Abnormal resistance switching behaviours of NiO thin films: possible occurrence of both formation and rupturing of conducting channels

Energy Technology Data Exchange (ETDEWEB)

Liu Chunli; Chae, S C; Chang, S H; Lee, S B; Noh, T W [ReCOE and FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Lee, J S; Kahng, B [Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Kim, D-W [Division of Nano Sciences and Department of Physics, Ewha Womens University, Seoul 120-750 (Korea, Republic of); Jung, C U [Department of Physics, Hankuk University of Foreign Studies, Yongin, Gyeonggi-do 449-791 (Korea, Republic of); Seo, S; Ahn, S-E [Samsung Advanced Institute of Technology, Suwon 440-600 (Korea, Republic of)], E-mail: twnoh@snu.ac.kr

2009-01-07

We report a detailed study on the abnormal resistance switching behaviours observed in NiO thin films which show unipolar resistance switching phenomena. During the RESET process, in which the NiO film changed from a low resistance state to a high resistance state, we sometimes observed that the resistance became smaller than the initial value. We simulated the resistance switching by using a random circuit breaker network model. We found that local conducting channels could be formed as well as ruptured during the RESET process, which result in the occurrence of such abnormal switching behaviours.

Parenchymal abnormalities in cerebral venous thrombosis: findings of magnetic resonance imaging and magnetic resonance angiography

International Nuclear Information System (INIS)

Ferreira, Clecia Santos; Pellini, Marcos; Boasquevisque, Edson; Souza, Luis Alberto M. de

2006-01-01

Objective: to determine the frequency and localization of parenchymal abnormalities in cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography as well as their correlation with the territory and affected venous drainage. Materials and methods: retrospective analysis (1996 to 2004) of 21 patients (3 male and 18 female) age range between 3 and 82 years (mean 40 years, median 36 years) with clinical and radiological diagnosis of cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography in 2D PC, 3D PC and contrast-enhanced 3D TOF sequences. The statistical analysis was performed with the qui-square test. Four patients had follow-up exams and three patients underwent digital subtraction angiography. Results: main predisposing factors were: infection, use of oral contraceptives, hormone replacement therapy and collagenosis. Predominant symptoms included: focal deficit, headache, alteration of consciousness level and seizures. Most frequent parenchymal manifestations were: cortical/subcortical edema or infarct, venous congestion and collateral circulation, meningeal enhancement and thalamic and basal ganglia edema or infarct. Occlusion occurred mainly in superior sagittal, left transverse, left sigmoid and straight sinuses. Cavernous sinus and cortical veins thrombosis are uncommon events. Conclusion: cerebral venous thrombosis is an uncommon cause of stroke, with favorable prognosis because of its reversibility. Diagnosis is highly dependent on the radiologist capacity to recognize the presentations of this disease, principally in cases where the diagnosis is suggested by parenchymal abnormalities rather than necessarily by visualization of the thrombus itself. An accurate and rapid diagnosis allows an immediate treatment, reducing the morbidity and mortality rates. (author)

Selection rules for single-chain-magnet behaviour in non-collinear Ising systems

International Nuclear Information System (INIS)

Vindigni, Alessandro; Pini, Maria Gloria

2009-01-01

The magnetic behaviour of molecular single-chain magnets is investigated in the framework of a one-dimensional Ising model with single spin-flip Glauber dynamics. Opportune modifications to the original theory are required in order to account for non-collinearity of local anisotropy axes between themselves and with respect to the crystallographic (laboratory) frame. The extension of Glauber's theory to the case of a collinear Ising ferrimagnetic chain is also discussed. Within this formalism, both the dynamics of magnetization reversal in zero field and the response of the system to a weak magnetic field, oscillating in time, are studied. Depending on the experimental geometry, selection rules are found for the occurrence of slow relaxation of the magnetization at low temperatures, as well as for resonant behaviour of the a.c. susceptibility as a function of temperature at low frequencies. The present theory applies successfully to some real systems, namely Mn-, Dy- and Co-based molecular magnetic chains, showing that single-chain-magnet behaviour is not only a feature of collinear ferro- and ferrimagnetic, but also of canted antiferromagnetic chains.

Selection rules for single-chain-magnet behaviour in non-collinear Ising systems

Energy Technology Data Exchange (ETDEWEB)

Vindigni, Alessandro [Laboratorium fuer Festkoerperphysik, ETH Zuerich, CH-8093 Zuerich (Switzerland); Pini, Maria Gloria [Istituto dei Sistemi Complessi, Consiglio Nazionale delle Ricerche, Via Madonna del Piano 10, I-50019 Sesto Fiorentino (Italy)], E-mail: vindigni@phys.ethz.ch

2009-06-10

The magnetic behaviour of molecular single-chain magnets is investigated in the framework of a one-dimensional Ising model with single spin-flip Glauber dynamics. Opportune modifications to the original theory are required in order to account for non-collinearity of local anisotropy axes between themselves and with respect to the crystallographic (laboratory) frame. The extension of Glauber's theory to the case of a collinear Ising ferrimagnetic chain is also discussed. Within this formalism, both the dynamics of magnetization reversal in zero field and the response of the system to a weak magnetic field, oscillating in time, are studied. Depending on the experimental geometry, selection rules are found for the occurrence of slow relaxation of the magnetization at low temperatures, as well as for resonant behaviour of the a.c. susceptibility as a function of temperature at low frequencies. The present theory applies successfully to some real systems, namely Mn-, Dy- and Co-based molecular magnetic chains, showing that single-chain-magnet behaviour is not only a feature of collinear ferro- and ferrimagnetic, but also of canted antiferromagnetic chains.

Study on patterns and prevalence of EEG abnormalities in children presenting with behavioural disturbances in psychiatry OPD, Gauhati Medical College and Hospital

Directory of Open Access Journals (Sweden)

Bobby Hmar

2016-01-01

Full Text Available Background of the study: Children with behavioural abnormalities and developmental disorders are often advised electroencephalography (EEG for evaluation of electrophysiological process of the brain to rule out any organic pathology. Various studies have reported abnormal EEG in these groups of children without history of clinical seizure on routine EEG and sleep EEG. Aim of the study: To study pattern and prevalence of EEG abnormalities in children with behavioural abnormalities without history of clinical seizure. Materials and methods: The study is a retrospective study. Ethical clearance has been obtained from institutional ethical committee for the study. To collect data, socio-demographic and clinical data proforma has been used. Data has been evaluated during the period from June 2011 to June 2014 as per selection criteria from the case history record of children with behavioural abnormalities attending child guidance clinic (CGC. Associations of abnormal EEG with various psychiatric diagnoses has been analysed and chi-square test has been used. p value <0.05 has been taken as test of significance. Result: Total 2011 children attended CGC from 2011 June to 2014 June. One hundred and ninety two children of various psychiatric diagnoses as per the tenth revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10 criteria had fulfilled the selection criteria and 113 children had done EEG. Abnormal EEG was found in 26.54% of children with various psychiatric diagnoses. Association was statistically significant (p<0.05. The EEG abnormalities were found more in male gender than female (p<0.05 and more in younger age group (four to ten years, p<0.05. Conclusion: Children with various psychiatric diagnoses have significant association with abnormal EEG without history of clinical seizure.

Magnetic resonance imaging in classification of congenital muscular dystrophies with brain abnormalities

NARCIS (Netherlands)

vanderKnaap, MS; Smit, LME; Barth, PG; CatsmanBerrevoets, CE; Brouwer, OF; Begeer, JH; deCoo, IFM; Valk, J.

A survey was performed of magnetic resonance imaging (MRI) findings in 21 patients with congenital muscular dystrophy (QID) with cerebral abnormalities to evaluate the contribution of MRI to the classification of CMD patients. In 5 patients with Walker-Warburg syndrome (WWS), MRI showed

Single molecule magnet behaviour in robust dysprosium-biradical complexes.

Science.gov (United States)

Bernot, Kevin; Pointillart, Fabrice; Rosa, Patrick; Etienne, Mael; Sessoli, Roberta; Gatteschi, Dante

2010-09-21

A Dy-biradical complex was synthesized and characterized down to very low temperature. ac magnetic measurements reveal single molecule magnet behaviour visible without any application of dc field. The transition to the quantum tunneling regime is evidenced. Photophysical and EPR measurements provide evidence of the excellent stability of these complexes in solution.

Magnetic relaxation behaviour in Pr_2NiSi_3

International Nuclear Information System (INIS)

Pakhira, Santanu; Mazumdar, Chandan; Ranganathan, R.

2016-01-01

Time dependent isothemal remanent magnetizatin (IRM) behaviour for polycrystalline compound Pr_2NiSi_3 have been studied below its characteristic temperature. The compound undergoes slow magnetic relaxation with time. Along with competing interaction, non-magnetic atom disorder plays an important role in formation of non-equilibrium glassy like ground state for this compound.

Abnormal findings on knee magnetic resonance imaging in asymptomatic NBA players.

Science.gov (United States)

Walczak, Brian E; McCulloch, Patrick C; Kang, Richard W; Zelazny, Anthony; Tedeschi, Fred; Cole, Brian J

2008-01-01

The purpose of this study was to evaluate the knees of asymptomatic National Basketball Association (NBA) players via magnetic resonance imaging (MRI) and confirm or dispute findings reported in the previous literature. It is thought that a variety of significant abnormalities affecting the knee exist in asymptomatic patients and that these findings can be accurately identified on MRI. Two months prior to the 2005 season, bilateral knee MRI examinations of 14 asymptomatic NBA players (28 knees) were evaluated for abnormalities of the articular cartilage, menisci, and patellar and quadriceps tendons. The presence of joint effusion, subchondral edema, and cystic lesions and the integrity of the collateral and cruciate ligaments were also assessed.

On the unusual magnetic behaviour of CeRh3B2

International Nuclear Information System (INIS)

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

2003-01-01

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

Prevalence of abnormal findings in magnetic resonance images of asymptomatic knees

International Nuclear Information System (INIS)

Fukuta, Shoji; Masaki, Kunihiro; Korai, Fumiaki

2002-01-01

One hundred fifteen asymptomatic Japanese volunteers aged from 13 to 76 years were examined by magnetic resonance imaging (MRI) to evaluate age-related meniscal degeneration and to determine the prevalence of discoid menisci. Each meniscus was graded in the anterior and posterior portions according to intrameniscal MRI signals. Discoid meniscus was diagnosed if a bow-tie configuration was noted on three or more contiguous sagittal sections. Meniscal abnormalities on MRI became more prevalent with age in both men and women. The posterior horn of the medial meniscus showed a significantly higher prevalence of degeneration than other parts of the meniscus. Discoid menisci were noted in 15 subjects (13% prevalence), always representing the lateral meniscus. Subchondral changes were observed in 13 subjects more than 40 years old, mostly women, and were located in the medial compartment. These abnormalities were not correlated with severity of degeneration in the posterior portion of the medial meniscus. This study demonstrates considerable prevalence of meniscal abnormalities in asymptomatic Japanese subjects. (author)

Prenatal exposure to phencyclidine produces abnormal behaviour and NMDA receptor expression in postpubertal mice.

Science.gov (United States)

Lu, Lingling; Mamiya, Takayoshi; Lu, Ping; Toriumi, Kazuya; Mouri, Akihiro; Hiramatsu, Masayuki; Kim, Hyoung-Chun; Zou, Li-Bo; Nagai, Taku; Nabeshima, Toshitaka

2010-08-01

Several studies have shown the disruptive effects of non-competitive N-methyl-d-aspartate (NMDA) receptor antagonists on neurobehavioural development. Based on the neurodevelopment hypothesis of schizophrenia, there is growing interest in animal models treated with NMDA antagonists at developing stages to investigate the pathogenesis of psychological disturbances in humans. Previous studies have reported that perinatal treatment with phencyclidine (PCP) impairs the development of neuronal systems and induces schizophrenia-like behaviour. However, the adverse effects of prenatal exposure to PCP on behaviour and the function of NMDA receptors are not well understood. This study investigated the long-term effects of prenatal exposure to PCP in mice. The prenatal PCP-treated mice showed hypersensitivity to a low dose of PCP in locomotor activity and impairment of recognition memory in the novel object recognition test at age 7 wk. Meanwhile, the prenatal exposure reduced the phosphorylation of NR1, although it increased the expression of NR1 itself. Furthermore, these behavioural changes were attenuated by atypical antipsychotic treatment. Taken together, prenatal exposure to PCP produced long-lasting behavioural deficits, accompanied by the abnormal expression and dysfunction of NMDA receptors in postpubertal mice. It is worth investigating the influences of disrupted NMDA receptors during the prenatal period on behaviour in later life.

Abnormal pulmonary vein drainage in upper right lobe associated with double aortic arch : magnetic resonance angiography

International Nuclear Information System (INIS)

Busto, M.; Dolz, J.L.; Capdevilla, A.; Castanon, M.; Mulet, J.

1997-01-01

We present the magnetic resonance (MR) and magnetic resonance angiography (MRA) findings in a case of abnormal pulmonary vein drainage from upper right lobe to superior vena cava, associated with double aortic arch, in a six-month-old boy. (Author) 9 refs

Abnormal magnetization behaviors in Sm–Ni–Fe–Cu alloys

International Nuclear Information System (INIS)

Yang, W.Y.; Zhang, Y.F.; Zhao, H.; Chen, G.F.; Zhang, Y.; Du, H.L.; Liu, S.Q.; Wang, C.S.; Han, J.Z.; Yang, Y.C.; Yang, J.B.

2016-01-01

The magnetization behaviors in Sm–Ni–Fe–Cu alloys at low temperatures have been investigated. It was found that the hysteresis loops show wasp-waisted character at low temperatures, which has been proved to be related to the existence of multi-phases, the Fe/Ni soft magnetic phases and the CaCu 5 -type hard magnetic phase. A smooth-jump behavior of the magnetization is observed at T>5 K, whereas a step-like magnetization process appears at T<5 K. The CaCu 5 -type phase is responsible for such abnormal magnetization behavior. The magnetic moment reversal model with thermal activation is used to explain the relation of the critical magnetic field (H cm ) to the temperature (T>5 K). The reversal of the moment direction has to cross over an energy barrier of about 6.6×10 −15 erg. The step-like jumps of the magnetization below 5 K is proposed to be resulted from a sharp increase of the sample temperature under the heat released by the irreversible domain wall motion. - Highlights: • Two different magnetization mechanisms, controlled by temperature, have been found in the Sm–Ni–Fe–Cu alloys. The smooth-jump behavior of the magnetization is observed at T>5 K and the step-like magnetization process appears at T<5 K. • The magnetic moment reversal model with thermal activation has been successfully used to explain the relation of the critical magnetic field (H cm ) to the temperature (T>5 K). The energy barrier for the reversal of the moment direction has been found to be about 6.6×10 −15 erg. • The transition field for the step-like jumps is very strict, independent from the magnetic sweep rate. This is remarkably different from the similar step-like jump behavior in reference [20]. • According to the SEM images and EDX analysis, two kinds of regions are found in the alloys. The Fe–Ni–Cu regions are surrounded by the 1:5 Sm–Ni–Fe–Cu regions and shows fish-bone like structure. An interesting thing is that the Fe–Ni–Cu regions are

Electric arc behaviour in dynamic magnetic fields

International Nuclear Information System (INIS)

Put'ko, V.F.

2000-01-01

The behaviour of an electric arc in different time-dependent (dynamic) magnetic fields was investigated. New possibilities were found for spatial and energy stabilisation of a discharge, for intensifying heat exchange, extending the electric arc and distributed control of electric arc plasma. Rotating, alternating and travelling magnetic fields were studied. It was found that under the effect of a relatively low frequency of variations of dynamic magnetic fields (f 1000 Hz) the arc stabilised at the axis of the discharge chamber, the pulsation level decreased and discharge stability increased. The borders between these two arc existence modes were formed by a certain critical field variation frequency the period of which was determined by the heat relaxation time of the discharge. (author)

Anisotropic Behaviour of Magnetic Power Spectra in Solar Wind Turbulence.

Science.gov (United States)

Banerjee, S.; Saur, J.; Gerick, F.; von Papen, M.

2017-12-01

Introduction:High altitude fast solar wind turbulence (SWT) shows different spectral properties as a function of the angle between the flow direction and the scale dependent mean magnetic field (Horbury et al., PRL, 2008). The average magnetic power contained in the near perpendicular direction (80º-90º) was found to be approximately 5 times larger than the average power in the parallel direction (0º- 10º). In addition, the parallel power spectra was found to give a steeper (-2) power law than the perpendicular power spectral density (PSD) which followed a near Kolmogorov slope (-5/3). Similar anisotropic behaviour has also been observed (Chen et al., MNRAS, 2011) for slow solar wind (SSW), but using a different method exploiting multi-spacecraft data of Cluster. Purpose:In the current study, using Ulysses data, we investigate (i) the anisotropic behaviour of near ecliptic slow solar wind using the same methodology (described below) as that of Horbury et al. (2008) and (ii) the dependence of the anisotropic behaviour of SWT as a function of the heliospheric latitude.Method:We apply the wavelet method to calculate the turbulent power spectra of the magnetic field fluctuations parallel and perpendicular to the local mean magnetic field (LMF). According to Horbury et al., LMF for a given scale (or size) is obtained using an envelope of the envelope of that size. Results:(i) SSW intervals always show near -5/3 perpendicular spectra. Unlike the fast solar wind (FSW) intervals, for SSW, we often find intervals where power parallel to the mean field is not observed. For a few intervals with sufficient power in parallel direction, slow wind turbulence also exhibit -2 parallel spectra similar to FSW.(ii) The behaviours of parallel and perpendicular power spectra are found to be independent of the heliospheric latitude. Conclusion:In the current study we do not find significant influence of the heliospheric latitude on the spectral slopes of parallel and perpendicular

Magnetic resonance imaging of neonatal brain. Assessment of normal and abnormal findings

International Nuclear Information System (INIS)

Hasegawa, Koh; Kadono, Naoko; Kawase, Shohji; Kihara, Minako; Matsuo, Yasutaka; Yoshioka, Hiroshi; Kinugasa, Akihiko; Sawada, Tadashi

1994-01-01

To establish the normal MRI appearance of the neonatal brain, magnetic resonance imaging (MRI) was performed on 124 neonates who admitted to our neonatal intensive care unit. Degree of myelination, ventricular size, width of the extracerebral space and focal lesion in the brain were evaluated to investigate the relationship between MRI findings of neonatal brain and the neurological prognosis. 85 neonates underwent MRI both at neonatal period and at the corrected age of one year. The change of abnormal MRI findings was evaluated. 19 neonates had abnormal neurological outcome on subsequent examinations. Delayed myelination, ventriculomegaly and large extracerebral space were seen in 13, 7 and 9 neonates respectively. 4, 3 and 5 neonates out of them showed abnormal neurological prognosis respectively. Of the 19 neonates with focal lesion in MRI, 2 had parenchymal hematoma in the brain, 2 had subdural hematoma, 5 had chronic hematoma following subependymal hemorrhage, 6 had cystic formation following subependymal hemorrhage, 2 had subcortical leukomalacia, one had periventricular leukomalacia and one had cyst in the parenchyma of cerebellum. 4 neonates of 19 with focal lesion in MRI showed abnormal development. Of the neonates who had abnormal neurological prognosis, 7 neonates showed no abnormal finding in MRI at neonatal period. 3 of them had mild mental retardation. MRI shows promise in the neonatal period. It facilitates recognition of abnormalities of neonatal brain and may be used to predict abnormal neurologic outcome. However physiological change in the brain of neonates, especially of premature neonates, should be considered on interpreting these findings. Awareness of developmental features should help to minimize misinterpretation of normal changes in the neonatal brain. (author)

Magnetic resonance imaging of neonatal brain. Assessment of normal and abnormal findings

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, Koh; Kadono, Naoko; Kawase, Shohji; Kihara, Minako; Matsuo, Yasutaka; Yoshioka, Hiroshi; Kinugasa, Akihiko; Sawada, Tadashi (Kyoto Prefectural Univ. of Medicine (Japan))

1994-11-01

To establish the normal MRI appearance of the neonatal brain, magnetic resonance imaging (MRI) was performed on 124 neonates who admitted to our neonatal intensive care unit. Degree of myelination, ventricular size, width of the extracerebral space and focal lesion in the brain were evaluated to investigate the relationship between MRI findings of neonatal brain and the neurological prognosis. 85 neonates underwent MRI both at neonatal period and at the corrected age of one year. The change of abnormal MRI findings was evaluated. 19 neonates had abnormal neurological outcome on subsequent examinations. Delayed myelination, ventriculomegaly and large extracerebral space were seen in 13, 7 and 9 neonates respectively. 4, 3 and 5 neonates out of them showed abnormal neurological prognosis respectively. Of the 19 neonates with focal lesion in MRI, 2 had parenchymal hematoma in the brain, 2 had subdural hematoma, 5 had chronic hematoma following subependymal hemorrhage, 6 had cystic formation following subependymal hemorrhage, 2 had subcortical leukomalacia, one had periventricular leukomalacia and one had cyst in the parenchyma of cerebellum. 4 neonates of 19 with focal lesion in MRI showed abnormal development. Of the neonates who had abnormal neurological prognosis, 7 neonates showed no abnormal finding in MRI at neonatal period. 3 of them had mild mental retardation. MRI shows promise in the neonatal period. It facilitates recognition of abnormalities of neonatal brain and may be used to predict abnormal neurologic outcome. However physiological change in the brain of neonates, especially of premature neonates, should be considered on interpreting these findings. Awareness of developmental features should help to minimize misinterpretation of normal changes in the neonatal brain. (author).

Behaviour of a neutral particle with spin in an axial magnetic field

International Nuclear Information System (INIS)

Sorokin, S.V.; Ehpp, V.Ya.

1982-01-01

Proceeding from the Tamm-Good equation taking into account the spin influence on motion trajectory, the neutral particle motion tracjectory and vector turn of spin polarizition in axial magnetic field have been found. The behaviour of a neutral particle possessing its own magnetic moment in an axially-symmetric stationary magnetic field is considered

Experimental results of superconducting magnet behaviour during discharging into the external load

Directory of Open Access Journals (Sweden)

Ladislav Grega

2008-12-01

Full Text Available The basic part of every SMES (Superconducting magnetic energy storage system is a superconducting magnet. All eventsof electrical nature which happen during its charging,, bypassing and discharging are transient. The article deals with experimentalresults of the superconducting magnet behaviour, especially during the period of its discharging into the prepared external load.

Magnetic resonance imaging of the elbow. Part II: Abnormalities of the ligaments, tendons, and nerves

Energy Technology Data Exchange (ETDEWEB)

Kijowski, Richard; Tuite, Michael; Sanford, Matthew [University of Wisconsin Hospital, Department of Radiology, Madison, WI (United States)

2005-01-01

Part II of this comprehensive review on magnetic resonance imaging of the elbow discusses the role of magnetic resonance imaging in evaluating patients with abnormalities of the ligaments, tendons, and nerves of the elbow. Magnetic resonance imaging can yield high-quality multiplanar images which are useful in evaluating the soft tissue structures of the elbow. Magnetic resonance imaging can detect tears of the ulnar collateral ligament and lateral collateral ligament of the elbow with high sensitivity and specificity. Magnetic resonance imaging can determine the extent of tendon pathology in patients with medial epicondylitis and lateral epicondylitis. Magnetic resonance imaging can detect tears of the biceps tendon and triceps tendon and can distinguishing between partial and complete tendon rupture. Magnetic resonance imaging is also helpful in evaluating patients with nerve disorders at the elbow. (orig.)

The emergence of complex behaviours in molecular magnetic materials.

Science.gov (United States)

Goss, Karin; Gatteschi, Dante; Bogani, Lapo

2014-09-14

Molecular magnetism is considered an area where magnetic phenomena that are usually difficult to demonstrate can emerge with particular clarity. Over the years, however, less understandable systems have appeared in the literature of molecular magnetic materials, in some cases showing features that hint at the spontaneous emergence of global structures out of local interactions. This ingredient is typical of a wider class of problems, called complex behaviours, where the theory of complexity is currently being developed. In this perspective we wish to focus our attention on these systems and the underlying problematic that they highlight. We particularly highlight the emergence of the signatures of complexity in several molecular magnetic systems, which may provide unexplored opportunities for physical and chemical investigations.

Normal and abnormal grain growth in fine-grained Nd-Fe-B sintered magnets prepared from He jet milled powders

Energy Technology Data Exchange (ETDEWEB)

Bittner, F., E-mail: f.bittner@ifw-dresden.de [IFW Dresden, Institute for Metallic Materials, PO Box 270116, 01171 Dresden (Germany); Technische Universität Dresden, Institute of Materials Science, 01062 Dresden (Germany); Woodcock, T.G. [IFW Dresden, Institute for Metallic Materials, PO Box 270116, 01171 Dresden (Germany); Schultz, L. [IFW Dresden, Institute for Metallic Materials, PO Box 270116, 01171 Dresden (Germany); Technische Universität Dresden, Institute of Materials Science, 01062 Dresden (Germany); Schwöbel, C. [Technische Universität Darmstadt, Materialwissenschaft, Alarich-Weiß-Str. 16, 64287 Darmstadt (Germany); Gutfleisch, O. [Technische Universität Darmstadt, Materialwissenschaft, Alarich-Weiß-Str. 16, 64287 Darmstadt (Germany); Fraunhofer ISC, Projektgruppe für Werkstoffkreisläufe und Ressourcenstrategie IWKS, Rodenbacher Chaussee 4, 63457 Hanau (Germany); Zickler, G.A.; Fidler, J. [Technische Universität Wien, Institute of Solid State Physics, Wiedner Hauptstr. 8-10, 1040 Wien (Austria); Üstüner, K.; Katter, M. [Vacuumschmelze GmbH & Co. KG, 63412 Hanau (Germany)

2017-03-15

Fine-grained, heavy rare earth free Nd-Fe-B sintered magnets were prepared from He jet milled powders with an average particle size of 1.5 µm by low temperature sintering at 920 °C or 980 °C. A coercivity of >1600 kA/m was achieved for an average grain size of 1.68 µm. Transmission electron microscopy showed that the distribution and composition of intergranular and grain boundary junction phases was similar to that in conventionally processed magnets. Microstructural analysis on different length scales revealed the occurrence of abnormal grain growth, which is unexpected for sintering temperatures below 1000 °C. A larger area fraction of abnormal grains was observed in the sample sintered at 920 °C compared to that sintered at 980 °C. Microtexture investigation showed a better crystallographic alignment of the abnormal grains compared to the fine-grained matrix, which is explained by a size dependent alignment of the powder particles during magnetic field alignment prior to sintering. Slightly larger particles in the initial powder show a better alignment and will act as nucleation sites for abnormal grain growth. Magneto-optical Kerr investigations confirmed the lower switching field of the abnormal grains compared to the fine-grained matrix. The demagnetisation curve of the sample sintered at 920 °C showed reduced rectangularity and this was attributed to a cooperative effect of the larger fraction of abnormal grains with low switching field and, as a minor effect, a reduced degree of crystallographic texture in this sample compared to the material sintered at 980 °C, which did not show the reduced rectangularity of the demagnetisation curve. - Highlights: • He Jet milling to reduce Nd-Fe-B grain size and to enhance coercivity. • Normal and abnormal grain growth observed for low temperature sintering. • Well oriented abnormal grown grains explained by size dependent field alignment. • Poor rectangularity is caused by low nucleation field of

Normal and abnormal grain growth in fine-grained Nd-Fe-B sintered magnets prepared from He jet milled powders

International Nuclear Information System (INIS)

Bittner, F.; Woodcock, T.G.; Schultz, L.; Schwöbel, C.; Gutfleisch, O.; Zickler, G.A.; Fidler, J.; Üstüner, K.; Katter, M.

2017-01-01

Fine-grained, heavy rare earth free Nd-Fe-B sintered magnets were prepared from He jet milled powders with an average particle size of 1.5 µm by low temperature sintering at 920 °C or 980 °C. A coercivity of >1600 kA/m was achieved for an average grain size of 1.68 µm. Transmission electron microscopy showed that the distribution and composition of intergranular and grain boundary junction phases was similar to that in conventionally processed magnets. Microstructural analysis on different length scales revealed the occurrence of abnormal grain growth, which is unexpected for sintering temperatures below 1000 °C. A larger area fraction of abnormal grains was observed in the sample sintered at 920 °C compared to that sintered at 980 °C. Microtexture investigation showed a better crystallographic alignment of the abnormal grains compared to the fine-grained matrix, which is explained by a size dependent alignment of the powder particles during magnetic field alignment prior to sintering. Slightly larger particles in the initial powder show a better alignment and will act as nucleation sites for abnormal grain growth. Magneto-optical Kerr investigations confirmed the lower switching field of the abnormal grains compared to the fine-grained matrix. The demagnetisation curve of the sample sintered at 920 °C showed reduced rectangularity and this was attributed to a cooperative effect of the larger fraction of abnormal grains with low switching field and, as a minor effect, a reduced degree of crystallographic texture in this sample compared to the material sintered at 980 °C, which did not show the reduced rectangularity of the demagnetisation curve. - Highlights: • He Jet milling to reduce Nd-Fe-B grain size and to enhance coercivity. • Normal and abnormal grain growth observed for low temperature sintering. • Well oriented abnormal grown grains explained by size dependent field alignment. • Poor rectangularity is caused by low nucleation field of

Magnetic relaxation behaviour in Pr{sub 2}NiSi{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Pakhira, Santanu, E-mail: santanupakhira20006@gmail.com; Mazumdar, Chandan; Ranganathan, R. [Condensed Matter Physics Division, Saha Institute Of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064 (India)

2016-05-06

Time dependent isothemal remanent magnetizatin (IRM) behaviour for polycrystalline compound Pr{sub 2}NiSi{sub 3} have been studied below its characteristic temperature. The compound undergoes slow magnetic relaxation with time. Along with competing interaction, non-magnetic atom disorder plays an important role in formation of non-equilibrium glassy like ground state for this compound.

Fetal magnetic resonance imaging in prenatal diagnosis of central nervous system abnormalities

International Nuclear Information System (INIS)

Morioka, Takato; Hashiguchi, Kimiaki; Kawamura, Tadao; Mihara, Futoshi; Hikino, Shunji; Nagata, Hideaki; Iwaki, Toru; Sasaki, Tomio

2005-01-01

The diagnostic value of fetal magnetic resonance imaging (MRI), performed in 42 pregnant women whose fetuses had structural abnormalities of the central nervous system identified with transabdominal ultrasonography from 1995 through 2002, was analyzed retrospectively. Half-Fourier acquisition single-shot turbo spin-echo (HASTE) T 2 -weighted imaging clearly delineated the cerebrospinal fluid (CSF) space and the malformed brain and spinal cord and provided valuable information for the diagnosis of structural abnormalities related to the CSF space, such as spina bifida with Chiari type II malformation (7 cases), colpocephaly with agenesis of the corpus callosum (7 cases), holoprosencephaly (6 cases), porencephaly (2 cases), lissencephaly with hydrocephalus (2 cases), and middle fossa arachnoid cyst (1 case). However, some difficulty was encountered in the diagnosis of rare pathologic conditions that were not related to the CSF space, such as epignathus, multiple arteriovenous fistulae, trapped suboccipital meningocele, and Turner syndrome. We conclude that HASTE T 2 -weighted imaging, which provides useful diagnostic images in a reasonable time, is a useful adjunct to ultrasonography to confirm or exclude certain abnormalities related to the CSF space. (author)

Corrosion behaviour of Nd-Fe-B permanent magnets

International Nuclear Information System (INIS)

Mummert, K.; El-Aziz, A.M.; Barkleit, G.; Schultz, L.; Rodewald, W.

2000-01-01

The corrosion behaviour of Nd-Fe-B permanent magnetic alloys as well as of single phases of these alloys have been investigated in sulphuric acid at room temperature and humid air at 150 C using mass loss and electrochemical techniques. Scanning electron microscopy and scanning probe microscopy were used to study the surface topography. The electrostatic surface potential was examined by scanning probe microscopy using tapping mode. A correlation between the electrostatic surface potential and the corrosion rate of these alloys was found. The higher the value of the electrostatic surface potential of the intergranular phases the higher is the corrosion sensitivity. The strength of the corrosion attack on the phases of sintered permanent magnetic alloys is as follows: Ferromagnetic phase < B-rich phase < Nd-rich phase. The differences in the chemical composition as well as in the preparation of these magnetic alloys have distinct influence on the corrosion resistance of the magnetic Nd-Fe-B alloys. (orig.)

Magnetic shape memory behaviour

International Nuclear Information System (INIS)

Brown, P.J.; Gandy, A.P.; Ishida, K.; Kainuma, R.; Kanomata, T.; Matsumoto, M.; Morito, H.; Neumann, K.-U.; Oikawa, K.; Ouladdiaf, B.; Ziebeck, K.R.A.

2007-01-01

Materials that can be transformed at one temperature T F , then cooled to a lower temperature T M and plastically deformed and on heating to T F regain their original shape are currently receiving considerable attention. In recovering their shape the alloys can produce a displacement or a force, or a combination of the two. Such behaviour is known as the shape memory effect and usually takes place by change of temperature or applied stress. For many applications the transformation is not sufficiently rapid or a change in temperature/pressure not appropriate. As a result, considerable effort is being made to find a ferromagnetic system in which the effect can be controlled by an applied magnetic field. The results of recent experiments on ferromagnetic shape memory compounds aimed at understanding the underlying mechanism will be reviewed

Magnetic and transport behaviour in Pr3X(X=In,Sn,Ga,Ge,Ni,Co,Ru,Ir) systems

International Nuclear Information System (INIS)

Garde, C.S.; Ray, J.

1998-01-01

Magnetic and transport studies on Pr 3 X (X=In, Sn, Ga, Ge, Ni, Co, Ru, Ir) systems gave evidence for complex magnetic behaviour. All the systems, except X=Sn, exhibit ferromagnetic ordering. The X=Sn system exhibits antiferromagnetic ordering. For X=Ga and Sn, metamagnetic behaviour has been observed. Crystal field effects are found to play an important role in influencing magnetic behaviour. The strength of the crystal field term has also been estimated. (orig.)

The geomagnetic environment in which sea turtle eggs incubate affects subsequent magnetic navigation behaviour of hatchlings.

Science.gov (United States)

Fuxjager, Matthew J; Davidoff, Kyla R; Mangiamele, Lisa A; Lohmann, Kenneth J

2014-09-22

Loggerhead sea turtle hatchlings (Caretta caretta) use regional magnetic fields as open-ocean navigational markers during trans-oceanic migrations. Little is known, however, about the ontogeny of this behaviour. As a first step towards investigating whether the magnetic environment in which hatchlings develop affects subsequent magnetic orientation behaviour, eggs deposited by nesting female loggerheads were permitted to develop in situ either in the natural ambient magnetic field or in a magnetic field distorted by magnets placed around the nest. In orientation experiments, hatchlings that developed in the normal ambient field oriented approximately south when exposed to a field that exists near the northern coast of Portugal, a direction consistent with their migratory route in the northeastern Atlantic. By contrast, hatchlings that developed in a distorted magnetic field had orientation indistinguishable from random when tested in the same north Portugal field. No differences existed between the two groups in orientation assays involving responses to orbital movements of waves or sea-finding, neither of which involves magnetic field perception. These findings, to our knowledge, demonstrate for the first time that the magnetic environment present during early development can influence the magnetic orientation behaviour of a neonatal migratory animal. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Magnetic resonance imaging of the elbow. Part I: Normal anatomy, imaging technique, and osseous abnormalities

International Nuclear Information System (INIS)

Kijowski, Richard; Tuite, Michael; Sanford, Matthew

2004-01-01

Part I of this comprehensive review on magnetic resonance imaging of the elbow discusses normal elbow anatomy and the technical factors involved in obtaining high-quality magnetic resonance images of the elbow. Part I also discusses the role of magnetic resonance imaging in evaluating patients with osseous abnormalities of the elbow. With proper patient positioning and imaging technique, magnetic resonance imaging can yield high-quality multiplanar images which are useful in evaluating the osseous structures of the elbow. Magnetic resonance imaging can detect early osteochondritis dissecans of the capitellum and can be used to evaluate the size, location, stability, and viability of the osteochondritis dissecans fragment. Magnetic resonance imaging can detect early stress injury to the proximal ulna in athletes. Magnetic resonance imaging can detect radiographically occult fractures of the elbow in both children and adults. Magnetic resonance imaging is also useful in children to further evaluate elbow fractures which are detected on plain-film radiographs. (orig.)

