leandro S; Homem, Márcio A; Paiva, Saul M; Ferreira, Meire C; Oliveira Ferreira, Fernanda; Ramos-Jorge, Maria L

    2013-03-01

    Few prospective studies on the anxiety of children in the dental office have been published. To monitor dental anxiety levels in children with and without previous experience with toothache over a period of six consecutive visits. A longitudinal study was carried out involving 167 children treated at a public dental service. Levels of anxiety in the dental setting were assessed in children without toothache (G1) and those with toothache (G2) using the modified Venham picture test (VPT). Data acquisition was carried out over a 6-week period, with each child treated in the dental office once a week. Six assessments of anxiety were performed in the waiting room prior to dental treatment. A significant reduction in anxiety scores occurred between appointments in both groups. In the inter-group comparison, G2 had significantly higher anxiety scores than G1. Although statistically significant reductions in anxiety scores occurred through to the fifth appointment, a tendency toward stagnation in anxiety scores was observed beginning with the fourth appointment. Dental anxiety scores were reduced over the course of six appointments. Children with toothache had higher levels of dental anxiety than those that had never experienced toothache. © 2012 The Authors. International Journal of Paediatric Dentistry © 2012 BSPD, IAPD and Blackwell Publishing Ltd.

  8. Retrospective Study of the Survival Rates of Indirect Pulp Therapy Versus Different Pulpotomy Medicaments.

    PubMed

    Wunsch, Patrice Barsamian; Kuhnen, Marissa M; Best, Al M; Brickhouse, Tegwyn H

    2016-10-15

    The purposes of this retrospective chart review were to determine: (1) how primary molars in need of vital pulp therapy (VPT) have been treated over a period of four years at a university-based pediatric dental practice (UBP); and which treatments-indirect pulp therapy (IPT), formocresol pulpotomy (FCP), and ferric sulfate pulpotomy (FSP)-have been successful. Electronic patient records (axiUm) that contained the procedure codes D3120 (pulp cap-indirect) or D3220 (therapeutic pulpotomy) were totaled by year. Visit records were queried again to identify treatment failures (i.e., extractions [D7140] or pulpectomy [D3221/D3240]). A total of 2,001 primary molar teeth were included in the study. Success was compared using a Kaplan-Meier analysis. At the three-year follow-up, IPT had a 96.2 percent survival rate, FCP had a 65.8 percent survival rate, and FSP had a 62.9 percent survival rate (P<.0001). Over a four-year period of time, IPT became the more commonly used vital pulp therapy treatment at a university-based pediatric dental practice and had a significantly better survival rate than FCP or FSP.

  9. Infrared Spectra of the n-PROPYL and i-PROPYL Radicals in Solid Para-Hydrogen

    NASA Astrophysics Data System (ADS)

    Pullen, Gregory T.; Franke, Peter R.; Douberly, Gary E.; Lee, Yuan-Pern

    2017-06-01

    We report the infrared spectra of the n-propyl and i-propyl radicals measured in solid para-hydrogen (p-H_2) matrices at 3.2 K. n-Propyl and i-propyl radicals were produced via the 248 nm irradiation of matrices formed by co-depositing p-H_2 and either 1-Iodopropane (n-propyl) or 2-Iodopropane (i-propyl). Secondary photolysis was used to group spectral lines all due to the same species. Lines in the C-H stretching region were compared to previous work using the Helium Nanodroplet Isolation (HENDI) technique, and are in excellent agreement. In addition to a few lines previously measured in Ar matrices, we observe many previously unreported bands below 2000 \\wn, which we attribute to the n-propyl and i-propyl radicals. The assignment of features below 2000 \\wn are made via comparisons to anharmonic VPT2+K frequency computations. Peter R. Franke, Daniel P. Tabor, Christopher P. Moradi, Gary E. Douberly, Jay Agarwal, Henry F. Schaefer III, and Edwin L. Sibert III, Journal of Chemical Physics 145, 224304 (2016).

  10. Generalized Vibrational Perturbation Theory for Rotovibrational Energies of Linear, Symmetric and Asymmetric Tops: Theory, Approximations, and Automated Approaches to Deal with Medium-to-Large Molecular Systems

    PubMed Central

    Piccardo, Matteo; Bloino, Julien; Barone, Vincenzo

    2015-01-01

    Models going beyond the rigid-rotor and the harmonic oscillator levels are mandatory for providing accurate theoretical predictions for several spectroscopic properties. Different strategies have been devised for this purpose. Among them, the treatment by perturbation theory of the molecular Hamiltonian after its expansion in power series of products of vibrational and rotational operators, also referred to as vibrational perturbation theory (VPT), is particularly appealing for its computational efficiency to treat medium-to-large systems. Moreover, generalized (GVPT) strategies combining the use of perturbative and variational formalisms can be adopted to further improve the accuracy of the results, with the first approach used for weakly coupled terms, and the second one to handle tightly coupled ones. In this context, the GVPT formulation for asymmetric, symmetric, and linear tops is revisited and fully generalized to both minima and first-order saddle points of the molecular potential energy surface. The computational strategies and approximations that can be adopted in dealing with GVPT computations are pointed out, with a particular attention devoted to the treatment of symmetry and degeneracies. A number of tests and applications are discussed, to show the possibilities of the developments, as regards both the variety of treatable systems and eligible methods. © 2015 Wiley Periodicals, Inc. PMID:26345131

  11. Anharmonic Computations Meet Experiments (IR, Raman, Neutron Diffraction) for Explaining the Behavior of 1,3,5-Tribromo-2,4,6-trimethylbenzene.

    PubMed

    Meinnel, Jean; Latouche, Camille; Ghanemi, Soumia; Boucekkine, Abdou; Barone, Vincenzo; Moréac, Alain; Boudjada, Ali

    2016-02-25

    In the present paper we first show the experimental Raman, infrared, and neutron INS spectra of tribromomesitylene (TBM) measured in the range 50-3200 cm(-1) using crystalline powders at 6 or 4 K. Then, the bond lengths and angles determined by neutron diffraction using a TBM single crystal at 14 K are compared to the computed ones at different levels of theory. Anharmonic computations were then performed on the relaxed structure using the VPT2 approach, and for the lowest normal modes, the HRAO model has led to a remarkable agreement for the assignment of the experimental signatures. A particularity appears for frequencies below 150 cm(-1), and in particular for those concerning the energy levels of "hindered rotation" of the three methyl groups, they must be calculated for one-dimensional symmetrical tops independent of the frame vibrations. This fact is consistent with the structure established by neutron diffraction: the protons of the methyl groups undergoing huge "libration" motions are widely spread in space. The values of the transitions between the librational levels determined by inelastic neutron scattering indicate that the hindering potentials are mainly due to intermolecular interactions different for each methyl group in the triclinic cell.

  12. Identification of plant vacuolar transporters mediating phosphate storage

    PubMed Central

    Liu, Tzu-Yin; Huang, Teng-Kuei; Yang, Shu-Yi; Hong, Yu-Ting; Huang, Sheng-Min; Wang, Fu-Nien; Chiang, Su-Fen; Tsai, Shang-Yueh; Lu, Wen-Chien; Chiou, Tzyy-Jen

    2016-01-01

    Plant vacuoles serve as the primary intracellular compartments for inorganic phosphate (Pi) storage. Passage of Pi across vacuolar membranes plays a critical role in buffering the cytoplasmic Pi level against fluctuations of external Pi and metabolic activities. Here we demonstrate that the SPX-MFS proteins, designated as PHOSPHATE TRANSPORTER 5 family (PHT5), also named Vacuolar Phosphate Transporter (VPT), function as vacuolar Pi transporters. Based on 31P-magnetic resonance spectroscopy analysis, Arabidopsis pht5;1 loss-of-function mutants accumulate less Pi and exhibit a lower vacuolar-to-cytoplasmic Pi ratio than controls. Conversely, overexpression of PHT5 leads to massive Pi sequestration into vacuoles and altered regulation of Pi starvation-responsive genes. Furthermore, we show that heterologous expression of the rice homologue OsSPX-MFS1 mediates Pi influx to yeast vacuoles. Our findings show that a group of Pi transporters in vacuolar membranes regulate cytoplasmic Pi homeostasis and are required for fitness and plant growth. PMID:27029856

  13. Enhanced Photoluminescence and Raman Properties of Al-Doped ZnO Nanostructures Prepared Using Thermal Chemical Vapor Deposition of Methanol Assisted with Heated Brass

    PubMed Central

    Thandavan, Tamil Many K.; Gani, Siti Meriam Abdul; San Wong, Chiow; Md. Nor, Roslan

    2015-01-01

    Vapor phase transport (VPT) assisted by mixture of methanol and acetone via thermal evaporation of brass (CuZn) was used to prepare un-doped and Al-doped zinc oxide (ZnO) nanostructures (NSs). The structure and morphology were characterized by field emission scanning electron microscopy (FESEM) and x-ray diffraction (XRD). Photoluminescence (PL) properties of un-doped and Al-doped ZnO showed significant changes in the optical properties providing evidence for several types of defects such as zinc interstitials (Zni), oxygen interstitials (Oi), zinc vacancy (Vzn), singly charged zinc vacancy (VZn-), oxygen vacancy (Vo), singly charged oxygen vacancy (Vo+) and oxygen anti-site defects (OZn) in the grown NSs. The Al-doped ZnO NSs have exhibited shifted PL peaks at near band edge (NBE) and red luminescence compared to the un-doped ZnO. The Raman scattering results provided evidence of Al doping into the ZnO NSs due to peak shift from 145 cm-1 to an anomalous peak at 138 cm-1. Presence of enhanced Raman signal at around 274 and 743 cm-1 further confirmed Al in ZnO NSs. The enhanced D and G band in all Al-doped ZnO NSs shows possible functionalization and doping process in ZnO NSs. PMID:25756598

  14. Enhanced photoluminescence and Raman properties of Al-Doped ZnO nanostructures prepared using thermal chemical vapor deposition of methanol assisted with heated brass.