Cerebral abnormalities: use of calculated T1 and T2 magnetic resonance images for diagnosis

International Nuclear Information System (INIS)

Mills, C.M.; Crooks, L.E.; Kaufman, L.; Brant-Zawadzki, M.

1984-01-01

The potential clinical importance of T1 and T2 relaxation times in distinguishing normal and pathologic tissue with magnetic resonance (MR) is discussed and clinical examples of cerebral abnormalities are given. Five patients with cerebral infarction, 15 with multiple sclerosis, two with Wilson disease, and four with tumors were imaged. Hemorrhagic and ischemic cerebrovascular accidents were distinguished using the spin echo technique. In the patients with multiple sclerosis, lesions had prolonged T1 and T2 times, but the definition of plaque was limited by spatial resolution. No abnormalities in signal intensity were seen in the patient with Wilson disease who was no longer severly disabled; abnormal increased signal intensity in the basal ganglia was found in the second patient with Wilson disease. Four tumors produced abnormal T1 and T2 relaxation times but these values alone were not sufficient for tumor characterization

Abnormal air righting behaviour in the spontaneously hypertensive rat model of ADHD.

Science.gov (United States)

Dommett, Eleanor J; Rostron, Claire L

2011-11-01

The spontaneously hypertensive rat (SHR) is the most commonly used model of attention-deficit hyperactivity disorder (ADHD), displaying the main symptoms of the disorder which are responsive to psychostimulant treatments. Research to date has focused on behavioural tests investigating functioning of the striatum or prefrontal cortex in these rats. However, there is now evidence that the superior colliculus, a structure associated with head and eye movements, may also be dysfunctional in ADHD. Therefore, the aim of this study was to investigate whether the SHR demonstrated impairment in collicular-dependent behaviour. To this end, we examined air righting behaviour, which has previously been shown to be modulated in a height-dependent manner reliant on a functional superior colliculus. We assessed SHR, Wistar Kyotos and Wistars on static righting and air righting at 50 and 10 cm drop heights. There were no differences in static righting, indicating that there were no gross motor differences that would confound air righting. Qualitative analysis of video footage of the righting did not reveal any changes previously associated with collicular damage, unique to the SHR. However, the SHR did show impairment in height-dependent modulation of righting in contrast to both control strains, such that the SHR failed to modulate righting latency according to drop height. This failure is indicative of collicular abnormality. Given that many rodent tests of attentional mechanisms involve head and eye orienting, which are heavily dependent on the colliculus, a collicular dysfunction has strong implications for the type of attentional task used in this strain.

Teratological effects of exposure to 20 mT, 50 Hz magnetic fields in CD1 mice

International Nuclear Information System (INIS)

Kowalczuk, C.I.; Sienkiewicz, Z.J.; Robbins, L.; Butland, B.K.; Haylock, R.G.E.; Thomas, J.M.; Saunders, R.D.

1992-09-01

Pregnant CD1 mice were exposed or sham-exposed for all or nearly all of the period of gestation to a 20 mT, 50 Hz magnetic fields. Pre-implantation and post-implantation survival rates were assessed, and fetuses examined for the presence of gross external, internal and skeletal abnormalities. Other pregnancies were allowed to come to term and the offspring assessed for the appearance of certain developmental indices and reflexive behaviours; at a later stage, simple assessments of juvenile and adult behaviour were carried out. The study revealed no statistically significant field-dependent effects on pre-implantation or post-implantation survival, sex ratio, or the incidence of internal or skeletal abnormalities. Magnetic field exposure was, however, associated with longer and heavier fetuses at term with fewer external abnormalities and an increased incidence of one class of supernumerary ribs. The postnatal behaviour tests revealed two minor field-dependent effects. From a comparison with other studies, it was considered that most of the above effects were due to chance, a result of the spurious significance seen when large numbers of tests are analysed separately. However, the reduction in the number of external abnormalities in the exposed group was highly significant. This effect has not been reported in other studies and might reflect differences in the selection of exposed and sham-exposed groups; however, an effect of magnetic field exposure cannot be dismissed. In general, the results of the present and other studies of mice and rats suggest that exposure for the duration of pregnancy to power frequency magnetic fields and other extremely low frequency (ELF) fields of up to 20 mT does not increase the incidence of postnatal death or the incidence of gross external, internal or skeletal abnormalities. Similar conclusions can be derived from studies carried out by other authors about the possible effects on pregnancy outcome of exposure to RF fields of 18

A symmetric, triply interlaced 3-D anionic MOF that exhibits both magnetic order and SMM behaviour.

Science.gov (United States)

Campo, J; Falvello, L R; Forcén-Vázquez, E; Sáenz de Pipaón, C; Palacio, F; Tomás, M

2016-11-14

A newly prepared 3-D polymer of cobalt citrate cubanes bridged by high-spin Co(ii) centres displays both single-molecule magnet (SMM) behaviour and magnetic ordering. Triple interpenetration of the 3-D diamondoid polymers yields a crystalline solid with channels that host cations and free water molecules, with the SMM behaviour of the Co 4 O 4 cores preserved. The octahedrally coordinated Co(ii) bridges are implicated in the onset of magnetic order at an experimentally accessible temperature.

Magnetic resonance imaging of the normal and abnormal pulmonary hila

International Nuclear Information System (INIS)

Webb, W.R.; Gamsu, G.; Stark, D.D.; Moore, E.H.

1984-01-01

Magnetic resonance (MR) images of the hila were reviewed in 25 normal subjects and 12 patients with unilateral or bilateral hilar masses. On spin echo MR images in normal patients, collections of soft tissue large enough to be confused with an abnormally enlarged lymph node were seen in three locations. In patients with a hilar mass, the mass was differentiated from hilar vasculature more easily using MR than contrast-enhanced CT. However, because the spatial resolution of MR is inferior to that of CT, bronchi were difficult to evaulate using MR. Electrocardiographic-gated images showed better resolution of hilar structures but may not be necessary for large masses

Low temperature magnetic behaviour of glass-covered magnetic microwires with gradient nanocrystalline microstructure

Energy Technology Data Exchange (ETDEWEB)

Serrano, I. G.; Hernando, A.; Marín, P. [Instituto de Magnetismo Aplicado, UCM-ADIF-CSIC, P.O. Box 155 las Rozas, Madrid 28230 (Spain)

2014-01-21

Slow nanocrystallization driving dynamics can be affected by the combination of two factors: sample residual stresses and sample geometry. This effect is evidenced at the initial stages of nanocrystallization of amorphous CoFeSiBCuNb magnetic microwires. Transmission electron microscopy observations indicate how crystallization at temperatures between 730 and 780 K results in a graded microstructure where the crystallization at the surface skin of the microwire, which remains almost amorphous, differs from that of the middle, where elongated grains are observed, and inner regions. However, samples annealed at higher temperatures present a homogeneous microstructure. The effect of gradient microstructure on magnetic properties has been also analyzed and a loss of bistable magnetic behaviour at low temperatures, from that obtained in the amorphous and fully nanocrystallized sample, has been observed and ascribed to changes in sign of magnetostriction for measuring temperatures below 100 K.

Critical magnetic behaviour in one and two dimensions

International Nuclear Information System (INIS)

Koebler, U.; Hoser, A.

2007-01-01

Critical magnetic data of magnets in which the phase transition is driven by one-dimensional (1D) or two-dimensional (2D) interactions are examined. Characteristic for 1D (2D) phase transitions is that only the longitudinal (in plane) correlation length diverges. The transverse (inter-layer) interactions are then not relevant although they may be finite. The condition for 1D (2D) phase transitions is that the ratio of transverse (inter-layer) to longitudinal (in plane) interactions is below some threshold value. This threshold defines the bandwidth of the 1D (2D) universality class. On the other hand, three-dimensional (3D) magnetic Bragg scattering relies on a finite transverse (inter-layer) correlation length. If this correlation length is relatively long the spin structure appears 3D. For materials with a pure spin moment the dimensionality can now conveniently be inferred from the universal power function by which the order parameter approaches saturation at the stable fixed point T=0. Using this criterion it is concluded that the critical behaviour of 2D magnets is essentially of the 2D Ising type but for 1D magnets of the 3D Ising type. Slight deviations from the ideal model exponents are, however, frequently observed. Universality for T->0 is not of the Ising type in the investigated magnets with a 3D spin

Study of the behaviour of chaotic magnetic field lines in a tokamak

International Nuclear Information System (INIS)

Hugon, M.; Mendonca, J.T.; Rebut, P.H.

1989-01-01

One plausible explanation for the observed anomalous energy losses in tokamaks is the existence of a confinement region in the plasma, where magnetic islands coexist with stochastic magnetic field lines. It is the purpose of the present work to elucidate the statistical behaviour of the stochastic field lines. This is done by numerically integrating the field line equations. (author) 4 refs., 2 figs

Nonlinear dynamic behaviour of a rotor-foundation system coupled through passive magnetic bearings with magnetic anisotropy - Theory and experiment

DEFF Research Database (Denmark)

Enemark, Søren; Santos, Ilmar F.

2016-01-01

In this work, the nonlinear dynamic behaviour of a vertical rigid rotor interacting with a flexible foundation by means of two passive magnetic bearings is quantified and evaluated. The quantification is based on theoretical and experimental investigation of the non-uniformity (anisotropy......) of the magnetic field and the weak nonlinearity of the magnetic forces. Through mathematical modelling the nonlinear equations of motion are established for describing the shaft and bearing housing lateral dynamics coupled via the nonlinear and non-uniform magnetic forces. The equations of motion are solved...

Magnetic field and pressure dependant resistivity behaviour of MnAs

Science.gov (United States)

Satya, A. T.; Amaladass, E. P.; Mani, Awadhesh

2018-04-01

The studies on the effect of magnetic field and external pressure on temperature dependant electrical resistivity behaviour of polycrystalline MnAs have been reported. At ambient pressure, ρ(T) shows a first order magnetic transition associated with change in sign of the temperature coefficient of resistivity from positive in the ferromagnetic (FM) phase to negative in the paramagnetic (PM) phase. The magneto resistance is negative and shows a peak at the FM transition temperature (T C ). The first order hysteresis width decreases with increase in magnetic field and the intersection of extrapolated linear variations of T C with field for the cooling and warming cycles enabled determination of the tricritical point. At high pressures, ρ(T) displays non monotonic variation exhibiting a low temperature minimum ({T}\\min L) and a high temperature maximum ({T}\\max H) accompanying broad thermal hysteresis above {T}\\min L. It is surmised that spin disorder scattering is responsible for the resistivity behaviour above {T}\\min L and the essential features of ρ(T) are qualitatively explained using Kasuya theoretical model. Below the {T}\\min L, ρ(T) follows linear logarithmic temperature dependence similar to the effect occurring due to Kondo type of scattering of conduction electrons with localised moments.

Usefulness of additional fetal magnetic resonance imaging in the prenatal diagnosis of congenital abnormalities.

Science.gov (United States)

We, Ji Sun; Young, Lee; Park, In Yang; Shin, Jong Chul; Im, Soo Ah

2012-12-01

Our aim was to compare the value of fetal magnetic resonance imaging (MRI) with detailed ultrasound in the prenatal diagnosis of congenital abnormalities. This retrospective study reviewed the medical records of pregnant women and their neonates who, after ultrasound, were suspected to have congenital abnormalities. They then underwent a detailed ultrasound examination and a fetal MRI in our institutions. Fetal MRI was performed in 81 cases. Each prenatal presumptive diagnosis, based on detailed ultrasound examination and fetal MRI, was compared with the postnatal confirmed diagnosis. In 58 cases, the data collected were confirmed by the postnatal diagnosis. Supplemental information from fetal MRI was useful in 17 of the 22 cases involving the central nervous system (CNS), two of two cases involving the thorax, nine of nine cases involving the genitourinary system, two of eight cases involving the gastrointestinal system, and ten of ten cases involving complex malformations. Fetal MRI did not provide significantly useful information or facilitate a more accurate diagnosis except for CNS abnormalities. Fetal MRI was not superior to an ultrasound examination in the prenatal detection of congenital abnormalities. A detailed ultrasound examination performed by experienced obstetricians had satisfactory accuracy in the diagnosis of fetal abnormalities compared with fetal MRI. Fetal MRI might be useful in appropriate cases in Korea. Greater effort is required to increase the ultrasound knowledge and skill of competent obstetricians.

Magnetic resonance imaging of articular cartilage abnormalities of the far posterior femoral condyle of the knee

Energy Technology Data Exchange (ETDEWEB)

Ogino, Shuhei; Huang, Thomas; Watanabe, Atsuya; Iranpour-Boroujeni, Tannaz; Yoshioka, Hiroshi (Dept. of Radiology, Brigham and Women' s Hospital, Boston, MA (United States)), e-mail: hiroshi@uci.edu

2010-01-15

Background: Incidental articular cartilage lesions of the far posterior femoral condyle (FPFC) are commonly detected. Whether or not these cartilage lesions are symptomatic or clinically significant is unknown. Purpose: To characterize and assess prevalence of articular cartilage abnormalities of the FPFC and associated bone marrow edema (BME) and/or internal derangements through magnetic resonance (MR) images. Material and Methods: 654 knee MR examinations were reviewed retrospectively. Sagittal fast spin-echo proton density-weighted images with and without fat suppression were acquired with a 1.5T scanner, and were evaluated by two readers by consensus. The following factors were assessed: 1) the prevalence of cartilage abnormalities, 2) laterality, 3) the type of cartilage abnormalities, 4) cartilage abnormality grading, 5) associated BME, 6) complications such as meniscal injury and cruciate ligament injury, and 7) knee alignment (femorotibial angle [FTA]). Results: Articular cartilage abnormalities of the FPFC were demonstrated in 157 of the 654 patients (24%). Of these, 40 patients demonstrated medial and lateral FPFC cartilage abnormalities and were thus counted as 80 cases. Focal lateral FPFC abnormalities were demonstrated in 117 of 197 cases (59.4%), while diffuse lateral FPFC abnormalities were demonstrated in 24 of 197 cases (12.2%). Focal medial FPFC abnormalities were demonstrated in 23 of 197 cases (11.6%), while diffuse medial FPFC abnormalities were demonstrated in 33 of 197 cases (16.8%). No statistically significant pattern of associated BME, FTA, or internal derangements including meniscal and cruciate ligament injury was demonstrated. Conclusion: Articular cartilage abnormalities of the FPFC are common and were demonstrated in 24% of patients or 30% of cases. Lateral FPFC abnormalities occur 2.5 times more frequently than medial FPFC abnormalities and were more frequently focal compared with medial cohorts. BME is associated in 36.5% of cases

Magnetic resonance and cranial ultrasound characteristics of periventricular white matter abnormalities in newborn infants

International Nuclear Information System (INIS)

Childs, Anne-Marie; Cornette, Luc; Ramenghi, Luca A.; Tanner, Steven F.; Arthur, Rosemary J.; Martinez, Delia; Levene, Malcolm I.

2001-01-01

OBJECTIVE: To characterize the range of abnormalities within the periventricular white matter (PVWM) in a cohort of newborns using magnetic resonance (MR) brain imaging and to compare the focal MR abnormalities with the cranial ultrasound (CUS) findings. METHODS: Retrospective study of MR brain and CUS findings of infants born in the 18-month period 1998-1999. PVWM abnormalities were identified by MR and focal lesions were characterized by size, number and distribution using a grading scale. Correspondence with CUS findings was assessed. RESULTS: 175 MR examinations corresponding to n = 105 preterm infants, (median GA 28, range 23-36 weeks) and n = 25 term infants (median GA 39, range 37-42 weeks) were analysed for PVWM abnormalities. In the preterm group, MR demonstrated a normal PVWM in n = 76, focal areas of altered signal intensity (SI) in PVWM in n = 26 and venous infarction inn 3. In the term group, MR demonstrated a normal PVWM in n = 15, focal areas of altered SI in PVWM in n = 4, oedematous PVWM in n = 2 and a middle cerebral artery infarction in n = 4. All infants with normal MR had normal CUS findings. A focal PVWM SI abnormality detectable on MR corresponded with an abnormality on CUS in only n = 10/30. CONCLUSIONS: MR appears considerably more sensitive than CUS in demonstrating the existence and extent of focal PVWM lesions in newborn infants. Satisfactory correspondence between the two imaging investigations is obtained only for cystic PVWM lesions. Childs, A.-M. et al. (2001)

Incidence and Evaluation of Incidental Abnormal Bone Marrow Signal on Magnetic Resonance Imaging

Directory of Open Access Journals (Sweden)

Gunjan L. Shah

2014-01-01

Full Text Available Purpose. The increased use of magnetic resonance imaging (MRI has resulted in reports of incidental abnormal bone marrow (BM signal. Our goal was to determine the evaluation of an incidental abnormal BM signal on MRI and the prevalence of a subsequent oncologic diagnosis. Methods. We conducted a retrospective cohort study of patients over age 18 undergoing MRI between May 2005 and October 2010 at Tufts Medical Center (TMC with follow-up through November 2013. The electronic medical record was queried to determine imaging site, reason for scan, evaluation following radiology report, and final diagnosis. Results. 49,678 MRIs were done with 110 patients meeting inclusion criteria. Twenty two percent underwent some evaluation, most commonly a complete blood count, serum protein electrophoresis, or bone scan. With median follow-up of 41 months, 6% of patients were diagnosed with malignancies including multiple myeloma, non-Hodgkins lymphoma, metastatic non-small cell lung cancer, and metastatic adenocarcinoma. One patient who had not undergone evaluation developed breast cancer 24 months after the MRI. Conclusions. Incidentally noted abnormal or heterogeneous bone marrow signal on MRI was not inconsequential and should prompt further evaluation.

Identification of age-dependent motor and neuropsychological behavioural abnormalities in a mouse model of Mucopolysaccharidosis Type II

Science.gov (United States)

Gleitz, Hélène F. E.; O’Leary, Claire; Holley, Rebecca J.

2017-01-01

Severe mucopolysaccharidosis type II (MPS II) is a progressive lysosomal storage disease caused by mutations in the IDS gene, leading to a deficiency in the iduronate-2-sulfatase enzyme that is involved in heparan sulphate and dermatan sulphate catabolism. In constitutive form, MPS II is a multi-system disease characterised by progressive neurocognitive decline, severe skeletal abnormalities and hepatosplenomegaly. Although enzyme replacement therapy has been approved for treatment of peripheral organs, no therapy effectively treats the cognitive symptoms of the disease and novel therapies are in development to remediate this. Therapeutic efficacy and subsequent validation can be assessed using a variety of outcome measures that are translatable to clinical practice, such as behavioural measures. We sought to consolidate current knowledge of the cognitive, skeletal and motor abnormalities present in the MPS II mouse model by performing time course behavioural examinations of working memory, anxiety, activity levels, sociability and coordination and balance, up to 8 months of age. Cognitive decline associated with alterations in spatial working memory is detectable at 8 months of age in MPS II mice using spontaneous alternation, together with an altered response to novel environments and anxiolytic behaviour in the open-field. Coordination and balance on the accelerating rotarod were also significantly worse at 8 months, and may be associated with skeletal changes seen in MPS II mice. We demonstrate that the progressive nature of MPS II disease is also seen in the mouse model, and that cognitive and motor differences are detectable at 8 months of age using spontaneous alternation, the accelerating rotarod and the open-field tests. This study establishes neurological, motor and skeletal measures for use in pre-clinical studies to develop therapeutic approaches in MPS II. PMID:28207863

Cerebral metabolic abnormalities in congestive heart failure detected by proton magnetic resonance spectroscopy.

Science.gov (United States)

Lee, C W; Lee, J H; Kim, J J; Park, S W; Hong, M K; Kim, S T; Lim, T H; Park, S J

1999-04-01

Using proton magnetic resonance spectroscopy, we investigated cerebral metabolism and its determinants in congestive heart failure (CHF), and the effects of cardiac transplantation on these measurements. Few data are available about cerebral metabolism in CHF. Fifty patients with CHF (ejection fraction OGM) and parietal white matter (PWM). Absolute levels of the metabolites (N-acetylaspartate, creatine, choline, myo-inositol) were calculated. In PWM only creatine level was significantly lower in CHF than in control subjects, but in OGM all four metabolite levels were decreased in CHF. The creatine level was independently correlated with half-recovery time and duration of heart failure symptoms in PWM (r = -0.56, p OGM (r = 0.58, p < 0.05). Cerebral metabolic abnormalities were improved after successful cardiac transplantation. This study shows that cerebral metabolism is abnormally deranged in advanced CHF and it may serve as a potential marker of the disease severity.

Uncomplicated obesity is associated with abnormal aortic function assessed by cardiovascular magnetic resonance

Directory of Open Access Journals (Sweden)

Channon Keith M

2008-02-01

Full Text Available Abstract Aims Obese subjects with insulin resistance and hypertension have abnormal aortic elastic function, which may predispose them to the development of left ventricular dysfunction. We hypothesised that obesity, uncomplicated by other cardiovascular risk factors, is independently associated with aortic function. Methods and results We used magnetic resonance imaging to measure aortic compliance, distensibility and stiffness index in 27 obese subjects (BMI 33 kg/m2 without insulin resistance and with normal cholesterol and blood pressure, and 12 controls (BMI 23 kg/m2. Obesity was associated with reduced aortic compliance (0.9 ± 0.1 vs. 1.5 ± 0.2 mm2/mmHg in controls, p -1 × 10-3, p Conclusion Aortic elastic function is abnormal in obese subjects without other cardiovascular risk factors. These findings highlight the independent importance of obesity in the development of cardiovascular disease.

Magnetic behaviour of hydrogenated La_0_._5Ca_0_._5MnO_3

International Nuclear Information System (INIS)

Lal, Ganesh; Punia, Khushboo; Kumar, Sudhish; Jyoti; Dolia, S.N.

2016-01-01

The half doped manganite La_0_._5Ca_0_._5MnO_3 have attracted considerable attention owing to its complex electrical and magnetic properties. This work is focused on the effects of hydrogenation on the magnetic behaviour of La_0_._5Ca_0_._5MnO_3. For hydrogenation the La_0_._5Ca_0_._5MnO_3 sample was annealed in a hydrogen atmosphere at 600°C for 6 hours in a reduction furnace and for reducing hydrogen the sample was heated in air at 600°C for 6 hours in a chamber furnace. Room temperature X-ray diffraction studies confirmed that the hydrogenation and annealing of the sample in air does not affect the single phase orthorhombic structure of La_0_._5Ca_0_._5MnO_3. These observations indicate that magnetic behaviour of La_0_._5Ca_0_._5MnO_3. can be tailored by hydrogenation

Effect of cerium on the corrosion behaviour of sintered (Nd,Ce)FeB magnet

Science.gov (United States)

Yang, Lijing; Bi, Mengxue; Jiang, Jianjun; Ding, Xuefeng; Zhu, Minggang; Li, Wei; Lv, Zhongshan; Song, Zhenlun

2017-06-01

For the balanced consumption of rare-earth elements, cerium (Ce) was partially used for NdFeB magnets instead of Nd. The corrosion behaviour of the (Nd,Ce)FeB magnet with different Ce contents in 3.5% NaCl solution was investigated by SEM, XRD, EDS and electrochemical tests. After immersion, the weight loss was calculated and the magnetic properties of the samples were measured. Results showed that Ce affected the corrosion of the (Nd,Ce)FeB magnet. Compared with the NdFeB magnet without Ce but of the same grade as the magnetic energy product, (Nd,Ce)FeB magnet showed better corrosion resistance. With increased Ce content, the corrosion resistances and magnetic properties of (Nd,Ce)FeB magnets were investigated.

Effects of magnetic field exposure on open field behaviour and nociceptive responses in mice.

Science.gov (United States)

Del Seppia, Cristina; Mezzasalma, Lorena; Choleris, Elena; Luschi, Paolo; Ghione, Sergio

2003-09-15

Results of previous studies have shown that nociceptive sensitivity in male C57 mice is enhanced by exposure to a regular 37 Hz or an irregularly varying (field. In order to test whether these fields affect more generally mouse behaviour, we placed Swiss CD-1 mice in a novel environment (open field test) and exposed them for 2 h to these two different magnetic field conditions. Hence, we analysed how duration and time course of various behavioural patterns (i.e. exploration, rear, edge chew, self-groom, sit, walk and sleep) and nociceptive sensitivity had been affected by such exposure. Nociceptive sensitivity was significantly greater in magnetically treated mice than in controls. The overall time spent in exploratory activities was significantly shorter in both magnetically treated groups (time), than in controls (42%). Conversely, the time spent in sleeping was markedly longer in the treated groups (both 27% of total time) than in controls (11%). These results suggest that exposure to altered magnetic fields induce a more rapid habituation to a novel environment.

Annealing behaviour of structural and magnetic properties of evaporated Co thin films

International Nuclear Information System (INIS)

Jergel, M; Halahovets, Y; Siffalovic, P; Mat'ko, I; Senderak, R; Majkova, E; Luby, S; Cheshko, I; Protsenko, S

2009-01-01

Cobalt thin films of 50 nm nominal thickness were e-beam evaporated on silicon substrates covered with thermal oxide. Two series of independent and cumulative vacuum annealings up to 600 deg. C and 650 deg. C, respectively, were performed. The x-ray diffraction, specular and non-specular x-ray reflectivity and longitudinal magneto-optical Kerr effect measurements were applied to probe the annealing behaviour of the film structure and magnetic properties. A gradual transition from the hexagonal close-packed (hcp) to the face-centred cubic (fcc) structure was observed. Evolution of the in-plane magnetic anisotropy is dominated by residual stresses which relax during the structural transformation. The coercivity follows the stress behaviour in the hcp phase up to 300 deg. C and increases abruptly above 400 deg. C due to improving the magneto-crystalline anisotropy in the growing fcc crystallites and enhanced surface/interface roughness.

Dynamic simulation of variable capacity refrigeration systems under abnormal conditions

International Nuclear Information System (INIS)

Liang Nan; Shao Shuangquan; Tian Changqing; Yan Yuying

2010-01-01

There are often abnormal working conditions at evaporator outlet of a refrigeration system, such as two-phase state in transient process, and it is essential to investigate such transient behaviours for system design and control strategy. In this paper, a dynamic lumped parameter model is developed to simulate the transient behaviours of refrigeration system with variable capacity in both normal and abnormal working conditions. The appropriate discriminant method is adopted to switch the normal and abnormal conditions smoothly and to eliminate the simulated data oscillation. In order to verify the dynamic model, we built a test system with variable frequency compressor, water-cooling condenser, evaporator and electronic expansion valve. Calculated values from the mathematical model show reasonable agreement with the experimental data. The simulation results show that the transient behaviours of the variable capacity refrigeration system in the abnormal working conditions can be calculated reliably with the dynamic model when the compressor rotary speed or the opening of electronic expansion valve changes abruptly.

The Frequency and Severity of Magnetic Resonance Imaging Abnormalities in Infants with Mild Neonatal Encephalopathy.

Science.gov (United States)

Walsh, Brian H; Neil, Jeffrey; Morey, JoAnn; Yang, Edward; Silvera, Michelle V; Inder, Terrie E; Ortinau, Cynthia

2017-08-01

To assess and contrast the incidence and severity of abnormalities on cerebral magnetic resonance imaging (MRI) between infants with mild, moderate, and severe neonatal encephalopathy who received therapeutic hypothermia. This retrospective cohort studied infants with mild, moderate, and severe neonatal encephalopathy who received therapeutic hypothermia at a single tertiary neonatal intensive care unit between 2013 and 2015. Two neuroradiologists masked to the clinical condition evaluated brain MRIs for cerebral injury after therapeutic hypothermia using the Barkovich classification system. Additional abnormalities not included in this classification system were also noted. The rate, pattern, and severity of abnormalities/injury were compared across the grades of neonatal encephalopathy. Eighty-nine infants received therapeutic hypothermia and met study criteria, 48 with mild neonatal encephalopathy, 35 with moderate neonatal encephalopathy, and 6 with severe neonatal encephalopathy. Forty-eight infants (54%) had an abnormality on MRI. There was no difference in the rate of overall MRI abnormalities by grade of neonatal encephalopathy (mild neonatal encephalopathy 54%, moderate neonatal encephalopathy 54%, and severe neonatal encephalopathy 50%; P= .89). Basal ganglia/thalamic injury was more common in those with severe neonatal encephalopathy (mild neonatal encephalopathy 4%, moderate neonatal encephalopathy 9%, severe neonatal encephalopathy 34%; P = .03). In contrast, watershed injury did not differ between neonatal encephalopathy grades (mild neonatal encephalopathy 36%, moderate neonatal encephalopathy 32%, severe neonatal encephalopathy 50%; P = .3). Mild neonatal encephalopathy is commonly associated with MRI abnormalities after therapeutic hypothermia. The grade of neonatal encephalopathy during the first hours of life may not discriminate adequately between infants with and without cerebral injury noted on MRI after therapeutic hypothermia

Magnetic behaviour of a new compound, Eu{sub 2}CuSi{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Majumdar, Subham; Mallik, R; Sampathkumaran, E V [Tata Institute of Fundamental Research, Mumbai (India)

1999-07-01

As a part of our program to synthesize new ternary Eu compounds, we report here the formation of Eu{sub 2}CuSi{sub 3} for the first time and its magnetic behaviour by magnetic susceptibility, electrical-resistivity and heat-capacity measurements. This compound is found to crystallize in an AlB{sub 2}-derived hexagonal structure. The results establish that Eu ions are divalent, undergoing long-range ferromagnetic-ordering below 38 K. (author)

The role of the interface on the magnetic behaviour of granular Fe50Ag50 film

International Nuclear Information System (INIS)

Fdez-Gubieda, M.L.; Sarmiento, G.; Fernandez Barquin, L.; Orue, I.

2007-01-01

The magnetic behaviour of a Fe 50 Ag 50 granular thin film has been studied by means of AC and DC magnetic measurements. Exchange coupling between magnetic nanoparticles appears at T=<200K decreasing the coercive field of the sample. Additionally, an exchange bias is observed at low temperature related to the existence of a spin disordered interface around the nanoparticles

Effect of cerium on the corrosion behaviour of sintered (Nd,Ce)FeB magnet

Energy Technology Data Exchange (ETDEWEB)

Yang, Lijing [CAS Key Laboratory of Magnetic Materials and Devices, Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Bi, Mengxue [CAS Key Laboratory of Magnetic Materials and Devices, Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Nano Science and Technology Institute, University of Science and Technology of China, Hefei 230026 (China); Jiang, Jianjun; Ding, Xuefeng [CAS Key Laboratory of Magnetic Materials and Devices, Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Zhu, Minggang; Li, Wei [Functional Materials Research Institute, Central Iron & Steel Research Institute, Beijing 100081 (China); Lv, Zhongshan [Ningbo Shuo Teng new material Co., Ltd., Cixi 315301 (China); Song, Zhenlun, E-mail: songzhenlun@nimte.ac.cn [CAS Key Laboratory of Magnetic Materials and Devices, Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

2017-06-15

Highlights: • A little Ce could promote the magnets for a better corrosion resistance. • With increased Ce contents, the corrosion resistances of magnets decrease. • As the corrosion developed, the magnetic properties decreased. - Abstract: For the balanced consumption of rare-earth elements, cerium (Ce) was partially used for NdFeB magnets instead of Nd. The corrosion behaviour of the (Nd,Ce)FeB magnet with different Ce contents in 3.5% NaCl solution was investigated by SEM, XRD, EDS and electrochemical tests. After immersion, the weight loss was calculated and the magnetic properties of the samples were measured. Results showed that Ce affected the corrosion of the (Nd,Ce)FeB magnet. Compared with the NdFeB magnet without Ce but of the same grade as the magnetic energy product, (Nd,Ce)FeB magnet showed better corrosion resistance. With increased Ce content, the corrosion resistances and magnetic properties of (Nd,Ce)FeB magnets were investigated.

Magnetic hysteresis at the domain scale of a multi-scale material model for magneto-elastic behaviour

Energy Technology Data Exchange (ETDEWEB)

Vanoost, D., E-mail: dries.vanoost@kuleuven-kulak.be [KU Leuven Technology Campus Ostend, ReMI Research Group, Oostende B-8400 (Belgium); KU Leuven Kulak, Wave Propagation and Signal Processing Research Group, Kortrijk B-8500 (Belgium); Steentjes, S. [Institute of Electrical Machines, RWTH Aachen University, Aachen D-52062 (Germany); Peuteman, J. [KU Leuven Technology Campus Ostend, ReMI Research Group, Oostende B-8400 (Belgium); KU Leuven, Department of Electrical Engineering, Electrical Energy and Computer Architecture, Heverlee B-3001 (Belgium); Gielen, G. [KU Leuven, Department of Electrical Engineering, Microelectronics and Sensors, Heverlee B-3001 (Belgium); De Gersem, H. [KU Leuven Kulak, Wave Propagation and Signal Processing Research Group, Kortrijk B-8500 (Belgium); TU Darmstadt, Institut für Theorie Elektromagnetischer Felder, Darmstadt D-64289 (Germany); Pissoort, D. [KU Leuven Technology Campus Ostend, ReMI Research Group, Oostende B-8400 (Belgium); KU Leuven, Department of Electrical Engineering, Microelectronics and Sensors, Heverlee B-3001 (Belgium); Hameyer, K. [Institute of Electrical Machines, RWTH Aachen University, Aachen D-52062 (Germany)

2016-09-15

This paper proposes a multi-scale energy-based material model for poly-crystalline materials. Describing the behaviour of poly-crystalline materials at three spatial scales of dominating physical mechanisms allows accounting for the heterogeneity and multi-axiality of the material behaviour. The three spatial scales are the poly-crystalline, grain and domain scale. Together with appropriate scale transitions rules and models for local magnetic behaviour at each scale, the model is able to describe the magneto-elastic behaviour (magnetostriction and hysteresis) at the macroscale, although the data input is merely based on a set of physical constants. Introducing a new energy density function that describes the demagnetisation field, the anhysteretic multi-scale energy-based material model is extended to the hysteretic case. The hysteresis behaviour is included at the domain scale according to the micro-magnetic domain theory while preserving a valid description for the magneto-elastic coupling. The model is verified using existing measurement data for different mechanical stress levels. - Highlights: • A ferromagnetic hysteretic energy-based multi-scale material model is proposed. • The hysteresis is obtained by new proposed hysteresis energy density function. • Avoids tedious parameter identification.

Abnormalities on magnetic resonance imaging seen acutely following mild traumatic brain injury: correlation with neuropsychological tests and delayed recovery

International Nuclear Information System (INIS)

Hughes, David G.; Jackson, Alan; Mason, Damon L.; Berry, Elizabeth; Hollis, Sally; Yates, David W.

2004-01-01

Mild traumatic brain injury (MTBI) is a common reason for hospital attendance and is associated with significant delayed morbidity. We studied a series of 80 persons with MTBI. Magnetic resonance imaging (MRI) and neuropsychological testing were used in the acute phase and a questionnaire for post-concussion syndrome (PCS) and return to work status at 6 months. In 26 subjects abnormalities were seen on MRI, of which 5 were definitely traumatic. There was weak correlation with abnormal neuropsychological tests for attention in the acute period. There was no significant correlation with a questionnaire for PCS and return to work status. Although non-specific abnormalities are frequently seen, standard MRI techniques are not helpful in identifying patients with MTBI who are likely to have delayed recovery. (orig.)

Magnetic resonance imaging in familial hypertrophic cardiomyopathy associated with abnormal thallium perfusion and cardiac enzymes

Energy Technology Data Exchange (ETDEWEB)

Nishimura, Tsunehiko; Nagata, Seiki; Sakakibara, Hiroshi

1988-05-01

Gated magnetic resonance imaging (MRI) was performed in 6 patients with familial hypertrophic cardiomyopathy associated with abnormal thallium perfusion, and 12 patients with ordinary hypertrophic cardiomyopathy. The patients with ordinary hypertrophic cardiomyopathy and abnormal thickening of the septal wall and normal left ventricular dimensions, while the patients with familial hypertrophic cardiomyopathy had focal wall thinning (usually involving the apical-septal wall) and dilated left ventricle in addition to hypertrophied heart. The quantitative measurement for cardiac dimensions using MRI was similar to that found on echocardiography in all cases. In addition, inhomogeneous signal intensities at left ventricular wall were observed in 3 cases of familial hypertrophic cardiomyopathy, which may suggest the existence of myocardial fibrosis. Gated MRI should be performed for early detection and follow-up of hypertrophic cardiomyopathy, since some patients will progress from hypertrophic cardiomyopathy to dilated cardiomyopathy.

A new differential equations-based model for nonlinear history-dependent magnetic behaviour

International Nuclear Information System (INIS)

Aktaa, J.; Weth, A. von der

2000-01-01

The paper presents a new kind of numerical model describing nonlinear magnetic behaviour. The model is formulated as a set of differential equations taking into account history dependence phenomena like the magnetisation hysteresis as well as saturation effects. The capability of the model is demonstrated carrying out comparisons between measurements and calculations

Motion behaviour of magneto-sensitive elastomers controlled by an external magnetic field for sensor applications

Energy Technology Data Exchange (ETDEWEB)

Volkova, T.I., E-mail: tatiana.volkova@tu-ilmenau.de [Technische Universität Ilmenau, Faculty of Mechanical Engineering, Technical Mechanics Group, D-98693 Ilmenau (Germany); Böhm, V., E-mail: valter.boehm@tu-ilmenau.de [Technische Universität Ilmenau, Faculty of Mechanical Engineering, Technical Mechanics Group, D-98693 Ilmenau (Germany); Kaufhold, T., E-mail: tobias.kaufhold@tu-ilmenau.de [Technische Universität Ilmenau, Faculty of Mechanical Engineering, Technical Mechanics Group, D-98693 Ilmenau (Germany); Popp, J., E-mail: jana.popp@tu-ilmenau.de [Technische Universität Ilmenau, Faculty of Mechanical Engineering, Technical Mechanics Group, D-98693 Ilmenau (Germany); Becker, F., E-mail: felix.becker@tu-ilmenau.de [Technische Universität Ilmenau, Faculty of Mechanical Engineering, Technical Mechanics Group, D-98693 Ilmenau (Germany); Borin, D.Yu., E-mail: dmitry.borin@tu-dresden.de [Technische Universität Dresden, Magnetofluiddynamics, Measuring and Automation Technology, D-01062 Dresden (Germany); Stepanov, G.V., E-mail: gstepanov@mail.ru [State Institute of Chemistry and Technology of Organoelement Compounds, 105118 Moscow (Russian Federation); Zimmermann, K., E-mail: klaus.zimmermann@tu-ilmenau.de [Technische Universität Ilmenau, Faculty of Mechanical Engineering, Technical Mechanics Group, D-98693 Ilmenau (Germany)

2017-06-01

The development of sensor systems with a complex adaptive regulation of the operating sensitivity and behaviour is an actual scientific and technical challenge. Smart materials like magneto-sensitive elastomers (MSE) are seen as one potential solution for this problem, since their mechanical properties may be controlled by external magnetic fields. The present paper deals with the investigation of elastic and damping properties of MSE containing magnetically soft particles under the influence of a uniform magnetic field. Based on the measurement of the first eigenfrequency of free bending vibrations of a fixed beam, the effective Young's modulus is evaluated theoretically and also numerically using Finite Element Method. It is shown that this parameter, as well as the first eigenfrequency of the beam, increases monotonically with the magnitude of the applied magnetic field. The results are aimed to develop an acceleration sensor with adaptive magnetically controllable sensitivity range for the detection of external mechanical stimuli of the environment. - Highlights: • The motion behaviour of magneto-sensitive elastomers (MSE) with magnetically soft particles is investigated. • The first eigenfrequency of free bending vibrations of an MSE beam can be controlled by a uniform magnetic field. • Based on the experimental results, the effective Young's modulus of the system is evaluated theoretically and numerically. • The Young's modulus increases monotonically with the magnitude of the applied magnetic field. • The controlled mechanical compliance of MSE may be used for development of sensor systems with adaptive sensitivity range.

Influence of dextran coating on the magnetic behaviour of iron oxide nanoparticles

International Nuclear Information System (INIS)

Dutz, Silvio; Andrae, Wilfried; Hergt, Rudolf; Mueller, Robert; Oestreich, Christiane; Schmidt, Christopher; Toepfer, Jorg; Zeisberger, Matthias; Bellemann, Matthias E.

2007-01-01

Magnetic iron oxide nanoparticles with mean diameters in the range from 10 to 30 nm were prepared by modified chemical precipitation routes. The particles were suspended in an aqueous solution by coating of the particles with carboxymethyldextran. A stability against agglomeration was achieved over a period of more than 7 days. In the present investigation, the structural and the magnetic properties of the nanoparticles were investigated. The influence of the dextran shell on the strength of the dipole-dipole interactions between the neighbouring particles was determined by investigation of the remanence behaviour (Henkel plot) of coated as well as of uncoated particles

The behaviour of the L3 muon chambers in a magnetic field

International Nuclear Information System (INIS)

Onvlee, J.

1989-01-01

L3 is one of the four detectors at LEP. It consists of many parts, each of which measures a specific property of the particles produced in the electron positron collisions. One of the specialities of the L3 detector is the high precision measurement of the momenta of the muons produced in the collisions. In order to curve the muon trajectories the detector is placed in a magnetic field of about 0.5 Tesla. The behaviour of the L3 muon drift chambers in this magnetic field is the main subject of this thesis. (author). 45 refs.; 47 figs.; 12 tabs

Anisotropic behaviour of transmission through thin superconducting NbN film in parallel magnetic field

Energy Technology Data Exchange (ETDEWEB)

Šindler, M., E-mail: sindler@fzu.cz [Institute of Physics ASCR, v. v. i., Cukrovarnická 10, CZ-162 53 Praha 6 (Czech Republic); Tesař, R. [Institute of Physics ASCR, v. v. i., Cukrovarnická 10, CZ-162 53 Praha 6 (Czech Republic); Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, CZ-121 16 Praha (Czech Republic); Koláček, J. [Institute of Physics ASCR, v. v. i., Cukrovarnická 10, CZ-162 53 Praha 6 (Czech Republic); Skrbek, L. [Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, CZ-121 16 Praha (Czech Republic)

2017-02-15

Highlights: • Transmission through thin NbN film in parallel magnetic field exhibits strong anisotropic behaviour in the terahertz range. • Response for a polarisation parallel with the applied field is given as weighted sum of superconducting and normal state contributions. • Effective medium approach fails to describe response for linear polarisation perpendicular to the applied magnetic field. - Abstract: Transmission of terahertz waves through a thin layer of the superconductor NbN deposited on an anisotropic R-cut sapphire substrate is studied as a function of temperature in a magnetic field oriented parallel with the sample. A significant difference is found between transmitted intensities of beams linearly polarised parallel with and perpendicular to the direction of applied magnetic field.

Behaviour of Earths Magnetic Field During Solar Eclipse ( 29 May 2006)

International Nuclear Information System (INIS)

Ozcep, F.; Alp, H.

2007-01-01

Interaction and relation between geophysical properties (gravity, geomagnetic field, etc.) of the Earth and Sun has been a fascinating topic ever since humanity habilitated the Earth. For example, the role of solar energy in sustaining agricultural activities was noted long ago and human beings are ever grateful to the Sun for his bounty. Since prehistoric times, many cultures have regarded the Sun as a deity. However, until recent decades, the contribution of Sun was assumed to be only in heat and light, which everybody could feel easily. Our aim is to study the behaviour of earths magnetic field during solar e clips ( 29 may 2006). Fort this aim, from 27 may 2006 hour 18.00 to 29 may 2006 hour 18.00, it was observed the earths magnetic field before, during and after solar eclipse. During this period, every 5 minute , magnetic field were measured by two proton magnetometer

Prevalence of knee abnormalities in patients with osteoarthritis and anterior cruciate ligament injury identified with peripheral magnetic resonance imaging: a pilot study

Energy Technology Data Exchange (ETDEWEB)

Wu, H. [McMaster Univ., Dept. of Medical Sciences, Hamilton, Ontario (Canada)]. E-mail: wuh5@mcmaster.ca; Webber, C. [Hamilton Health Sciences, Dept. of Nuclear Medicine, Hamilton, Ontario (Canada); McMaster Univ., Dept. of Radiology, Hamilton, Ontario (Canada); Fuentes, C.O. [Hamilton Health Sciences, Dept. of Radiology, Hamilton, Ontario (Canada); Benson, R.; Beattie, K. [McMaster Univ., Dept. of Medical Sciences, Hamilton, Ontario (Canada); Adachi, J.D.; Xie, X. [McMaster Univ., Dept. of Medical Sciences, Hamilton, Ontario (Canada); Jabbari, F. [Hamilton Health Sciences, Hamilton, Ontario (Canada); Levy, D.R. [McMaster Univ., Sports Medicine, Dept. of Family Medicine and Dept. of Medicine, Hamilton, Ontario (Canada)

2007-06-15

To assess, with a peripheral magnetic resonance imaging system (pMRI), the prevalence of bony and soft tissue abnormalities in the knee joints of normal subjects, osteoarthritis (OA) patients, and individuals who have suffered an anterior cruciate ligament (ACL) rupture; and 2) to compare the prevalence among groups. Magnetic resonance (MR) images of 28 healthy, 32 OA, and 26 ACL damaged knees were acquired with a 1.0-T pMRI system. Two radiologists grade the presence and severity of 9 MR image features: cartilage degeneration, osteophytes, subchondral cyst, bone marrow edema, meniscal abnormality, ligament integrity, loose bodies, popliteal cysts, and joint effusion. Ten of 28 healthy (35.7%), 24 of 26 ACL (92.3%), and all OA knees (100%) showed prevalent cartilage defects; 5 healthy (17.9%), 20 ACL (76.9%), and all OA knees (100%) had osteophytes; and 9 normal (32.1%), 21 ACL (80.8%), and 29 OA knees (90.6%) had meniscal abnormalities. One-half of the knees in the OA group (16 of 32, 50%) had subchondral cysts, and almost one-half had bone marrow edema (15 of 32, 46.9%). These features were not common in the ACL group (7.7%, and 11.5%, respectively) and were not observed in healthy knees. The OA group had the most severe cartilage defects, osteophytes, bone marrow edema, subchondral cysts, and meniscal abnormalities; the ACL group showed more severe cartilage defects, osteophytes, and meniscal abnormalities than did normal subjects. The results suggest that knees that have sustained ACL damage have OA-like features, most subjects (19 of 26, 73.1%) could be identified as in the early stage of OA. The prominent abnormalities present in ACL-damaged knees are cartilage defects, osteophytes, and meniscal abnormalities. (author)

Prevalence of knee abnormalities in patients with osteoarthritis and anterior cruciate ligament injury identified with peripheral magnetic resonance imaging: a pilot study

International Nuclear Information System (INIS)

Wu, H.; Webber, C.; Fuentes, C.O.; Benson, R.; Beattie, K.; Adachi, J.D.; Xie, X.; Jabbari, F.; Levy, D.R.

2007-01-01

To assess, with a peripheral magnetic resonance imaging system (pMRI), the prevalence of bony and soft tissue abnormalities in the knee joints of normal subjects, osteoarthritis (OA) patients, and individuals who have suffered an anterior cruciate ligament (ACL) rupture; and 2) to compare the prevalence among groups. Magnetic resonance (MR) images of 28 healthy, 32 OA, and 26 ACL damaged knees were acquired with a 1.0-T pMRI system. Two radiologists grade the presence and severity of 9 MR image features: cartilage degeneration, osteophytes, subchondral cyst, bone marrow edema, meniscal abnormality, ligament integrity, loose bodies, popliteal cysts, and joint effusion. Ten of 28 healthy (35.7%), 24 of 26 ACL (92.3%), and all OA knees (100%) showed prevalent cartilage defects; 5 healthy (17.9%), 20 ACL (76.9%), and all OA knees (100%) had osteophytes; and 9 normal (32.1%), 21 ACL (80.8%), and 29 OA knees (90.6%) had meniscal abnormalities. One-half of the knees in the OA group (16 of 32, 50%) had subchondral cysts, and almost one-half had bone marrow edema (15 of 32, 46.9%). These features were not common in the ACL group (7.7%, and 11.5%, respectively) and were not observed in healthy knees. The OA group had the most severe cartilage defects, osteophytes, bone marrow edema, subchondral cysts, and meniscal abnormalities; the ACL group showed more severe cartilage defects, osteophytes, and meniscal abnormalities than did normal subjects. The results suggest that knees that have sustained ACL damage have OA-like features, most subjects (19 of 26, 73.1%) could be identified as in the early stage of OA. The prominent abnormalities present in ACL-damaged knees are cartilage defects, osteophytes, and meniscal abnormalities. (author)

Energy expenditure in frontotemporal dementia: a behavioural and imaging study

Science.gov (United States)

Ahmed, Rebekah M; Landin-Romero, Ramon; Collet, Tinh-Hai; van der Klaauw, Agatha A; Devenney, Emma; Henning, Elana; Kiernan, Matthew C; Piguet, Olivier; Farooqi, I Sadaf; Hodges, John R

2017-01-01

Abstract See Finger (doi:10.1093/aww312) for a scientific commentary on this article. Abnormal eating behaviour and metabolic parameters including insulin resistance, dyslipidaemia and body mass index are increasingly recognized as important components of neurodegenerative disease and may contribute to survival. It has previously been established that behavioural variant frontotemporal dementia is associated with abnormal eating behaviour characterized by increased sweet preference. In this study, it was hypothesized that behavioural variant frontotemporal dementia might also be associated with altered energy expenditure. A cohort of 19 patients with behavioural variant frontotemporal dementia, 13 with Alzheimer’s disease and 16 (age- and sex-matched) healthy control subjects were studied using Actiheart devices (CamNtech) to assess resting and stressed heart rate. Actiheart devices were fitted for 7 days to measure sleeping heart rate, activity levels, and resting, active and total energy expenditure. Using high resolution structural magnetic resonance imaging the neural correlates of increased resting heart rate were investigated including cortical thickness and region of interest analyses. In behavioural variant frontotemporal dementia, resting (P = 0.001), stressed (P = 0.037) and sleeping heart rate (P = 0.038) were increased compared to control subjects, and resting heart rate (P = 0.020) compared to Alzheimer disease patients. Behavioural variant frontotemporal dementia was associated with decreased activity levels compared to controls (P = 0.002) and increased resting energy expenditure (P = 0.045) and total energy expenditure (P = 0.035). Increased resting heart rate correlated with behavioural (Cambridge Behavioural Inventory) and cognitive measures (Addenbrooke’s Cognitive Examination). Increased resting heart rate in behavioural variant frontotemporal dementia correlated with atrophy involving the mesial temporal cortex, insula, and amygdala

Adrenal gland abnormalities detected by magnetic resonance imaging in patients with antiphospholipid syndrome.

Science.gov (United States)

Shahin, A A; El Desouky, S M; Awadallah, M Y; Megahed, D E

2017-03-01

Adrenal infarction is a rare complication of antiphospholipid syndrome (APS). The purpose of the current study is to detect and study the magnetic resonance imaging (MRI) findings of adrenal glands in APS patients. In a cross-sectional study, the data of 20 patients with primary or secondary APS were compared to 20 SLE patients without antiphospholipid antibody (aPL) syndrome (controls). MRI of the abdomen showing the adrenal glands was performed. Of the patients, 80% were females with a mean age 32.45 ± 9.93 years, and mean disease duration of 46.65 ± 58.71 months. Adrenal gland abnormalities in the MRI study were detected in 35 % of APS patients vs. no abnormalities detected in the SLE controls. Adrenal gland enlargement was found in all patients (35 %). Capsular enhancement (infarction or hemorrhagic infarction) was found in 5 patients, increased stranding of the surrounding fat planes (inflammatory process) in 4 patients and increased signal on T1WI and T2WI (hemorrhage) in 3 patients. In patients with adrenal gland involvement, 71.4 % had triple aPL positivity compared to 23.1 % in patients with normal adrenal findings (p = 0.04). Adrenal gland abnormalities on MRI were detected in 35 % of the APS patients (whether primary or secondary); thus, increased focus on management is needed. This percentage is not small and needs to be focused on in terms of management.

Abnormal Repetitive Behaviours: Shared Phenomenology and Pathophysiology

Science.gov (United States)

Muehlmann, A. M.; Lewis, M. H.

2012-01-01

Background: Self-injurious behaviour (SIB) is a devastating problem observed in individuals with various neurodevelopmental disorders, including specific genetic syndromes as well as idiopathic intellectual and developmental disability. Although an increased prevalence of SIB has been documented in specific genetic mutations, little is known about…

The role of the interface on the magnetic behaviour of granular Fe{sub 50}Ag{sub 50} film

Energy Technology Data Exchange (ETDEWEB)

Fdez-Gubieda, M.L. [Dpto. Electricidad y Electronica. Universidad del Pais Vasco Apdo 644. 48080 Bilbao (Spain)]. E-mail: malu@we.lc.ehu.es; Sarmiento, G. [Dpto. Electricidad y Electronica. Universidad del Pais Vasco Apdo 644. 48080 Bilbao (Spain); Fernandez Barquin, L. [CITIMAC, Universidad de Cantabria, Avda. de los Castros s/n, 39005 Santander (Spain); Orue, I. [SGIKER, Servicios Generales de medidas magneticas, Universidad del Pais Vasco (Spain)

2007-03-15

The magnetic behaviour of a Fe{sub 50}Ag{sub 50} granular thin film has been studied by means of AC and DC magnetic measurements. Exchange coupling between magnetic nanoparticles appears at T=<200K decreasing the coercive field of the sample. Additionally, an exchange bias is observed at low temperature related to the existence of a spin disordered interface around the nanoparticles.

Anomalous behaviour of the magnetic susceptibility of the mixed spin-1 and spin- 1/2 anisotropic Heisenberg model in the Oguchi approximation

International Nuclear Information System (INIS)

Bobak, Andrej; Dely, Jan; Pokorny, Vladislav

2010-01-01

The effects of both an exchange anisotropy and a single-ion anisotropy on the magnetic susceptibility of the mixed spin-1 and spin- 1/2 Heisenberg model are investigated by the use of an Oguchi approximation. Particular emphasis is given to the simple cubic lattice with coordination number z = 6 for which the magnetic susceptibility is determined numerically. Anomalous behaviour in the thermal variation of the magnetic susceptibility in the low-temperature region is found due to the applied negative single-ion anisotropy field strength. Also, the difference between the behaviours of the magnetic susceptibility of the Heisenberg and Ising models is discussed.

Open questions in the magnetic behaviour of high-temperature superconductors

International Nuclear Information System (INIS)

Cohen, L.F.; Jensen, Henrik Jeldtoft

1997-01-01

A principally experimental review of vortex behaviour in high-temperature superconductors is presented. The reader is first introduced to the basic concepts needed to understand the magnetic properties of type II superconductors. The concepts of vortex melting, the vortex glass, vortex creep, etc are also discussed briefly. The bulk part of the review relates the theoretical predictions proposed for the vortex system in high temperature superconductors to experimental findings. The review ends with an attempt to direct the reader to those areas which still require further clarification. (author)

Effect of horizontal strong static magnetic field on swimming behaviour of Paramecium caudatum

Science.gov (United States)

Fujiwara, Yoshihisa; Tomishige, Masahiko; Itoh, Yasuhiro; Fujiwara, Masao; Shibata, Naho; Kosaka, Toshikazu; Hosoya, Hiroshi; Tanimoto, Yoshifumi

2006-05-01

Effect of horizontal strong static magnetic field on swimming behaviour of Paramecium caudatum was studied by using a superconducting magnet. Around a centre of a round vessel, random swimming at 0 T and aligned swimming parallel to the magnetic field (MF) of 8 T were observed. Near a wall of the vessel, however, swimming round and round along the wall at 0 T and aligned swimming of turning at right angles upon collision with the wall, which was remarkable around 1-4 T, were detected. It was experimentally revealed that the former MF-induced parallel swimming at the vessel centre was caused physicochemically by the parallel magnetic orientation of the cell itself. From magnetic field dependence of the extent of the orientation, the magnetic susceptibility anisotropy (χ ∥-χ ⊥) was first obtained to be 3.4× 10-23 emu cell-1 at 298 K for Paramecium caudatum. The orientation of the cell was considered to result from the magnetic orientation of the cell membrane. On the other hand, although mechanisms of the latter swimming near the vessel wall regardless of the absence and presence of the magnetic field are unclear at present, these experimental results indicate that whether the cell exists near the wall alters the magnetic field effect on the swimming in the horizontal magnetic field.

Magnetic Resonance Neurography Visualizes Abnormalities in Sciatic and Tibial Nerves in Patients With Type 1 Diabetes and Neuropathy.

Science.gov (United States)

Vaeggemose, Michael; Pham, Mirko; Ringgaard, Steffen; Tankisi, Hatice; Ejskjaer, Niels; Heiland, Sabine; Poulsen, Per L; Andersen, Henning

2017-07-01

This study evaluates whether diffusion tensor imaging magnetic resonance neurography (DTI-MRN), T2 relaxation time, and proton spin density can detect and grade neuropathic abnormalities in patients with type 1 diabetes. Patients with type 1 diabetes ( n = 49) were included-11 with severe polyneuropathy (sDPN), 13 with mild polyneuropathy (mDPN), and 25 without polyneuropathy (nDPN)-along with 30 healthy control subjects (HCs). Clinical examinations, nerve conduction studies, and vibratory perception thresholds determined the presence and severity of DPN. DTI-MRN covered proximal (sciatic nerve) and distal (tibial nerve) nerve segments of the lower extremity. Fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) were calculated, as were T2 relaxation time and proton spin density obtained from DTI-MRN. All magnetic resonance findings were related to the presence and severity of neuropathy. FA of the sciatic and tibial nerves was lowest in the sDPN group. Corresponding with this, proximal and distal ADCs were highest in patients with sDPN compared with patients with mDPN and nDPN, as well as the HCs. DTI-MRN correlated closely with the severity of neuropathy, demonstrating strong associations with sciatic and tibial nerve findings. Quantitative group differences in proton spin density were also significant, but less pronounced than those for DTI-MRN. In conclusion, DTI-MRN enables detection in peripheral nerves of abnormalities related to DPN, more so than proton spin density or T2 relaxation time. These abnormalities are likely to reflect pathology in sciatic and tibial nerve fibers. © 2017 by the American Diabetes Association.

Magnetic behaviour of nano-particles of Fe2.8Zn0.2O4

Indian Academy of Sciences (India)

Magnetic behaviour of nano-particles of Fe2.8Zn0.2O4. SUBHASH CHANDER, SEEMA LAKHANPAL, ANJALI KRISHNAMURTHY,. BIPIN K SRIVASTAVA and V K ASWAL∗. Department of Physics, University of Rajasthan, Jaipur 302 004, India. *Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 ...

Olfaction in Eating Disorders and Abnormal Eating Behaviour: A Systematic Review

Directory of Open Access Journals (Sweden)

Mohammed Anisul eIslam

2015-09-01

Full Text Available The study provides a systematic review that explores the current literature on olfactory capacity in abnormal eating behavior to present a basis for discussion on whether research in olfaction in eating disorders may offer additional insights with regard to the complex etiopathology of ED and abnormal eating behaviors. Electronic databases (Medline, PsycINFO, PubMed, Science Direct and Web of Science were searched using the components in relation to olfaction and combining them with the components related to abnormal eating behavior. Out of 1,352 articles, 14 articles were selected (820 patients and 385 control participants for this review. The highest number of existing literature on olfaction in ED were carried out with AN patients (78.6% followed by BN (35.7% and obesity (14.3%. The general findings support that olfaction is altered in AN and Obesity and indicates towards there being no differences in olfactory capacity between BN patients and the general population. Due to the limited number of studies and heterogeneity this review stresses on the importance of more research on olfaction and abnormal eating behavior.

Parenchymal abnormalities in cerebral venous thrombosis: findings of magnetic resonance imaging and magnetic resonance angiography; Alteracoes parenquimatosas na trombose venosa cerebral: aspectos da ressonancia magnetica e da angiorressonancia

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Clecia Santos; Pellini, Marcos [Universidade Federal, Rio de Janeiro, RJ (Brazil). Faculdade de Medicina. Dept. de Radiologia]. E-mail: csferreira@superig.com.br; Boasquevisque, Edson [Universidade do Estado do Rio de Janeiro, (UERJ), RJ (Brazil). Faculdade de Medicina. Dept. de Patologia; Souza, Luis Alberto M. de [Hospital da Beneficencia Portuguesa do Rio de Janeiro, RJ (Brazil). Servico de Imagem. Setor de Ressonancia Magnetica

2006-09-15

Objective: to determine the frequency and localization of parenchymal abnormalities in cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography as well as their correlation with the territory and affected venous drainage. Materials and methods: retrospective analysis (1996 to 2004) of 21 patients (3 male and 18 female) age range between 3 and 82 years (mean 40 years, median 36 years) with clinical and radiological diagnosis of cerebral venous thrombosis on magnetic resonance imaging and magnetic resonance angiography in 2D PC, 3D PC and contrast-enhanced 3D TOF sequences. The statistical analysis was performed with the qui-square test. Four patients had follow-up exams and three patients underwent digital subtraction angiography. Results: main predisposing factors were: infection, use of oral contraceptives, hormone replacement therapy and collagenosis. Predominant symptoms included: focal deficit, headache, alteration of consciousness level and seizures. Most frequent parenchymal manifestations were: cortical/subcortical edema or infarct, venous congestion and collateral circulation, meningeal enhancement and thalamic and basal ganglia edema or infarct. Occlusion occurred mainly in superior sagittal, left transverse, left sigmoid and straight sinuses. Cavernous sinus and cortical veins thrombosis are uncommon events. Conclusion: cerebral venous thrombosis is an uncommon cause of stroke, with favorable prognosis because of its reversibility. Diagnosis is highly dependent on the radiologist capacity to recognize the presentations of this disease, principally in cases where the diagnosis is suggested by parenchymal abnormalities rather than necessarily by visualization of the thrombus itself. An accurate and rapid diagnosis allows an immediate treatment, reducing the morbidity and mortality rates. (author)

Allelic interaction of F1 pollen sterility loci and abnormal chromosome behaviour caused pollen sterility in intersubspecific autotetraploid rice hybrids.

Science.gov (United States)

He, J H; Shahid, M Q; Li, Y J; Guo, H B; Cheng, X A; Liu, X D; Lu, Y G

2011-08-01

The intersubspecific hybrids of autotetraploid rice has many features that increase rice yield, but lower seed set is a major hindrance in its utilization. Pollen sterility is one of the most important factors which cause intersubspecific hybrid sterility. The hybrids with greater variation in seed set were used to study how the F(1) pollen sterile loci (S-a, S-b, and S-c) interact with each other and how abnormal chromosome behaviour and allelic interaction of F(1) sterility loci affect pollen fertility and seed set of intersubspecific autotetraploid rice hybrids. The results showed that interaction between pollen sterility loci have significant effects on the pollen fertility of autotetraploid hybrids, and pollen fertility further decreased with an increase in the allelic interaction of F(1) pollen sterility loci. Abnormal ultra-structure and microtubule distribution patterns during pollen mother cell (PMC) meiosis were found in the hybrids with low pollen fertility in interphase and leptotene, suggesting that the effect-time of pollen sterility loci interaction was very early. There were highly significant differences in the number of quadrivalents and bivalents, and in chromosome configuration among all the hybrids, and quadrivalents decreased with an increase in the seed set of autotetraploid hybrids. Many different kinds of chromosomal abnormalities, such as chromosome straggling, chromosome lagging, asynchrony of chromosome disjunction, and tri-fission were found during the various developmental stages of PMC meiosis. All these abnormalities were significantly higher in sterile hybrids than in fertile hybrids, suggesting that pollen sterility gene interactions tend to increase the chromosomal abnormalities which cause the partial abortion of male gametes and leads to the decline in the seed set of the autotetraploid rice hybrids. © 2011 The Author(s).

Abnormal eating attitudes and weight-loss behaviour of adolescent ...

African Journals Online (AJOL)

2014-06-18

Jun 18, 2014 ... as anorexia nervosa, bulimia nervosa and eating disorder not ... The existence of eating disorders and abnormal eating attitudes in ...... Skyes DK, Leuser B, Melia M, Gross M. A demographic analysis of 252 patients with.

Low protein diet fed exclusively during mouse oocyte maturation leads to behavioural and cardiovascular abnormalities in offspring.

Science.gov (United States)

Watkins, Adam J; Wilkins, Adrian; Cunningham, Colm; Perry, V Hugh; Seet, Meei J; Osmond, Clive; Eckert, Judith J; Torrens, Christopher; Cagampang, Felino R A; Cleal, Jane; Gray, William P; Hanson, Mark A; Fleming, Tom P

2008-04-15

Early embryonic development is known to be susceptible to maternal undernutrition, leading to a disease-related postnatal phenotype. To determine whether this sensitivity extended into oocyte development, we examined the effect of maternal normal protein diet (18% casein; NPD) or isocaloric low protein diet (9% casein; LPD) restricted to one ovulatory cycle (3.5 days) prior to natural mating in female MF-1 mice. After mating, all females received NPD for the remainder of gestation and all offspring were litter size adjusted and fed standard chow. No difference in gestation length, litter size, sex ratio or postnatal growth was observed between treatments. Maternal LPD did, however, induce abnormal anxiety-related behaviour in open field activities in male and female offspring (P size or nephron number was altered by diet treatment (P < 0.05). These data demonstrate the sensitivity of mouse maturing oocytes in vivo to maternal protein undernutrition and identify both behavioural and cardiovascular postnatal outcomes, indicative of adult disease. These outcomes probably derive from a direct effect of protein restriction, although indirect stress mechanisms may also be contributory. Similar and distinct postnatal outcomes were observed here compared with maternal LPD treatment during post-fertilization preimplantation development which may reflect the relative contribution of the paternal genome.

Behaviour of large-area avalanche photodiodes under intense magnetic fields for VUV- visible- and X-ray photon detection

International Nuclear Information System (INIS)

Fernandes, L.M.P.; Antognini, A.; Boucher, M.; Conde, C.A.N.; Huot, O.; Knowles, P.; Kottmann, F.; Ludhova, L.; Mulhauser, F.; Pohl, R.; Schaller, L.A.; Santos, J.M.F. dos; Taqqu, D.; Veloso, J.F.C.A.

2003-01-01

The behaviour of large-area avalanche photodiodes for X-rays, visible and vacuum-ultra-violet (VUV) light detection in magnetic fields up to 5 T is described. For X-rays and visible light detection, the photodiode pulse amplitude and energy resolution were unaffected from 0 to 5 T, demonstrating the insensitivity of this type of detector to strong magnetic fields. For VUV light detection, however, the photodiode relative pulse amplitude decreases with increasing magnetic field intensity reaching a reduction of about 24% at 5 T, and the energy resolution degrades noticeably with increasing magnetic field

Regional brain metabolite abnormalities in inherited prion disease and asymptomatic gene carriers demonstrated in vivo by quantitative proton magnetic resonance spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Waldman, A.D.; Cordery, R.J.; Godbolt, A.; Rossor, M.N. [University College London, Dementia Research Group, Department of Neurodegenerative Disease, Institute of Neurology, London (United Kingdom); Imperial College of Science, Technology and Medicine, Division of Neuroscience and Psychological Medicine, Faculty of Medicine, London (United Kingdom); MacManus, D.G. [University College London, NMR Research Unit, Department of Clinical Neurology, Institute of Neurology, London (United Kingdom); Collinge, J. [University College London, MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, London (United Kingdom)

2006-06-15

Inherited prion diseases are caused by mutations in the gene which codes for prion protein (PrP), leading to proliferation of abnormal PrP isomers in the brain and neurodegeneration; they include Gerstmann-Straeussler-Scheinker disease (GSS), fatal familial insomnia (FFI) and familial Creutzfeldt-Jakob disease (fCJD). We studied two patients with symptomatic inherited prion disease (P102L) and two pre-symptomatic P102L gene carriers using quantitative magnetic resonance spectroscopy (MRS). Short echo time spectra were acquired from the thalamus, caudate region and frontal white matter, metabolite levels and ratios were measured and z-scores calculated for individual patients relative to age-matched normal controls. MRS data were compared with structural magnetic resonance imaging. One fCJD case had generalised atrophy and showed increased levels of myo-inositol (MI) in the thalamus (z=3.7). The other had decreased levels of N-acetylaspartate (z=4) and diffuse signal abnormality in the frontal white matter. Both asymptomatic gene carriers had normal imaging, but increased frontal white matter MI (z=4.3, 4.1), and one also had increased MI in the caudate (z=5.3). Isolated MI abnormalities in asymptomatic gene carriers are a novel finding and may reflect early glial proliferation, prior to significant neuronal damage. MRS provides potential non-invasive surrogate markers of early disease and progression in inherited prion disease. (orig.)

Regional brain metabolite abnormalities in inherited prion disease and asymptomatic gene carriers demonstrated in vivo by quantitative proton magnetic resonance spectroscopy

International Nuclear Information System (INIS)

Waldman, A.D.; Cordery, R.J.; Godbolt, A.; Rossor, M.N.; MacManus, D.G.; Collinge, J.

2006-01-01

Inherited prion diseases are caused by mutations in the gene which codes for prion protein (PrP), leading to proliferation of abnormal PrP isomers in the brain and neurodegeneration; they include Gerstmann-Straeussler-Scheinker disease (GSS), fatal familial insomnia (FFI) and familial Creutzfeldt-Jakob disease (fCJD). We studied two patients with symptomatic inherited prion disease (P102L) and two pre-symptomatic P102L gene carriers using quantitative magnetic resonance spectroscopy (MRS). Short echo time spectra were acquired from the thalamus, caudate region and frontal white matter, metabolite levels and ratios were measured and z-scores calculated for individual patients relative to age-matched normal controls. MRS data were compared with structural magnetic resonance imaging. One fCJD case had generalised atrophy and showed increased levels of myo-inositol (MI) in the thalamus (z=3.7). The other had decreased levels of N-acetylaspartate (z=4) and diffuse signal abnormality in the frontal white matter. Both asymptomatic gene carriers had normal imaging, but increased frontal white matter MI (z=4.3, 4.1), and one also had increased MI in the caudate (z=5.3). Isolated MI abnormalities in asymptomatic gene carriers are a novel finding and may reflect early glial proliferation, prior to significant neuronal damage. MRS provides potential non-invasive surrogate markers of early disease and progression in inherited prion disease. (orig.)

Behaviour of the order parameter of the simple magnet in an external field

Directory of Open Access Journals (Sweden)

M.P.Kozlovskii

2005-01-01

Full Text Available The effect of a homogeneous external field on the three-dimensional uniaxial magnet behaviour near the critical point is investigated within the framework of the nonperturbative collective variables method using the ρ4 model. The research is carried out for the low-temperature region. The analytic explicit expressions for the free energy, average spin moment and susceptibility are obtained for weak and strong fields in comparison with the field value belonging to the pseudocritical line. The calculations are performed on the microscopic level without any adjusting parameters. It is established that the long-wave fluctuations of the order parameter play a crucial role in forming a crossover between the temperature-dependence and field-dependence critical behaviour of the system.

Transient Behaviour of Superconducting Magnet Systems of Fusion Reactor ITER during Safety Discharge

Directory of Open Access Journals (Sweden)

A. M. Miri

2008-01-01

Full Text Available To investigate the transient behaviour of the toroidal and poloidal field coils magnet systems of the International Thermonuclear Experimental Reactor during safety discharge, network models with lumped elements are established. Frequency-dependant values of the network elements, that is, inductances and resistances are calculated with the finite element method. That way, overvoltages can be determined. According to these overvoltages, the insulation coordination of coils has to be selected.

Abnormal left superior temporal gyrus volumes in children and adolescents with bipolar disorder: a magnetic resonance imaging study.

Science.gov (United States)

Chen, Hua Hsua; Nicoletti, Mark A; Hatch, John P; Sassi, Roberto B; Axelson, David; Brambilla, Paolo; Monkul, E Serap; Keshavan, Matcheri S; Ryan, Neal D; Birmaher, Boris; Soares, Jair C

2004-06-03

Abnormalities in left superior temporal gyrus (STG) have been reported in adult bipolar patients. However, it is not known whether such abnormalities are already present early in the course of this illness. Magnetic resonance imaging (MRI) morphometric analysis of STG was performed in 16 DSM-IV children and adolescents with bipolar disorder (mean age+/-SD 15.5+/-3.4 years) and 21 healthy controls (mean age+/-SD 16.9+/-3.8 years). Subjects underwent a 3D spoiled gradient recalled acquisition MRI examination. Using analysis of covariance with age, gender and intra-cranial brain volume as covariates, we found significantly smaller left total STG volumes in bipolar patients (12.5+/-1.5 cm(3)) compared with healthy controls (13.6+/-2.5 cm(3)) (F=4.45, d.f.=1, 32, P=0.04). This difference was accounted for by significantly smaller left and right STG white matter volumes in bipolar patients. Decreased white matter connections may be the core of abnormalities in STG, which is an important region for speech, language and communication, and could possibly underlie neurocognitive deficits present in bipolar patients.