    PubMed

    Thandavan, Tamil Many K; Gani, Siti Meriam Abdul; San Wong, Chiow; Md Nor, Roslan

    2015-01-01

    Vapor phase transport (VPT) assisted by mixture of methanol and acetone via thermal evaporation of brass (CuZn) was used to prepare un-doped and Al-doped zinc oxide (ZnO) nanostructures (NSs). The structure and morphology were characterized by field emission scanning electron microscopy (FESEM) and x-ray diffraction (XRD). Photoluminescence (PL) properties of un-doped and Al-doped ZnO showed significant changes in the optical properties providing evidence for several types of defects such as zinc interstitials (Zni), oxygen interstitials (Oi), zinc vacancy (Vzn), singly charged zinc vacancy (VZn-), oxygen vacancy (Vo), singly charged oxygen vacancy (Vo+) and oxygen anti-site defects (OZn) in the grown NSs. The Al-doped ZnO NSs have exhibited shifted PL peaks at near band edge (NBE) and red luminescence compared to the un-doped ZnO. The Raman scattering results provided evidence of Al doping into the ZnO NSs due to peak shift from 145 cm-1 to an anomalous peak at 138 cm-1. Presence of enhanced Raman signal at around 274 and 743 cm-1 further confirmed Al in ZnO NSs. The enhanced D and G band in all Al-doped ZnO NSs shows possible functionalization and doping process in ZnO NSs.

  15. Defect-induced large spin-orbit splitting in monolayer PtSe2

    NASA Astrophysics Data System (ADS)

    Absor, Moh. Adhib Ulil; Santoso, Iman; Harsojo, Abraha, Kamsul; Ishii, Fumiyuki; Saito, Mineo

    2017-09-01

    The effect of spin-orbit coupling on the electronic properties of monolayer (ML) PtSe2 is dictated by the presence of the crystal inversion symmetry to exhibit a spin-polarized band without the characteristic of spin splitting. Through fully relativistic density-functional theory calculations, we show that large spin-orbit splitting can be induced by introducing point defects. We calculate the stability of native point defects such as a Se vacancy (VSe), a Se interstitial (Sei), a Pt vacancy (VPt), and a Pt interstitial (Pti) and find that both the VSe and Sei have the lowest formation energy. We also find that, in contrast to the Sei case exhibiting spin degeneracy in the defect states, the large spin-orbit splitting up to 152 meV is observed in the defect states of the VSe. Our analyses of orbital contributions to the defect states show that the large spin splitting is originated from the strong hybridization between Pt-dx 2+y 2+dx y and Se-px+py orbitals. Our study clarifies that the defects play an important role in the spin-splitting properties of the PtSe2 ML, which is important for designing future spintronic devices.

  16. Near-Infrared Spectroscopy of Small Protonated Water Clusters

    NASA Astrophysics Data System (ADS)

    Wagner, J. Philipp; McDonald, David C., II; McCoy, Anne B.; Duncan, Michael A.

    2017-06-01

    Small protonated water clusters and their argon tagged analogues of the general formula H^{+}(H_{2}O)_{n}Ar_{m} have been generated in a pulsed electric discharge source. Clusters containing n=1-8 water molecules were mass-selected and their absorptions in the near-infrared were probed with a tunable Nd/colonYAG pumped OPA/OPA laser system in the region from 4850-7350 cm^{-1}. A doublet corresponding to overtones of the free O-H stretches of the external waters was observed around 7200 cm^{-1} that was continuously decreasing in intensity with increasing cluster size. Broad, mostly featureless absorptions were found around 5300 cm^{-1} associated with stretch/bend combinations and with the hydrogen bonded waters in the core of the clusters. Vibrational assignments were substantiated by comparison to anharmonic frequency computations via second-order vibrational perturbation theory (VPT2) at the MP2/aug-cc-pVTZ level of theory.

  17. Lifetime Performance Studies on Vacuum Photo-Triodes in the ECAL at CMS

    NASA Astrophysics Data System (ADS)

    Wood, John

    2011-10-01

    The electromagnetic calorimeter (ECAL) is a crucial sub-detector of the Compact Muon Solenoid (CMS) at the Large Hadron Collider (LHC). It uses scintillation light fr om approximately 83,000 Lead Tungstate (PbWO4) crystals to make precision measurements of high energy photons and electrons. In the endcaps of the ECAL this scinti llation light is collected at the rear of the crystal and converted to an analog electric current with radiation hard, single stage photmultipliers known as Vacuum Pho to-Triodes (VPTs). The response of the VPTs is dependent on several effects including orientation within the magnetic field, calibration and scintillation light expos ure rates, and time between successive exposures. The High Energy Physics group at the University of Virginia (UVa) uses a 3.8 T large-bore superconducting solenoid m agnet to simulate conditions at the LHC and to study the long term behavior of these VPTs under various light and magnetic field conditions. Also, using the ECAL lase r and LED calibration system, UVa is also able to study the response of the VPTs in situ at the CMS detector in order to understand and quantitatively assess the perfo rmance of the VPTs over time. Herein we will report on these remote and in-situ studies of VPT characteristics and performance.

  18. Visual learning by imitation with motor representations.

    PubMed

    Lopes, Manuel; Santos-Victor, José

    2005-06-01

    We propose a general architecture for action (mimicking) and program (gesture) level visual imitation. Action-level imitation involves two modules. The viewpoint Transformation (VPT) performs a "rotation" to align the demonstrator's body to that of the learner. The Visuo-Motor Map (VMM) maps this visual information to motor data. For program-level (gesture) imitation, there is an additional module that allows the system to recognize and generate its own interpretation of observed gestures to produce similar gestures/goals at a later stage. Besides the holistic approach to the problem, our approach differs from traditional work in i) the use of motor information for gesture recognition; ii) usage of context (e.g., object affordances) to focus the attention of the recognition system and reduce ambiguities, and iii) use iconic image representations for the hand, as opposed to fitting kinematic models to the video sequence. This approach is motivated by the finding of visuomotor neurons in the F5 area of the macaque brain that suggest that gesture recognition/imitation is performed in motor terms (mirror) and rely on the use of object affordances (canonical) to handle ambiguous actions. Our results show that this approach can outperform more conventional (e.g., pure visual) methods.

  19. Acupuncture for the treatment of chronic painful peripheral diabetic neuropathy: a long-term study.

    PubMed

    Abuaisha, B B; Costanzi, J B; Boulton, A J

    1998-02-01

    Forty-six diabetic patients with chronic painful peripheral neuropathy were treated with acupuncture analgesia to determine its efficacy and long-term effectiveness. Twenty-nine (63%) patients were already on standard medical treatment for painful neuropathy. Patients initially received up to six courses of classical acupuncture analgesia over a period of 10 weeks, using traditional Chinese Medicine acupuncture points. Forty-four patients completed the study with 34 (77%) showing significant improvement in their primary and/or secondary symptoms (P < 0.01). These patients were followed up for a period of 18-52 weeks with 67% were able to stop or reduce their medications significantly. During the follow-up period only eight (24%) patients required further acupuncture treatment. Although 34 (77%) patients noted significant improvement in their symptoms, only seven (21%) noted that their symptoms cleared completely. All the patients but one finished the full course of acupuncture treatment without reported or observed side effects. There were no significant changes either in the peripheral neurological examination scores, VPT or in HbA1c during the course of treatment. These data suggest that acupuncture is a safe and effective therapy for the long-term management of painful diabetic neuropathy, although its mechanism of action remains speculative.

  20. On the synthesis of AlPO4-21 molecular sieve by vapor phase transport method and its phase transformation to AlPO4-15 molecular sieve

    NASA Astrophysics Data System (ADS)

    Shao, Hui; Chen, Jingjing; Chen, Xia; Leng, Yixin; Zhong, Jing

    2015-04-01

    An experimental design was applied to the synthesis of AlPO4-21 molecular sieve (AWO structure) by vapor phase transport (VPT) method, using tetramethylguanidine (TMG) as the template. In this study, the effects of crystallization time, crystallization temperature, phosphor content, template content and water content in the synthesis gel were investigated. The materials obtained were characterized by X-ray diffraction, scanning electron microscopy and fourier transform infrared spectroscopy (FT-IR). Microstructural analysis of the crystal growth in vapor synthetic conditions revealed a revised crystal growth route from zeolite AlPO4-21 to AlPO4-15 in the presence of the TMG. Homogenous hexagonal prism AlPO4-21 crystals with size of 7 × 3 μm were synthesized at a lower temperature (120 °C), which were completely different from the typical tabular parallelogram crystallization microstructure of AlPO4-21 phase. The crystals were transformed into AlPO4-21 phase with higher crystallization temperature, longer crystallization time, higher P2O5/Al2O3 ratio and higher TMG/Al2O3 ratio.

  1. The cogeneration steam turbine of the Tp-35/40-8.8 type

    NASA Astrophysics Data System (ADS)

    Valamin, A. Ye.; Kultyshev, A. Yu.; Goldberg, A. A.; Sakhnin, Yu. A.; Shekhter, M. V.; Paneque Aguilera, H. C.; Stepanov, M. Yu.; Shibaev, T. L.

    2012-12-01

    The main performance characteristics of the turbine, descriptions of the electrohydraulic control and protection system (EHCPS), the heat flow diagram, arrangement decisions, and motivation for selecting them, are given. The steam turbine presented by the Ural Turbine Works (UTW) is intended for replacing the VPT-25 turbine the service life of which has already expired at the Novokuybyshevsk CHP plant. The mixed-pressure turbine will operate in combination of the double-circuit heat recovery boiler (HRB) in a parallel scheme. High-pressure (HP) steam will be supplied from the main steam header to which high-pressure steam from the power boilers and the HRB will be fed, while low-pressure (LP) steam will be supplied directly from the HRB. For the turbine, nozzle steam distribution and the two-row control stage are adopted. The turbine has a process steam extraction line with its stop and control valve and heating steam extraction line leading to the main steam collector.

  2. Unusual Fusion Proteins of HIV-1

    PubMed Central

    Langer, Simon; Sauter, Daniel

    2017-01-01

    Despite its small genome size, the Human Immunodeficiency Virus 1 (HIV-1) is one of the most successful pathogens and has infected more than 70 million people worldwide within the last decades. In total, HIV-1 expresses 16 canonical proteins from only nine genes within its 10 kb genome. Expression of the structural genes gag, pol, and env, the regulatory genes rev and tat and the accessory genes vpu, nef, vpr, and vif enables assembly of the viral particle, regulates viral gene transcription, and equips the virus to evade or counteract host immune responses. In addition to the canonically expressed proteins, a growing number of publications describe the existence of non-canonical fusion proteins in HIV-1 infected cells. Most of them are encoded by the tat-env-rev locus. While the majority of these fusion proteins (e.g., TNV/p28tev, p186Drev, Tat1-Rev2, Tat^8c, p17tev, or Ref) are the result of alternative splicing events, Tat-T/Vpt is produced upon programmed ribosomal frameshifting, and a Rev1-Vpu fusion protein is expressed due to a nucleotide polymorphism that is unique to certain HIV-1 clade A and C strains. A better understanding of the expression and activity of these non-canonical viral proteins will help to dissect their potential role in viral replication and reveal how HIV-1 optimized the coding potential of its genes. The goal of this review is to provide an overview of previously described HIV-1 fusion proteins and to summarize our current knowledge of their expression patterns and putative functions. PMID:28119676

  3. Investigating the Ground-State Rotamers of n-Propylperoxy Radical

    DOE PAGES

    Hoobler, Preston Reece; Turney, Justin Matthew; Schaefer III, Henry

    2016-11-01

    The n-propylperoxy radical has been described as a molecule of critical importance to studies of low temperature combustion. Ab initio methods were used to study this three-carbon alkylperoxy radical, normal propylperoxy. Reliable CCSD(T)/ANO0 geometries were predicted for the molecule's five rotamers. For each rotamer, energetic predictions were made using basis sets as large as the cc-pV5Z in conjunction with coupled cluster levels of theory up to CCSDT(Q). Along with the extrapolations, corrections for relativistic effects, zero-point vibrational energies, and diagonal Born--Oppenheimer corrections were used to further refine energies. The results indicate that the lowest conformer is the gauche-gauche (GG) rotamermore » followed by the gauche-trans (0.12 kcal mol^-1 above GG), trans-gauche (0.44 kcal mol^-1), gauche'-gauche (0.47 kcal mol^-1), and trans-trans (0.57 kcal mol^-1). Fundamental vibrational frequencies were obtained using second-order vibrational perturbation theory (VPT2). This is the first time anharmonic frequencies have been computed for this system. The most intense IR features include all but one of the C-H stretches. The O-O fundamental (1063 cm^-1 for the GG structure) also has a significant IR intensity, 19.6 km mol^-1. The anharmonicity effects on the potential energy surface were also used to compute vibrationally averaged r_g,0 K bond lengths, accounting for zero-point vibrations present within the molecule.« less

  4. Investigating the Ground-State Rotamers of n-Propylperoxy Radical

    SciTech Connect

    Hoobler, Preston Reece; Turney, Justin Matthew; Schaefer III, Henry

    2016-11-01

    The n-propylperoxy radical has been described as a molecule of critical importance to studies of low temperature combustion. Ab initio methods were used to study this three-carbon alkylperoxy radical, normal propylperoxy. Reliable CCSD(T)/ANO0 geometries were predicted for the molecule's five rotamers. For each rotamer, energetic predictions were made using basis sets as large as the cc-pV5Z in conjunction with coupled cluster levels of theory up to CCSDT(Q). Along with the extrapolations, corrections for relativistic effects, zero-point vibrational energies, and diagonal Born--Oppenheimer corrections were used to further refine energies. The results indicate that the lowest conformer is the gauche-gauche (GG) rotamer followed by the gauche-trans (0.12 kcal mol^-1 above GG), trans-gauche (0.44 kcal mol^-1), gauche'-gauche (0.47 kcal mol^-1), and trans-trans (0.57 kcal mol^-1). Fundamental vibrational frequencies were obtained using second-order vibrational perturbation theory (VPT2). This is the first time anharmonic frequencies have been computed for this system. The most intense IR features include all but one of the C-H stretches. The O-O fundamental (1063 cm^-1 for the GG structure) also has a significant IR intensity, 19.6 km mol^-1. The anharmonicity effects on the potential energy surface were also used to compute vibrationally averaged r_g,0 K bond lengths, accounting for zero-point vibrations present within the molecule.

  5. Foot Small Muscle Atrophy is present before the detection of Clinical Neuropathy

    PubMed Central

    Greenman, Robert L; Khaodhiar, Lalita; Lima, Christina; Dinh, Thanh; Giurini, John M; Veves, Aristidis

    2005-01-01

    OBJECTIVE To characterize structural changes and the metabolic profile in the foot muscles and correlate them with diabetic neuropathy measurements using a phosphorus-31 (31P) rapid acquisition with relaxation enhancement (RARE) MRI method. RESEARCH DESIGN AND METHODS Twelve control subjects, nine non-neuropathic and 12 neuropathic diabetic patients were studied using 31P RARE and proton (1H) MRI at 3 Tesla. The ratio of the total cross-sectional area of the foot to that of the muscle tissue was calculated from trans-axial 1H and 31P images. The average 31P concentration across the metatarsal head region was measured from the 31P images. RESULTS The muscle/total-area ratio was different among all three groups: 0.55 ± 0.04 (means ± SD); 0.44 ± 0.05; and 0.06 ± 0.06 for controls, non-neuropathic and neuropathic subjects respectively, (p <0.0001). The average 31P concentration was also different among all groups: 27.7 ± 3.8 mM; 21.7 ± 4.8; and 7.9 ± 8.8 for controls, non-neuropathic and neuropathic subjects respectively, (p <0.0001). The muscle/total-area ratios strongly correlated with clinical measurements: Neuropathy Disability Score (NDS) (r = −0.83, p <0.0001), Vibration Perception Threshold (VPT) (r= −0.79, p <0.0001) and Semmes-Weinstein Monofilaments (SWM) (r = −0.87, p <0.0001). CONCLUSIONS Small muscle atrophy is present in diabetes before clinical peripheral neuropathy can be detected using standard techniques available in clinical practice. The 31P RARE MRI method evaluates the severity of muscle atrophy, even in the early stages when neuropathy is absent. This technique may prove a useful diagnostic tool that can identify early stage diabetic foot problems. PMID:15920063

  6. Two paramagnetic iron states at the Verwey phase transition in magnetite

    NASA Astrophysics Data System (ADS)

    Stankowski, J.; Kempiński, W.; Łoś, S.; Bednarski, W.; Waplak, S.; Micnas, R.