Abnormal energy deposition on the wall through plasma disruptions

International Nuclear Information System (INIS)

Yamazaki, K.; Schmidt, G.L.

1984-07-01

The dissipation of plasma kinetic and magnetic energy during sawtooth oscillstions and disruptions in tokamaks is analyzed using Kadomtsev's disruption model and the plasma-circuit equations. New simple scalings of several characteristic times are obtained for sawteeth and for thermal and magnetic energy quenches of disruptions. The abnormal energy deposition on the wall during major or minor disruptions, estimated from this analysis, is compared with bolometric measurements in the PDX tokamak. Especially, magnetic energy dissipation during current termination period is shown to be reduced by the strong coupling of the plasma current with external circuits. These analyses are found to be useful to predict the phenomenological behavior of plasma disruptions in large future tokamaks, and to estimate abnormal heat deposition on the wall during plasma disruptions. (author)

Hemorheological abnormalities in human arterial hypertension

Science.gov (United States)

Lo Presti, Rosalia; Hopps, Eugenia; Caimi, Gregorio

2014-05-01

Blood rheology is impaired in hypertensive patients. The alteration involves blood and plasma viscosity, and the erythrocyte behaviour is often abnormal. The hemorheological pattern appears to be related to some pathophysiological mechanisms of hypertension and to organ damage, in particular left ventricular hypertrophy and myocardial ischemia. Abnormalities have been observed in erythrocyte membrane fluidity, explored by fluorescence spectroscopy and electron spin resonance. This may be relevant for red cell flow in microvessels and oxygen delivery to tissues. Although blood viscosity is not a direct target of antihypertensive therapy, the rheological properties of blood play a role in the pathophysiology of arterial hypertension and its vascular complications.

Abnormal Spontaneous Neural Activity in Obsessive-Compulsive Disorder: A Resting-State Functional Magnetic Resonance Imaging Study.

Science.gov (United States)

Ping, Li; Su-Fang, Li; Hai-Ying, Han; Zhang-Ye, Dong; Jia, Luo; Zhi-Hua, Guo; Hong-Fang, Xiong; Yu-Feng, Zang; Zhan-Jiang, Li

2013-01-01

Neuroimaging studies of obsessive-compulsive disorder have found abnormalities in orbitofronto-striato-thalamic circuitry, including the orbitofrontal cortex, anterior cingulate cortex, caudate, and thalamus, but few studies have explored abnormal intrinsic or spontaneous brain activity in the resting state. We investigated both intra- and inter-regional synchronized activity in twenty patients with obsessive-compulsive disorder and 20 healthy controls using resting-state functional magnetic resonance imaging. Regional homogeneity (ReHo) and functional connectivity methods were used to analyze the intra- and inter-regional synchronized activity, respectively. Compared with healthy controls, patients with obsessive-compulsive disorder showed significantly increased ReHo in the orbitofrontal cortex, cerebellum, and insula, and decreased ReHo in the ventral anterior cingulate cortex, caudate, and inferior occipital cortex. Based on ReHo results, we determined functional connectivity differences between the orbitofrontal cortex and other brain regions in both patients with obsessive-compulsive disorder and controls. We found abnormal functional connectivity between the orbitofrontal cortex and ventral anterior cingulate cortex in patients with obsessive-compulsive disorder compared with healthy controls. Moreover, ReHo in the orbitofrontal cortex was correlated with the duration of obsessive-compulsive disorder. These findings suggest that increased intra- and inter-regional synchronized activity in the orbitofrontal cortex may have a key role in the pathology of obsessive-compulsive disorder. In addition to orbitofronto-striato-thalamic circuitry, brain regions such as the insula and cerebellum may also be involved in the pathophysiology of obsessive-compulsive disorder.

Quasi-one-dimensional magnetic behaviour of the Ising system CsFeCl3.2aq

NARCIS (Netherlands)

Kopinga, K.; Steiner, M.; Jonge, de W.J.M.

1985-01-01

The magnetic behaviour of the quasi-one-dimensional system CsFeCl3.2aq(aq=H2O, D2O) has been investigated by heat capacity measurements, quasi-elastic neutron scattering and spin-cluster resonance. the experiments demonstrate that below 25K the compound is a very good realisation of an (S=1/2) Ising

Correlative magnetic resonance imaging in the evaluation of aortic and pulmonary artery abnormalities

Energy Technology Data Exchange (ETDEWEB)

Risius, B.; O' Donnell, J.K.; Geisinger, M.A.; Zelch, M.G.; George, C.R.; Graor, R.A.; Moodie, D.S.

1985-05-01

Magnetic resonance imaging (MRI) yields excellent quality images of the cardiovascular system utilizing the inherent natural contrast between flowing blood and the surrounding anatomic structures. To evaluate the clinical usefulness of MRI in the noninvasive diagnosis of large vessel disorders, the authors have performed MRI on 40 pts with either aortic or pulmonary artery abnormalities (18 thoracic or abdominal aortic aneurysms, 8 aorto-occlusive disease, 6 dissecting aneurysms, 4 Marfan's syndrome, 2 pulmonary artery aneurysms 1 pulmonary artery occlusion, 1 aortic coarctation). Images were obtained in the transverse, coronal and sagital body planes utilizing a 0.6T superconductive magnet. Cardiac and/or respiratory gating was employed in most cases. Correlation was made for all studies with conventional or digital subtraction angiography, computed tomography, and/or ultrasound. The diagnostic information obtained by MRI equaled or exceeded that obtained by other imaging techniques except for the few cases where cardiac arrhythmias precluded adequate gated acquisition. All aneurysms and their relationships to adjacent structures were readily demonstrated as were the presence or absence of mural thrombi and dissecting intimal flaps. Angiographically demonstrated atherosclerotic plaques and luminal stenoses were seen by MRI in all patients without arrhythmias. The authors concluded that MRI is a powerful noninvasive diagnostic aid in the delineation of large vessel disorders, especially where knowledge of anatomic interrelationships can guide surgical or other interventional planning.

Abnormal mitochondria in Rett syndrome: one case report.

Science.gov (United States)

Mak, S C; Chi, C S; Chen, C H; Shian, W J

1993-08-01

A 6-year-9-month-old girl with the characteristic features of Rett syndrome is reported. Clinically, she had microcephaly, psychomotor arrest, deterioration of communication, autistic behaviour, loss of language development, gait apraxia and stereotyped hand washing movement. Amino acid and organic acid analysis were normal. An abnormal rise in serum lactate was noted 120 minutes after oral glucose loading. Muscle biopsy was performed and there was no specific finding noted under light microscope. Electron microscopic evaluation revealed mild accumulation of mitochondria at subsarcolemmal area with abnormal tubular cristae. The cause of Rett syndrome remains obscure. Several articles concerning abnormal mitochondrial morphology or respiratory enzymes have been reported. The exact pathogenesis requires further investigation.

Abnormal energy deposition on the wall through plasma disruptions

International Nuclear Information System (INIS)

Yamazaki, K.; Schmidt, G.L.

1984-01-01

The dissipation of plasma kinetic and magnetic energy during sawtooth oscillations and disruptions in tokamak is analyzed using Kadomtsev's disruption model and the plasma-circuit equations. New simple scalings of several characteristic times are obtained for sawteeth and for thermal and magnetic energy quenches of disruptions. The abnormal energy deposition on the wall during major or minor disruptions, estimated from this analysis, is compared with bolometric measurements in the PDX tokamak. Especially, magnetic energy dissipation during the current termination period is shown to be reduced by the strong coupling of the plasma current with external circuits. These analyses are found to be useful to predict the phenomenological behavior of plasma disruptions in large future tokamaks, and to estimate abnormal heat deposition on the wall during plasma disruptions. (orig.)

LHCb : Behaviour of Multi-anode Photomultipliers in Magnetic Fields for the LHCb RICH Upgrde

CERN Multimedia

Gambetta, Silvia

2015-01-01

A key feature of the LHCb upgrade, scheduled for 2019, is to remove the first level trigger and its data reduction from 40MHz to 1MHz, which is implemented in the on-detector readout electronics. The consequence for the LHCb Ring Imaging Cherenkov (RICH) detectors is that the Hybrid Photon Detectors need to be replaced as the readout chip is inside the detector vacuum. The baseline for replacement are Multianode Photomultiplier tubes (MaPMT) and new readout electronics. The MaPMTs will be located in the fringe field of the LHCb dipole magnet with residual fields up to 25 G. Therefore, their behaviour in magnetic fields is critical. Here we report about studies of the Hamamatsu models R11265 and H12700 in a magnetic field in an effort to qualify them for use in the LHCb RICH upgrade. Comparisons to the known model R7600 are also made. Measurements of the collection efficiency and gain were performed for all three space directions as a function of the magnetic field strength. In addition to measurements with ba...

Study of the influence of surface anisotropy and lattice structure on the behaviour of a small magnetic cluster

International Nuclear Information System (INIS)

Hernandez, Laura; Pinettes, Claire

2005-01-01

We have studied by Monte Carlo simulations the thermal behaviour of a small (N=13 particles) cluster described by a Heisenberg model, including nearest-neighbour ferromagnetic interactions and radial surface anisotropy, in an applied magnetic field. We have studied three different lattice structures: hexagonal close packed, face centered cubic and icosahedral. We show that the zero-field thermal behaviour depends not only on the value of the anisotropy constant but also on the lattice structure. The behaviour in an applied field, additionally depends, on the different orientations of the field with respect to the crystal axes. According to these relative orientations, hysteresis cycles show different step-like characteristics

Study of the influence of surface anisotropy and lattice structure on the behaviour of a small magnetic cluster

Energy Technology Data Exchange (ETDEWEB)

Hernandez, Laura [Laboratoire de Physique Theorique et Modelisation, CNRS-UMR 8089, Universite de Cergy-Pontoise, 5 mail Gay Lussac, Neuville-sur-Oise, 95031 Cergy-Pontoise, Cedex (France)]. E-mail: Laura.Hernandez@ptm.u-cergy.fr; Pinettes, Claire [Laboratoire de Physique Theorique et Modelisation, CNRS-UMR 8089, Universite de Cergy-Pontoise, 5 mail Gay Lussac, Neuville-sur-Oise, 95031 Cergy-Pontoise, Cedex (France)

2005-08-15

We have studied by Monte Carlo simulations the thermal behaviour of a small (N=13 particles) cluster described by a Heisenberg model, including nearest-neighbour ferromagnetic interactions and radial surface anisotropy, in an applied magnetic field. We have studied three different lattice structures: hexagonal close packed, face centered cubic and icosahedral. We show that the zero-field thermal behaviour depends not only on the value of the anisotropy constant but also on the lattice structure. The behaviour in an applied field, additionally depends, on the different orientations of the field with respect to the crystal axes. According to these relative orientations, hysteresis cycles show different step-like characteristics.

[Magnetic resonance imaging as a prenatal diagnostic tool supplementary to ultrasound in diagnosing fetal and gestational abnormalities].

Science.gov (United States)

Porat, Shay; Agid, Ronit; Elchalal, Uriel; Ezra, Yossi; Gomori, J Moshe; Nadjari, Michelle

2002-04-01

The use of Magnetic Resonance Imaging (MRI) as a prenatal and gestational imaging modality supplementary to ultrasound has become widespread with the advent of rapid MR sequences in the last few years. These sequences allow acquisition of high-resolution images of the fetus in a single breath-holding period of the mother, with minimal fetal motion artifacts. We describe our experience with this modality in the diagnosis of prenatal and gestational abnormalities. The study population consisted of 39 pregnant women who had a total of 40 MRI examinations from 7/1998 to 7/2000. The indication for all examinations was a suspected fetal or gestational abnormality as suggested by ultrasound scan, laboratory tests or by family history. In 31 cases (77.5%) a correlation was found between the ultrasound findings and the MR imaging, of which in 6 cases (15%) the MRI added new valuable information. In 9 cases (22.5%) the MRI ruled out findings suspected by ultrasound. The prenatal findings were compared with postnatal clinical follow-up, imaging or pathology report in 26 cases (66.6%). In two cases the clinical outcome and postnatal imaging were discordant with the prenatal imaging findings in ultrasound and MRI. Although not proven, MRI is considered safe during pregnancy because it does not use ionizing radiation. It depicts fetal anatomy and pathology well. Also uterine, placental and other maternal structures are well demonstrated. This tool is useful in cases in which there is a suspicion of a malformed fetus or abnormal placenta by an ultrasound examination or in cases in which an ultrasound examination is limited by technical factors. MRI was found to help parents and doctors decide about the fate of a suspected abnormal pregnancy by adding valuable information supplemental to ultrasound examination.

Brain abnormalities detected on magnetic resonance imaging of amphetamine users presenting to an emergency department: a pilot study.

Science.gov (United States)

Fatovich, Daniel M; McCoubrie, David L; Song, Swithin J; Rosen, David M; Lawn, Nick D; Daly, Frank F

2010-09-06

To determine the prevalence of occult brain abnormalities in magnetic resonance imaging of active amphetamine users. Prospective convenience study in a tertiary hospital emergency department (ED). Patients presenting to the ED for an amphetamine-related reason were eligible for inclusion. We collected demographic data, drug use data, and performed a mini-mental state examination (MMSE). The proportion of patients with an abnormality on their MRI scan. Of 38 patients enrolled, 30 had MRI scans. Nineteen were male and their mean age was 26.7 +/- 5.4 years (range 19-41 years). The mean age of first amphetamine use was 18 years (range 13-26 years). Sixteen patients used crystal methamphetamine (mean amount 2.5 g/week), nine used amphetamine ("speed") (mean amount 2.9 g/week), and 23 used ecstasy (mean amount 2.3 tablets/week). Marijuana was smoked by 26 (mean amount 5.9 g/week), and 28 drank alcohol (mean amount 207 g/week). The median MMSE score was 27/30 (interquartile range, 26-29). Abnormalities on brain MRI scans were identified in six patients, most commonly an unidentified bright object (n = 4). In this pilot study of brain MRI of young people attending the ED with an amphetamine-related presentation, one in five had an occult brain lesion. While the significance of this is uncertain, it is congruent with evidence that amphetamines cause brain injury.

Neurological abnormalities predict disability

DEFF Research Database (Denmark)

Poggesi, Anna; Gouw, Alida; van der Flier, Wiesje

2014-01-01

To investigate the role of neurological abnormalities and magnetic resonance imaging (MRI) lesions in predicting global functional decline in a cohort of initially independent-living elderly subjects. The Leukoaraiosis And DISability (LADIS) Study, involving 11 European centres, was primarily aimed...... at evaluating age-related white matter changes (ARWMC) as an independent predictor of the transition to disability (according to Instrumental Activities of Daily Living scale) or death in independent elderly subjects that were followed up for 3 years. At baseline, a standardized neurological examination.......0 years, 45 % males), 327 (51.7 %) presented at the initial visit with ≥1 neurological abnormality and 242 (38 %) reached the main study outcome. Cox regression analyses, adjusting for MRI features and other determinants of functional decline, showed that the baseline presence of any neurological...

Diagnosis of abnormally invasive posterior placentation: the role of MR imaging.

Science.gov (United States)

Kocher, Madison R; Sheafor, Douglas H; Bruner, Evelyn; Newman, Charles; Mateus Nino, Julio Fernando

2017-06-01

Abnormally invasive placentation is becoming more common with a recent increase in cesarean sections and maternal age, among other risk factors. Ultrasonography is the first line-imaging, but it can be difficult to diagnose when limiting factors are present. Failure to recognize this serious placental abnormality precludes us from making the appropriate plan for the delivery and consequently can lead to fatal results. In this report, we present a case in which magnetic resonance imaging was used to diagnose posterior placenta increta missed by multiple sonographic examinations in a patient with previous myomectomies, and we also include a review of the literature on this topic. It is our conclusion that magnetic resonance imaging is superior to sonography to diagnose abnormally invasive placentation in cases of posterior placenta previa and high pretesting probability.

Diagnosis of abnormally invasive posterior placentation: the role of MR imaging

Directory of Open Access Journals (Sweden)

Madison R. Kocher, BS

2017-06-01

Full Text Available Abnormally invasive placentation is becoming more common with a recent increase in cesarean sections and maternal age, among other risk factors. Ultrasonography is the first line-imaging, but it can be difficult to diagnose when limiting factors are present. Failure to recognize this serious placental abnormality precludes us from making the appropriate plan for the delivery and consequently can lead to fatal results. In this report, we present a case in which magnetic resonance imaging was used to diagnose posterior placenta increta missed by multiple sonographic examinations in a patient with previous myomectomies, and we also include a review of the literature on this topic. It is our conclusion that magnetic resonance imaging is superior to sonography to diagnose abnormally invasive placentation in cases of posterior placenta previa and high pretesting probability.

Modulating the single-molecule magnet behaviour in phenoxo-O bridged Dy2 systems via subtle structural variations

Science.gov (United States)

Wang, Wen-Min; Zhao, Xiao-Yu; Qiao, Hui; Bai, Li; Han, Hong-Fei; Fang, Ming; Wu, Zhi-Lei; Zou, Ji-Yong

2017-09-01

In search of simple approaches to rationally modulate the single-molecule magnet behaviour in polynuclear lanthanide compound, a new system containing two structurally closely related dinuclear dysprosium complexes, namely [Dy2(hfac)4L2] (1) and [Dy2(hfac)4L‧2] (2) (hfac = hexafluoroacetylacetonate, HL = 2-[4-methylaniline-imino]methyl]-8-hydroxyquinoline and HL' = 2-[(3,4-dimethylaniline)-imino]methyl]-8-hydroxyquinoline), are successfully synthesized and the structure-dependent magnetic properties are investigated. The two Dy2 compounds display only slight variations in the coordination geometries of the center Dy(III) ion but display remarkably different single-molecule magnet behaviors with the anisotropic barriers (ΔE/kB) of 9.91 K for 1 and 20.57 K for 2. The different magnetic relaxation behaviors of the two Dy2 complexes mainly originate from the different chemical environments of the central DyIII ions.

Normal or abnormal? 'Normative uncertainty' in psychiatric practice.

Science.gov (United States)

Bassett, Andrew M; Baker, Charley

2015-06-01

The 'multicultural clinical interaction' presents itself as a dilemma for the mental health practitioner. Literature describes two problematic areas where this issues emerges--how to make an adequate distinction between religious rituals and the rituals that may be symptomatic of 'obsessive compulsive disorder' (OCD), and how to differentiate 'normative' religious or spiritual beliefs, behaviours, and experiences from 'psychotic' illnesses. When it comes to understanding service user's 'idioms of distress', beliefs about how culture influences behaviour can create considerable confusion and 'normative uncertainty' for mental health practitioners. In the absence of clear diagnostic and assessment criteria on distinguishing between 'culture' and 'psychopathology', practitioners have had to rely on their own intuition and seek out possible 'strategies' or 'procedures' from a contradictory and cross-disciplinary evidence base. Decontextualisation of service users' experiences may result in the pathologisation of culturally 'normative' phenomenon, 'category fallacy' errors, and poor health care experiences and outcomes for service users.This paper situates this dilemma within a wider debate that has concerned both the biomedical and social sciences, namely, the unresolved question of 'normality' or 'abnormality'. Indeed, issues that arise from dilemmas surrounding the question of 'culture' or 'psychopathology' are intimately tied to wider cultural ideas about what is considered 'normal'. The disciplines of psychiatry, psychology, and medical anthropology have struggled to establish workable criteria against which to judge behaviour as 'normal', 'abnormal', or 'pathological'. Three models for understanding mental 'abnormality' are evident in 'transcultural psychiatry' (what is now commonly known as 'cultural psychiatry'), and these models have corresponded closely to the interpretive models used by anthropologists attempting to make sense of the apparent diversity of

Abnormal optical behaviour of InAsSb quantum dots grown on GaAs substrate by molecular beam epitaxy

International Nuclear Information System (INIS)

Rihani, J.; Ben Sedrine, N.; Sallet, V.; Harmand, J.C.; Oueslati, M.; Chtourou, R.

2008-01-01

InAs(Sb) quantum dots (QDs) samples were grown on GaAs (001) substrate by Molecular Beam Epitaxy (MBE). The structural characterization by Atomic Force Microscopy (AFM) of samples shows that InAsSb islands size increases strongly with antimony incorporation in InAs/GaAs QDs and decreases with reducing the growth temperature from 520 deg. C to 490 deg. C. Abnormal optical behaviour was observed in room temperature (RT) photoluminescence (PL) spectra of samples grown at high temperature (520 deg. C). Temperature dependent PL study was investigated and reveals an anomalous evolution of emission peak energy (EPE) of InAsSb islands, well-known as 'S-inverted curve' and attributed to the release of confined carriers from the InAsSb QDs ground states to the InAsSb wetting layer (WL) states. With only decreasing the growth temperature, the S-inverted shape was suppressed indicating a fulfilled 3D-confinement of carriers in the InAsSb/GaAs QD sample

Diffuse phalangeal signal abnormality on magnetic resonance imaging: phalangeal microgeodic disease

Energy Technology Data Exchange (ETDEWEB)

Radhakrishnan, Rupa; Emery, Kathleen H.; Merrow, Arnold C. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

2017-03-15

Phalangeal microgeodic disease is a rare and benign self-limited condition involving the phalanges, often in the setting of cold exposure, with characteristic MR imaging abnormalities. Radiographic case descriptions are predominantly from Asia and Europe, with only seven cases using MR to characterize phalangeal microgeodic disease. In this study we describe the MR imaging appearance of unusual and striking phalangeal signal abnormality compatible with phalangeal microgeodic disease at our institution in North America. We retrospectively reviewed cases presenting at our institution with unusual or unexplained phalangeal signal abnormalities between 2001 and 2014. We reviewed the MR imaging appearances in conjunction with radiographs and any other available imaging investigations. Of 189 examinations reviewed during the study period, 8 imaging studies in 6 patients met the study inclusion criteria. Signal abnormality was present in 57 of 112 phalanges (51%), frequently involving the distal phalanges (70%, 28 of 40), followed by the middle phalanges (56%, 18 of 32) and the proximal phalanges (28%, 11 of 40). The pattern of involvement was most commonly diaphysis (38%), followed by metaphysis (32%) and epiphysis (30%). The extent of MR signal abnormality was greater than that suspected based on clinical presentation or on radiographs. The presence of unexplained diffuse characteristic marrow involvement of multiple painful phalanges on MR images, often in the setting of cold exposure, should raise the possibility of phalangeal microgeodic disease. Consideration of this diagnosis based on MR findings would lead to a more conservative management and avoid unnecessary invasive diagnostic procedures. (orig.)

Abnormal gas-liquid-solid phase transition behaviour of water observed with in situ environmental SEM.

Science.gov (United States)

Chen, Xin; Shu, Jiapei; Chen, Qing

2017-04-24

Gas-liquid-solid phase transition behaviour of water is studied with environmental scanning electron microscopy for the first time. Abnormal phenomena are observed. At a fixed pressure of 450 Pa, with the temperature set to -7 °C, direct desublimation happens, and ice grows continuously along the substrate surface. At 550 Pa, although ice is the stable phase according to the phase diagram, metastable liquid droplets first nucleate and grow to ~100-200 μm sizes. Ice crystals nucleate within the large sized droplets, grow up and fill up the droplets. Later, the ice crystals grow continuously through desublimation. At 600 Pa, the metastable liquid grows quickly, with some ice nuclei floating in it, and the liquid-solid coexistence state exists for a long time. By lowering the vapour pressure and/or increasing the substrate temperature, ice sublimates into vapour phase, and especially, the remaining ice forms a porous structure due to preferential sublimation in the concave regions, which can be explained with surface tension effect. Interestingly, although it should be forbidden for ice to transform into liquid phase when the temperature is well below 0 °C, liquid like droplets form during the ice sublimation process, which is attributed to the surface tension effect and the quasiliquid layers.

Structural stability, electronic and magnetic behaviour of spin-polarized YCoVZ (Z = Si, Ge) and YCoTiZ (Z = Si, Ge) Heusler alloys

Energy Technology Data Exchange (ETDEWEB)

Rasool, Muhammad Nasir, E-mail: nasir4iub@gmail.com [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur, 63100 (Pakistan); Hussain, Altaf, E-mail: altafiub@yahoo.com [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur, 63100 (Pakistan); Javed, Athar [Department of Physics, University of the Punjab, Lahore, 54590 (Pakistan); Khan, Muhammad Azhar; Iqbal, F. [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur, 63100 (Pakistan)

2016-11-01

The structural stability, electronic and magnetic behaviour of YCoVZ (Z = Si, Ge) and YCoTiZ (Z = Si, Ge) Heusler alloys have been studied by first principle approach. Generalized gradient approximation (GGA) based on density functional theory (DFT) has been applied to investigate the properties of quaternary Heusler alloys. The YCoVSi, YCoVGe, YCoTiSi and YCoTiGe Heusler alloys of Type-3 structure are found to be stable in spin-polarized/magnetic phase. The YCoVSi and YCoVGe alloys exhibit nearly spin gapless semiconductor (SGS) behaviour while YCoTiSi and YCoTiGe alloys show half-metallic ferromagnetic (HMF) behaviour. For YCoVSi, YCoVGe, YCoTiSi and YCoTiGe alloys, the calculated energy band gaps in spin down (↓) channel are 0.60, 0.54, 0.68 and 0.44 eV, respectively. The YCoVZ and YCoTiZ alloys are found to have integral value of total magnetic moment (M{sub T}), thus obeying the Slater-Pauling rule, M{sub T} = (N{sub v}–18)μ{sub B}. - Highlights: • Four Heusler alloys i.e. YCoVZ (Z = Si, Ge) and YCoTiZ (Z = Si, Ge) are studied. • Type-3 crystal structure of all four alloys is stable in magnetic phase. • The compressibility (S) follows the order: S{sub YCoVSi} > S{sub YCoTiSi} > S{sub YCoVGe} > S{sub YCoTiGe}. • Half metallic ferromagnetic behaviour is observed in all four alloys. • All four alloys obey the Slater-Pauling rule, M{sub T} = (N{sub v} – 18)μ{sub B}.

Unsupervised behaviour-specific dictionary learning for abnormal event detection

DEFF Research Database (Denmark)

Ren, Huamin; Liu, Weifeng; Olsen, Søren Ingvor

2015-01-01

the training data is only a small proportion of the surveillance data. Therefore, we propose behavior-specific dictionaries (BSD) through unsupervised learning, pursuing atoms from the same type of behavior to represent one behavior dictionary. To further improve the dictionary by introducing information from...... potential infrequent normal patterns, we refine the dictionary by searching ‘missed atoms’ that have compact coefficients. Experimental results show that our BSD algorithm outperforms state-of-the-art dictionaries in abnormal event detection on the public UCSD dataset. Moreover, BSD has less false alarms...

A functional Magnetic Resonance Imaging study of neurohemodynamic abnormalities during emotion processing in subjects at high risk for schizophrenia

Science.gov (United States)

Venkatasubramanian, Ganesan; Puthumana, Dawn Thomas K.; Jayakumar, Peruvumba N.; Gangadhar, B. N.

2010-01-01

Background: Emotion processing abnormalities are considered among the core deficits in schizophrenia. Subjects at high risk (HR) for schizophrenia also show these deficits. Structural neuroimaging studies examining unaffected relatives at high risk for schizophrenia have demonstrated neuroanatomical abnormalities involving neo-cortical and sub-cortical brain regions related to emotion processing. The brain functional correlates of emotion processing in these HR subjects in the context of ecologically valid, real-life dynamic images using functional Magnetic Resonance Imaging (fMRI) has not been examined previously. Aim: To examine the neurohemodynamic abnormalities during emotion processing in unaffected subjects at high risk for schizophrenia in comparison with age-, sex-, handedness- and education-matched healthy controls, using fMRI. Materials and Methods: HR subjects for schizophrenia (n=17) and matched healthy controls (n=16) were examined. The emotion processing of fearful facial expression was examined using a culturally appropriate and valid tool for Indian subjects. The fMRI was performed in a 1.5-T scanner during an implicit emotion processing paradigm. The fMRI analyses were performed using the Statistical Parametric Mapping 2 (SPM2) software. Results: HR subjects had significantly reduced brain activations in left insula, left medial frontal gyrus, left inferior frontal gyrus, right cingulate gyrus, right precentral gyrus and right inferior parietal lobule. Hypothesis-driven region-of-interest analysis revealed hypoactivation of right amygdala in HR subjects. Conclusions: Study findings suggest that neurohemodynamic abnormalities involving limbic and frontal cortices could be potential indicators for increased vulnerability toward schizophrenia. The clinical utility of these novel findings in predicting the development of psychosis needs to be evaluated. PMID:21267363

Magnetic resonance imaging compared with echocardiography in the evaluation of pulmonary artery abnormalities in children with tetralogy of Fallot following palliative and corrective surgery

International Nuclear Information System (INIS)

Greenberg, S.B.; Crisci, K.L.; Koenig, P.; Robinson, B.; Anisman, P.; Russo, P.

1997-01-01

Background. Abnormalities of the pulmonary arteries following palliative or corrective surgery for tetralogy of Fallot (TOF) are common. Our purpose was to compare the usefulness of magnetic resonance imaging (MRI) and echocardiography in the post- operative evaluation of the pulmonary arteries in children with TOF. Objective. Our hypothesis was that MRI is more sensitive than echocardiography in the detection of branch pulmonary artery abnormalities in children with TOF. Materials and methods. Pulmonary artery MRI and echocardiography were performed in 20 children following palliative and/or corrective surgery for TOF. MRI and echocardiography were compared in their ability to detect abnormalities of the pulmonary arteries. Angiographic or surgical correlation was available in 15 children. A perfusion scan for confirmation of pulmonary artery patency was available in one additional child. Results. Abnormalities of the branch pulmonary arteries identified by MRI included: absence or occlusion (2), focal stenosis (15), hypoplasia (2), aneurysm (1), and non-confluence (1). Echocardiography could not adequately visualize the right and left branch pulmonary arteries in eight and ten children, respectively. Echocardiography missed stenosis in 13 branch pulmonary arteries, patency of hypoplastic pulmonary arteries in two children, non-confluence of the pulmonary arteries in one child, and a left pulmonary artery aneurysm in one child. Abnormalities identified by MRI were confirmed in 16 children by angiography, surgery or perfusion scan. Conclusion. MRI is more sensitive than echocardiography for the evaluation of branch pulmonary artery abnormalities in children following surgery for TOF. (orig.)

Shoulder magnetic resonance imaging abnormalities, wheelchair propulsion, and gender.

Science.gov (United States)

Boninger, Michael L; Dicianno, Brad E; Cooper, Rory A; Towers, Jeffrey D; Koontz, Alicia M; Souza, Aaron L

2003-11-01

To investigate the relationship between pushrim forces and the progression of shoulder injuries in manual wheelchair users. Longitudinal case series. Biomechanics laboratory and magnetic resonance imaging (MRI) facility at a Veterans Health Administration medical center and university hospital, respectively. Fourteen individuals with spinal cord injury (8 men, 6 women) who used manual wheelchairs. Subjects propelled their own wheelchairs on a dynamometer at 0.9 and 1.8m/s. Bilateral biomechanical data were obtained by using force and moment sensing pushrims at time 1. Bilateral shoulder MR images were also completed on 2 occasions, at time 1 and, approximately 2 years later, at time 2. The peak pushrim forces in a pushrim coordinate system were calculated, weight normalized and averaged over 5 strokes (presented as % body weight). MRI abnormalities were graded by using a summated scale. Differences between scores between times 1 and 2 were calculated. Subjects were divided into 2 groups based on change in MRI score. Seven subjects were in the group with worsening scores (MRI+; mean, 8.14 points; range, 5-16), and 7 were in the group with improving or unchanging scores (MRI-; mean, -1.00 point; range, -5 to 1). There was no significant difference between groups with respect to age, body mass index, or years from injury. There were significantly more women in the MRI+ group (6 women, 1 man) than in the MRI- group (7 men) (P=.001). The MRI+ group used significantly greater weight-normalized radial force, or force directed toward the axle at time 1, to propel their wheelchairs at each speed (Ppay particular attention to women who use wheelchairs. Reducing forces during wheelchair propulsion may minimize the likelihood of developing shoulder injuries.

BENDING BEHAVIOUR OF MAGNETIC COTTON YARNS

Directory of Open Access Journals (Sweden)

LUPU Iuliana G.

2017-05-01

Full Text Available Magnetic yarns are composite yarns, i.e. they combine elements of various natures and properties, with proven potential for electromagnetic interference (EMI shielding. In this paper, different mixtures of hard and soft magnetic powder were chosen to cover materials made of cotton yarn. The physical properties and bending behavior of the produced composite yarns were investigated in order to evaluate the yarns for further textile processing.The cotton yarn used as base material was covered with hard (barium hexaferrite BaFe12O19 and soft (Black Toner magnetic particles. An in-house developed laboratory equipment has been used to cover the twist cotton yarns with seven mixtures having different amounts of magnetic powder (30% – 50%. The bending behavior of the coated yarns was evaluated based on the average width of cracks which appeared on the yarn surface after repeated flexural tests. The obtained results revealed that usage of a polyurethane adhesive in the coating solution prevents crack formation on the surface of hard magnetic yarns after flexural tests. At the same time, the higher the mass percentage of hard magnetic powder in the mixture, the higher was the cracks’ width. The soft magnetic yarns are more flexible and a smaller crack width is observed on their surface. Both the coating solution composition and the powder diameter are expected to influence the bending behavior of coated yarns.

Magnetic anisotropies and magnetic switching in Co films

Science.gov (United States)

Bland, J. A. C.; Baird, M. J.; Leung, H. T.; Ives, A. J. R.; Mackay, K. D.; Hughes, H. P.

1992-07-01

We have used the magneto-optical Kerr effect to investigate the role of the substrate and growth conditions in determining the magnetic switching behaviour of Co films in the thickness range 100-200 Å supported by GaAs(001) and Si(111) substrates. We discuss the anisotropic magnetic hysteresis behaviour observed for Co/GaAs and Co/Si films in terms of coherent rotation of the magnetisation vector during magnetic switching. Equivalent films supported by glass substrates are found to be almost isotropic in-plane. The in-plane coercive and saturation fields are observed to lie in the range 20-80 Oe but perpendicular saturation fields of 25 and 19 kOe are found for the Co/Si and Co/GaAs systems respectively which substantially exceed the demagnetising field in each case. The measured perpendicular anisotropy fields differ strongly from the values for hcp and bcc Co and are attributed to the details of the interface and film structure. We also report strongly frequency dependent magnetic switching behaviour in these Co films.

Studying the effect of elastic-plastic strain and hydrogen sulphide on the magnetic behaviour of pipe steels as applied to their testing

Directory of Open Access Journals (Sweden)

Povolotskaya Anna

2018-01-01

Full Text Available The paper reports results of magnetic measurements made on samples of the 12GB pipe steel (strength group X42SS designed for producing pipes to be used in media with high hydrogen sulphide content, both in the initial state and after exposure to hydrogen sulphide, for 96, 192 and 384 hours under uniaxial elastic-plastic tension. At the stage of elastic deformation there is a unique correlation between the coercive force measured on a minor hysteresis loop in weak fields and tensile stress, which enables this parameter to be used for the evaluation of elastic stresses in pipes made of the 12 GB pipe steel under different conditions, including a hydrogen sulphide containing medium. The effect of the value of preliminary plastic strain, viewed as the initial stress-strain state, on the magnetic behaviour of X70 pipe steels under elastic tension and compression is studied. Plastic strain history affects the magnetic behaviour of the material during subsequent elastic deformation since plastic strain induces various residual stresses, and this necessitates taking into account the initial stress-strain state of products when developing magnetic techniques for the determination of their stress-strain parameters during operation.

Abnormal laughter-like vocalisations replacing speech in primary progressive aphasia

Science.gov (United States)

Rohrer, Jonathan D.; Warren, Jason D.; Rossor, Martin N.

2009-01-01

We describe ten patients with a clinical diagnosis of primary progressive aphasia (PPA) (pathologically confirmed in three cases) who developed abnormal laughter-like vocalisations in the context of progressive speech output impairment leading to mutism. Failure of speech output was accompanied by increasing frequency of the abnormal vocalisations until ultimately they constituted the patient's only extended utterance. The laughter-like vocalisations did not show contextual sensitivity but occurred as an automatic vocal output that replaced speech. Acoustic analysis of the vocalisations in two patients revealed abnormal motor features including variable note duration and inter-note interval, loss of temporal symmetry of laugh notes and loss of the normal decrescendo. Abnormal laughter-like vocalisations may be a hallmark of a subgroup in the PPA spectrum with impaired control and production of nonverbal vocal behaviour due to disruption of fronto-temporal networks mediating vocalisation. PMID:19435636

White matter microstructural abnormalities in the frontal lobe of adults with antisocial personality disorder.

Science.gov (United States)

Sundram, Frederick; Deeley, Quinton; Sarkar, Sagari; Daly, Eileen; Latham, Richard; Craig, Michael; Raczek, Malgorzata; Fahy, Tom; Picchioni, Marco; Barker, Gareth J; Murphy, Declan G M

2012-02-01

Antisocial personality disorder (ASPD) and psychopathy involve significant interpersonal and behavioural impairments. However, little is known about their underlying neurobiology and in particular, abnormalities in white matter (WM) microstructure. A preliminary diffusion tensor magnetic resonance imaging (DT-MRI) study of adult psychopaths employing tractography revealed abnormalities in the right uncinate fasciculus (UF) (Craig et al., 2009), indicating fronto-limbic disconnectivity. However, it is not clear whether WM abnormalities are restricted to this tract or are or more widespread, including other tracts which are involved in connectivity with the frontal lobe. We performed whole brain voxel-based analyses on WM fractional anisotropy (FA) and mean diffusivity (MD) maps acquired with DT-MRI to compare 15 adults with ASPD and healthy age, handedness and IQ-matched controls. Also, within ASPD subjects we related differences in FA and MD to measures of psychopathy. Significant WM FA reduction and MD increases were found respectively in ASPD subjects relative to controls. FA was bilaterally reduced in the genu of corpus callosum while in the right frontal lobe FA reduction was found in the UF, inferior fronto-occipital fasciculus (IFOF), anterior corona radiata and anterior limb and genu of the internal capsule. These differences negatively correlated with measures of psychopathy. Also in the right frontal lobe, increased MD was found in the IFOF and UF, and the corpus callosum and anterior corona radiata. There was a significant positive correlation between MD and psychopathy scores. The present study confirms a previous report of reduced FA in the UF. Additionally, we report for the first time, FA deficits in tracts involved in interhemispheric as well as frontal lobe connectivity in conjunction with MD increases in the frontal lobe. Hence, we provide evidence of significant WM microstructural abnormalities in frontal brain regions in ASPD and psychopathy

MRI abnormalities of sacroiliac joints in early spondylarthropathy

DEFF Research Database (Denmark)

Puhakka, K B; Jurik, A G; Schiøttz-Christensen, Berit

2004-01-01

OBJECTIVE: To describe changes in chronic and acute magnetic resonance imaging (MRI) abnormalities of the sacroiliac joints (SIJs) in early spondylarthropathy (SpA), and to associate these findings with computed tomography (CT), X-ray, and clinical findings during a 1-year follow-up. METHODS...

The prevalence of abnormal eating behaviour in a representative sample of the French diabetic population.

Science.gov (United States)

Ryan, M; Gallanagh, J; Livingstone, M B; Gaillard, C; Ritz, P

2008-12-01

To assess the relationship between abnormal eating behaviour (AEB) and diabetes in a sample of French adult patients with type 1 (T1D) and type 2 (T2D) diabetes. Ninety-four consecutively recruited patients self-completed a series of validated questionnaires. Over one-fourth of men with T1D (26%) or T2D (27%) and 11% of female T2D patients reported consistent and pathological overeating or binge-eating during the previous six months. Glycaemic control in these T1D patients was poorer than in T1D patients defined as normal eaters (NORM) (11.9% versus 9.6%), but did not reach statistical significance (P=0.08), and no significant difference was observed in the T2D group (P=0.61) either. T2D patients reported being markedly more restrained when eating than did the T1D patients (P=0.002), and their restraint increased along with their BMI (Phunger (P=0.02) and disinhibition (P=0.003) than did the NORM patients. AEB is present in French diabetic patients at levels that are probably higher than among the general population. These results highlight the need for: (1) greater awareness among diabetes clinicians of the problem; (2) regular screening of diabetic patients for AEB; and (3) adaptation of therapeutic and dietary recommendations for this patient subgroup.

A magnetic resonance spectroscopy study of antisocial behaviour disorder, psychopathy and violent crime among military conscripts.

Science.gov (United States)

Basoglu, Cengiz; Semiz, Umit; Oner, Ozgur; Gunay, Huseyin; Ebrinc, Servet; Cetin, Mesut; Sildiroglu, Onur; Algul, Ayhan; Ates, Alpay; Sonmez, Guner

2008-04-01

Prefrontal and/or temporo-limbic abnormalities associated with antisocial personality disorder (APD), high psychopathy scores and violent behaviours can readily be evaluated by neuroimaging methods. In this study, we compared the brain metabolites in adult male military conscripts with APD, high psychopathy scores and serious violent crimes (n = 15) with age- and educational-level-matched healthy controls (n = 15) by means of magnetic resonance spectroscopy. All cases were diagnosed by means of the Diagnostic Statistical Manual-IV APD module of the Structured Clinical Interview for DSM III-R Axis II Disorders (SCID-II) semistructured questionnaire in Turkish. The psychopathy scores were evaluated by means of the Hare Psychopathy Checklist-Revised translated into Turkish (PCL-R). PCL-R is a 20-item, reliable and valid instrument for assessment of psychopathy, both in categorical and dimensional natures. All patients had a total score of 29 (of possible 40) or higher from PCL-R, indicating a high degree of psychopathy. Our results showed no significant differences in ratio of N-acetyl aspartate (NAA), creatine (Cr) and choline-related compounds in the right dorsolateral prefrontal cortex, anterior cingulate cortex (ACC) and amygdala-hippocampus regions of cases compared with controls. ACC NAA/Cr was significantly negatively correlated with both the PCL-R total score and the PCL-R factor I score (interpersonal/affective problems) among the cases. As ACC plays an important role in decision-making and emotional information processing, we postulate that the lower NAA/Cr ratio, suggesting impaired neural integrity, may increase the severity of interpersonal/affective problems of the psychopathy factor in male subjects exhibiting APD, high psychopathy overall scores and violent crimes.

Magnetic resonance imaging compared with echocardiography in the evaluation of pulmonary artery abnormalities in children with tetralogy of Fallot following palliative and corrective surgery

Energy Technology Data Exchange (ETDEWEB)

Greenberg, S.B.; Crisci, K.L.; Koenig, P.; Robinson, B.; Anisman, P.; Russo, P. [St. Christopher`s Hospital for Children, Front Street at Erie Avenue, Philadelphia, PA 19134 (United States)

1997-12-01

Background. Abnormalities of the pulmonary arteries following palliative or corrective surgery for tetralogy of Fallot (TOF) are common. Our purpose was to compare the usefulness of magnetic resonance imaging (MRI) and echocardiography in the post- operative evaluation of the pulmonary arteries in children with TOF. Objective. Our hypothesis was that MRI is more sensitive than echocardiography in the detection of branch pulmonary artery abnormalities in children with TOF. Materials and methods. Pulmonary artery MRI and echocardiography were performed in 20 children following palliative and/or corrective surgery for TOF. MRI and echocardiography were compared in their ability to detect abnormalities of the pulmonary arteries. Angiographic or surgical correlation was available in 15 children. A perfusion scan for confirmation of pulmonary artery patency was available in one additional child. Results. Abnormalities of the branch pulmonary arteries identified by MRI included: absence or occlusion (2), focal stenosis (15), hypoplasia (2), aneurysm (1), and non-confluence (1). Echocardiography could not adequately visualize the right and left branch pulmonary arteries in eight and ten children, respectively. Echocardiography missed stenosis in 13 branch pulmonary arteries, patency of hypoplastic pulmonary arteries in two children, non-confluence of the pulmonary arteries in one child, and a left pulmonary artery aneurysm in one child. Abnormalities identified by MRI were confirmed in 16 children by angiography, surgery or perfusion scan. Conclusion. MRI is more sensitive than echocardiography for the evaluation of branch pulmonary artery abnormalities in children following surgery for TOF. (orig.) With 2 figs., 3 tabs., 11 refs.

Experimental observation of nonlinear behaviour in a helium plasma discharge in the presence of a nonuniform magnetic field

International Nuclear Information System (INIS)

Toma, M.; Sanduloviciu, M.

1994-01-01

The nonlinear behaviour in an electrical discharge plasma due to the action of an external nonuniform magnetic field is presented. The discharge geometry and the magnetic field configuration ('inverse' cylindrical magnetron discharge) were so chosen that there is a possibility to control the net electron flux in a certain region of a positive electrode. The plasma discharge nonlinearity manifested in the profile of the current-voltage, current-magnetic field and current-gas pressure characteristics by the appearance of the anomalous negative resistance, in the bistability and hysteresis and also in the periodical and chaotic variation of the discharge current. The profile of the current variation vs control discharge parameters was related to the appearance of a space charge structure in the shape of nearly spherical bulges, delimited from the surrounding plasma by a double layer. (Author)

Imaging Characteristics of Venous Parenchymal Abnormalities.

Science.gov (United States)

Arnoux, Audrey; Triquenot-Bagan, Aude; Andriuta, Daniela; Wallon, David; Guegan-Massardier, Evelyne; Leclercq, Claire; Martinaud, Olivier; Castier-Amouyel, Mélody; Godefroy, Olivier; Bugnicourt, Jean-Marc

2017-12-01

There are few published data on the patterns of parenchymal imaging abnormalities in a context of cerebral venous thrombosis (CVT). The objectives of the present study were to describe the patterns of parenchymal lesions associated with CVT and to determine the lesion sites. We included 44 consecutively hospitalized patients with CVT and parenchymal lesions on magnetic resonance imaging. The diagnosis of CVT had been confirmed by magnetic resonance imaging/magnetic resonance venography. Magnetic resonance imaging patterns for CVT were retrospectively analyzed with regard to the lesion's type, shape, and site. The most frequent stroke subtype was hemorrhagic ischemia (in 56.8% of cases), followed by intracerebral hematoma (in 22.72% of cases) and nonhemorrhagic ischemia (in 20.45% of cases). Although there were no significant differences between these 3 groups with regard to the clinical and radiological characteristics, we observed a nonsignificant trend ( P =0.08) toward a shorter time interval between hospital admission and magnetic resonance imaging for nonhemorrhagic stroke. The CVT parenchymal abnormalities were centered on 6 main foci and were related to the site of venous occlusion: (1) the inferior parietal lobule (n=20; 44.5%), associated mainly with occlusion of the transverse sinus (n=10) or pure cortical veins (n=10); (2) the inferior and posterior temporal regions (n=10; 22.75%), associated mainly with occlusion of the transverse sinus (n=9); (3) the parasagittal frontal region (n=6; 13.6%), associated mainly with occlusion of the superior sagittal sinus (n=4) or the transverse sinus (n=4); (4) the thalamus (n=5; 11.3%) associated with occlusion of the straight sinus (n=5); (5) the cerebellar hemisphere (n=2; 4.5%), associated in both cases with occlusion of the transverse sinus; and (6) the deep hemispheric regions (n=3; 6.8%), associated with occlusion of the superior sagittal sinus in all cases. Parenchymal lesions caused by CVT display specific

Magnetocaloric effect and its implementation in critical behaviour ...

Indian Academy of Sciences (India)

Model; manganites; magnetization; magnetocaloric effect; critical exponent. 1. Introduction. Large number of magnetocaloric effect (MCE) materials have attracted much ... external magnetic field, which is advantageous for applica- tion as magnetic ... of the magnetic phase transition and critical behaviour can be obtained by ...

Magnetic behaviour in metal-organic frameworks

Indian Academy of Sciences (India)

The article describes the synthesis, structure and magnetic investigations of a series of metal-organic framework compounds formed with Mn+2 and Ni+2 ions. The structures, determined using the single crystal X-ray diffraction, indicated that the structures possess two- and three-dimensional structures with magnetically ...

Behavioural alterations are independent of sickness behaviour in chronic experimental Chagas disease.

Science.gov (United States)

Vilar-Pereira, Glaucia; Ruivo, Leonardo Alexandre de Souza; Lannes-Vieira, Joseli

2015-12-01

The existence of the nervous form of Chagas disease is a matter of discussion since Carlos Chagas described neurological disorders, learning and behavioural alterations in Trypanosoma cruzi-infected individuals. In most patients, the clinical manifestations of the acute phase, including neurological abnormalities, resolve spontaneously without apparent consequence in the chronic phase of infection. However, chronic Chagas disease patients have behavioural changes such as psychomotor alterations, attention and memory deficits, and depression. In the present study, we tested whether or not behavioural alterations are reproducible in experimental models. We show that C57BL/6 mice chronically infected with the Colombian strain of T. cruzi (150 days post-infection) exhibit behavioural changes as (i) depression in the tail suspension and forced swim tests, (ii) anxiety analysed by elevated plus maze and open field test sand and (iii) motor coordination in the rotarod test. These alterations are neither associated with neuromuscular disorders assessed by the grip strength test nor with sickness behaviour analysed by temperature variation sand weight loss. Therefore, chronically T. cruzi-infected mice replicate behavioural alterations (depression and anxiety) detected in Chagas disease patients opening an opportunity to study the interconnection and the physiopathology of these two biological processes in an infectious scenario.

Magnetic and optical bistability in tetrairon(III) single molecule magnets functionalized with azobenzene groups.

Science.gov (United States)

Prasad, Thazhe Kootteri; Poneti, Giordano; Sorace, Lorenzo; Rodriguez-Douton, Maria Jesus; Barra, Anne-Laure; Neugebauer, Petr; Costantino, Luca; Sessoli, Roberta; Cornia, Andrea

2012-07-21

Tetrairon(III) complexes known as "ferric stars" have been functionalized with azobenzene groups to investigate the effect of light-induced trans-cis isomerization on single-molecule magnet (SMM) behaviour. According to DC magnetic data and EPR spectroscopy, clusters dispersed in polystyrene (4% w/w) exhibit the same spin (S = 5) and magnetic anisotropy as bulk samples. Ligand photoisomerization, achieved by irradiation at 365 nm, has no detectable influence on static magnetic properties. However, it induces a small but significant acceleration of magnetic relaxation as probed by AC susceptometry. The pristine behaviour can be almost quantitatively recovered by irradiation with white light. Our studies demonstrate that magnetic and optical bistability can be made to coexist in SMM materials, which are of current interest in molecular spintronics.

Magnetic and thermal behaviour of the amorphous ferromagnet Fe79B16Si5

International Nuclear Information System (INIS)

Shaisha, E.E.; Bahgat, A.A.

1985-01-01

Spin waves in the amorphous ferromagnet Fe 79 B 16 Si 5 are studied by Moessbauer effect spectroscopy. The magnetic hyperfine field (MHF) is measured at the Fe sites of such a ferromagnet, which exhibits a temperature dependence of the form, H(T)/H(0) = (1 - BT/sup 3/2/ - CT/sup 5/2/), indicative of spin wave excitations in amorphous ferromagnets. The T/sup 3/2/ behaviour and the distribution of the exchange interactions are studied in detail as a function of the MHF. The spin wave excitations constant B/sub 3/2/ = BT/sub C//sup 3/2/ = 0.3 +- 0.05 and C/sub 5/2/ = CT/sub C//sup 5/2/ = 0.3 +- 0.05,Are obtained by fitting the experimental data, and where T/sub C/ = 670 K. The results sh=ow that the contribution of C/sub 5/2/ is extremely effective above 124 K, while the ratio C/sub 5/2//C/sub 3/2/ = 1.0 indicates that the present magnetic interaction is of long range order character. On the other hand, fluctuations of the exchange interaction constant are found to decrease with increasing temperature. Some information regarding the directions of the magnetic moments are obtained during the study of the magnetic anisotropy course. The values of the Einstein and Debye temperatures as measured from the thermal shift results are theta/sub E/ = 250 K and theta/sub D/ = 350 K,And from the Moessbauer factor measurements theta/sub E/ = 165 K and theta/sub D/ = 285 K. (autho=r)

Rare-earth magnets and their applications. Vol. 2. Proceedings

International Nuclear Information System (INIS)

Schultz, L.; Mueller, K.H.

1998-01-01

The following topics were dealt with: permanent magnets, rare- earth magnets, manufacturing, markets, powder metallurgy, sintering, mechanical alloying, nanocrystalline magnets, Curie temperature, domain structure, exchange coupling, stoichiometry effects, coercive force, remanence, magnetisation distribution, demagnetisation, mechanical properties, deformation behaviour, microstructure, grain size effects, texture, magnetic anisotropy, hydrogen assisted processing, nitriding, hydrogen embrittlement, permanent magnet motors, permanent magnet generators, brushless machines, linear motors, DC motors, AC motors, servomotors, magnetic levitation, magnetic field calculations, magnetic damping, magnet system design, system optimisation, corrosion protection, magnetometers, hard magnetic films, magnetostriction, magnetic multilayers, spin glass behaviour

Neurological abnormalities predict disability: the LADIS (Leukoaraiosis And DISability) study

NARCIS (Netherlands)

Poggesi, A.; Gouw, A.; van der Flier, W.M.; Pracucci, G.; Chabriat, H.; Erkinjuntti, T.; Fazekas, F.; Ferro, J.M.; Blahak, C.; Langhorne, P.; O'Brien, J.; Schmidt, R.; Visser, M.C.; Wahlund, L.O.; Waldemar, G.; Wallin, A.; Scheltens, P.; Inzitari, D.; Pantoni, L.

2014-01-01

To investigate the role of neurological abnormalities and magnetic resonance imaging (MRI) lesions in predicting global functional decline in a cohort of initially independent-living elderly subjects. The Leukoaraiosis And DISability (LADIS) Study, involving 11 European centres, was primarily aimed

Magnetic behaviour of densely packed hexagonal arrays of Ni nanowires: Influence of geometric characteristics

International Nuclear Information System (INIS)

Vazquez, M.; Pirota, K.; Torrejon, J.; Navas, D.; Hernandez-Velez, M.

2005-01-01

Densely packed arrays of magnetic nanowires with hexagonal symmetry have been prepared by electrodeposition filling of the nanopores in alumina membranes previously formed by self-assembling induced by anodization. The influence of geometrical characteristics of arrays of Ni nanowires on their hysteresis loops have been studied. These characteristics are controlled by suitable choosing of preparation parameters: nanowires diameter ranges between 18 and 80 nm for lattice parameter of hexagonal symmetry of 65 and 105 nm, while length of nanowires is taken between 500 and 2000 nm. Additionally, the temperature dependence of coercivity when applying the field parallel to the nanowires or in-plane of the membrane has been measured. All these results allows us to conclude that magnetic behaviour is determined by the balance between different energy contributions, namely, the shape anisotropy of individual nanowires, the magnetostatic interaction among nanowires (confirmed to play a decisive role), and seemingly the magnetoelastic anisotropy induced in the nanowires by the alumina matrix through temperature changes as a consequence of their different thermal expansion coefficients

Crystallite-growth, phase transition, magnetic properties, and sintering behaviour of nano-CuFe2O4 powders prepared by a combustion-like process

International Nuclear Information System (INIS)

Köferstein, Roberto; Walther, Till; Hesse, Dietrich; Ebbinghaus, Stefan G.

2014-01-01

The synthesis of nano-crystalline CuFe 2 O 4 powders by a combustion-like process is described herein. Phase formation and evolution of the crystallite size during the decomposition process of a (CuFe 2 )—precursor gel were monitored up to 1000 °C. Phase-pure nano-sized CuFe 2 O 4 powders were obtained after reaction at 750 °C for 2 h resulting in a crystallite size of 36 nm, which increases to 96 nm after calcining at 1000 °C. The activation energy of the crystallite growth process was calculated as 389 kJ mol −1 . The tetragonal⇄cubic phase transition occurs between 402 and 419 °C and the enthalpy change (ΔH) was found to range between 1020 and 1229 J mol −1 depending on the calcination temperature. The optical band gap depends on the calcination temperature and was found between 2.03 and 1.89 eV. The shrinkage and sintering behaviour of compacted powders were examined. Dense ceramic bodies can be obtained either after conventional sintering at 950 °C or after a two-step sintering process at 800 °C. Magnetic measurements of both powders and corresponding ceramic bodies show that the saturation magnetization rises with increasing calcination-/sintering temperature up to 49.1 emu g −1 (2.1 µ B fu −1 ), whereas the coercivity and remanence values decrease. - Graphical abstract: A cheap one-pot synthesis was developed to obtain CuFe 2 O 4 nano-powders with different crystallite sizes (36–96 nm). The optical band gaps, phase transition temperatures and enthalpies were determined depending on the particle size. The sintering behaviour of nano CuFe 2 O 4 was studied in different sintering procedures. The magnetic behaviour of the nano-powders as well as the corresponding ceramic bodies were investigated. - Highlights: • Eco-friendly and simple synthesis for nano CuFe 2 O 4 powder using starch as polymerization agent. • Monitoring the phase evolution and crystallite growth kinetics during the synthesis. • Determination of the optical band gap

Patterning nanostructures to study magnetization processes

International Nuclear Information System (INIS)

Atkinson, D

2005-01-01

Lithography techniques such as electron-beam lithography and focused-ion-beam milling are widely used to fabricate structures with dimensions well below 1 μm. These techniques have been used to produce planar magnetic structures with sub-micrometer dimensions and well controlled geometry. This has allowed the study of basic magnetic behaviour and the development of structures with potential for applications in magnetic recording and magnetic logic devices. The techniques of electron beam lithography and focused-ion-beam milling for the fabrication of magnetic nanostructures are outlined here. These techniques have been used to fabricate ribbon-like planar nanowires to study the behaviour of the individual magnetic domain walls which mediate the reversal process in such elongated structures. These methods allow the production of structures in which the location of domain wall formation and position can be controlled, allowing separation and study of the domain wall nucleation and propagation processes. Domain wall injection and domain wall propagation behaviour are investigated and shown to be stochastic processes

Endogenous opioids are involved in abnormal stereotyped behaviour of tethered sows

NARCIS (Netherlands)

Cronin, G.M.; Wiepkema, P.R.; Ree, van J.M.

1985-01-01

Tethered sows continuously performed stereotypies during a substantial part of the day time. A single subcutaneous injection with naloxone significantly decreased the profound stereotypies, while explorative behaviours of pigs were not affected by naloxone. In addition a long-term effect of naloxone

Endogenous opioids are involved in abnormal stereotyped behaviours of tethered sows

NARCIS (Netherlands)

Cronin, G.M.; Wiepkema, P.R.; Ree, J.M. van

1985-01-01

Tethered sows continuously performed stereotypies during a substantial part of the day time. A single subcutaneous injection with naloxone significantly decreased the profound stereotypies, while explorative behaviours of pigs were not affected by naloxone. In addition a long-term effect of naloxone

Multiple-decker phthalocyaninato dinuclear lanthanoid(III) single-molecule magnets with dual-magnetic relaxation processes.

Science.gov (United States)

Katoh, Keiichi; Horii, Yoji; Yasuda, Nobuhiro; Wernsdorfer, Wolfgang; Toriumi, Koshiro; Breedlove, Brian K; Yamashita, Masahiro

2012-11-28

The SMM behaviour of dinuclear Ln(III)-Pc multiple-decker complexes (Ln = Tb(3+) and Dy(3+)) with energy barriers and slow-relaxation behaviour were explained by using X-ray crystallography and static and dynamic susceptibility measurements. In particular, interactions among the 4f electrons of several dinuclear Ln(III)-Pc type SMMs have never been discussed on the basis of the crystal structure. For dinuclear Tb(III)-Pc complexes, a dual magnetic relaxation process was observed. The relaxation processes are due to the anisotropic centres. Our results clearly show that the two Tb(3+) ion sites are equivalent and are consistent with the crystal structure. On the other hand, the mononuclear Tb(III)-Pc complex exhibited only a single magnetic relaxation process. This is clear evidence that the magnetic relaxation mechanism depends heavily on the dipole-dipole (f-f) interactions between the Tb(3+) ions in the dinuclear systems. Furthermore, the SMM behaviour of dinuclear Dy(III)-Pc type SMMs with smaller energy barriers compared with that of Tb(III)-Pc and slow-relaxation behaviour was explained. Dinuclear Dy(III)-Pc SMMs exhibited single-component magnetic relaxation behaviour. The results indicate that the magnetic relaxation properties of dinuclear Ln(III)-Pc multiple-decker complexes are affected by the local molecular symmetry and are extremely sensitive to tiny distortions in the coordination geometry. In other words, the spatial arrangement of the Ln(3+) ions (f-f interactions) in the crystal is important. Our work shows that the SMM properties can be fine-tuned by introducing weak intermolecular magnetic interactions in a controlled SMM spatial arrangement.

Evolution of the microstructure, chemical composition and magnetic behaviour during the synthesis of alkanethiol-capped gold nanoparticles

International Nuclear Information System (INIS)

Guerrero, E.; Rojas, T.C.; Multigner, M.; Crespo, P.; Munoz-Marquez, M.A.; Garcia, M.A.; Hernando, A.; Fernandez, A.

2007-01-01

In the present paper, we show an exhaustive microstructural characterization of thiol-capped gold nanoparticles (NPs) with two different average particle sizes. These samples are compared with the polymer-like Au(I) phase formed as a precursor during the synthesis of the thiol-capped gold NPs. The set of analysed samples shows different microstructures at the nanoscale with different proportions of Au atoms bonded either to S or to Au atoms. It has been experimentally shown that the presence of a ferromagnetic-like behaviour is associated to the formation of NPs with simultaneous presence of Au-Au and Au-S bonds. In order to explain such magnetic behaviour a possible model is proposed based on the spin-orbit coupling so that localized charges and/or spins (Au-S bonds) can trap conduction electrons (Au-Au bonds) in orbits

Occipital dysplasia and associated cranial spinal cord abnormalities in two dogs

International Nuclear Information System (INIS)

Bagley, R.S.; Harrington, M.L.; Tucker, R.L.; Sande, R.D.; Root, C.R.; Kramer, R.W.

1996-01-01

Occipital dysplasia was found in association with cervical spinal cord abnormalities in two dogs. One dog presented for tetraparesis and cervical hyperesthesia, the other for historical cervical hyperesthesia and mild paraparesis. In dog 1, a midline cervical spinal cord defect consistent with a communicating syrinx was found. In the other dog, a presumptive syringo/hydromyelia of the cervical spinal cord was found on magnetic resonance imaging. While occipital dysplasia alone is not thought to cause any clinical abnormalities, the dogs of this report suggest that intramedullary central nervous system abnormalities may be present concurrently with occipital dysplasia and should be considered as a possible cause of the clinical signs. The relationship between occipital dysplasia and syringo/hydromyelia in these dogs remains unclear, however, similar associated abnormalities are occasionally found in humans with Chiari malformation

Prognostic value of proton magnetic resonance spectroscopy findings in near drowning patients: reversibility of the early metabolite abnormalities relates with a good outcome

International Nuclear Information System (INIS)

Aragao, Maria de Fatima Vasco; Law, Meng; Prola Netto, Joao; Naidich, Thomas; Valenca, Marcelo Moraes

2009-01-01

In two children with near drowning hypoxic encephalopathy and normal-appearing structural MRI, acute proton magnetic resonance spectroscopy ( 1 H MRS) showed biochemical alterations that correctly indicated prognosis and helped to guide management decisions. Elevation of the lipid-lactate and glutamine-glutamate peaks, on the early (72 hour) 1 H MRS, predicts a poor prognosis. Absence of lipid-lactate and glutamine-glutamate peaks on the early 1 H MRS and reversibility of early mild metabolite abnormalities on follow up examination relates with good outcome. (author)

Abnormal neuronal migration: radiologic-clinic study

International Nuclear Information System (INIS)

Martinez Fernandez, M.; Menor Serrano, F.; Bordon Ferre, F.; Garcia Tena, J.; Esteban Hernandez, E.; Sanguesa Nebot, C.; Marti Bonnati, L.

1994-01-01

We present our experience in 18 pediatric patients with abnormal neuronal migration. Seven cases of heterotopia of the gray matter, 7 agyria-pachygyria complexes, 1 case of polymicrogyria, 2 cases of schizencephaly and 1 case of hemimegalencephaly were diagnosed by means of ultrasonography, computed tomography and magnetic resonance. The clinical picture was reviewed in each case, with special attention to the occurrence of convulsions, psycho motor development and visual changes. In general, the greater the morphological change, the greater the neurological involvement in these patients. However, the two cases of schizencephaly presented mild clinical expression. Magnetic resonance increases the diagnostic yield in neuronal migration disorders. Nevertheless, either ultrasonography or, especially, computed tomography is useful as a first diagnostic approach in these malformative disorders. (Author)

The effect of housing on the diurnal behavioural profile of beef heifers

Directory of Open Access Journals (Sweden)

Mary Clare Hickey

2014-02-01

Full Text Available The objectives were to determine 1. the behaviour of heifers at pasture or housed on slats, and 2. the effect of housing on behavioural adaptation when moved to pasture. Forty-five continental crossbred heifers were assigned to either housing on slats at 3 m2 head-1for 5 months (H, grazing for 5 months (G or housing for 4 months, prior to grazing (HG. Lying and eating behaviour was recorded periodically for H, G and for HG post-turnout. Per day, G animals spent longer (p<0.01 eating and had a greater (p<0.001 number of daily lying bouts than H animals. While there were minor differences between G and HG animals in the 24 h period after turnout, there was no difference between G and HG animals in time spent eating, lying or in the number of lying bouts on day 1, 2, 3 or 10 post turnout. While abnormal lying behaviour was observed in 3 animals before turnout, there was no abnormal lying behaviour in HG animals by 48 h post turnout. The alteration in behaviour due to housing was not permanent.

Gadolinium enhanced cardiovascular magnetic resonance in Anderson-Fabry disease. Evidence for a disease specific abnormality of the myocardial interstitium.

Science.gov (United States)

Moon, James C C; Sachdev, Bhavesh; Elkington, Andrew G; McKenna, William J; Mehta, Atul; Pennell, Dudley J; Leed, Philip J; Elliott, Perry M

2003-12-01

Anderson-Fabry Disease (AFD), an X-linked disorder of sphingolipid metabolism, is a cause of idiopathic left ventricular hypertrophy but the mechanism of hypertrophy is poorly understood. Gadolinium enhanced cardiovascular magnetic resonance can detect focal myocardial fibrosis. We hypothesised that hyperenhancement would be present in AFD. Eighteen males (mean 43+/-14 years) and eight female heterozygotes (mean 48+/-12 years) with AFD underwent cine and late gadolinium cardiovascular magnetic resonance. Nine male (50%) had myocardial hyperenhancement ranging from 3.4% to 20.6% (mean 7.7+/-5.7%) of total myocardium; in males, percentage hyperenhancement related to LV mass index (r=0.78, P=0.0002) but not to ejection fraction or left ventricular volumes. Lesser hyperenhancement was also found in four (50%) heterozygous females (mean 4.6%). In 12 (92%) patients with abnormal gadolinium uptake, hyperenhancement occurred in the basal infero-lateral wall where, unlike myocardial infarction, it was not sub-endocardial. In two male patients with severe LVH (left ventricular hypertrophy) and systolic impairment there was additional hyperenhancement in other myocardial segments. These observations suggests that myocardial fibrosis occurs in AFD and may contribute to the hypertrophy and the natural history of the disease.

Magnetic Resonance Imaging (MRI) -- Head

Medline Plus

Full Text Available ... by the interpreting radiologist. Frequently, the differentiation of abnormal (diseased) tissue from normal tissues is better with ... Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic ...

Cognitive correlates of neuroimaging abnormalities in the onset of schizophrenia: A case report

OpenAIRE

Grassi, Silvia; Orsenigo, Giulia; Serati, Marta; Caletti, Elisabetta; Altamura, Alfredo Carlo; Buoli, Massimiliano

2017-01-01

Increasing evidence shows that cognitive impairment and brain abnormalities can appear early in the first episodes of schizophrenia, but it is currently debated how brain changes can correlate with clinical presentation of schizophrenic patients. Of note, this report describes the case of a young schizophrenic male presenting parietal magnetic resonance/positron emission tomography abnormalities and cognitive impairment, documented by specific neuropsychological tests. In our knowledge only f...

Neuroimaging of aggressive and violent behaviour in children and adolescents

Directory of Open Access Journals (Sweden)

Philipp Sterzer

2009-10-01

Full Text Available In recent years, a number of functional and structural neuroimaging studies have investigated the neural bases of aggressive and violent behaviour in children and adolescents. Most functional neuroimaging studies have persued the hypothesis that pathological aggression is a consequence of deficits in the neural circuits involved in emotion processing. There is converging evidence for deficient neural responses to emotional stimuli in youths with a propensity towards aggressive behaviour. In addition, recent neuroimaging work has suggested that aggressive behaviour is also associated with abnormalities in neural processes that subserve both the inhibitory control of behaviour and the flexible adaptation of behaviour in accord with reinforcement information. Structural neuroimaging studies in children and adolescents with conduct problems are still scarce, but point to deficits in brain structures in volved in the processing of social information and in the regulation of social and goal directed behaviour. The indisputable progress that this research field has made in recent years notwithstanding, the overall picture is still rather patchy and there are inconsistencies between studies that await clarification. Despite this, we attempt to provide an integrated view on the neural abnormalities that may contribute to various forms of juvenile aggression and violence, and discuss research strategies that may help to provide a more profound understanding of these important issues in the future.

Magnetization process of heat assisted magnetic recording by micro-magnetic simulation

International Nuclear Information System (INIS)

Shiiki, Kazuo; Motojima, Hisanori

2010-01-01

Magnetization reversal in a uniform magnetic field and one bit recording process by a thin film head in the heat assisted magnetic recording system of TbFeCo medium are studied by using the micro-magnetic simulation and the heat equation. The Landau-Lifsitz-Gilbert equation is solved for magnetic parameters at temperatures as the time goes by. It is found that magnetization proceeds as a progressive wave, although this behaviour may not limit the recording speed. The recording bit is expanded by the thermal fluctuation. The expansion can be suppressed as the medium thickness increases, because the thermal fluctuation is small in the thick medium. So the control of the medium thickness is important very much to achieve a high-density heat-assisted recording.

Prognostic value of proton magnetic resonance spectroscopy findings in near drowning patients: reversibility of the early metabolite abnormalities relates with a good outcome

Energy Technology Data Exchange (ETDEWEB)

Aragao, Maria de Fatima Vasco; Law, Meng; Prola Netto, Joao; Naidich, Thomas [Mount Sinai School of Medicine, New York, NY (United States). Dept. of Radiology], e-mail: aragao@truenet.com; Valenca, Marcelo Moraes [Federal University of Pernambuco (UFPE), Recife, PE (Brazil). Dept. of Neuropsychiatry and Behavioral Studies

2009-03-15

In two children with near drowning hypoxic encephalopathy and normal-appearing structural MRI, acute proton magnetic resonance spectroscopy ({sup 1}H MRS) showed biochemical alterations that correctly indicated prognosis and helped to guide management decisions. Elevation of the lipid-lactate and glutamine-glutamate peaks, on the early (72 hour) {sup 1}H MRS, predicts a poor prognosis. Absence of lipid-lactate and glutamine-glutamate peaks on the early {sup 1}H MRS and reversibility of early mild metabolite abnormalities on follow up examination relates with good outcome. (author)

Computational Analysis of Static and Dynamic Behaviour of Magnetic Suspensions and Magnetic Bearings

Science.gov (United States)

Britcher, Colin P. (Editor); Groom, Nelson J.

1996-01-01

Static modelling of magnetic bearings is often carried out using magnetic circuit theory. This theory cannot easily include nonlinear effects such as magnetic saturation or the fringing of flux in air-gaps. Modern computational tools are able to accurately model complex magnetic bearing geometries, provided some care is exercised. In magnetic suspension applications, the magnetic fields are highly three-dimensional and require computational tools for the solution of most problems of interest. The dynamics of a magnetic bearing or magnetic suspension system can be strongly affected by eddy currents. Eddy currents are present whenever a time-varying magnetic flux penetrates a conducting medium. The direction of flow of the eddy current is such as to reduce the rate-of-change of flux. Analytic solutions for eddy currents are available for some simplified geometries, but complex geometries must be solved by computation. It is only in recent years that such computations have been considered truly practical. At NASA Langley Research Center, state-of-the-art finite-element computer codes, 'OPERA', 'TOSCA' and 'ELEKTRA' have recently been installed and applied to the magnetostatic and eddy current problems. This paper reviews results of theoretical analyses which suggest general forms of mathematical models for eddy currents, together with computational results. A simplified circuit-based eddy current model proposed appears to predict the observed trends in the case of large eddy current circuits in conducting non-magnetic material. A much more difficult case is seen to be that of eddy currents in magnetic material, or in non-magnetic material at higher frequencies, due to the lower skin depths. Even here, the dissipative behavior has been shown to yield at least somewhat to linear modelling. Magnetostatic and eddy current computations have been carried out relating to the Annular Suspension and Pointing System, a prototype for a space payload pointing and vibration

Nanostructured silicon ferromagnet collected by a permanent neodymium magnet.