    2006-06-01

    At the Verwey phase transition (VPT) region a wide line of the ferromagnetic resonance (FMR) and a narrow EPR spectrum were observed. The EPR line at 125 K occurred and then disappeared below 85 K. This unexpected phenomenon is observed only if iron charge state transformation is present. Simulation of both FMR as well as EPR spectra has indicated the presence of two different iron clusters in the Fe 3O 4 structure. Best fit of both spectra yielded g=2.4 and 4.1 for FMR, and g=2.8 and 3.4 for EPR. The presence of two-component (EPR, FMR) spectra at about T is due to a frustration of charge distribution in the B-sublattice as a result of the orthorhombic Pmca pseudosymmetry constraints on the atomic positions in monoclinic symmetry cell P2/c. The paramagnetic (EPR) center observed is an admixtured Fe 2+ state in antiferromagnetically ordered A-sublattice ferromagnetically coupled with the B-lattice. Two paramagnetic defects observed (EPR) of localized spin states are evoked by two valency states of Fe 2.4 and Fe 2.6 below T. They can originate from two types of Fe 4O 4 cubes: "electron-rich" and" electron-poor" at a ratio 3:1 [J.P. Wright, J.P. Attfield, P.G. Radaelli, Phys. Rev. Lett. 87 (2001) 266401; Phys. Rev. B 66 (2002) 214422] or from two types of bond dimerization (H. Seo, M. Ogata, H. Fukuyama, Phys. Rev. B65 (2002) 85107).

  7. A randomized trial of the effects of the noble gases helium and argon on neuroprotection in a rodent cardiac arrest model.

    PubMed

    Zuercher, Patrick; Springe, Dirk; Grandgirard, Denis; Leib, Stephen L; Grossholz, Marius; Jakob, Stephan; Takala, Jukka; Haenggi, Matthias

    2016-04-04

    The noble gas xenon is considered as a neuroprotective agent, but availability of the gas is limited. Studies on neuroprotection with the abundant noble gases helium and argon demonstrated mixed results, and data regarding neuroprotection after cardiac arrest are scant. We tested the hypothesis that administration of 50% helium or 50% argon for 24 h after resuscitation from cardiac arrest improves clinical and histological outcome in our 8 min rat cardiac arrest model. Forty animals had cardiac arrest induced with intravenous potassium/esmolol and were randomized to post-resuscitation ventilation with either helium/oxygen, argon/oxygen or air/oxygen for 24 h. Eight additional animals without cardiac arrest served as reference, these animals were not randomized and not included into the statistical analysis. Primary outcome was assessment of neuronal damage in histology of the region I of hippocampus proper (CA1) from those animals surviving until day 5. Secondary outcome was evaluation of neurobehavior by daily testing of a Neurodeficit Score (NDS), the Tape Removal Test (TRT), a simple vertical pole test (VPT) and the Open Field Test (OFT). Because of the non-parametric distribution of the data, the histological assessments were compared with the Kruskal-Wallis test. Treatment effect in repeated measured assessments was estimated with a linear regression with clustered robust standard errors (SE), where normality is less important. Twenty-nine out of 40 rats survived until day 5 with significant initial deficits in neurobehavioral, but rapid improvement within all groups randomized to cardiac arrest. There were no statistical significant differences between groups neither in the histological nor in neurobehavioral assessment. The replacement of air with either helium or argon in a 50:50 air/oxygen mixture for 24 h did not improve histological or clinical outcome in rats subjected to 8 min of cardiac arrest.

  8. a Protocol for High-Accuracy Theoretical Thermochemistry

    NASA Astrophysics Data System (ADS)

    Welch, Bradley; Dawes, Richard

    2017-06-01

    Theoretical studies of spectroscopy and reaction dynamics including the necessary development of potential energy surfaces rely on accurate thermochemical information. The Active Thermochemical Tables (ATcT) approach by Ruscic^{1} incorporates data for a large number of chemical species from a variety of sources (both experimental and theoretical) and derives a self-consistent network capable of making extremely accurate estimates of quantities such as temperature dependent enthalpies of formation. The network provides rigorous uncertainties, and since the values don't rely on a single measurement or calculation, the provenance of each quantity is also obtained. To expand and improve the network it is desirable to have a reliable protocol such as the HEAT approach^{2} for calculating accurate theoretical data. Here we present and benchmark an approach based on explicitly-correlated coupled-cluster theory and vibrational perturbation theory (VPT2). Methyldioxy and Methyl Hydroperoxide are important and well-characterized species in combustion processes and begin the family of (ethyl-, propyl-based, etc) similar compounds (much less is known about the larger members). Accurate anharmonic frequencies are essential to accurately describe even the 0 K enthalpies of formation, but are especially important for finite temperature studies. Here we benchmark the spectroscopic and thermochemical accuracy of the approach, comparing with available data for the smallest systems, and comment on the outlook for larger systems that are less well-known and characterized. ^{1}B. Ruscic, Active Thermochemical Tables (ATcT) values based on ver. 1.118 of the Thermochemical Network (2015); available at ATcT.anl.gov ^{2}A. Tajti, P. G. Szalay, A. G. Császár, M. Kállay, J. Gauss, E. F. Valeev, B. A. Flowers, J. Vázquez, and J. F. Stanton. JCP 121, (2004): 11599.

  9. Peripheral Neuropathy and Nerve Dysfunction in Individuals at High Risk for Type 2 Diabetes: The PROMISE Cohort.

    PubMed

    Lee, C Christine; Perkins, Bruce A; Kayaniyil, Sheena; Harris, Stewart B; Retnakaran, Ravi; Gerstein, Hertzel C; Zinman, Bernard; Hanley, Anthony J

    2015-05-01

    Emerging evidence suggests that peripheral neuropathy begins in the early stages of diabetes pathogenesis. Our objective was to describe the prevalence of peripheral neuropathy and nerve dysfunction according to glucose tolerance and metabolic syndrome status and examine how these conditions are associated with neurological changes in individuals at risk for type 2 diabetes. We studied 467 individuals in the longitudinal PROMISE (Prospective Metabolism and Islet Cell Evaluation) cohort. Peripheral neuropathy was defined by Michigan Neuropathy Screening Instrument (MNSI) scores (>2), and the severity of nerve dysfunction was measured objectively by vibration perception thresholds (VPTs) using a neurothesiometer. Metabolic syndrome was defined using the International Diabetes Federation/American Heart Association harmonized criteria. The prevalence of peripheral neuropathy was 29%, 49%, and 50% for normal glycemia, prediabetes, and new-onset diabetes, respectively (P < 0.001 for trend). The mean VPT was 6.5 V for normal glycemia, 7.9 V for prediabetes, and 7.6 V for new-onset diabetes (P = 0.024 for trend). Prediabetes was associated with higher MNSI scores (P = 0.01) and VPTs (P = 0.004) versus normal glycemia, independent of known risk factors. Additionally, progression of glucose intolerance over 3 years predicted a higher risk of peripheral neuropathy (P = 0.007) and nerve dysfunction (P = 0.002). Metabolic syndrome was not independently associated with MNSI scores or VPTs. In individuals with multiple risk factors for diabetes, prediabetes was associated with similar risks of peripheral neuropathy and severity of nerve dysfunction as new-onset diabetes. Prediabetes, but not metabolic syndrome, was independently associated with both the presence of peripheral neuropathy and the severity of nerve dysfunction. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit

  10. Critical interpretation of CH– and OH– stretching regions for infrared spectra of methanol clusters (CH{sub 3}OH){sub n} (n = 2–5) using self-consistent-charge density functional tight-binding molecular dynamics simulations

    SciTech Connect

    Nishimura, Yoshifumi; Lee, Yuan-Pern; Irle, Stephan; Witek, Henryk A.

    2014-09-07

    Vibrational infrared (IR) spectra of gas-phase O–H⋅⋅⋅O methanol clusters up to pentamer are simulated using self-consistent-charge density functional tight-binding method using two distinct methodologies: standard normal mode analysis and Fourier transform of the dipole time-correlation function. The twofold simulations aim at the direct critical assignment of the C–H stretching region of the recently recorded experimental spectra [H.-L. Han, C. Camacho, H. A. Witek, and Y.-P. Lee, J. Chem. Phys. 134, 144309 (2011)]. Both approaches confirm the previous assignment (ibid.) of the C–H stretching bands based on the B3LYP/ANO1 harmonic frequencies, showing that ν{sub 3}, ν{sub 9}, and ν{sub 2} C–H stretching modes of the proton-accepting (PA) and proton-donating (PD) methanol monomers experience only small splittings upon the cluster formation. This finding is in sharp discord with the assignment based on anharmonic B3LYP/VPT2/ANO1 vibrational frequencies (ibid.), suggesting that some procedural faults, likely related to the breakdown of the perturbational vibrational treatment, led the anharmonic calculations astray. The IR spectra based on the Fourier transform of the dipole time-correlation function include new, previously unaccounted for physical factors such as non-zero temperature of the system and large amplitude motions of the clusters. The elevation of temperature results in a considerable non-homogeneous broadening of the observed IR signals, while the presence of large-amplitude motions (methyl group rotations and PA-PD flipping), somewhat surprisingly, does not introduce any new features in the spectrum.

  11. Anharmonic Vibrational Analysis of the Infrared and Raman Gas-Phase Spectra of s-trans- and s-gauche-1,3-Butadiene.

    PubMed

    Krasnoshchekov, Sergey V; Craig, Norman C; Boopalachandran, Praveenkumar; Laane, Jaan; Stepanov, Nikolay F

    2015-10-29

    A quantum-mechanical (hybrid MP2/cc-pVTZ and CCSD(T)/cc-pVTZ) full quartic potential energy surface (PES) in rectilinear normal coordinates and the second-order operator canonical Van Vleck perturbation theory (CVPT2) are employed to predict the anharmonic vibrational spectra of s-trans- and s-gauche-butadiene (BDE). These predictions are used to interpret their infrared and Raman scattering spectra. New high-temperature Raman spectra in the gas phase are presented in support of assignments for the gauche conformer. The CVPT2 solution is based on a PES and electro-optical properties (EOP; dipole moment and polarizability) expanded in Taylor series. Higher terms than those routinely available from Gaussian09 software were calculated by numerical differentiation of quadratic force fields and EOP using the MP2/cc-pVTZ model. The integer coefficients of the polyad quantum numbers were derived for both conformers of BDE. Replacement of harmonic frequencies by their counterparts from the CCSD(T)/cc-pVTZ model significantly improved the agreement with experimental data for s-trans-BDE (root-mean-square deviation ≈ 5.5 cm(-1)). The accuracy in predicting the rather well-studied spectrum of fundamentals of s-trans-BDE assures good predictions of the spectrum of s-gauche-BDE. A nearly complete assignment of fundamentals was obtained for the gauche conformer. Many nonfundamental transitions of the BDE conformers were interpreted as well. The predictions of multiple Fermi resonances in the complex CH-stretching region correlate well with experiment. It is shown that solving a vibrational anharmonic problem through a numerical-analytic implementation of CVPT2 is a straightforward and computationally advantageous approach for medium-size molecules in comparison with the standard second-order vibrational perturbation theory (VPT2) based on analytic expressions.

  12. Bile salt-stimulated lipase of human milk: characterization of the enzyme from preterm and term milk

    SciTech Connect

    Freed, L.M.; Hamosh, P.; Hamosh, M.

    1986-03-01

    The bile salt-stimulated lipase (BSSL) of human milk is an important digestive enzyme in the newborn whose pancreatic function is immature. Milk from mothers delivering premature infants (preterm milk) has similar levels of BSSL activity to that of mothers of term infants (term milk). This study has determined whether the BSSL in preterm milk has the same characteristics as that in term milk. Milk samples were collected during the first 12 wk of lactation from seven mothers of infants born at 26-30 wk (very preterm, VPT), 31-37 wk (preterm, PT) and 37-42 wk (term, T) gestation. BSSL activity was measured using /sup 3/H-triolein emulsion as substrate. Time course, bile salt and enzyme concentration, pH and pH stability were studied, as well as inhibition of BSSL by eserine. The characteristics of BSSL from preterm and term milk were identical as were comparisons between colostrum and mature milk BSSL. BSSL from all milk sources had a neutral-to-alkaline pH optimum (pH 7.3-8.9), was stable at low pH for 60 min, and was 95-100% inhibited by eserine (greater than or equal to 0.6 mM). BSSL activity, regardless of enzyme source, was bile-salt dependent and was stimulated only by primary bile salts (taurocholate, glycocholate). The data indicate that the BSSL in milks of mothers delivering as early as 26 wk gestation is identical to that in term milk.

  13. Comparison of diabetes patients with “demyelinating” diabetic sensorimotor polyneuropathy to those diagnosed with CIDP

    PubMed Central

    Dunnigan, Samantha K; Ebadi, Hamid; Breiner, Ari; Katzberg, Hans D; Lovblom, Leif E; Perkins, Bruce A; Bril, Vera

    2013-01-01

    Background We have previously identified a subset of diabetic sensorimotor polyneuropathy (DSP) patients with probable demyelination related to poor glycemic control. We aimed to determine whether the clinical characteristics and electrodiagnostic classification of nerve injury in diabetes patients with “demyelinating” DSP (D-DSP) differed from those diagnosed with chronic inflammatory demyelinating polyneuropathy (CIDP) (CIDP + diabetes mellitus [DM]). Methods D-DSP (56) and CIDP + DM (67) subjects underwent clinical examination and nerve conduction studies (NCS), and were compared using analysis of variance, contingency tables, and Kruskal–Wallis analyses. Results Of the 123 subjects with a mean age of 60.5 ± 15.6 years and mean hemoglobin A1c (HbA1c) of 8.2 ± 2.2%, 54% had CIDP + DM and 46% had D-DSP. CIDP + DM subjects were older (P = 0.0003), had shorter duration of diabetes (P = 0.005), and more severe neuropathy as indicated by Toronto Clinical Neuropathy Score (TCNS) (P = 0.003), deep tendon reflexes (P = 0.02), and vibration perception thresholds (VPT) (P = 0.01, P = 0.02). The mean HbA1c value for D-DSP subjects (8.9 ± 2.3%) was higher than in CIDP + DM subjects (7.7 ± 2.0%, P = 0.02). Conclusions The clinical phenotype and electrophysiological profile of CIDP + DM patients is marked by more severe neuropathy and better glycemic control than in patients with D-DSP. These findings indicate that these two conditions – despite similarities in their electrophysiological pattern of demyelination – likely differ in etiology. PMID:24363969

  14. Spectroscopic Studies of Molecular Systems relevant in Astrobiology

    NASA Astrophysics Data System (ADS)

    Fornaro, Teresa

    2016-01-01

    double-ζ quality such as N07D and SNSD. Such a protocol has been then applied to the dimers of nucleobases in order to study the perturbation on the vibrational frequencies and infrared intensities induced by the intermolecular hydrogen-bonding interactions. Efforts have been made to challenge the problems of simulating strongly anharmonic vibrations within hydrogen-bonded bridges, focusing on the requirement of a very accurate description of the underlying potential energy surface. Improvements for such vibrations have been achieved by means of hybrid models, where the harmonic part of the force-field is computed at a higher level of theory like B2PLYP, or by application of the less demanding ONIOM B2PLYP:B3LYP scheme, which is a focused model where only the part of the molecular system forming the hydrogen bonds is treated at B2PLYP level of theory. Moreover, for improving the vibrational frequencies of modes like the stretching of C=O and N-H functional groups, which are particularly sensitive to hydrogen-bonding, correction parameters for the B3LYP-D3/N07D frequencies have been determined. Afterwards, the treatment of the vibrational properties of nucleobases in condensed phases has been faced, focusing on uracil in the solid state. In particular, a heptamer cluster of uracil molecules has been considered as model to represent the properties in the solid state. The relative vibrational frequencies have been computed at anharmonic level within the VPT2 framework, combining two cost-effective approaches, namely the hybrid B3LYP-D3/N07D:DFTBA model, where the harmonic frequencies are computed with B3LYP-D3/N07D method and the anharmonic corrections are evaluated with the less expensive DFTBA method, and the reduced dimensionality VPT2 (RD-VPT2) approach, in which only selected vibrational modes are calculated anharmonically (including the couplings with the other modes) while the remaining modes are treated at the harmonic level, using the B3LYP-D3/N07D method only

  15. Anharmonic vibrational analyses for the 1-silacyclopropenylidene molecule and its three isomers

    NASA Astrophysics Data System (ADS)

    Wu, Qunyan; Hao, Qiang; Wilke, Jeremiah J.; Simmonett, Andrew C.; Yamaguchi, Yukio; Li, Qianshu; Fang, De-Cai; Schaefer, Henry F., III

    2012-05-01

    The global minimum among possible structures of SiC2H2 has been experimentally and theoretically determined to be 1-silacyclopropenylidene (1S). In 1994 Maier and Reisenauer reported the generation of 1-silacyclopropenylidene and its three isomers (2S-4S) by pulsed-flash pyrolysis followed by matrix-spectroscopic identification. Reliable quartic force fields for 1-silacyclopropenylidene and its three isomers are determined employing ab initio coupled-cluster theory with single, double, and perturbative triple excitations [CCSD(T)] and the correlation-consistent core-valence quadruple zeta (cc-pCVQZ) basis set. Second-order vibrational perturbation theory (VPT2) has been utilized to determine equilibrium and zero-point vibration corrected rotational constants, centrifugal distortion constants, and harmonic and anharmonic vibrational frequencies. The distances between the average nuclear positions (r α ) are also determined. The predicted rotational constants, centrifugal distortion constants, and anharmonic frequencies for the four lowest-lying isomers (1S-4S) of SiC2H2, as well as their 13C and deuterated isotopologues, agree well with available experiments. Excluding the CH and CD stretching modes, the mean absolute deviation between theoretical anharmonic and experimental fundamental frequencies for isomer 1-silacyclopropenylidene (1S) is 4.1 cm-1 (5 isotopologues, 25 modes). The corresponding deviation for ethynylsilanediyl (2 S) is 4.9 cm-1 (7 isotopologues, 38 modes) without the SiH and SiD stretching modes, while it is 8.6 cm-1 (5 isotopologues, 22 modes) for silacyclopropyne (4S) without the SiC s-stretching, SiH2 a-stretching and SiD2 wagging modes. By comparing the theoretical harmonic and anharmonic with the experimental fundamental vibrational frequencies for the four isomers (1S-4S), it is demonstrated that the anharmonic effects greatly improve the harmonic results. This theoretically derived spectroscopic data should aid in the experimental detection

  16. Electrochemical skin conductance to detect sudomotor dysfunction, peripheral neuropathy and the risk of foot ulceration among Saudi patients with diabetes mellitus.