Science.gov (United States)

Okuno, Takahisa; Thürmer, Stephan; Kanoh, Hirofumi

2017-11-30

Nanostructured silicon (N-Si) was prepared by anodic electroetching of p-type silicon wafers. The obtained magnetic particles were separated by a permanent neodymium magnet as a magnetic nanostructured silicon (mN-Si). The N-Si and mN-Si exhibited different magnetic properties: the N-Si exhibited ferromagnetic-like behaviour, whereas the mN-Si exhibited superparamagnetic-like behaviour.

Magnetic resonance tomography for trauma of the cervical spine

International Nuclear Information System (INIS)

Meydam, K.; Sehlen, S.; Schlenkhoff, D.; Kiricuta, J.C.; Beyer, H.K.

1986-01-01

Twenty patients who had suffered spinal trauma were examined by magnetic resonance tomography. Fifteen patients with first degree trauma in Erdmann's classification showed no abnormality. Magnetic resonance tomography of the cervical spine appears to be a suitable method for investigating patients with whiplash injuries. It is indicated following severe flexion injuries with subluxations and neurological symptoms, since it is the only method that can demonstrate the spinal cord directly and completely and show the extent of cord compression. For patients with thoracic trauma and rapidly developing neurological symptoms, magnetic resonance tomography is ideal for showing post-traumatic syringomyelia. Magnetic resonance tomography following whiplash injuries is recommended if plain films of the cervical spine show any abnormalities, as well as for the investigation of acute or sub-acute neurological abnormalities. The various findings are discussed. (orig.) [de

Magnetic resonance tomography for trauma of the cervical spine

Energy Technology Data Exchange (ETDEWEB)

Meydam, K.; Sehlen, S.; Schlenkhoff, D.; Kiricuta, J.C.; Beyer, H.K.

1986-12-01

Twenty patients who had suffered spinal trauma were examined by magnetic resonance tomography. Fifteen patients with first degree trauma in Erdmann's classification showed no abnormality. Magnetic resonance tomography of the cervical spine appears to be a suitable method for investigating patients with whiplash injuries. It is indicated following severe flexion injuries with subluxations and neurological symptoms, since it is the only method that can demonstrate the spinal cord directly and completely and show the extent of cord compression. For patients with thoracic trauma and rapidly developing neurological symptoms, magnetic resonance tomography is ideal for showing post-traumatic syringomyelia. Magnetic resonance tomography following whiplash injuries is recommended if plain films of the cervical spine show any abnormalities, as well as for the investigation of acute or sub-acute neurological abnormalities. The various findings are discussed.

Early rheumatoid arthritis and its differentiation from other joint abnormalities

International Nuclear Information System (INIS)

Boutry, Nathalie; Carmo, Clarissa Canella Moraes do; Flipo, Rene-Marc; Cotten, Anne

2009-01-01

The introduction of disease-modifying antirheumatic drugs has created new demands on imaging to early identify patients with rheumatoid arthritis and opened new prospects in therapeutic management of patients with aggressive disease. Therefore, new imaging modalities such as magnetic resonance imaging and ultrasound have developed during the past few years in this field. In some cases, both magnetic resonance imaging and ultrasound may be also useful in making the distinction between early rheumatoid arthritis and other joints abnormalities, including early psoriatic arthritis. This article will review key aspects of important advances in imaging in rheumatoid arthritis, particularly focusing on magnetic resonance imaging and ultrasound.

Magnetic brane-worlds

International Nuclear Information System (INIS)

Barrow, John D; Hervik, Sigbjorn

2002-01-01

We investigate brane-worlds with a pure magnetic field and a perfect fluid. We extend earlier work to brane-worlds and find new properties of the Bianchi type I brane-world. We find new asymptotic behaviours on approach to singularity and classify the critical points of the dynamical phase space. It is known that the Einstein equations for the magnetic Bianchi type I models are in general oscillatory and are believed to be chaotic, but in the brane-world model this chaotic behaviour does not seem to be possible

Dynamic interaction between rotor and axially-magnetized passive magnetic bearing considering magnetic eccentricity

DEFF Research Database (Denmark)

Enemark, Søren; Santos, Ilmar

2014-01-01

with a multibody system composed of rigid rotor and flexible foundation. The magnetic eccentricities of the shaft magnets are modelled using the distances (amplitudes) and directions (phase angles) between the shaft axis and the centre of the magnetic fields generated. A perturbation method, i.e. harmonic......-linear stiffness. In this investigation passive magnetic bearings using axially- aligned neodymium cylinder magnets are investigated. The cylinder magnets are axially magnetised for rotor as well as bearings. Compared to bearings with radial magnetisation, the magnetic stiffness of axially-aligned bearings...... is considerably lower, nevertheless they allow for asymmetric stiffness mounting, and it could be beneficial for rotor stabilization. A theoretical model is proposed to describe the non-linear rotor-bearing dynamics. It takes into account non-linear behaviour of the magnetic forces and their interaction...

Behavioural consequences of visual deprivation occurring at hatch or in the early life of chickens

DEFF Research Database (Denmark)

Hocking, Paul M.; Haldane, Kirsty-Anne; Davidson, Emma M.

2015-01-01

characteristic behaviours of both blind and sighted birds. Individual behaviour, group aggregation and behavioural synchrony were compared at 1, 5 and 9 weeks of age (experiment 1) and in the parents of these chicks at 9–13 months of age (experiment 2). Responses to visual and physical isolation were assessed...... at 1, 5 and 9 weeks. Analyses of home-pen behaviour showed that both rdd and beg had difficulty locating or consuming food during the first week of life. WL and rdd did not engage in abnormal behaviour (circle walking, air pecking, star gazing) at 1, 5 and 9 weeks whereas both beg and rdd adults did so...... visual isolation from conspecifics rdd chicks behaved like blind birds in some respects (e.g. decreased movement) and as sighted birds in others (e.g. peeping). The vision of rdd was apparently diminished compared with sighted controls (WL) even from an early age. It was concluded that abnormal...

Reward Abnormalities Among Women with Full and Subthreshold Bulimia Nervosa: A Functional Magnetic Resonance Imaging Study

Science.gov (United States)

Bohon, Cara; Stice, Eric

2010-01-01

Objective To test the hypothesis that women with full and subthreshold bulimia nervosa show abnormal neural activation in response to food intake and anticipated food intake relative to healthy control women. Method Females with and without full/subthreshold bulimia nervosa recruited from the community (N = 26) underwent functional magnetic resonance imaging (fMRI) during receipt and anticipated receipt of chocolate milkshake and a tasteless control solution. Results Women with bulimia nervosa showed trends for less activation than healthy controls in the right anterior insula in response to anticipated receipt of chocolate milkshake (versus tasteless solution) and in the left middle frontal gyrus, right posterior insula, right precentral gyrus, and right mid dorsal insula in response to consumptions of milkshake (versus tasteless solution). Discussion Bulimia nervosa may be related to potential hypo-functioning of the brain reward system, which may lead these individuals to binge eat to compensate for this reward deficit, though the hypo-responsivity might be a result of a history of binge eating highly palatable foods. PMID:21997421

Reward abnormalities among women with full and subthreshold bulimia nervosa: a functional magnetic resonance imaging study.

Science.gov (United States)

Bohon, Cara; Stice, Eric

2011-11-01

To test the hypothesis that women with full and subthreshold bulimia nervosa show abnormal neural activation in response to food intake and anticipated food intake relative to healthy control women. Females with and without full/subthreshold bulimia nervosa recruited from the community (N = 26) underwent functional magnetic resonance imaging (fMRI) during receipt and anticipated receipt of chocolate milkshake and a tasteless control solution. Women with bulimia nervosa showed trends for less activation than healthy controls in the right anterior insula in response to anticipated receipt of chocolate milkshake (vs. tasteless solution) and in the left middle frontal gyrus, right posterior insula, right precentral gyrus, and right mid dorsal insula in response to consumptions of milkshake (vs. tasteless solution). Bulimia nervosa may be related to potential hypofunctioning of the brain reward system, which may lead these individuals to binge eat to compensate for this reward deficit, though the hypo-responsivity might be a result of a history of binge eating highly palatable foods. Copyright © 2010 Wiley Periodicals, Inc.

Microstructural development of cobalt ferrite ceramics and its influence on magnetic properties

Science.gov (United States)

Kim, Gi-Yeop; Jeon, Jae-Ho; Kim, Myong-Ho; Suvorov, Danilo; Choi, Si-Young

2013-11-01

The microstructural evolution and its influence on magnetic properties in cobalt ferrite were investigated. The cobalt ferrite powders were prepared via a solid-state reaction route and then sintered at 1200 °C for 1, 2, and 16 h in air. The microstructures from sintered samples represented a bimodal distribution of grain size, which is associated with abnormal grain growth behavior. And thus, with increasing sintering time, the number and size of abnormal grains accordingly increased but the matrix grains were frozen with stagnant grain growth. In the sample sintered for 16 h, all of the matrix grains were consumed and the abnormal grains consequently impinged on each other. With the appearance of abnormal grains, the magnetic coercivity significantly decreased from 586.3 Oe (1 h sintered sample) to 168.3 Oe (16 h sintered sample). This is due to the magnetization in abnormal grains being easily flipped. In order to achieve high magnetic coercivity of cobalt ferrite, it is thus imperative to fabricate the fine and homogeneous microstructure.

Influence of the magnetic dead layer thickness of Mg-Zn ferrites nanoparticle on their magnetic properties

Energy Technology Data Exchange (ETDEWEB)

El-Sayed, H.M. [Physics Department, Faculty of Science, Ain Shams University, Cairo (Egypt); Ali, I.A.; Azzam, A. [Nuclear Physics Department, Nuclear Research Center, Atomic Energy Authority (Egypt); Sattar, A.A. [Physics Department, Faculty of Science, Ain Shams University, Cairo (Egypt)

2017-02-15

Nanoparticle ferrite with chemical formula Mg{sub (1−x)}Zn{sub x}Fe{sub 2}O{sub 4} (where x=0.0, 0.2, 0.4, 0.6, 0.8 and 1) were prepared by sol-gel technique. Single phase structure of these ferrites was confirmed using X-ray diffraction (XRD). Transmission Electron Microscope (TEM) showed that the particle size of the samples in the range of (5.7–10.6 nm). The hysteresis studies showed superparamagnetic behaviour at room temperature. The magnetization behaviour with Zn-content is expressed in the light of Yafet-Kittel angles. The dead layer thickness (t) was calculated and its effect on the magnetization and magnetic losses was debated. The Specific Absorption Rate (SAR) in an alternating magnetic field with frequency 198 kHz for these ferrites has been studied. It is found that, the thickness of magnetic dead layer of the surface of the materials has greatly affected the SAR value of the samples. - Highlights: • Synthesis of Mg-Zn nanoparticle ferrite by sol-gel technique. • Methods of dead layer thickness calculation. • Magnetic behaviour explanation. • Relation between the Specific Absorption Rate, dead layer thickness and particle size.

Structures and magnetic behaviours of TiO2–Mn–TiO2 multilayers

International Nuclear Information System (INIS)

Fa-Min, Liu; Peng, Ding; Jian-Qi, Li

2010-01-01

The TiO 2 -Mn-TiO 2 multilayers are successfully grown on glass and silicon substrates by alternately using radio frequency reactive magnetron sputtering and direct current magnetron sputtering. The structures and the magnetic behaviours of these films are characterised with x-ray diffraction, transmission electron microscope (TEM), vibrating sample magnetometer, and superconducting quantum interference device (SQUID). It is shown that the multi-film consists of a mixture of anatase and rutile TiO 2 with an embedded Mn nano-film. It is found that there are two turning points from ferromagnetic phase to antiferromagnetic phase. One is at 42 K attributed to interface coupling between ferromagnetic Mn 3 O 4 and antiferromagnetic Mn 2 O 3 , and the other is at 97 K owing to the interface coupling between ferromagnetic Mn and antiferromagnetic MnO. The samples are shown to have ferromagnetic behaviours at room temperature from hysteresis in the M-H loops, and their ferromagnetism is found to vary with the thickness of Mn nano-film. Moreover, the Mn nano-film has a critical thickness of about 18.5 nm, which makes the coercivity of the multi-film reach a maximum of about 3.965×10 −2 T. (cross-disciplinary physics and related areas of science and technology)

The peak in anomalous magnetic viscosity

International Nuclear Information System (INIS)

Collocott, S.J.; Watterson, P.A.; Tan, X.H.; Xu, H.

2014-01-01

Anomalous magnetic viscosity, where the magnetization as a function of time exhibits non-monotonic behaviour, being seen to increase, reach a peak, and then decrease, is observed on recoil lines in bulk amorphous ferromagnets, for certain magnetic prehistories. A simple geometrical approach based on the motion of the state line on the Preisach plane gives a theoretical framework for interpreting non-monotonic behaviour and explains the origin of the peak. This approach gives an expression for the time taken to reach the peak as a function of the applied (or holding) field. The theory is applied to experimental data for bulk amorphous ferromagnet alloys of composition Nd 60−x Fe 30 Al 10 Dy x , x = 0, 1, 2, 3 and 4, and it gives a reasonable description of the observed behaviour. The role played by other key magnetic parameters, such as the intrinsic coercivity and fluctuation field, is also discussed. When the non-monotonic behaviour of the magnetization of a number of alloys is viewed in the context of the model, features of universal behaviour emerge, that are independent of alloy composition. - Highlights: • Development of a simple geometrical model based on the Preisach model which gives a complete explanation of the peak in the magnetic viscosity. • Geometrical approach is extended by considering equations that govern the motion of the state line. • The model is used to deduce the relationship between the holding field and the time it takes to reach the peak. • The model is tested with experimental results for a range of Nd–Fe–Al–Dy bulk amorphous ferromagnets. • There is good agreement between the model and the experimental data

Parenchymal abnormalities associated with developmental venous anomalies

Energy Technology Data Exchange (ETDEWEB)

San Millan Ruiz, Diego; Gailloud, Philippe [Johns Hopkins Hospital, Division of Interventional Neuroradiology, Baltimore, MD (United States); Delavelle, Jacqueline [Geneva University Hospital, Neuroradiology Section, Department of Radiology and Medical Informatics, Geneva (Switzerland); Yilmaz, Hasan; Ruefenacht, Daniel A. [Geneva University Hospital, Section of Interventional Neuroradiology, Department of Clinical Neurosciences, Geneva (Switzerland); Piovan, Enrico; Bertramello, Alberto; Pizzini, Francesca [Verona City Hospital, Service of Neuroradiology, Verona (Italy)

2007-12-15

To report a retrospective series of 84 cerebral developmental venous anomalies (DVAs), focusing on associated parenchymal abnormalities within the drainage territory of the DVA. DVAs were identified during routine diagnostic radiological work-up based on magnetic resonance imaging (MRI) (60 cases), computed tomography (CT) (62 cases) or both (36 cases). Regional parenchymal modifications within the drainage territory of the DVA, such as cortical or subcortical atrophy, white matter density or signal alterations, dystrophic calcifications, presence of haemorrhage or a cavernous-like vascular malformation (CVM), were noted. A stenosis of the collecting vein of the DVA was also sought for. Brain abnormalities within the drainage territory of a DVA were encountered in 65.4% of the cases. Locoregional brain atrophy occurred in 29.7% of the cases, followed by white matter lesions in 28.3% of MRI investigations and 19.3% of CT investigations, CVMs in 13.3% of MRI investigations and dystrophic calcification in 9.6% of CT investigations. An intracranial haemorrhage possibly related to a DVA occurred in 2.4% cases, and a stenosis on the collecting vein was documented in 13.1% of cases. Parenchymal abnormalities were identified for all DVA sizes. Brain parenchymal abnormalities were associated with DVAs in close to two thirds of the cases evaluated. These abnormalities are thought to occur secondarily, likely during post-natal life, as a result of chronic venous hypertension. Outflow obstruction, progressive thickening of the walls of the DVA and their morphological organization into a venous convergence zone are thought to contribute to the development of venous hypertension in DVA. (orig.)

Longitudinal effects of environmental enrichment on behaviour and physiology of pigs reared on an intensive-stock farm

Directory of Open Access Journals (Sweden)

Augusto Vitale

2011-10-01

Full Text Available The aim of this paper was to provide a longitudinal evaluation of the effects of physical enrichments on the behaviour and physiology of intensive stock-farming pigs. Twenty-eight crossbred pigs of both sexes, were exposed to four types of enrichments (hemp ropes, steel chains, plastic balls, rubber hoses over a period of eleven weeks. This investigation was based on specific abnormal behaviours and physiological indicators, including hematologic parameters. For behavioural score, focal sampling was used with recording of abnormal behaviours (body-, tail- and ear-biting, belly nosing, running, and interaction with objects (for Enriched pigs. The presence of skin injuries was also recorded. In general, the frequency of abnormal behaviours was significantly reduced in the Enriched group. A timerelated profile appeared in the use of the enrichments. Males showed higher occurrence of skin injuries than females. Physiological measurements, such as levels of complement system, white blood cells and neutrophils, were lower in pigs from the Enriched group. Enriched pigs, as a whole, presented much lower levels of serum DHEA-S concentration over two weeks. The findings of this study show the successful provision of appropriate enrichments to encourage behaviours which may result in satisfactory animal oral interaction with the enriching objects, preventing them biting pen-mates. In this respect, the objects proposed were strongly effective in producing changes in behaviour which could mitigate inadequate conditions, such as the relationship between animal body weight and the available space allowance.

Evaluation of biexponential relaxation behaviour in the human brain by magnetic resonance imaging

DEFF Research Database (Denmark)

Kjaer, L; Thomsen, C; Henriksen, O

1989-01-01

Quantitative estimation of individual biologic components in relaxation curves obtained in vivo may increase the specificity of tissue characterization by magnetic resonance imaging. In this study, the potential of biexponential curve analysis was evaluated in T1 and T2 measurements on the human...... brain at 1.5 tesla. Optimal experimental conditions were carefully observed, including the use of long TR values and a very small voxel size. T1 determination was based on a 12-points partial saturation inversion recovery pulse sequence. T2 determination involved a multiple spin echo sequence with 32...... echoes. No genuine biexponentiality was demonstrated in the T1 and T2 relaxation processes of white matter, cortical grey matter, or cerebrospinal fluid. Thus, a monoexponential model seems adequate for description of the relaxation behaviour in these cases. Furthermore, the results suggest...

Association of Retinopathy and Retinal Microvascular Abnormalities With Stroke and Cerebrovascular Disease.

Science.gov (United States)

Hughes, Alun D; Falaschetti, Emanuela; Witt, Nicholas; Wijetunge, Sumangali; Thom, Simon A McG; Tillin, Therese; Aldington, Steve J; Chaturvedi, Nish

2016-11-01

Abnormalities of the retinal circulation may be associated with cerebrovascular disease. We investigated associations between retinal microvascular abnormalities and (1) strokes and subclinical cerebral infarcts and (2) cerebral white matter lesions in a UK-based triethnic population-based cohort. A total of 1185 participants (age, 68.8±6.1 years; 77% men) underwent retinal imaging and cerebral magnetic resonance imaging. Cerebral infarcts and white matter hyperintensities were identified on magnetic resonance imaging, retinopathy was graded, and retinal vessels were measured. Higher retinopathy grade (odds ratio [OR], 1.40 [95% confidence interval (95% CI), 1.16-1.70]), narrower arteriolar diameter (OR, 0.98 [95% CI, 0.97-0.99]), fewer symmetrical arteriolar bifurcations (OR, 0.84 [95% CI, 0.75-0.95]), higher arteriolar optimality deviation (OR, 1.16 [95% CI, 1.00-1.34]), and more tortuous venules (OR, 1.20 [95% CI, 1.09-1.32]) were associated with strokes/infarcts and white matter hyperintensities. Associations with quantitative retinal microvascular measures were independent of retinopathy. Abnormalities of the retinal microvasculature are independently associated with stroke, cerebral infarcts, and white matter lesions. © 2016 American Heart Association, Inc.

Abnormal Brain Responses to Action Observation in Complex Regional Pain Syndrome.

Science.gov (United States)

Hotta, Jaakko; Saari, Jukka; Koskinen, Miika; Hlushchuk, Yevhen; Forss, Nina; Hari, Riitta

2017-03-01

Patients with complex regional pain syndrome (CRPS) display various abnormalities in central motor function, and their pain is intensified when they perform or just observe motor actions. In this study, we examined the abnormalities of brain responses to action observation in CRPS. We analyzed 3-T functional magnetic resonance images from 13 upper limb CRPS patients (all female, ages 31-58 years) and 13 healthy, age- and sex-matched control subjects. The functional magnetic resonance imaging data were acquired while the subjects viewed brief videos of hand actions shown in the first-person perspective. A pattern-classification analysis was applied to characterize brain areas where the activation pattern differed between CRPS patients and healthy subjects. Brain areas with statistically significant group differences (q frontal gyrus, secondary somatosensory cortex, inferior parietal lobule, orbitofrontal cortex, and thalamus. Our findings indicate that CRPS impairs action observation by affecting brain areas related to pain processing and motor control. This article shows that in CRPS, the observation of others' motor actions induces abnormal neural activity in brain areas essential for sensorimotor functions and pain. These results build the cerebral basis for action-observation impairments in CRPS. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

Transient knockdown of tyrosine hydroxylase during development has persistent effects on behaviour in adult zebrafish (Danio rerio.

Directory of Open Access Journals (Sweden)

Isabel Formella

Full Text Available Abnormal dopamine (DA signaling is often suggested as causative in schizophrenia. The other prominent hypothesis for this disorder, largely driven by epidemiological data, is that certain adverse events during the early stages of brain development increase an individual's risk of developing schizophrenia later in life. However, the clinical and preclinical literature consistently implicates behavioural, cognitive, and pharmacological abnormalities, implying that DA signaling is abnormal in the adult brain. How can we reconcile these two major hypotheses underlying much of the clinical and basic research into schizophrenia? In this study we have transiently knocked down tyrosine hydroxylase (TH, the rate limiting enzyme in DA synthesis gene expression in the early stages of brain development in zebrafish using morpholinos. We show that by adulthood, TH and DA levels have returned to normal and basic DA-mediated behaviours, such as locomotion, are also normal. However, when they were exposed to a novel environment the levels of freezing and immediate positioning in deeper zones were significantly reduced in these adult fish. The neurochemistry underlying these behaviours is complex, and the exact mechanisms for these abnormal behaviours remains unknown. This study demonstrates that early transient alterations in DA ontogeny can produce persistent alterations in adult brain function and suggests that the zebrafish may be a promising model animal for future studies directed at clarifying the basic neurodevelopmental mechanisms behind complex psychiatric disease.

Modelling the magnetic behaviour of square-pyramidal Co(II)5 aggregates: tuning SMM behaviour through variations in the ligand shell.

Science.gov (United States)

Klöwer, Frederik; Lan, Yanhua; Nehrkorn, Joscha; Waldmann, Oliver; Anson, Christopher E; Powell, Annie K

2009-07-27

Three new mu4-bridged Co(II)5 clusters with similar core motifs have been synthesised with the use of N-tert-butyldiethanolamine (tbdeaH2) and pivalic acid (piv): [Co(II)5(mu4-N3)(tbdea)2(mu-piv)4(piv)(CH3CN)2].CH3CN (1), [Co(II)5(mu4-Cl)(Cl)(tbdea)2(mu-piv)4(pivH)2] (2) and [Co(II)5(mu4-N3)(Cl)(tbdea)2(mu-piv)4(pivH)2] (3). Magnetic measurements were performed for all three compounds. It was found that while the chloride-bridged cluster 2 does not show an out-of-phase signal, which excludes single-molecule magnet (SMM) behaviour, the azide-bridged compounds 1 and 3 show out-of-phase signals as well as frequency dependence of the ac susceptibility, as expected for SMMs. We confirmed that 1 is a SMM with zero-field quantum tunnelling of the magnetisation at 1.8 K. Compound 3 is likely a SMM with a blocking temperature well below 1.8 K. We established a physical model to fit the chiT versus T and M versus B curves of the three compounds to reproduce the observed SMM trend. The analysis showed that small changes in the ligand shell modify not only the magnitude of exchange constants, but also affect the J and g matrices in a non-trivial way.

Remnants of occipital vertebrae: proatlas segmentation abnormalities.

Science.gov (United States)

Menezes, Arnold H; Fenoy, Kathleen A

2009-05-01

Developmental remnants around the foramen magnum, or proatlas segmentation abnormalities, have been recorded in postmortem studies but very rarely in a clinical setting. Because of their rarity, the pathological anatomy has been misunderstood, and treatment has been fraught with failures. The objectives of this prospective study were to understand the correlative anatomy, pathology, and embryology and to recognize the clinical presentation and gain insights on the treatment and management. Our craniovertebral junction (CVJ) database started in 1977 and comprises 5200 cases. This prospective study has retrieval capabilities. Neurodiagnostic studies changed with the evolution of imaging. Seventy-two patients were recognized as having symptomatic proatlas segmentation abnormalities. Ventral bony masses from the clivus or medial occipital condyle occurred in 66% (44/72), lateral or anterolateral compressive masses in 37% (27 of 72 patients), and dorsal bony compression in 17% (12 of 72 patients). Hindbrain herniation was associated in 33%. The age at presentation was 3 to 23 years. Motor symptoms occurred in 72% (52 of 72 patients); palsies in Cranial Nerves IX, X, and XII in 33% (24 of 72 patients); and vertebrobasilar symptoms in 25% (18 of 72 patients). Trauma precipitated symptoms in 55% (40 of 72 patients). The best definition of the abnormality was demonstrated by 3-dimensional computed tomography combined with magnetic resonance imaging. Treatment was aimed at decompression of the pathology and stabilization. Remnants of the occipital vertebrae around the foramen magnum were recognized in 72 of 5200 CVJ cases (7.2%). Magnetic resonance imaging with 3-dimensional computed tomography of the CVJ provides the best definition and understanding of the lesions. Brainstem myelopathy and lower cranial nerve deficits are common clinical presentations in the first and second decades of life. Treatment is aimed at decompression of the pathology and CVJ stabilization.

REM behaviour disorder detection associated with neurodegenerative diseases

DEFF Research Database (Denmark)

Kempfner, Jacob; Sorensen, Gertrud; Zoetmulder, Marielle

2010-01-01

Abnormal skeleton muscle activity during REM sleep is characterized as REM Behaviour Disorder (RBD), and may be an early marker for different neurodegenerative diseases. Early detection of RBD is therefore highly important, and in this ongoing study a semi-automatic method for RBD detection......, a computerized algorithm has been attempted implemented. By analysing the REM and non-REM EMG activity, using advanced signal processing tools combined with a statistical classifier, it is possible to discriminate normal and abnormal EMG activity. Due to the small number of patients, the overall performance...

Abnormally large energy spread of electron beams extracted from plasma sources

Energy Technology Data Exchange (ETDEWEB)

Winter, H [Technische Univ., Vienna (Austria). Inst. fuer Allgemeine Physik

1976-07-01

Intense electron beams extracted from DUOPLASMATRON-plasma cathodes show a high degree of modulation in intensity and an abnormally large energy spread; these facts cannot be explained simply by the temperature of the plasma electrons and the discharge structure. However, an analysis of the discharge stability behaviour and the interaction of source- and extracted beam-plasma leads to an explanation for the observed effects.

Micro magnetic modeling of magnetization reversal in permanent magnets

International Nuclear Information System (INIS)

Toussaint, J.C.; Kevorkian, B.; Givord, D.; Rossignol, M.F.

1996-01-01

Micro magnetic numerical 3 D calculation is presented in this paper to investigate the effect of a soft magnetic heterogeneity on the magnetization reversal of a single hard magnetic grain. Both equilibrium and transient magnetization configurations are obtained by solving the dynamic Landau-Lifshitz-Gilbert (L.L.G.) equation. A modified forward difference method is used to integrate the time dependent L.L.G. equation without conflicting with the constraint of constant magnetic moment. A continuum view of the material medium is adopted and the spatial finite difference method is used to describe the system as a set of cubic elements. In each element the magnetization is interpolated with quadratic polynomial functions and constrained to follow the Brown condition at the surface. A multigrid approach is developed to calculate the magnetic potential and the resulting stray field associated with a given microstructure. The calculated properties are compared to actual properties of Nd Fe B sintered magnets. Assuming a soft nucleus of 160 angstrom diameter and 80 angstrom depth, the calculated coercive field is about 1.45 T, close to experimental values and the calculated angular dependence of H c resembles experimental behaviours. (author)

What constitutes healthy eating behaviour and lifestyle?

African Journals Online (AJOL)

Enrique

To what extent should doctors be concerned about the risks of abnormal eating behaviour? Having often asked medical students what they believe doctors should know about eating disorders I was recently pleased to hear a different answer to the ones usually offered. Students usually get it right with regard to making the ...

Corrosion behaviour of zirconium alloys in the autoclaves of Embalse nuclear power plant

International Nuclear Information System (INIS)

Bordoni, Roberto A.; Olmedo, Ana M.; Villegas, Marina; Miyagusuku, Marcela; Maroto, Alberto J. G.; Sainz, Ricardo A.; Fernandez, Alberto N.; Allemandi, Walter D.

1999-01-01

The corrosion behaviour of zirconium alloys coupons attached to the holders of the autoclaves located out of core in the primary circuit of Embalse nuclear power plant is described. The Zr-2.5 Nb coupons of the autoclaves at the higher temperature (305 C degrees) and the Zry-4 coupons of the autoclaves at 265 and 305 C degrees installed in 1988 had a normal corrosion behaviour, after 3500 of full power days. While, the Zr-2.5 Nb coupons, at 265 C degrees, showed the presence of white oxide nuclei and a weight gain indicating an abnormal corrosion behaviour which might be attributed to the material microstructure. Complementary tests, made in the period September 1991-April 1993, showed that the abnormal corrosion behaviour observed for the Canadian coupons installed in 1983 was due to a surface contamination of the Zry-4 coupons and due to the microstructure of the Zr-2.5 Nb coupons. The normal corrosion behaviour for both alloys installed in 1986, showed that the resin ingress to the primary circuit that occurred in 1988, do not affect the performance of these materials. (author)

Abnormal fear circuitry in Attention Deficit Hyperactivity Disorder: A controlled magnetic resonance imaging study.

Science.gov (United States)

Spencer, Andrea E; Marin, Marie-France; Milad, Mohammed R; Spencer, Thomas J; Bogucki, Olivia E; Pope, Amanda L; Plasencia, Natalie; Hughes, Brittany; Pace-Schott, Edward F; Fitzgerald, Maura; Uchida, Mai; Biederman, Joseph

2017-04-30

We examined whether non-traumatized subjects with Attention Deficit Hyperactivity Disorder (ADHD) have dysfunctional activation in brain structures mediating fear extinction, possibly explaining the statistical association between ADHD and other disorders characterized by aberrant fear processing such as PTSD. Medication naïve, non-traumatized young adult subjects with (N=27) and without (N=20) ADHD underwent a 2-day fear conditioning and extinction protocol in a 3T functional magnetic resonance imaging (fMRI) scanner. Skin conductance response (SCR) was recorded as a measure of conditioned response. Compared to healthy controls, ADHD subjects had significantly greater insular cortex activation during early extinction, lesser dorsal anterior cingulate cortex (dACC) activation during late extinction, lesser ventromedial prefrontal cortex (vmPFC) activation during late extinction learning and extinction recall, and greater hippocampal activation during extinction recall. Hippocampal and vmPFC deficits were similar to those documented in PTSD subjects compared to traumatized controls without PTSD. Non-traumatized, medication naive adults with ADHD had abnormalities in fear circuits during extinction learning and extinction recall, and some findings were consistent with those previously documented in subjects with PTSD compared to traumatized controls without PTSD. These findings could explain the significant association between ADHD and PTSD as well as impaired emotion regulation in ADHD. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Effect of Fe addition on the magnetic and giant magneto-impedance behaviour of CoCrSiB rapidly solidified alloys

Energy Technology Data Exchange (ETDEWEB)

Kumari, Seema; Chattoraj, I; Panda, A K; Mitra, A; Pal, S K [National Metallurgical Laboratory, Jamshedpur 831 007 (India)

2006-05-21

Thermal electrical resistivity, magnetic hysteresis and magneto-impedance behaviour of melt spun and annealed Co{sub 71-X}Fe{sub X}Cr{sub 7}Si{sub 8}B{sub 14} (X = 0, 2, 3.2, 4, 6, 8 and 12 at.%) were investigated. The addition of Fe in the system changed crystallization as well as the magnetic properties of the materials. The alloy containing 6 at.% Fe showed an increase in resistivity during the first crystallization process. A TEM micrograph indicated the formation of nanostructure during the crystallization process. The GMI properties of the alloys are evaluated at a driving current amplitude of 5 mA and a frequency of 4 MHz. The two-peak behaviour in the GMI profile was observed for all the samples. It is found that the alloy with 4 at.% Fe has the maximum GMI ratio because of the nearly zero magnetostriction value of the sample. About 62% change in the GMI ratio was observed in the alloy with 4 at.% Fe when annealed at 673 K. The anisotropy field was also minimum for the annealed alloy. The results were explained by the formation of directional ordering and the reduction of the magnetostriction constant of the alloy due to nanocrystallization during the annealing process.

Cognition and brain abnormalities on MRI in pituitary patients

International Nuclear Information System (INIS)

Brummelman, Pauline; Sattler, Margriet G.A.; Meiners, Linda C.; Berg, Gerrit van den; Klauw, Melanie M. van der; Elderson, Martin F.; Dullaart, Robin P.F.; Koerts, Janneke; Werumeus Buning, Jorien; Tucha, Oliver; Wolffenbuttel, Bruce H.R.; Bergh, Alfons C.M. van den; Beek, André P. van

2015-01-01

Highlights: • Cognitive impairments are frequently observed in treated NFA patients. • NFA patients with cognitive impairments do not show brain abnormalities on MRI more frequently than patients without cognitive impairments. • The absence of brain abnormalities on brain MRI does not exclude impairments of cognition. - Abstract: Purpose: The extent to which cognitive dysfunction is related to specific brain abnormalities in patients treated for pituitary macroadenoma is unclear. Therefore, we compared brain abnormalities seen on Magnetic Resonance Imaging (MRI) in patients treated for nonfunctioning pituitary macroadenoma (NFA) with or without impairments in cognitive functioning. Methods: In this cross-sectional design, a cohort of 43 NFA patients was studied at the University Medical Center Groningen. White matter lesions (WMLs), cerebral atrophy, (silent) brain infarcts and abnormalities of the temporal lobes and hippocampi were assessed on pre-treatment and post-treatment MRI scans. Post-treatment cognitive examinations were performed using a verbal memory and executive functioning test. We compared our patient cohort with large reference populations representative of the Dutch population. Results: One or more impairments on both cognitive tests were frequently observed in treated NFA patients. No treatment effects were found with regard to the comparison between patients with and without impairments in executive functioning. Interestingly, in patients with one or more impairments on verbal memory function, treatment with radiotherapy had been given more frequently (74% in the impaired group versus 40% in the unimpaired group, P = 0.025). Patients with or without any brain abnormality on MRI did not differ in verbal memory or executive functioning. Conclusions: Brain abnormalities on MRI are not observed more frequently in treated NFA patients with impairments compared to NFA patients without impairments in verbal memory or executive functioning

Cognition and brain abnormalities on MRI in pituitary patients

Energy Technology Data Exchange (ETDEWEB)

Brummelman, Pauline [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); Sattler, Margriet G.A. [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen (Netherlands); Department of Radiation Oncology, Netherlands Cancer Institute – Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Meiners, Linda C. [Department of Radiology, University of Groningen, University Medical Center Groningen (Netherlands); Berg, Gerrit van den; Klauw, Melanie M. van der [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); Elderson, Martin F. [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); LifeLines Cohort Study and Biobank, University of Groningen, University Medical Center Groningen (Netherlands); Dullaart, Robin P.F. [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); Koerts, Janneke [Department of Clinical and Developmental Neuropsychology, University of Groningen, Groningen (Netherlands); Werumeus Buning, Jorien, E-mail: j.werumeus.buning@umcg.nl [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); Tucha, Oliver [Department of Clinical and Developmental Neuropsychology, University of Groningen, Groningen (Netherlands); Wolffenbuttel, Bruce H.R. [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); LifeLines Cohort Study and Biobank, University of Groningen, University Medical Center Groningen (Netherlands); Bergh, Alfons C.M. van den [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen (Netherlands); Beek, André P. van, E-mail: a.p.van.beek@umcg.nl [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands)

2015-02-15

Highlights: • Cognitive impairments are frequently observed in treated NFA patients. • NFA patients with cognitive impairments do not show brain abnormalities on MRI more frequently than patients without cognitive impairments. • The absence of brain abnormalities on brain MRI does not exclude impairments of cognition. - Abstract: Purpose: The extent to which cognitive dysfunction is related to specific brain abnormalities in patients treated for pituitary macroadenoma is unclear. Therefore, we compared brain abnormalities seen on Magnetic Resonance Imaging (MRI) in patients treated for nonfunctioning pituitary macroadenoma (NFA) with or without impairments in cognitive functioning. Methods: In this cross-sectional design, a cohort of 43 NFA patients was studied at the University Medical Center Groningen. White matter lesions (WMLs), cerebral atrophy, (silent) brain infarcts and abnormalities of the temporal lobes and hippocampi were assessed on pre-treatment and post-treatment MRI scans. Post-treatment cognitive examinations were performed using a verbal memory and executive functioning test. We compared our patient cohort with large reference populations representative of the Dutch population. Results: One or more impairments on both cognitive tests were frequently observed in treated NFA patients. No treatment effects were found with regard to the comparison between patients with and without impairments in executive functioning. Interestingly, in patients with one or more impairments on verbal memory function, treatment with radiotherapy had been given more frequently (74% in the impaired group versus 40% in the unimpaired group, P = 0.025). Patients with or without any brain abnormality on MRI did not differ in verbal memory or executive functioning. Conclusions: Brain abnormalities on MRI are not observed more frequently in treated NFA patients with impairments compared to NFA patients without impairments in verbal memory or executive functioning

Alterations and abnormal mitosis of wheat chromosomes induced by wheat-rye monosomic addition lines.