    PubMed

    Sheshah, Eman; Madanat, Amal; Al-Greesheh, Fahad; Al-Qaisi, Dalal; Al-Harbi, Mohammad; Aman, Reem; Al-Ghamdi, Abdul Aziz; Al-Madani, Khaled

    2015-01-01

    Sudomotor dysfunction is manifested clinically as abnormal sweating leading to dryness of feet skin and increased risk of foot ulceration. The aim of this study was to test the performance of foot electrochemical skin conductance (ESC) to detect diabetic peripheral neuropathy and the risk of foot ulceration against traditional methods in Saudi patients with diabetes mellitus. This cross-sectional study was conducted on 296 Saudi patients with diabetes mellitus. Painful neuropathic symptoms were evaluated using the neuropathy symptom score (NSS). The risk of foot ulceration and diabetic peripheral neuropathy were determined using the neuropathy disability score (NDS). Vibration perception threshold (VPT) was assessed using neurothesiometer. Neurophysiological assessment of the right and left sural, peroneal and tibial nerves was performed in 222 participants. Diabetic peripheral neuropathy was defined according to the definition of the American Academy of Neurology. ESC was measured with Sudoscan. Feet-ESC decreased as the scores of sensory and motor function tests increased. Feet-ESC decreased as the NSS, NDS and severity of diabetic peripheral neuropathy increased. Sensitivity of feet-ESC < 50μS to detect diabetic peripheral neuropathy assessed by VPT ≥ 25 V, NDS ≥ 3, NDS ≥ 6 was 90.1, 61 and 63.8 % respectively and specificity 77, 85 and 81.9 % respectively. Sensitivity of feet-ESC < 70μS to detect diabetic peripheral neuropathy assessed by VPT ≥ 25 V, NDS ≥ 3, NDS ≥ 6 was 100, 80.6 and 80.9 % respectively. Sensitivity and specificity of feet-ESC < 70μS to detect confirmed-diabetic peripheral neuropathy were 67.5 and 58.9 % respectively. Sudoscan a simple and objective tool can be used to detect diabetic peripheral neuropathy and the risk of foot ulceration among patients with diabetes mellitus. Prospective studies to confirm our results are warranted.

  17. Fabrication and characterization of ZnO nanowires grown on Ti substrate

    NASA Astrophysics Data System (ADS)

    Meng, Gang; Fang, Xiaodong; Tao, Ruhua; Dong, Weiwei; Deng, Zanhong; Zhou, Shu

    2009-07-01

    Zinc oxide (ZnO) with a wide band gap of 3.37 eV, and a large exciton binding energy of 60 mV at room temperature, is one of the most important n-type semiconductor, that has potential applications in the area of short-wavelength optoelectronic devices, gas sensors, solar cells, and field emitters. Some advanced nanodevices based on one-dimensional (1-D) ZnO nanomaterials have been successfully demonstrated in the past few years. The types of substrate have a great influence on the properties of ZnO nanostrctural devices. Semiconductor substrates such as Si and Al2O3 were widely used for the collection or epitaxial growth of ZnO nanostructures, for metal substrate, Fe and Cu foil has also been used as substrate, there are few reports on ZnO nanowires grown on Ti foil, Ti is an important electrode metal that ohmic contact can be appropriately achieved, which is critical for semiconductor device application. Besides, both Ti and ZnO show good biocompatibility, it is expected that ZnO nanowires/ Ti show good performance on bio-sensors. In this paper, 1-D ZnO nanostructures have been successfully fabricated on the conductive Ti substrate via a vapor phase transport (VPT) method by carbothermal reduction of ZnO and graphite powder mixture in a tube furnace at 850°C. The final products were characterized by means of field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), high-solution transmission electron microscope (HRTEM) (equipped with selected area electron diffraction, SAED), and photoluminescence (PL) spectroscopy. FE SEM results show that dense, ultra-long (>10μm), and locally aligned ZnO nanowire arrays were grown on the Ti foil. The diameter of nanowires exhibits a wide range from 150 nm to about 500nm. Structural characterizations (XRD, SAED, HRTEM) indicate the as synthesized nanostructures have a ZnO wurtzite structure and are perfect single crystalline without any defects or impurities. The growth direction is [0001]. Optical

  18. Infrared absorption of methanol clusters (CH3OH)n with n = 2-6 recorded with a time-of-flight mass spectrometer using infrared depletion and vacuum-ultraviolet ionization.

    PubMed

    Han, Hui-Ling; Camacho, Cristopher; Witek, Henryk A; Lee, Yuan-Pern

    2011-04-14

    We investigated IR spectra in the CH- and OH-stretching regions of size-selected methanol clusters, (CH(3)OH)(n) with n = 2-6, in a pulsed supersonic jet by using the IR-VUV (vacuum-ultraviolet) ionization technique. VUV emission at 118 nm served as the source of ionization in a time-of-flight mass spectrometer. The tunable IR laser emission served as a source of predissociation or excitation before ionization. The variations of intensity of protonated methanol cluster ions (CH(3)OH)(n)H(+) and CH(3)OH(+) and (CH(3)OH)(2)(+) were monitored as the IR laser light was tuned across the range 2650-3750 cm(-1). Careful processing of these action spectra based on photoionization efficiencies and the production and loss of each cluster due to photodissociation yielded IR spectra of the size-selected clusters. Spectra of methanol clusters in the OH region have been extensively investigated; our results are consistent with previous reports, except that the band near 3675 cm(-1) is identified as being associated with the proton acceptor of (CH(3)OH)(2). Spectra in the CH region are new. In the region 2800-3050 cm(-1), bands near 2845, 2956, and 3007 cm(-1) for CH(3)OH split into 2823, 2849, 2934, 2955, 2984, and 3006 cm(-1) for (CH(3)OH)(2) that correspond to proton donor and proton acceptor, indicating that the methanol dimer has a preferred open-chain structure. In contrast, for (CH(3)OH)(3), the splitting diminishes and the bands near 2837, 2954, and 2987 cm(-1) become narrower, indicating a preferred cyclic structure. Anharmonic vibrational wavenumbers predicted for the methanol open-chain dimer and the cyclic trimer with the B3LYP∕VPT2∕ANO1 level of theory are consistent with experimental results. For the tetramer and pentamer, the spectral pattern similar to that of the trimer but with greater widths was observed, indicating that the most stable structures are also cyclic.

  19. Magnesium bicarbonate and carbonate interactions in aqueous solutions: An infrared spectroscopic and quantum chemical study

    NASA Astrophysics Data System (ADS)

    Stefánsson, Andri; Lemke, Kono H.; Bénézeth, Pascale; Schott, Jacques

    2017-02-01

    The interaction of magnesium with bicarbonate and carbonate ions in aqueous solutions was studied using infrared spectroscopy and quantum chemical calculations. Using the infrared vibrational bands for HCO3- and CO32- at 1200-1450 cm-1 (δC-OH, vS and v3) together with their molar absorptivity (ε), the concentrations of the HCO3- and CO32- ions and the corresponding Mg ion pairs have been determined. In the absence of Mg2+, measured spectra were accurately reproduced assuming that only HCO3- and CO32- were present in solution. Upon addition of Mg2+ at fixed pH, infrared spectra were observed to shift indicating presence of the MgHCO3+ and MgCO3 (aq) ion pairs. From measurements, the second ionization constant of carbonic acid and the MgHCO3+ and MgCO3 (aq) ion pair formation constants have been obtained, these being logK2 = -10.34 ± 0.04, logKMgHCO3+ = 1.12 ± 0.11 and logKMgCO3 = 2.98 ± 0.06, respectively. To support our experimental infrared measurements and to gain further insight into the molecular nature of the ion pair formation, density functional theory (DFT) calculations with VPT2 anharmonic correction were conducted. The most stable geometries predicted for the MgHCO3+ and MgCO3 (aq) ion pairs were a bi-dentate [MgHCO3]+(H2O)n and a monodentate [MgHCO3]+(OH)(H2O)n complexes, respectively. The predicted frequencies for HCO3-, CO32- and MgHCO3+ were found to shift toward those experimentally measured with an increasing H2O solvation number where possible band shifts were predicted for MgCO3 (aq) relative to CO32-, this being dependent on the exact structure and hydration of the bulk MgCO3 (aq) ion pair. Experimentally, the ion pair formations were found to have insignificant effects on the δC-OH, vS and v3 vibrational frequencies. The speciation of dissolved inorganic carbon may be significantly influenced by ion pair formation, particularly in alkaline solutions where they may be the predominant species.

  20. High-speed dual Langmuir probe.

    PubMed

    Lobbia, Robert B; Gallimore, Alec D

    2010-07-01

    In an effort to temporally resolve the electron density, electron temperature, and plasma potential for turbulent plasma discharges, a unique high-speed dual Langmuir probe (HDLP) has been developed. A traditional single Langmuir probe of cylindrical geometry (exposed to the plasma) is swept simultaneously with a nearby capacitance and noise compensating null probe (fully insulated from the plasma) to enable bias sweep rates on a microsecond timescale. Traditional thin-sheath Langmuir probe theory is applied for interpretation of the collected probe data. Data at a sweep rate of 100 kHz are presented; however the developed system is capable of running at 1 MHz-near the upper limit of the applied electrostatic Langmuir probe theory for the investigated plasma conditions. Large sets (100,000 sweeps at each of 352 spatial locations) of contiguous turbulent plasma properties are collected using simple electronics for probe bias driving and current measurement attaining 80 dB signal-to-noise measurements with dc to 1 MHz bandwidth. Near- and far-field plume measurements with the HDLP system are performed downstream from a modern Hall effect thruster where the time-averaged plasma properties exhibit the approximate ranges: electron density n(e) from (1x10(15))-(5x10(16)) m(-3), electron temperature T(e) from 1 to 3.5 eV, and plasma potential V(p) from 5 to 15 V. The thruster discharge of 200 V (constant anode potential) and 2 A (average discharge current) displays strong, 2.2 A peak-to-peak, current oscillations at 19 kHz, characteristic of the thruster "breathing mode" ionization instability. Large amplitude discharge current fluctuations are typical for most Hall thrusters, yet the HDLP system reveals the presence of the same 19 kHz fluctuations in n(e)(t), T(e)(t), and V(p)(t) throughout the entire plume with peak-to-peak divided by mean plasma properties that average 94%. The propagation delays between the discharge current fluctuations and the corresponding plasma

  1. Quantitative neurosensory findings, symptoms and signs in young vibration exposed workers

    PubMed Central

    2013-01-01

    Background Long-term exposure to hand-held vibrating tools may cause the hand arm vibration syndrome (HAVS) including vibration induced white fingers and sensorineural symptoms. The aim was to study early neurosensory effects by quantitative vibrotactile and monofilament tests in young workers with hand-held vibration exposure. Methods This cross-sectional study consisted of 142 young, male machine shop and construction workers with hand-held exposure to vibrating tools. They were compared with 41 non-vibration exposed subjects of the same age-group. All participants passed a structured interview, answered several questionnaires and had a physical examination including the determination of vibrotactile perception thresholds (VPTs) at two frequencies (31.5 and 125 Hz) and Semmes Weinstein’s Monofilament test. Results In the vibration exposed group 8% of the workers reported episodes of tingling sensations and 10% numbness in their fingers. Approximately 5–10% of the exposed population displayed abnormal results on monofilament tests. The vibrotactile testing showed significantly increased VPTs for 125 Hz in dig II bilaterally (right hand, p = 0.01; left hand, p = 0.024) in the vibration exposed group. A multiple regression analysis (VPT - dependent variable; age, height, examiner and five different vibration dose calculations – predictor variables) in dig II bilaterally showed rather low R2-values. None of the explanatory variables including five separately calculated vibration doses were included in the models, neither for the total vibration exposed group, nor for the highest exposed quartile. A logistic multiple regression analysis (result of monofilament testing - dependent variable; age, height, examiner and five vibration dose calculations – predictor variables) of the results of monofilament testing in dig II bilaterally gave a similar outcome. None of the independent variables including five calculated vibration doses were included in the

  2. 'Geoba-Raman-try': calibration of spectroscopic barometers for mineral inclusions (Invited)

    NASA Astrophysics Data System (ADS)

    Kohn, M. J.

    2013-12-01

    Determination of pressure-temperature (P-T) conditions of mineral formation underpins many crustal and mantle petrogenetic endeavors. Trace element thermometry has vastly improved T constraints, but P remains elusive and is still mainly based on solid state net-transfer reactions restricted to particular assemblages and whole-rock compositions. Novel Raman micro-spectroscopy may expand the range of geobarometers. At the P-T conditions of entrapment, no pressure mismatch occurs between inclusion and host (ΔP = 0). During cooling and exhumation, however, different thermal expansivities and compressibilities between host and inclusions impart a residual pressure (ΔP≠0) whose magnitude depends on entrapment P-T, V(P,T) and the shear modulus of the host phase. Many Raman peak positions are P-dependent, allowing ΔP to be measured. Based on shear moduli and V(P,T) (Holland & Powell, 2011, JMG), and assuming inclusions are small so that the host behaves as an infinite medium, a distribution of P-T-ΔP conditions may be calculated for various host-inclusion pairs and fit to simplified barometric calibrations. Distributions were calculated over P=0 to 25 kbar and T=400 to 900 °C for α-quartz- and graphite-bearing assemblages and P=35 to 150 kbar and T=800 to 1400 °C for diamond-bearing assemblages. These lead to the following calibrations (P in bars, T in K): Graphite-in-Grt (GriG): P = 1.491ΔP+1.129T+184*exp(ΔP/(9T))-1197 Qtz-in-Grt (QuiG): P = 0.8586ΔP+18.31T+12922*exp(ΔP/(27T))-21615 MgGrt-in-Dia (GriD, <90 kb): P = 2.07ΔP+50.8T+971*exp(ΔP/(15T))-13881 MgGrt-in-Dia (GriD, >90 kb): P = 2.31ΔP+52.0T+363*exp(ΔP/(15T))-18327 Coe-in-Dia (CoiD, <90 kb): P = 1.56ΔP+2.82T+143.7*exp(ΔP/(15T))-532 Coe-in-Dia (CoiD, >90 kb): P = 1.82ΔP-0.68T+13.54*exp(ΔP/(15T))-8197 Qtz-in-Omp (QuiO): P = 1.027ΔP+18.52T+10043*exp(ΔP/(17T))-18975 Qtz-in-Rt (QuiR): P = 0.7537ΔP+17.73T+14793*exp(ΔP/(26T))-23379 Qtz-in-Zrc (QuiZ): P = 1.007ΔP+20.32T+8108*exp(ΔP/(26T))-16410 For

  3. Stabile Expression von Sulfotransferasen - allein oder in Kombination mit Cytochrom P450 - in Zelllinien für Mutagenitätsuntersuchungen

    NASA Astrophysics Data System (ADS)

    Pabel, Ulrike

    2003-10-01

    -dimethylaminoazobenzol; 0,1 µM für 2-Aminoanthracen; 10 µM für 2,4-Diaminotoluol). Die stärkste Aktivierung von 2-Acetylaminofluoren und 3′-Methyl-4-dimethylaminoazobenzol erfolgte in der Zelllinie, die CYP1A2 und SULT1A2 koexprimierte; die stärkste Aktivierung von 2,4-Diaminotoluol und 2-Aminoanthracen erfolgte in der Zelllinie, die CYP1A2 und SULT1A1 koexprimierte. Sowohl SULT1A1 als auch SULT1A2 sind im Menschen genetisch polymorph. Ein unterschiedlich starkes Aktivierungspotenzial der Alloenzyme könnte eine individuell unterschiedliche Suszeptibilität für die durch aAA ausgelöste Kanzerogenese bedingen. In HPRT-Mutationsuntersuchungen mit rekombinanten Zellen zeigten die allelischen Varianten der SULT1A2 starke Unterschiede in ihrem Aktivierungpotenzial. Nur in der Zelllinie, die das Alloenzym SULT1A2*1 mit CYP1A2 koexprimierte, wurde 2-Acetylaminofluoren zum Mutagen aktiviert. Zur Aktivierung von 3′-Methyl-4-dimethylaminoazobenzol waren jedoch sowohl das Alloenzym SULT1A2*1 als auch das Alloenzym SULT1A2*2 in der Lage. Die Alloenzyme der SULT1A1 zeigten ein ähnlich gutes Aktivierungspotenzial für aAA. In früheren Studien wurde gezeigt, dass die SULT1C1 der Ratte eine wichtige Rolle bei der Aktivierung der aAA in dieser Spezies spielt. Dahingegen war die humane SULT1C1 nicht in der Lage die untersuchten aAA zu aktivieren. Die Kenntnis solcher Spezieunterschiede könnte wichtig sein um unterschiedliche Organotropismen aAA in Menschen und Tiermodellen zu erklären, da SULT mit starker Gewebespezifität exprimiert werden und das Expressionsmuster für die einzelnen SULT-Formen in Menschen und Ratten sich stark unterscheidet. Aromatic amines and amides (aAA) represent a group of chemicals with great toxicological importance due to their wide distribution in the environment and their carcinogenic potency. The carcinogenicity of aAA is mediated by the mutagenic action of highly reactive metabolites. They are frequently formed by N-hydroxylation of the exocyclic

  4. Chemomechanical properties and the applications of semi-confined hydrogel microstructures

    NASA Astrophysics Data System (ADS)