Directory of Open Access Journals (Sweden)

Shulan Fu

Full Text Available BACKGROUND: Wheat-rye addition lines are an old topic. However, the alterations and abnormal mitotic behaviours of wheat chromosomes caused by wheat-rye monosomic addition lines are seldom reported. METHODOLOGY/PRINCIPAL FINDINGS: Octoploid triticale was derived from common wheat T. aestivum L. 'Mianyang11'×rye S. cereale L. 'Kustro' and some progeny were obtained by the controlled backcrossing of triticale with 'Mianyang11' followed by self-fertilization. Genomic in situ hybridization (GISH using rye genomic DNA and fluorescence in situ hybridization (FISH using repetitive sequences pAs1 and pSc119.2 as probes were used to analyze the mitotic chromosomes of these progeny. Strong pSc119.2 FISH signals could be observed at the telomeric regions of 3DS arms in 'Mianyang11'. However, the pSc119.2 FISH signals were disappeared from the selfed progeny of 4R monosomic addition line and the changed 3D chromosomes could be transmitted to next generation stably. In one of the selfed progeny of 7R monosomic addition line, one 2D chromosome was broken and three 4A chromosomes were observed. In the selfed progeny of 6R monosomic addition line, structural variation and abnormal mitotic behaviour of 3D chromosome were detected. Additionally, 1A and 4B chromosomes were eliminated from some of the progeny of 6R monosomic addition line. CONCLUSIONS/SIGNIFICANCE: These results indicated that single rye chromosome added to wheat might cause alterations and abnormal mitotic behaviours of wheat chromosomes and it is possible that the stress caused by single alien chromosome might be one of the factors that induced karyotype alteration of wheat.

Magnetic behavioural change of silane exposed graphene nanoflakes

Energy Technology Data Exchange (ETDEWEB)

Ray, Sekhar C., E-mail: raysc@unisa.ac.za [Department of Physics, College of Science, Engineering and Technology, University of South Africa, Private Bag X6, Florida, 1710, Science Campus, Christiaan de Wet and Pioneer Avenue, Florida Park, Johannesburg 1710 (South Africa); Mishra, D. K. [Department of Physics, College of Science, Engineering and Technology, University of South Africa, Private Bag X6, Florida, 1710, Science Campus, Christiaan de Wet and Pioneer Avenue, Florida Park, Johannesburg 1710 (South Africa); Department of Physics, Institute of Technical Research and Education, Siksha ‘O’ Anusandhan University, Khandagiri Square, Bhubaneswar 751030, Odisha (India); Strydom, A. M. [Highly Correlated Matter Research Group, Physics Department, University of Johannesburg, PO Box 524, Auckland Park 2006 (South Africa); Papakonstantinou, P. [Nanotechnology and Integrated Bioengineering Center (NIBEC), School of Engineering, University of Ulster, Jordanstown Campus, Newtownabbey BT37 0QB (United Kingdom)

2015-09-21

The electronic structures and magnetic properties of graphene nanoflakes (GNFs) exposed to an organo-silane precursor [tetra-methyl-silane, Si(CH{sub 3}){sub 4}] were studied using atomic force microscopy, electron field emission (EFE), x-ray photoelectron spectroscopy (XPS), and magnetization. The result of XPS indicates that silyl radical based strong covalent bonds were formed in GNFs, which induced local structural relaxations and enhanced sp{sup 3} hybridization. The EFE measurements show an increase in the turn-on electric field from 9.8 V/μm for pure GNFs to 26.3 V/μm for GNFs:Si having highest Si/(Si + C) ratio ( ≅ 0.35) that also suggests an enhancement of the non-metallic sp{sup 3} bonding in the GNFs matrix. Magnetic studies show that the saturation magnetization (Ms) is decreased from 172.53 × 10{sup −6} emu/g for pure GNFs to 13.00 × 10{sup −6} emu/g for GNFs:Si with the highest Si/(Si + C) ratio 0.35, but on the other side, the coercivity (Hc) increases from 66 to 149 Oe due to conversion of sp{sup 2} → sp{sup 3}-hybridization along with the formation of SiC and Si-O bonding in GNFs. The decrease in saturation magnetization and increase in coercivity (Hc) in GNFs on Si-functionalization are another routes to tailor the magnetic properties of graphene materials for magnetic device applications.

Incidence of abnormal retropharyngeal lymph nodes in sinonasal malignancies among adults

Energy Technology Data Exchange (ETDEWEB)

Sai, Asari; Shimono, Taro; Yamamoto, Akira; Takeshita, Toru; Miki, Yukio [Osaka City University Graduate School of Medicine, Department of Diagnostic and Interventional Radiology, Osaka (Japan); Ohsawa, Masahiko; Wakasa, Kenichi [Osaka City University Graduate School of Medicine, Department of Diagnostic Pathology, Osaka (Japan)

2014-12-15

The aim of this study is to investigate the relationship between abnormal retropharyngeal lymph nodes (RPLNs) and sinonasal malignancies among adults. Magnetic resonance and computed tomography images from 89 patients over 20 years old who were all histopathologically confirmed to have sinonasal malignancies from September 2001 to April 2014 were assessed retrospectively. Abnormal RPLNs were determined as those >5 mm in shortest axis or showing heterogeneous enhancement on axial images. Locations of sinonasal malignancies were categorized using the anterior border of the pterygopalatine fossa as a boundary: (a) anterior lesions, only present anterior to the boundary, or (b) posterior lesions, present or extending posterior to the boundary. Fisher's exact test was used for the analysis of the relationship between frequency of abnormal RPLNs and lesion location. Abnormal RPLNs were present in 13 of 89 patients (15 %), including 6 of 41 squamous cell carcinomas (15 %), 4 of 24 malignant lymphomas (17 %), 3 of 5 olfactory neuroblastomas (60 %), and 0 of 19 others (0 %). Four of the 39 patients (10 %) with anterior lesions showed abnormal RPLNs, compared to 9 of 50 patients (18 %) with posterior lesions. No significant difference in frequency of abnormal RPLNs was apparent between anterior and posterior lesions (P = 0.37). In primary sinonasal malignancies among adults, the highest incidence of abnormal RPLNs was seen with olfactory neuroblastoma. The frequency of abnormal RPLNs was unaffected by the location of sinonasal malignancies among adults. (orig.)

CT findings of cerebral palsy and behaviour development

International Nuclear Information System (INIS)

Sakamoto, Zenji

1987-01-01

It is well recognized that CT scan is very useful in the early diagnosis of cerebral palsy. The author has studied this time the CT scan findings of cerebral palsy children in their relations to the type of palsy, cause of palsy, complications in the central nervous system, and prognosis of behaviour development, in order to predict the prognosis of behaviour development. Dilatation of the contralateral cerebral ventricle was found in 82 % of hemiplegic type. Abnormal EEG was found in 73 %, but their behaviour development was satisfactory, with good development of speech regardless to the side of palsy. This might be helped by compensational function of the brain due to plasticity. Diplegia presented bilateral moderate dilatation of ventricles with favorable prognosis. Tetraplegia was caused mostly by asphyxia or congenital anomaly and revealed marked dilatation of ventricles or severe cortical atrophy. Some cases presented diffuse cortical low-density, often associated with abnormal EEG, and their prognosis was worst. Athetosis had normal CT finding or mild ventricular dilatation, but all cases of ataxia presented normal CT findings. Hypotonia had mild ventricular dilatation. Two of three mixed type cases had normal CT findings and another had mild ventricular dilatation. No correlation was found between ventricular dilatation and behaviour development, but statistically significant difference was found in the cases with 30 % or more Evans' ratio (P < 0.05). Prognosis of severe ventricular dilatation cases was poor. (author)

MR imaging of cerebral abnormalities in utero.

Science.gov (United States)

Thickman, D; Mintz, M; Mennuti, M; Kressel, H Y

1984-12-01

In view of the lack of ionizing radiation, ability to image in a variety of planes, and high contrast resolution, magnetic resonance (MR) imaging may have a role in obstetrical management. Three fetuses with severe cerebral abnormalities were studied by MR in utero. The findings were correlated with ultrasound examinations and with autopsy results. Ventricular dilatation and progression of hydrocephalus were detected by MR. Although fetal motion may affect image quality, diagnostically useful images were obtained with imaging times of 2.5 min.

A Single Center Experience on the Management of Placental Invasion Abnormalities

Directory of Open Access Journals (Sweden)

Alper Biler

2016-03-01

Full Text Available Objective: The aim of this study is to investigate our management of placental invasion abnormalities. Methods: A retrospective study was conducted on pa­tients admitted to a tertiary referral center with a diagno­sis of placental invasion abnormalities between 2011 and 2015. Risk factors and perinatal outcomes associated with placental invasion abnormalities were identified. Results: The overall incidence of placental invasion ab­normalities during the 5-year period was 8.3/10000 de­liveries, which showed an increasing trend. Ultrasonog­raphy and magnetic resonance imaging correctly identi­fied placental invasion abnormality in 36.7% and 68.7% cases, respectively. Majority of patients (55.1% with ad­herent placenta were diagnosed at the time of delivery. Of these patients, 22.4% underwent hysterectomy, 83.8% required at least one of the additional surgical procedures and 55% were transfused at least four units of packed red blood cell. Conclusion: Since placental invasion abnormalities are associated with significant morbidity, delivery should be scheduled in a tertiary center with appropriate expertise and facilities. J Clin Exp Invest 2016; 7 (1: 14-18

Quasi-steady state, low current behaviour of a magnetized coaxial plasma source

International Nuclear Information System (INIS)

Gray, Travis K; Mayo, Robert M; Bourham, Mohamed A

2005-01-01

The Coaxial Plasma Source-1 facility (Mayo R M et al 1995 Plasma Sources Sci. Technol. 4 47) was modified from a short pulse, high current (SPHC) pulse forming network (PFN) with very low inductance (∼200 nH) to a large inductance ladder circuit. This modification allows for a longer, flat top gun current pulse that eliminates the under-damped, sinusoidal behaviour of the gun current with consequent interruptions in plasma parameters. The new PFN was designed to produce a current waveform for a much longer period (∼1 ms). As a consequence of increasing the pulse length, the magnitude of the gun current was reduced as no additional energy storage was added to the PFN. The characterization of the electrical and plasma behaviour of the experiment operated with the long pulse, low current (LPLC) PFN is presented. The gun currents produced by the LPLC PFN are approximately one-fifth in magnitude of the gun currents produced by the SPHC PFN. Axial plasma parameters were measured near the muzzle of the plasma source, and electron densities were found to range from 1 x 10 19 m -3 to 7 x 10 19 m -3 depending upon the axial location. These values are approximately 1-2 orders of magnitude less than the electron densities produced by the SPHC PFN at the same locations. Electron temperatures range from 30 to 60 eV at these locations and are very similar to those produced by the SPHC PFN. A resistive MHD model was applied as an order estimate of the plasma resistivity and demonstrates reasonable agreement with measured values of the magnetized coaxial gun resistance

Quasi-steady state, low current behaviour of a magnetized coaxial plasma source

Energy Technology Data Exchange (ETDEWEB)

Gray, Travis K; Mayo, Robert M; Bourham, Mohamed A [Department of Nuclear Engineering, North Carolina State University, Raleigh, NC 27695-7909 (United States)

2005-11-15

The Coaxial Plasma Source-1 facility (Mayo R M et al 1995 Plasma Sources Sci. Technol. 4 47) was modified from a short pulse, high current (SPHC) pulse forming network (PFN) with very low inductance ({approx}200 nH) to a large inductance ladder circuit. This modification allows for a longer, flat top gun current pulse that eliminates the under-damped, sinusoidal behaviour of the gun current with consequent interruptions in plasma parameters. The new PFN was designed to produce a current waveform for a much longer period ({approx}1 ms). As a consequence of increasing the pulse length, the magnitude of the gun current was reduced as no additional energy storage was added to the PFN. The characterization of the electrical and plasma behaviour of the experiment operated with the long pulse, low current (LPLC) PFN is presented. The gun currents produced by the LPLC PFN are approximately one-fifth in magnitude of the gun currents produced by the SPHC PFN. Axial plasma parameters were measured near the muzzle of the plasma source, and electron densities were found to range from 1 x 10{sup 19} m{sup -3} to 7 x 10{sup 19} m{sup -3} depending upon the axial location. These values are approximately 1-2 orders of magnitude less than the electron densities produced by the SPHC PFN at the same locations. Electron temperatures range from 30 to 60 eV at these locations and are very similar to those produced by the SPHC PFN. A resistive MHD model was applied as an order estimate of the plasma resistivity and demonstrates reasonable agreement with measured values of the magnetized coaxial gun resistance.

Posterior fossa abnormalities in high-risk term infants: comparison of ultrasound and MRI

Energy Technology Data Exchange (ETDEWEB)

Steggerda, S.J.; Smits-Wintjens, V.E.H.J.; Verbon, P.; Walther, F.J. [Leiden University Medical Centre, Department of Neonatology, Leiden (Netherlands); Bruine, F.T. de [Leiden University Medical Centre, Department of Radiology, Leiden (Netherlands); Wezel-Meijler, G. van [Leiden University Medical Centre, Department of Radiology, Leiden (Netherlands); Isala Hospital, Department of Neonatology, Zwolle (Netherlands)

2015-09-15

We aimed to assess the characteristics of posterior fossa (PF) abnormalities in a cohort of high-risk term neonates, as well as the diagnostic performance of cranial ultrasound (CUS) with additional mastoid fontanelle (MF) views for the detection of these abnormalities, with magnetic resonance imaging (MRI) being the reference standard. In this retrospective study, 113 term neonates with CUS and subsequent MRI were included. Sensitivity, specificity, and predictive values of routine CUS and CUS with MF views were calculated. Posterior fossa abnormalities were diagnosed on CUS in 46 of 113 infants. MRI confirmed these findings in 43 and showed additional abnormalities in 32 infants. The sensitivity and specificity of anterior fontanelle views for major PF abnormalities as seen on MRI were 16 % and 99 %. Adding MF views increased the sensitivity of US to 82 %. The sensitivity and specificity of MF views for the detection of any (major or minor) PF abnormality were 57 % and 95 %. Especially acute hypoxic-ischemic injury and small subdural and punctate cerebellar haemorrhage remained undetected by CUS. PF abnormalities are frequent in high-risk term infants. MF-CUS enables early diagnosis of major PF abnormalities. We therefore advocate to perform MF-CUS in high-risk term neonates. (orig.)

Posterior fossa abnormalities in high-risk term infants: comparison of ultrasound and MRI

International Nuclear Information System (INIS)

Steggerda, S.J.; Smits-Wintjens, V.E.H.J.; Verbon, P.; Walther, F.J.; Bruine, F.T. de; Wezel-Meijler, G. van

2015-01-01

We aimed to assess the characteristics of posterior fossa (PF) abnormalities in a cohort of high-risk term neonates, as well as the diagnostic performance of cranial ultrasound (CUS) with additional mastoid fontanelle (MF) views for the detection of these abnormalities, with magnetic resonance imaging (MRI) being the reference standard. In this retrospective study, 113 term neonates with CUS and subsequent MRI were included. Sensitivity, specificity, and predictive values of routine CUS and CUS with MF views were calculated. Posterior fossa abnormalities were diagnosed on CUS in 46 of 113 infants. MRI confirmed these findings in 43 and showed additional abnormalities in 32 infants. The sensitivity and specificity of anterior fontanelle views for major PF abnormalities as seen on MRI were 16 % and 99 %. Adding MF views increased the sensitivity of US to 82 %. The sensitivity and specificity of MF views for the detection of any (major or minor) PF abnormality were 57 % and 95 %. Especially acute hypoxic-ischemic injury and small subdural and punctate cerebellar haemorrhage remained undetected by CUS. PF abnormalities are frequent in high-risk term infants. MF-CUS enables early diagnosis of major PF abnormalities. We therefore advocate to perform MF-CUS in high-risk term neonates. (orig.)

Magnetic force microscopy: advanced technique for the observation of magnetic domains

International Nuclear Information System (INIS)

Asenjo, A.; Garcia, J. M.; Vazquez, M.

2001-01-01

An overview on the Magnetic Force Microscopy, MFM, as an advanced technique to observe magnetic domains and walls is displayed. Basic concepts are first introduced on the domain structure formation as well as on other techniques to observe magnetic domains. Afterwards, the MFM instrumentation is described making also an emphasis in micro magnetic consideration to interpret the images. Finally, a set of selected advanced magnetic materials with different domain structures is chosen to show the wide possibilities of this techniques to characterise the surface magnetic behaviour. The domain structure of materials as commercial magnetic recording media, thin films and multilayers, amorphous micro tubes, nanocrystalline ribbons, perovskites or magnetic nano wires is shown. (Author) 16 refs

Laryngeal carcinoma after radiation therapy: correlation of abnormal MR imaging signal patterns in laryngeal cartilage with the risk of recurrence

NARCIS (Netherlands)

Castelijns, J. A.; van den Brekel, M. W.; Tobi, H.; Smit, E. M.; Golding, R. P.; van Schaik, C.; Snow, G. B.

1996-01-01

To correlate abnormal magnetic resonance (MR) imaging signal patterns in cartilage with the effectiveness of radiation treatment. Eighty previously untreated patients underwent MR imaging and radiation therapy with a curative intent. Cartilage was considered to have an abnormal signal pattern if it

Finite element simulation of the micromagnetic behaviour of nanoelements

International Nuclear Information System (INIS)

Ridley, P.H.W.

2000-06-01

Over recent years the investigation into the magnetic behaviour of nanostructured permalloy has become more advanced due to improvements in numerical micromagnetic methods on the theoretical side and high accuracy electron-beam lithography methods experimentally. The interest in such structures of magnetic material is increasing mainly due to the possible potential use in future high-density magnetic storage media applications. When the material is discretized into a nanoelement structure at the sub micron level theoretical micromagnetic techniques may be employed in order to investigate the magnetization behaviour. This thesis describes a theoretical study of the hysteresis and domain behaviour in thin film permalloy nanoelements. To carry out our investigations we have developed a dynamical micromagnetic model based on the use of the finite element method. The results presented in this thesis begin with a test of the performance of our model. We then proceed with an investigation into the effect of size, elongation and geometry on the transition states for single nanoelements. The investigation is then extended to look at the magnetization behaviour of arrays of interacting nanoelements in relation to their separation and material properties. The reversal mechanism of the arrays is very sensitive to the degree of disorder. In the case of an aligned uniaxial anisotropy a highly symmetric cooperative switching mechanism is observed. A large anisotropy has the effect of stabilizing states during the reversal process leading to distinctive switching. A random anisotropy breaks this high symmetry sufficiently to reduce the cooperative switching leading to a relatively random reversal of individual elements. The theoretical predictions are compared with experimental observations. (author)

A two-stage model for in vivo assessment of brain tumor perfusion and abnormal vascular structure using arterial spin labeling.

Directory of Open Access Journals (Sweden)

Patrick W Hales

Full Text Available The ability to assess brain tumor perfusion and abnormalities in the vascular structure in vivo could provide significant benefits in terms of lesion diagnosis and assessment of treatment response. Arterial spin labeling (ASL has emerged as an increasingly viable methodology for non-invasive assessment of perfusion. Although kinetic models have been developed to describe perfusion in healthy tissue, the dynamic behaviour of the ASL signal in the brain tumor environment has not been extensively studied. We show here that dynamic ASL data acquired in brain tumors displays an increased level of 'biphasic' behaviour, compared to that seen in healthy tissue. A new two-stage model is presented which more accurately describes this behaviour, and provides measurements of perfusion, pre-capillary blood volume fraction and transit time, and capillary bolus arrival time. These biomarkers offer a novel contrast in the tumor and surrounding tissue, and provide a means for measuring tumor perfusion and vascular structural abnormalities in a fully non-invasive manner.

Qualitative and quantitative EEG abnormalities in violent offenders with antisocial personality disorder.

Science.gov (United States)

Reyes, Ana Calzada; Amador, Alfredo Alvarez

2009-02-01

Resting eyes closed electroencephalogram was studied in a group of violent offenders evaluated at Psychiatric Department of the Legal Medicine Institute in Cuba (18 with antisocial personality disorder, ASPD, and 10 without psychiatric diagnosis). Characteristics of the EEG visual inspection and the use of frequency domain quantitative analysis techniques (narrow band spectral parameters) are described. Both groups were compared to Cuban normative database. High incidences of electroencephalographic abnormalities were found in both groups of violent offenders. The most frequent were: electrogenesis alterations, attenuated alpha rhythm and theta and delta activities increase in the frontal lobe. In the quantitative analysis theta and delta frequencies were increased and alpha activity was decreased in both groups. Differences appear for the topographical patterns present in subjects of both groups. EEG abnormalities were more severe in ASPD than in control group. Results suggest that EEG abnormalities in violent offenders should reflect aspects of brain dysfunction related to antisocial behaviour.

Syringomyelia and Craniocervical Junction Abnormalities in Chihuahuas.

Science.gov (United States)

Kiviranta, A-M; Rusbridge, C; Laitinen-Vapaavuori, O; Hielm-Björkman, A; Lappalainen, A K; Knowler, S P; Jokinen, T S

2017-11-01

Chiari-like malformation (CM) and syringomyelia (SM) are widely reported in Cavalier King Charles Spaniels and Griffon Bruxellois dogs. Increasing evidence indicates that CM and SM also occur in other small and toy breed dogs, such as Chihuahuas. To describe the presence of SM and craniocervical junction (CCJ) abnormalities in Chihuahuas and to evaluate the possible association of CCJ abnormalities with SM. To describe CM/SM-related clinical signs and neurologic deficits and to investigate the association of CM/SM-related clinical signs with signalment, SM, or CCJ abnormalities. Fifty-three client-owned Chihuahuas. Prospective study. Questionnaire analyses and physical and neurologic examinations were obtained before magnetic resonance and computed tomography imaging. Images were evaluated for the presence of SM, CM, and atlantooccipital overlapping. Additionally, medullary kinking, dorsal spinal cord compression, and their sum indices were calculated. Scratching was the most common CM/SM-related clinical sign and decreased postural reaction the most common neurologic deficit in 73 and 87% of dogs, respectively. Chiari-like malformation and SM were present in 100 and 38% of dogs, respectively. Syringomyelia was associated with the presence of CM/SM-related clinical signs (P = 0.034), and medullary kinking and sum indices were higher in dogs with clinical signs (P = 0.016 and P = 0.007, respectively). Syringomyelia and CCJ abnormalities are prevalent in Chihuahuas. Syringomyelia was an important factor for the presence of CM/SM-related clinical signs, but many dogs suffered from similar clinical signs without being affected by SM, highlighting the clinical importance of CCJ abnormalities in Chihuahuas. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Alterations and Abnormal Mitosis of Wheat Chromosomes Induced by Wheat-Rye Monosomic Addition Lines

Science.gov (United States)

Fu, Shulan; Yang, Manyu; Fei, Yunyan; Tan, Feiquan; Ren, Zhenglong; Yan, Benju; Zhang, Huaiyu; Tang, Zongxiang

2013-01-01

Background Wheat-rye addition lines are an old topic. However, the alterations and abnormal mitotic behaviours of wheat chromosomes caused by wheat-rye monosomic addition lines are seldom reported. Methodology/Principal Findings Octoploid triticale was derived from common wheat T. aestivum L. ‘Mianyang11’×rye S. cereale L. ‘Kustro’ and some progeny were obtained by the controlled backcrossing of triticale with ‘Mianyang11’ followed by self-fertilization. Genomic in situ hybridization (GISH) using rye genomic DNA and fluorescence in situ hybridization (FISH) using repetitive sequences pAs1 and pSc119.2 as probes were used to analyze the mitotic chromosomes of these progeny. Strong pSc119.2 FISH signals could be observed at the telomeric regions of 3DS arms in ‘Mianyang11’. However, the pSc119.2 FISH signals were disappeared from the selfed progeny of 4R monosomic addition line and the changed 3D chromosomes could be transmitted to next generation stably. In one of the selfed progeny of 7R monosomic addition line, one 2D chromosome was broken and three 4A chromosomes were observed. In the selfed progeny of 6R monosomic addition line, structural variation and abnormal mitotic behaviour of 3D chromosome were detected. Additionally, 1A and 4B chromosomes were eliminated from some of the progeny of 6R monosomic addition line. Conclusions/Significance These results indicated that single rye chromosome added to wheat might cause alterations and abnormal mitotic behaviours of wheat chromosomes and it is possible that the stress caused by single alien chromosome might be one of the factors that induced karyotype alteration of wheat. PMID:23936213

Effects of Two-Year Treatment with the Cholinesterase Inhibitor Rivastigmine on Behavioural Symptoms in Alzheimer’s Disease

Directory of Open Access Journals (Sweden)

Michael Rösler

1999-01-01

Full Text Available Alzheimer’s disease (AD is accompanied by prominent behavioural disturbances. They cause significant distress for both caregivers and patients and can play a major role in the decision to institutionalise AD patients. Recent evidence suggests that cholinergic deficiencies not only contribute to the memory and cognitive abnormalities of AD but are also responsible for some behavioural abnormalities seen over the course of the disease. In this study we assessed the ability of rivastigmine, a pseudo-irreversible cholinesterase inhibitor, to improve behavioural and psychopathologic symptoms in AD. The analysis included 34 patients present in the Germanarm of the international study B303 who received and completed long-term treatment with rivastigmine in the open-label study B305. Assessments of behaviour and psychopathological symptoms were performed using the behavioural component of the Clinicians Interview Based Impression of Change Plus (CIBIC-Plus. Results show that long-term treatment with rivastigmine can slow the progression of behavioural and psychopathological symptoms of AD. Behavioural symptoms showing stabilisation included aggressiveness, activity disturbances, hallucinations and paranoid features. Results also suggest that patients treated earlier with rivastigmine may attain a greater benefit compared with patients whose treatment is delayed 6 months. Further studies examining the effects of rivastigmine on behavioural disturbances in AD are therefore warranted.

The effects of acute tryptophan depletion on speech and behavioural mimicry in individuals at familial risk for depression

NARCIS (Netherlands)

Hogenelst, Koen; Sarampalis, Anastasios; Leander, N. Pontus; Müller, Barbara C.N.; Schoevers, Robert A.; aan het Rot, Marije

Major depressive disorder (MDD) has been associated with abnormalities in speech and behavioural mimicry. These abnormalities may contribute to the impairments in interpersonal functioning that are often seen in MDD patients. MDD has also been associated with disturbances in the brain serotonin

Nonlinear dynamics of a magnetically driven Duffing-type spring–magnet oscillator in the static magnetic field of a coil

International Nuclear Information System (INIS)

Donoso, Guillermo; Ladera, Celso L

2012-01-01

We study the nonlinear oscillations of a forced and weakly dissipative spring–magnet system moving in the magnetic fields of two fixed coaxial, hollow induction coils. As the first coil is excited with a dc current, both a linear and a cubic magnet-position dependent force appear on the magnet–spring system. The second coil, located below the first, excited with an ac current, provides the oscillating magnetic driving force on the system. From the magnet–coil interactions, we obtain, analytically, the nonlinear motion equation of the system, found to be a forced and damped cubic Duffing oscillator moving in a quartic potential. The relative strengths of the coefficients of the motion equation can be easily set by varying the coils’ dc and ac currents. We demonstrate, theoretically and experimentally, the nonlinear behaviour of this oscillator, including its oscillation modes and nonlinear resonances, the fold-over effect, the hysteresis and amplitude jumps, and its chaotic behaviour. It is an oscillating system suitable for teaching an advanced experiment in nonlinear dynamics both at senior undergraduate and graduate levels. (paper)

Wear behaviour of Zr-based in situ bulk metallic glass matrix ...

Indian Academy of Sciences (India)

based bulk metallic glasses; in situ composites; ductile phase; wear behaviours. 1. Introduction ... crystalline alloys [2], which led to an abnormal phenomenon that the wear ... of BMGs does not follow the empirical Archard's wear equa- tion which ...

Multi-modality imaging review of congenital abnormalities of kidney and upper urinary tract.

Science.gov (United States)

Ramanathan, Subramaniyan; Kumar, Devendra; Khanna, Maneesh; Al Heidous, Mahmoud; Sheikh, Adnan; Virmani, Vivek; Palaniappan, Yegu

2016-02-28

Congenital abnormalities of the kidney and urinary tract (CAKUT) include a wide range of abnormalities ranging from asymptomatic ectopic kidneys to life threatening renal agenesis (bilateral). Many of them are detected in the antenatal or immediate postnatal with a significant proportion identified in the adult population with varying degree of severity. CAKUT can be classified on embryological basis in to abnormalities in the renal parenchymal development, aberrant embryonic migration and abnormalities of the collecting system. Renal parenchymal abnormalities include multi cystic dysplastic kidneys, renal hypoplasia, number (agenesis or supernumerary), shape and cystic renal diseases. Aberrant embryonic migration encompasses abnormal location and fusion anomalies. Collecting system abnormalities include duplex kidneys and Pelvi ureteric junction obstruction. Ultrasonography (US) is typically the first imaging performed as it is easily available, non-invasive and radiation free used both antenatally and postnatally. Computed tomography (CT) and magnetic resonance imaging (MRI) are useful to confirm the ultrasound detected abnormality, detection of complex malformations, demonstration of collecting system and vascular anatomy and more importantly for early detection of complications like renal calculi, infection and malignancies. As CAKUT are one of the leading causes of end stage renal disease, it is important for the radiologists to be familiar with the varying imaging appearances of CAKUT on US, CT and MRI, thereby helping in prompt diagnosis and optimal management.

Single-molecule magnets ``without'' intermolecular interactions

Science.gov (United States)

Wernsdorfer, W.; Vergnani, L.; Rodriguez-Douton, M. J.; Cornia, A.; Neugebauer, P.; Barra, A. L.; Sorace, L.; Sessoli, R.

2012-02-01

Intermolecular magnetic interactions (dipole-dipole and exchange) affect strongly the magnetic relaxation of crystals of single-molecule magnets (SMMs), especially at low temperature, where quantum tunneling of the magnetization (QTM) dominates. This leads to complex many-body problems [l]. Measurements on magnetically diluted samples are desirable to clearly sort out the behaviour of magnetically-isolated SMMs and to reveal, by comparison, the effect of intermolecular interactions. Here, we diluted a Fe4 SMM into a diamagnetic crystal lattice, affording arrays of independent and iso-oriented magnetic units. We found that the resonant tunnel transitions are much sharper, the tunneling efficiency changes significantly, and two-body QTM transitions disappear. These changes have been rationalized on the basis of a dipolar shuffling mechanism and of transverse dipolar fields, whose effect has been analyzed using a multispin model. Our findings directly prove the impact of intermolecular magnetic couplings on the SMM behaviour and disclose the magnetic response of truly-isolated giant spins in a diamagnetic crystalline environment.[4pt] [1] W. Wernsdorfer, at al, PRL 82, 3903 (1999); PRL 89, 197201 (2002); Nature 416, 406 (2002); IS Tupitsyn, PCE Stamp, NV Prokof'ev, PRB 69, 132406 (2004).

A review of transcranial magnetic stimulation and multimodal neuroimaging to characterize post-stroke neuroplasticity

Directory of Open Access Journals (Sweden)

Angela Michelle Auriat

2015-10-01

Full Text Available Following stroke, the brain undergoes various stages of recovery where the central nervous system can reorganize neural circuitry (neuroplasticity both spontaneously and with the aid of behavioural rehabilitation and non-invasive brain stimulation. Multiple neuroimaging techniques can characterize common structural and functional stroke-related deficits, and importantly, help predict recovery of function. Diffusion tensor imaging (DTI typically reveals increased overall diffusivity throughout the brain following stroke, and is capable of indexing the extent of white matter damage. Magnetic resonance spectroscopy (MRS provides an index of metabolic changes in surviving neural tissue after stroke, serving as a marker of brain function. The neural correlates of altered brain activity after stroke have been demonstrated by abnormal activation of sensorimotor cortices during task performance, and at rest, using functional magnetic resonance imaging (fMRI. Electroencephalography (EEG has been used to characterize motor dysfunction in terms of increased cortical amplitude in the sensorimotor regions when performing upper-limb movement, indicating abnormally increased cognitive effort and planning in individuals with stroke. Transcranial magnetic stimulation (TMS work reveals changes in ipsilesional and contralesional cortical excitability in the sensorimotor cortices. The severity of motor deficits indexed using TMS has been linked to the magnitude of activity imbalance between the sensorimotor cortices. In this paper we will provide a narrative review of data from studies utilizing DTI, MRS, fMRI, EEG and brain stimulation techniques focusing on TMS and its combination with uni and multi-modal neuroimaging methods to assess recovery after stroke. Approaches that delineate the best measures with which to predict or positively alter outcomes will be highlighted.

Field-Induced Single-Ion Magnet Behaviour in Two New Cobalt(II Coordination Polymers with 2,4,6-Tris(4-pyridyl-1,3,5-triazine

Directory of Open Access Journals (Sweden)

Dong Shao

2017-12-01

Full Text Available We herein reported the syntheses, crystal structures, and magnetic properties of a two-dimensional coordination polymer {[CoII(TPT2/3(H2O4][CH3COO]2·(H2O4}n (1 and a chain compound {[CoII(TPT2(CHOO2(H2O2]}n (2 based on the 2,4,6-Tris(4-pyridyl-1,3,5-triazine (TPT ligand. Structure analyses showed that complex 1 had a cationic hexagonal framework structure, while 2 was a neutral zig-zag chain structure with different distorted octahedral coordination environments. Magnetic measurements revealed that both complexes exhibit large easy-plane magnetic anisotropy with the zero-field splitting parameter D = 47.7 and 62.1 cm−1 for 1 and 2, respectively. This magnetic anisotropy leads to the field-induced slow magnetic relaxation behaviour. However, their magnetic dynamics are quite different; while complex 1 experienced a dominating thermally activated Orbach relaxation at the whole measured temperature region, 2 exhibited multiple relaxation pathways involving direct, Raman, and quantum tunneling (QTM processes at low temperatures and Orbach relaxation at high temperatures. The present complexes enlarge the family of framework-based single-ion magnets (SIMs and highlight the significance of the structural dimensionality to the final magnetic properties.