    Ding, Zhenwen

    Environmentally sensitive hydrogels are three-dimensional crosslinked polymer networks capable of undergoing reversible volume change in response to different stimuli such as temperature, pH, ionic strength, electric field, etc. The integration of these soft polymeric materials with conventional micromachined hard materials (such as silicon and glass) offers unique opportunities to enhance their applications and functionalities. Many such applications require the hydrogel to be trapped in a semi-confined structure. This calls for a careful study of hydrogel thermodynamics, kinetics, and chemomechanical properties associated with such a confinement. This physiochemical understanding is essential in order to design hydrogel-based smart sensing and actuating microdevices. This Ph.D. thesis consists of two parts. The first part will be focused on the physical concepts and measurements of the physical parameters of hydrogels. We will discuss the hydrogel network structure, kinetics of hydrogel volume phase transition (VPT), biomolecule diffusion in hydrogel network, and characterizations of hydrogel properties. In the second part, we will discuss the applications of semi-confined hydrogel structures in microsystems. A high-resolution technique for fabricating hydrogel microstructures will be presented. In this method, squeeze-film is used to generate hydrogel thin film on a smooth substrate. Parylene passivation and dry etching are utilized for micropatterning. This method allows for the integration of hydrogel with MEMS and NEMS microstructures in order to fabricate miniaturized devices for sensing and actuating. Subsequently, two applications will be discussed using the patterning technique: a hydrogel diffraction grating and a hydrogel-based integrated-antenna pH sensor. Microscale patterning of biomolecules (DNA, antibody, enzyme, etc.) on solid surfaces is necessary for the successful development of many biotechnological microdevices. We developed a hydrogel

  5. Optimal geometries and harmonic vibrational frequencies of the global minima of water clusters (H2O)n, n = 2–6, and several hexamer local minima at the CCSD(T) level of theory

    SciTech Connect

    Miliordos, Evangelos; Aprà, Edoardo; Xantheas, Sotiris S.

    2013-01-01

    (T) harmonic frequencies, when corrected using the MP2 anharmonicities obtained from second order vibrational perturbation theory (VPT2), produce anharmonicCCSD(T) estimates that are within < 60 cm-1 from the measured infrared (IR) active bands of the n=2-6 clusters and furthermore trace the observed red shifts with respect to the monomer (Δν) quite accurately. The energetic order between the various hexamer isomers on the PES (prism has the lowest energy) previously reported at MP2 was found to be preserved at the CCSD(T) level, whereas the inclusion of anharmonic corrections further stabilizes the cage among the hexamer isomers.

  6. Integrated Cooling System for Induction Motor Traction Drives, CARAT Program Phase Two Final Report

    SciTech Connect

    Konrad, Charles E.

    2002-12-03

    This Program is directed toward improvements in electric vehicle/hybrid electric vehicle traction systems, and in particular, the development of a low cost, highly efficient, compact traction motor-controller system targeted for high volume automotive use. Because of the complex inter-relationships between the motor and the controller, the combination of motor and controller must be considered as a system in the design and evaluation of overall cost and performance. The induction motor is ideally suited for use as a traction motor because of its basic ruggedness, low cost, and high efficiency. As one can see in Figure 1.1, the induction motor traction drive has been continually evolving through a succession of programs spanning the past fifteen years. VPT marketed an induction motor-based traction drive system, the EV2000, which proved to be a reliable, high performance system that was used in a wide range of vehicles. The EV2000 drives evolved from the Modular Electric Vehicle Program (MEVP) and has been used in vehicles ranging in size from 3,000 lb. autos and utility vans, to 32,000 lb. city transit buses. Vehicles powered by the EV2000 induction motor powertrain have accumulated over 2 million miles of service. The EV2000 induction motor system represents 1993 state-of-the-art technology, and evolved from earlier induction motor programs that drove induction motor speeds up to 15,000 rpm to reduce the motor size and cost. It was recognized that the improvements in power density and motor cost sought in the PNGV program could only be achieved through increases in motor speed. Esson’s Rule for motor power clearly states that the power obtainable from a given motor design is the product of motor speed and volume. In order to meet the CARAT Program objectives, the maximum speed goal of the induction motor designed in this Program was increased from 15,000 rpm to 20,000 rpm while maintaining the efficiency and durability demonstrated by lower speed designs done in

  7. A novel thermodynamic model of Mg2SiO4 with a superior representation of experimental data predicts negligible layering in mantle convection

    NASA Astrophysics Data System (ADS)

    Jacobs, M. H.; de Jong, B. H.; van den Berg, A. P.

    2005-12-01

    substances behave quasi-harmonically. The predicted Clapeyron slope of the post- spinel phase boundary is -(2.0±0.5) MPa/K. These results, have been included in a numerical model of convection in the Earth's mantle revealing no layered convection in the transition zone. Our model includes the recently discovered post-perovskite phase (P~125 GPa) based on ab-initio results and V-P-T measurements by Murakami et al. [6]. The convection results indicate that the post- perovskite layer at the bottom of the mantle is a time-dependent phenomenon strongly affected by core temperature of a cooling earth. References [1] M.H.G. Jacobs and B.H.W.S. de Jong, Geochim. Cosmochim. Acta (2005), in press. [2] S.W. Kieffer, Rev. Geophys. Space Physics, 17 (1979) 35-59. [3] M.H.G. Jacobs, B.H.W.S. de Jong and A.P. van den Berg, Calphad (2005), submitted. [4] T. Inoue, Y. Tanimoto, T. Irifune, T. Suzuki, H. Fukui and O. Ohtaka, Phys. Earth Planet. Int. 143-144 (2004) 279-290. [5] I. Suzuki, J. Phys. Earth, 27 (1979) 53-61. [6] M. Murakami, K. Hirose, K. Kawamura, N. Sata and Y. Ohishi, Science, 304 (2004) 855-855

  8. Growth

    NASA Astrophysics Data System (ADS)

    Waag, Andreas

    This chapter is devoted to the growth of ZnO. It starts with various techniques to grow bulk samples and presents in some detail the growth of epitaxial layers by metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), and pulsed laser deposition (PLD). The last section is devoted to the growth of nanorods. Some properties of the resulting samples are also presented. If a comparison between GaN and ZnO is made, very often the huge variety of different growth techniques available to fabricate ZnO is said to be an advantage of this material system. Indeed, growth techniques range from low cost wet chemical growth at almost room temperature to high quality MOCVD growth at temperatures above 1, 000∘C. In most cases, there is a very strong tendency of c-axis oriented growth, with a much higher growth rate in c-direction as compared to other crystal directions. This often leads to columnar structures, even at relatively low temperatures. However, it is, in general, not straight forward to fabricate smooth ZnO thin films with flat surfaces. Another advantage of a potential ZnO technology is said to be the possibility to grow thin films homoepitaxially on ZnO substrates. ZnO substrates are mostly fabricated by vapor phase transport (VPT) or hydrothermal growth. These techniques are enabling high volume manufacturing at reasonable cost, at least in principle. The availability of homoepitaxial substrates should be beneficial to the development of ZnO technology and devices and is in contrast to the situation of GaN. However, even though a number of companies are developing ZnO substrates, only recently good quality substrates have been demonstrated. However, these substrates are not yet widely available. Still, the situation concerning ZnO substrates seems to be far from low-cost, high-volume production. The fabrication of dense, single crystal thin films is, in general, surprisingly difficult, even when ZnO is grown on a ZnO substrate. However

  9. AAS 228: Day 1 morning

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-06-01

    occur at different times and have different depths in the light curve each time they orbit. Their misalignment may have been caused by a past collision with another planet, which was kicked out of the system in the process. The LIGO-VIRGO Forum on Hunting Gravitational Wave Counterparts(by Gourav Khullar)This parallel session, organized by Peter Shawhan (University of Maryland, advancedLIGO) discussed the first major followup campaign of the GW150914 gravitational wave (GW) discovery event by the physics and astronomy community around the world. It was extremely exciting to hear the speakers talk of the actual process behind the mega-collaborative effort following the first GW event. This paper, published on June 3rd this year, was described by Peter, with a strong emphasis on the timeline following the GW alert in raw LIGO data back in September 2015, along with description of the sky map and raw data given to different facilities and collaborations that LIGO-VIRGO had signed Memorandums of Understanding (MOUs) with for rapid and robust followups. The talk also focussed on resources and tutorials available now to unpack and characterize future alerts data from LIGO-VIRGO. This talk was followed by the description of the all sky survey PAN-STARRS, and its joint efforts with LIGO. It was pointed out that PAN-STARRS had already scanned the sky multiple times, which gave the program an edge in determining transients, i.e. recent features appearing on their new maps but not the old. This extensive survey also allowed better characterization of the transient source, which would be the next step for PAN-STARRS and other similar projects. Our @LIGO booth at #AAS228 is up and running drop by for a chat about #gravitationalwaves pic.twitter.com/akt9wsVPT6 pic.twitter.com/kmPz3oxzJf LIGO (@LIGO) June 13, 2016Following this was a talk by Andy Howell, of the newly formed Las Cumbres Observatory A Global Telescope Network (LCOGT), made up of multiple telescopes across the US, Chile