Dielectric and polarization behaviour of cellulose electro-active paper (EAPap)

International Nuclear Information System (INIS)

Yun, Gyu-Young; Kim, Joo-Hyung; Kim, Jaehwan

2009-01-01

Dielectric and polarization behaviour of electro-active paper (EAPap) were studied to understand the detailed material behaviour of EAPap as a novel smart material. It was revealed that the dielectric constant of EAPap was temperature and frequency dependent. The largest change in the dielectric constant was observed near 0 0 C while the highest dielectric constant was obtained at around 100 0 C, which might be related to the dipolar behaviour of the hydroxyl structure of cellulose and adsorbed or existing internal water molecules in cellulose EAPap. By thermal stimulated current measurement for polarization behaviour of cellulose EAPap, it was shown that the maximum current was observed in the temperature range 105-110 0 C. Compared with the polarization behaviour in the low temperature range, abnormal polarization was observed under an applied field mainly due to the trapped space charge in EAPap, which indicates that cellulose EAPap has a similar material behaviour to that of electret polymers. (fast track communication)

Heat-capacity behaviour of Ce{sub 2}Pd{sub 2}In

Energy Technology Data Exchange (ETDEWEB)

Mallik, R; Sampathkumaran, E V [Tata Institute of Fundamental Research, Mumbai (India)

1997-12-31

We report here the magnetic behaviour of Ce{sub 2}Pd{sub 2}In by heat capacity (C) and magnetization studies and propose that this compound exhibits two magnetic transitions, T{sub N}=4.5K and T{sub C}=3.6K. 3 refs., 1 fig.

Dynamics of magnetic moments in high-Tc superconductors. Final report

International Nuclear Information System (INIS)

Holland-Moritz, E.; Jostarndt, H.D.

1992-01-01

The central topic of this research project was the question why PrBa 2 Cu 3 O 7 does not become superconducting. For this purpose, Pr specimens were investigated as well as for comparison purposes, specimens of the neighbouring rare earth Nd, by means of inelastic magnetic neutron scattering as a function of temperature and the pulse transmission. As the reason for the suppression of superconductivity, an anomalously large hybridization of 4f electrons of Pr with the p-electrons of oxygen was observed, which causes the magnetic atomic temperatures, which are abnormally high in comparison with other rare earth 1:2:3 systems. The present it is not known whether superconductivity is suppressed spatial correlations of the magnetic 4f-moments. In addition, in this project could be proven successfully for the first time, the high-energy crystal field stimulations in PrBa 2 Cu 3 O 7 as well as in PrBa 2 Cu 3 O 6 . The temperature dependence of the quasielastic line width in NdBa 2 Cu 3 O 7-δ shows a distinctive anomaly at 100 K, which means approximately near to the superconducting transition temperature of the O 7 -systems. It is remarkable that this anomaly occurs in the non-superconducting O 6 -systems as well. This behaviour is not yet completely understood. (orig./UU) [de

Beyond Behaviour: Is Social Anxiety Low in Williams Syndrome?

Science.gov (United States)

Dodd, Helen F.; Schniering, Carolyn A.; Porter, Melanie A.

2009-01-01

Individuals with Williams syndrome (WS) exhibit striking social behaviour that may be indicative of abnormally low social anxiety. The present research aimed to determine whether social anxiety is unusually low in WS and to replicate previous findings of increased generalised anxiety in WS using both parent and self report. Fifteen individuals…

Spatially correlated disorder in striped precursor magnetic modulations

International Nuclear Information System (INIS)

Porta, Marcel; Castan, Teresa; LLoveras, Pol; Planes, Antoni; Saxena, Avadh

2007-01-01

We use a Ginzburg-Landau model that includes long-range dipolar interactions and spatially correlated quenched-in disorder coupled to the local magnetization to study the properties of the precursor magnetic modulations as a function of the characteristics of the disorder. We find that although the modulation pattern is very robust and does not depend on details of the pair correlation function G(r), the scaling behaviour of the characteristic length of the striped magnetic modulations depends on the behaviour of G(r) for small values of r

Latest news from the Magnet System

CERN Multimedia

Delruelle, N; Ruber, R; Zaitsev, I

The Last Barrel Toroid Coil Successfully Tested From June 6th to the 14th the last of the eight Barrel Toroid coils was tested on-surface (i.e. before being lowered into the ATLAS cavern). In the very early morning of June 7th, the coil reached the nominal operation current, 20.5 kA, and the maximum test current, 22 kA, without any problem. The electrical, thermal and mechanical behaviour of the coil was as expected and no 'strange' or abnormal phenomena were observed. Directly after a slow dump of the current, a second ramp to maximum current was performed, followed by a provoked quench (fast dump). The figure below shows the magnet current during these two ramps versus time. Several additional quenches and a steady state test were performed to complete the test. Presently the coil is at room temperature again and is being prepared for transport to point 1 (the ATLAS site) on 14 July. With the successful test of the eighth coil, the on-surface test program for the Barrel Toroid coils is finished. Within on...

Magnetic starspots

International Nuclear Information System (INIS)

Jahn, K.; Stepien, K.

1984-01-01

Models of large magnetic starspots with an axisymmetric untwisted magnetic field on late type stars are discussed. It is assumed that the magnetic field reduces the efficiency of convection inside the spot. A unique relation between the stellar mass and the difference of effective temperatures of the spot and the surrounding photosphere is adopted from observations. It is equivalent to the reduction of a s (the mixing length theory parameter) inside the spot to the value 0.15 independently of the stellar mass. The surface magnetic field of large spots covering a considerable part of the stellar surface is a decreasing function of the magnetic flux. Hence a coverage of a star by magnetic regions rapidly increases as a function of the magnetic flux in a narrow range of fluxes. This behaviour can explain the Vaughan-Preston gap. Recent observations of magnetic fields on G and K type stars are in a good agreement with our predictions. 35 refs., 3 figs., 4 tabs. (author)

Migraine and magnetic resonance spectroscopy

DEFF Research Database (Denmark)

Younis, Samaira; Hougaard, Anders; Vestergaard, Mark B.

2017-01-01

Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation in the meth......Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation...... in the methodology and quality of the MRS migraine studies over time, some results were consistent and reproducible. 31P-MRS studies suggested reduced availability of neuronal energy and implied a mitochondrial dysfunction in the migraine brain. 1H-MRS studies reported interictal abnormalities in the excitatory...... and inhibitory neurotransmitters, glutamate and g-aminobutyric acid (GABA), suggesting persistent altered excitability in migraine patients. N-Acetylaspartate levels were decreased in migraine, probably due to a mitochondrial dysfunction and abnormal energy metabolism. The reported abnormalities may increase...

Phase composition and magnetic properties in nanocrystalline permanent magnets based on misch-metal

Science.gov (United States)

Ma, Q.; Wang, J.; Zhang, Z. Y.; Zhang, X. F.; Liu, F.; Liu, Y. L.; Jv, X. M.; Li, Y. F.; Wang, G. F.

2017-09-01

The magnetic properties and phase composition of magnets based on misch-metal (MM) with nominal composition of MM13+xFe84-xB6.5 with x = 0.5, 1, 1.5, 2 and 2.5 using melt-spinning method were investigated. For x = 1.5, it could exhibit best magnetic properties (Hcj = 753.02 kA m-1, (BH)max = 70.77 kJ m-3). X-ray diffraction and energy dispersive spectroscopy show that the multi hard magnetic phase of RE2Fe14B (RE = La, Ce, Pr, Nd) existed in the magnets. The domain wall pinning effect and the exchange coupling interaction between grains are dependent on the abnormal RE-rich phase composition. Optimizing the phase constitution is necessary to improve magnetic properties in MM-Fe-B magnets for utilizing the rare earth resource in a balanced manner.

Abnormal air righting behaviour in the spontaneously hypertensive rat model of ADHD

OpenAIRE

Dommett, Eleanor J; Rostron, Claire L

2011-01-01

The spontaneously hypertensive rat (SHR) is the most commonly used model of attention-deficit hyperactivity disorder (ADHD), displaying the main symptoms of the disorder which are responsive to psychostimulant treatments. Research to date has focused on behavioural tests investigating functioning of the striatum or prefrontal cortex in these rats. However, there is now evidence that the superior colliculus, a structure associated with head and eye movements, may also be dysfunctional in ADHD....

Ionospheric behaviour during storm recovery phase

Science.gov (United States)

Buresova, D.; Lastovicka, J.; Boska, J.; Sindelarova, T.; Chum, J.

2012-04-01

Intensive ionospheric research, numerous multi-instrumental observations and large-scale numerical simulations of ionospheric F region response to magnetic storm-induced disturbances during the last several decades were primarily focused on the storm main phase, in most cases covering only a few hours of the recovery phase following after storm culmination. Ionospheric behaviour during entire recovery phase still belongs to not sufficiently explored and hardly predictable features. In general, the recovery phase is characterized by an abatement of perturbations and a gradual return to the "ground state" of ionosphere. However, observations of stormy ionosphere show significant departures from the climatology also within this phase. This paper deals with the quantitative and qualitative analysis of the ionospheric behaviour during the entire recovery phase of strong-to-severe magnetic storms at middle latitudes for nowadays and future modelling and forecasting purposes.

Feeling Abnormal: Simulation of Deviancy in Abnormal and Exceptionality Courses.

Science.gov (United States)

Fernald, Charles D.

1980-01-01

Describes activity in which student in abnormal psychology and psychology of exceptional children classes personally experience being judged abnormal. The experience allows the students to remember relevant research, become sensitized to the feelings of individuals classified as deviant, and use caution in classifying individuals as abnormal.…

Magnetic soft mode behaviour investigated via multi-spin flip Raman spectroscopy on near surface Cd1-xMnxTe/Cd1-yMgyTe quantum wells

International Nuclear Information System (INIS)

Kehl, Christian

2011-01-01

The main motivation for this thesis was the experimental confirmation of the theoretically predicted magnetic soft mode and the analysis of its dependence on the hole-concentration and external B-field, as well as its disappearance with increasing sample temperature. For that purpose, CdMnTe/CdMgTe QWs (Mn: 0.6%, 1.0%) positioned close to the sample surface (13-19 nm) were investigated in an in-plane applied external magnetic field (up to 4.5 T in Voigt-geometry) via a two-colour experiment i.e. using two light sources. This allows the spin excitation of Mn-ions by simultaneously tuning the hole-concentration towards the ferromagnetic phase transition by photo-generated carriers. Thus, one tuneable laser is responsible for resonant below-barrier excitation as a probe for Multi-SF Raman scattering. The other laser excites photo-generated carriers from above barrier (2.41 eV) for tuning the hole concentration in the QW. Positioning the QW close to the sample surface causes a surface-induced p-doping of the QW (intrinsic hole concentration in the QW) and enables the active tuning of the hole concentration by photo-generated carriers due to different tunnelling behaviour of electrons and holes from the QW to the surface. The Mn-g-factor was decreased by quasi-continuously increasing the above-barrier illumination, while the below-barrier excitation was kept at a constant low power. This results in a Mn-g-factor reduction starting from its atomic value g=2.01 to lowest evaluated Mn-g-factor in this thesis g=1.77. This is a magnetic softening of 12%. Apart from the general magnetic soft mode behaviour at low temperatures, one of the main experimental results in this thesis is the confirmation of the theoretical prediction that the magnetic soft mode behaviour in the external B-field does not only depend on the carrier concentration but also on the B-field strength itself. An additional aspect is the temperature dependence of the magnetic soft mode. The Mn

Magnetic and anomalous magnetic viscosity in the bulk amorphous ferromagnet Pr58Fe24Al18 and partially amorphous ferromagnet Pr60Fe24Al16

International Nuclear Information System (INIS)

Collocott, S.J.; Dunlop, J.B.

2009-01-01

A number of ferromagnetic Pr-Fe-Al alloys have been prepared by argon arc melting and quenching into a copper mould. The alloy of composition Pr 58 Fe 24 Al 18 is identified as being amorphous (bulk metallic glass or bulk amorphous ferromagnet), and a range of magnetic measurements have been performed to explore differences and similarities between it and a partially amorphous alloy, containing a significant crystalline fraction, Pr 60 Fe 24 Al 16 . For both alloys, measurements of the irreversible susceptibility, and magnetic viscosity on the major hysteresis loop are reported. From the magnetic viscosity data, the fluctuation field is determined. The behaviour of the anomalous magnetic viscosity (non-monotonic behaviour of the magnetic viscosity, where the magnetisation as a function of time is seen to increase, reach a peak, and then decrease), on the recoil curve that leads to the dc demagnetised state is investigated. Both alloys display non-monotonic behaviour. After dc demagnetisation, spontaneous remagnetisation is observed in both alloys, and some comments are made on the thermal remagnetisation behaviour of the amorphous alloy. The anomalous magnetic viscosity is interpreted in the context of the Preisach model, as it predicts a simple functional relationship between the time taken to reach a peak and the applied magnetic field. The experimental data for both alloys is in good agreement with this prediction.

Metabolomic changes in patients with chronic obstructive pulmonary disease with abnormal Savda syndrome.

Science.gov (United States)

Xu, Wei-Fang; Upur, Halmurat; Wu, Yu-Hua; Mamtimin, Batur; Yang, Jian; Ga, Yong-Juan; You, Li

2015-02-01

The aim of this study was to determine the metabolic biomarkers for abnormal Savda syndrome in patients with chronic obstructive pulmonary disease (COPD). Based on Traditional Uyghur Medicine (TUM) theory, a total of 103 patients with COPD were classified into abnormal Savda and non-abnormal Savda syndrome groups and 52 healthy volunteers acted as the control group. Blood samples from the three groups were analyzed using nuclear magnetic resonance (NMR) spectroscopy combined with orthogonal projection to latent structure-discriminant analysis. NMR tests showed that the regional distributions of the patients with COPD with abnormal Savda syndrome, those with non-abnormal Savda syndrome and the control group were completely separate (P>0.05). The patients with COPD with abnormal Savda syndrome exhibited relatively low levels of amino acids, glycoproteins and unsaturated lipids (PAbnormal Savda syndrome was one of the main types of syndrome among the patients with COPD; increased age, a longer duration of illness and a higher disease severity were characteristic of this type of syndrome. In addition, the present study provided biochemical evidence for the TUM theory-based classification of patients with COPD; these biomarkers can be used in the clinic for the diagnosis of COPD with abnormal Savda syndrome. The study also demonstrated that the plasma metabolic disorder in patients with COPD with abnormal Savda syndrome was more serious than that in the control and COPD with non-abnormal Savda syndrome groups. The plasma metabolic disorder was also associated with a low immune function of the body and endocrine and energy metabolism disorders.

Diagnostic reliability of 3.0-T MRI for detecting osseous abnormalities of the temporomandibular joint.

Science.gov (United States)

Sawada, Kunihiko; Amemiya, Toshihiko; Hirai, Shigenori; Hayashi, Yusuke; Suzuki, Toshihiro; Honda, Masahiko; Sisounthone, Johnny; Matsumoto, Kunihito; Honda, Kazuya

2018-01-01

We compared the diagnostic reliability of 3.0-T magnetic resonance imaging (MRI) for detection of osseous abnormalities of the temporomandibular joint (TMJ) with that of the gold standard, cone-beam computed tomography (CBCT). Fifty-six TMJs were imaged with CBCT and MRI, and images of condyles and fossae were independently assessed for the presence of osseous abnormalities. The accuracy, sensitivity, and specificity of 3.0-T MRI were 0.88, 1.0, and 0.73, respectively, in condyle evaluation and 0.91, 0.75, and 0.95 in fossa evaluation. The McNemar test showed no significant difference (P > 0.05) between MRI and CBCT in the evaluation of osseous abnormalities in condyles and fossae. The present results indicate that 3.0-T MRI is equal to CBCT in the diagnostic evaluation of osseous abnormalities of the mandibular condyle.

Nonverbal expressive behaviour in schizophrenia and social phobia.

Science.gov (United States)

Del-Monte, Jonathan; Raffard, Stéphane; Salesse, Robin N; Marin, Ludovic; Schmidt, Richard C; Varlet, Manuel; Bardy, Benoît G; Philippe Boulenger, Jean; Christine Gély-Nargeot, Marie; Capdevielle, Delphine

2013-11-30

Expressive behaviour plays a crucial role in the success of social interactions. Abnormality of expressive behaviour has been reported in interpersonal interactions of patients suffering from schizophrenia and social phobia, two debilitating mental disorders with important social deficits. However, no study has compared the expressive behaviour in these two disorders. Thirty schizophrenia patients, 21 social phobia patients and 30 healthy controls were evaluated and compared on expressive, cognitive and clinical dimensions. Expressive behaviour was assessed using the Motor Affective subscale of the Motor-Affective-Social-Scale (MASS). Covariables include the Positive and Negative Syndrome Scale (PANSS), the anxiety level Liebowitz-Social-Anxiety-Scale (LSAS) and cognitive tasks. After controlling for depression, schizophrenia and social phobia patients both exhibited significantly fewer expressive behaviours compared to healthy controls. Moreover, our results showed specific signatures: schizophrenia patients performed fewer spontaneous gestures (hand gestures and smiles) whereas social phobia patients had an impaired ability to produce voluntary smiles in comparison to healthy controls. Interestingly, poor social functioning was significantly correlated with a decrease of expressive behaviour for schizophrenia patients. Expressive behaviour is impaired in different ways in social phobia and schizophrenia and is associated in schizophrenia with poorer social functioning. The Motor Affective subscale of the MASS is an interesting tool for assessing the dysfunction of interpersonal expressive behaviour in mental disorders. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

The different aspects of magnetism in cerium compounds

International Nuclear Information System (INIS)

Sereni, J. G.

1999-01-01

Different factors related to the formation of the Cerium magnetic ground state are analyzed from its electronic structure, following a decreasing scale of energy. The studied behaviours include from nonmagnetic states, like those with valence instability, to different magnetic phase diagrams. The competition between the Kondo effect, which screens the magnetic moments and the magnetic interactions, that tends to order them is also described. In the ordered phase boundary the phenomena related to the incipient magnetisms are analyzed and related to deviations from the Fermi liquid behaviour and divergences of the thermodynamic parameters when the temperature tend to zero. Some experimental techniques are described and the difference between thermodynamical and control parameters analyzed. Particular attention is paid to the effect of pressure and ligand substitution. (Author) 22 refs

Results of tests under normal and abnormal operating conditions concerning LMFBR fuel element behaviour

International Nuclear Information System (INIS)

Languille, A.; Bergeonneau, P.; Essig, C.; Guerin, Y.

1985-04-01

The objective of this paper is to improve the knowledge on LMFBR fuel element behaviour during protected and unprotected transients in RAPSODIE and PHENIX reactors in order to evaluate its reliability. The range of the tests performed in these reactors is sufficiently large to cover normal and also extreme off normal conditions such as fuel melting. Results of such tests allow to better establish transient design limits for reactor structural components in particular for fuel pin cladding which play a lead role in controlling the accident sequence. Three main topics are emphasized in this paper: fuel melting during slow over-power excursions; influence of the fuel element geometrical evolution on reactivity feedback effects and reactor dynamic behaviour; clad damage evaluation during a transient (essentially very severe loss of flow)

Modelling magnetic laminations under arbitrary starting state and flux waveform

International Nuclear Information System (INIS)

Bottauscio, Oriano; Chiampi, Mario; Ragusa, Carlo

2005-01-01

A numerical model able to predict the behaviour of a magnetic sheet under arbitrary supply conditions has been developed. The electromagnetic field problem is formulated in terms of an electric vector potential, which provides the magnetic field strength evolution. The hysteretic behaviour of the material is represented through the dynamic Preisach model where the activation law of the bi-state operators is modified in order to guarantee a smooth response. The problem has been solved through a time step procedure using the fixed Point technique for handling nonlinearity. The model has been validated by comparison with suitable experiments and it is applied to the investigation of the influence of the materials' starting state on the magnetic behaviour

Genetics and Genomics of Animal Behaviour and Welfare - Challanges and possibilities

DEFF Research Database (Denmark)

Jensen, Per; Buitenhuis, Bart; Kjaer, Joergen

2008-01-01

Traditionally, the contribution of applied ethology to animal welfare science has concentrated on understanding the reactions of animals to their housing conditions. Domestication has had small effects on fundamental aspects of animal behaviour, and therefore, the needs of present day domesticated...... animals are closely related to the evolutionary history of the ancestors. However, the last decades have seen an unprecedented intensification of selection for increased production, which has significant side-effects on behaviour and welfare. Understanding the nature of such side-effects have therefore...... methods applied on behaviour and welfare related variables. Significant improvements in levels of fearfulness and abnormal behaviour have been achieved by selecting populations against these traits. As a next step, it is necessary to map the loci involved in affecting these traits, and quantitative trait...

Magnetism in the nineties

International Nuclear Information System (INIS)

Freeman, A.J.; Gschneider, K.A. Jr

1991-01-01

This special volume aims at providing a historical perspective of the developments that have taken place since the first volume of the Journal of Magnetism and Magnetic Materials, that appeared in late 1975, to identify the most important issues and to provide a perspective for developments anticipated in the 1990's. The papers contained in this book cover many of the scientifically exciting and technologically important aspects of magnetism. They deal with research on various materials including amorphous, permanent and semiconducting magnets, magnetic and magneto-optic recording materials, strongly correlated electron systems and high Tc-superconductors. Several important experimental methods for measuring magnetic behaviour are covered, but the book also contains in-depth theoretical research of fundamental problems in magnetism

The influence of surface functionalization on the enhanced internalization of magnetic nanoparticles in cancer cells

International Nuclear Information System (INIS)

Villanueva, Angeles; Canete, Magdalena; Calero, Macarena; Roca, Alejandro G; Veintemillas-Verdaguer, Sabino; Serna, Carlos J; Del Puerto Morales, Maria; Miranda, Rodolfo

2009-01-01

The internalization and biocompatibility of iron oxide nanoparticles surface functionalized with four differently charged carbohydrates have been tested in the human cervical carcinoma cell line (HeLa). Neutral, positive, and negative iron oxide nanoparticles were obtained by coating with dextran, aminodextran, heparin, and dimercaptosuccinic acid, resulting in colloidal suspensions stable at pH 7 with similar aggregate size. No intracellular uptake was detected in cells incubated with neutral charged nanoparticles, while negative particles showed different behaviour depending on the nature of the coating. Thus, dimercaptosuccinic-coated nanoparticles showed low cellular uptake with non-toxic effects, while heparin-coated particles showed cellular uptake only at high nanoparticle concentrations and induced abnormal mitotic spindle configurations. Finally, cationic magnetic nanoparticles show excellent properties for possible in vivo biomedical applications such as cell tracking by magnetic resonance imaging (MRI) and cancer treatment by hyperthermia: (i) they enter into cells with high effectiveness, and are localized in endosomes; (ii) they can be easily detected inside cells by optical microscopy, (iii) they are retained for relatively long periods of time, and (iv) they do not induce any cytotoxicity.

Structural brain abnormalities in early onset first-episode psychosis

DEFF Research Database (Denmark)

Pagsberg, A K; Baaré, W F C; Raabjerg Christensen, A M

2007-01-01

BACKGROUND: Brain morphometry in children and adolescents with first-episode psychosis offer a unique opportunity for pathogenetic investigations. METHODS: We compared high-resolution 3D T1-weighted magnetic resonance images of the brain in 29 patients (schizophrenia, schizotypal disorder......, delusional disorder or other non-organic psychosis), aged 10-18 to those of 29 matched controls, using optimized voxel-based morphometry. RESULTS: Psychotic patients had frontal white matter abnormalities, but expected (regional) gray matter reductions were not observed. Post hoc analyses revealed...

Corroboration of in utero MRI using post-mortem MRI and autopsy in foetuses with CNS abnormalities

International Nuclear Information System (INIS)

Whitby, E.H.; Variend, S.; Rutter, S.; Paley, M.N.J.; Wilkinson, I.D.; Davies, N.P.; Sparey, C.; Griffiths, P.D.

2004-01-01

AIMS: To corroborate the findings of in utero magnetic resonance imaging (MRI) with autopsy and post-mortem MRI in cases of known or suspected central nervous system (CNS) abnormalities on ultrasound and to compare the diagnostic accuracy of ante-natal ultrasound and in utero MRI. METHODS: Twelve pregnant women, whose foetuses had suspected central nervous system abnormalities underwent in utero MRI. The foetuses were imaged using MRi before autopsy. The data were used to evaluate the diagnostic accuracy of in utero MRI when compared with a reference standard of autopsy and post-mortem MRI in 10 cases and post-mortem MRI alone in two cases. RESULTS: The diagnostic accuracy of antenatal ultrasound and in utero MRI in correctly characterizing brain and spine abnormalities were 42 and 100%, respectively. CONCLUSION: In utero MRI provides a useful adjuvant to antenatal ultrasound when assessing CNS abnormalities by providing more accurate anatomical information. Post-mortem MRI assists the diagnosis of macroscopic structural abnormalities

Neonatal Brain Abnormalities and Memory and Learning Outcomes at 7 Years in Children Born Very Preterm

Science.gov (United States)

Omizzolo, Cristina; Scratch, Shannon E; Stargatt, Robyn; Kidokoro, Hiroyuki; Thompson, Deanne K; Lee, Katherine J; Cheong, Jeanie; Neil, Jeffrey; Inder, Terrie E; Doyle, Lex W; Anderson, Peter J

2014-01-01

Using prospective longitudinal data from 198 very preterm and 70 full term children, this study characterised the memory and learning abilities of very preterm children at 7 years of age in both verbal and visual domains. The relationship between the extent of brain abnormalities on neonatal magnetic resonance imaging (MRI) and memory and learning outcomes at 7 years of age in very preterm children was also investigated. Neonatal MRI scans were qualitatively assessed for global, white-matter, cortical grey-matter, deep grey-matter, and cerebellar abnormalities. Very preterm children performed less well on measures of immediate memory, working memory, long-term memory, and learning compared with term born controls. Neonatal brain abnormalities, and in particular deep grey matter abnormality, were associated with poorer memory and learning performance at 7 years in very preterm children, especially global, white-matter, grey-matter and cerebellar abnormalities. Findings support the importance of cerebral neonatal pathology for predicting later memory and learning function. PMID:23805915

Slow magnetic relaxation and single-molecule toroidal behaviour in a family of heptanuclear {Cr"I"I"ILn"I"I"I_6} (Ln=Tb, Ho, Er) complexes

Energy Technology Data Exchange (ETDEWEB)

Vignesh, Kuduva R. [IITB-Monash Research Academy, IIT Bombay, Powai, Mumbai (India); Langley, Stuart K. [School of Science and the Environment, Division of Chemistry, Manchester Metropolitan University, Manchester (United Kingdom); Swain, Abinash; Rajaraman, Gopalan [Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai (India); Moubaraki, Boujemaa; Murray, Keith S. [School of Chemistry, Monash University, Clayton, VIC (Australia); Damjanovic, Marko; Wernsdorfer, Wolfgang [Institute Neel, CNRS, Universite Grenoble Alpes, Grenoble (France); Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany)

2018-01-15

The synthesis, magnetic properties, and theoretical studies of three heterometallic {Cr"I"I"ILn"I"I"I_6} (Ln=Tb, Ho, Er) complexes, each containing a metal topology consisting of two Ln{sub 3} triangles connected via a Cr{sup III} linker, are reported. The {CrTb_6} and {CrEr_6} analogues display slow relaxation of magnetization in a 3000 Oe static magnetic field. Single-crystal measurements reveal opening up of the hysteresis loop for {CrTb_6} and {CrHo_6} molecules at low temperatures. Ab initio calculations predict toroidal magnetic moments in the two Ln{sub 3} triangles, which are found to couple, stabilizing a con-rotating ferrotoroidal ground state in Tb and Ho examples and extend the possibility of observing toroidal behaviour in non Dy{sup III} complexes for the first time. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

SRS Behaviour with a superconducting 5-Tesla wiggler insertion

International Nuclear Information System (INIS)

Suller, V.P.; Marks, N.; Poole, M.W.; Walker, R.P.

1983-01-01

A 5 Tesla superconducting wavelength shifting wiggler magnet has been inserted into the SRS lattice. Observations have been made of the behaviour of the stored electron beam with the magnet powered. Betatron tune shifts and modulation of the betatron function have been measured and good agreement obtained with theory. Closed orbit changes have been examined and the stored beam lifetime optimised. The magnet is fully operational and is producing intense x-ray beams for users

Diagnostic accuracy of post mortem MRI for abdominal abnormalities in foetuses and children

Energy Technology Data Exchange (ETDEWEB)

Arthurs, Owen J., E-mail: owen.arthurs@gosh.nhs.uk [Department of Radiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London (United Kingdom); Institute of Child Health, UCL, London (United Kingdom); Thayyil, Sudhin, E-mail: s.thayyil@imperial.ac.uk [Perinatal Neurology and Neonatology, Imperial College London, London (United Kingdom); Owens, Catherine M., E-mail: Catherine.owens@gosh.nhs.uk [Department of Radiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London (United Kingdom); Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London (United Kingdom); Cardiorespiratory Division, Great Ormond Street Hospital for Children NHS Foundation Trust, London (United Kingdom); Olsen, Oystein E., E-mail: oystein.olsen@gosh.nhs.uk [Department of Radiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London (United Kingdom); Institute of Child Health, UCL, London (United Kingdom); Wade, Angie, E-mail: a.wade@ucl.ac.uk [Clinical Epidemiology, Nutrition and Biostatistics Section, UCL Institute of Child health, London (United Kingdom); Addison, Shea, E-mail: shea.addison@imperial.ac.uk [Perinatal Neurology and Neonatology, Imperial College London, London (United Kingdom); Jones, Rod, E-mail: rod.jones@gosh.nhs.uk [Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London (United Kingdom); Cardiorespiratory Division, Great Ormond Street Hospital for Children NHS Foundation Trust, London (United Kingdom); Norman, Wendy, E-mail: wendy.norman@gosh.nhs.uk [Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London (United Kingdom); Cardiorespiratory Division, Great Ormond Street Hospital for Children NHS Foundation Trust, London (United Kingdom); Scott, Rosemary J., E-mail: rosemary.scott@uclh.nhs.uk [Department of Histopathology, University College London Hospital NHS Trust, London (United Kingdom); and others

2015-03-15

Highlights: •Postmortem MR imaging (PMMR) has high overall accuracy for abdominal pathology in foetuses, newborns and children. •PMMR is particularly good at detecting renal abnormalities, and relatively poor at detecting intestinal abnormalities. •In clinical practice, PMMR may be a useful alternative or adjunct to conventional autopsy in foetuses and children for detecting abdominal abnormalities. -- Abstract: Background: To compare the diagnostic accuracy of post-mortem magnetic resonance imaging (PMMR) specifically for abdominal pathology in foetuses and children, compared to conventional autopsy. Methods: Institutional ethics approval and parental consent was obtained. 400 unselected foetuses and children underwent PMMR using a 1.5 T Siemens Avanto MR scanner before conventional autopsy. PMMR images and autopsy findings were reported blinded to the other data respectively. Results: Abdominal abnormalities were found in 70/400 (12%) autopsies. Overall sensitivity and specificity (95% confidence interval) of PMMR for abdominal pathology was 72.5% (61.0, 81.6) and 90.8% (87.0, 93.6), with positive (PPV) and negative predictive values (NPV) of 64.1% (53.0, 73.9) and 93.6% (90.2, 95.8) respectively. PMMR was good at detecting renal abnormalities (sensitivity 80%), particularly in foetuses, and relatively poor at detecting intestinal abnormalities (sensitivity 50%). Overall accuracy was 87.4% (83.6, 90.4). Conclusions: PMMR has high overall accuracy for abdominal pathology in foetuses, newborns and children. PMMR is particularly good at detecting renal abnormalities, and relatively poor at detecting intestinal abnormalities. In clinical practice, PMMR may be a useful alternative or adjunct to conventional autopsy in foetuses and children for detecting abdominal abnormalities.

Diagnostic accuracy of post mortem MRI for abdominal abnormalities in foetuses and children

International Nuclear Information System (INIS)

Arthurs, Owen J.; Thayyil, Sudhin; Owens, Catherine M.; Olsen, Oystein E.; Wade, Angie; Addison, Shea; Jones, Rod; Norman, Wendy; Scott, Rosemary J.

2015-01-01

Highlights: •Postmortem MR imaging (PMMR) has high overall accuracy for abdominal pathology in foetuses, newborns and children. •PMMR is particularly good at detecting renal abnormalities, and relatively poor at detecting intestinal abnormalities. •In clinical practice, PMMR may be a useful alternative or adjunct to conventional autopsy in foetuses and children for detecting abdominal abnormalities. -- Abstract: Background: To compare the diagnostic accuracy of post-mortem magnetic resonance imaging (PMMR) specifically for abdominal pathology in foetuses and children, compared to conventional autopsy. Methods: Institutional ethics approval and parental consent was obtained. 400 unselected foetuses and children underwent PMMR using a 1.5 T Siemens Avanto MR scanner before conventional autopsy. PMMR images and autopsy findings were reported blinded to the other data respectively. Results: Abdominal abnormalities were found in 70/400 (12%) autopsies. Overall sensitivity and specificity (95% confidence interval) of PMMR for abdominal pathology was 72.5% (61.0, 81.6) and 90.8% (87.0, 93.6), with positive (PPV) and negative predictive values (NPV) of 64.1% (53.0, 73.9) and 93.6% (90.2, 95.8) respectively. PMMR was good at detecting renal abnormalities (sensitivity 80%), particularly in foetuses, and relatively poor at detecting intestinal abnormalities (sensitivity 50%). Overall accuracy was 87.4% (83.6, 90.4). Conclusions: PMMR has high overall accuracy for abdominal pathology in foetuses, newborns and children. PMMR is particularly good at detecting renal abnormalities, and relatively poor at detecting intestinal abnormalities. In clinical practice, PMMR may be a useful alternative or adjunct to conventional autopsy in foetuses and children for detecting abdominal abnormalities

Effects of a static magnetic field of 3.5 T on reproductive behaviour of mice, embryonic and foetal development and some haematological parameters

International Nuclear Information System (INIS)

Zimmermann, B.; Hentschel, D.

1987-01-01

To investigate possibilities of magnetic resonance imaging at high magnetic fields in humans, a whole-body magnet with a magnetic field density of 4 T was developed. Due to the few data that are available at present on biological effects and side effects of such high fields, a reproduction experiment with NMRI mice was performed using a crossover design. The mice were allowed to mate during a 7-day period within the field or after their stay in the field. The number of pregnant mice and foetuses were recorded and compared to the controls. Another group was held within the magnetic field during the whole period of pregnancy until day 18, one day before delivery. In all groups, development of the foetuses was studied. Additionally, haematological parameters of the males and females were estimated and necroscopy was performed. Brains, lungs and optical nerves were investigated using pathohistological techniques. It could be shown that in case of mating within the magnetic field, the number of pregnant mice was considerably reduced. This effect was, however, completely reversible if mating occurred after the stay in the field. Malformations retardations or an increased number of resorptions were never found. The haematological parameters were, in general, not changed. Necroscopy as well as pathohistological investigations showed no pathological alterations. Therefore, it appears that whereas high magnetic fields reduce the activity of mating behaviour, they do not exert any influence on physiological parameters. (orig.) [de

A case report of spinal dural arteriovenous fistula: origins, determinants, and consequences of abnormal vascular malformations

OpenAIRE

Zakhary, Sherry M.; Hoehmann, Christopher L.; Cuoco, Joshua A.; Hitscherich, Kyle; Alam, Hamid; Torres, German

2017-01-01

A spinal dural arteriovenous fistula is an abnormally layered connection between radicular arteries and venous plexus of the spinal cord. This vascular condition is relatively rare with an incidence of 5–10 cases per million in the general population. Diagnosis of spinal dural arteriovenous fistula is differentiated by contrast-enhanced magnetic resonance angiography or structural magnetic resonance imaging, but a definitive diagnosis requires spinal angiography methods. Here, we report a cas...

Magnetic resonance imaging markers for early diagnosis of Parkinson's disease

Institute of Scientific and Technical Information of China (English)

Silvia Marino; Rosella Ciurleo; Giuseppe Di Lorenzo; Marina Barresi; Simona De Salvo; Sabrina Giacoppo; Alessia Bramanti; Pietro Lanzafame; Placido Bramanti

2012-01-01

Parkinson's disease (PD) is a neurodegenerative disorder characterized by selective and progressive degeneration, as well as loss of dopaminergic neurons in the substantia nigra. In PD, approximately 60-70% of nigrostriatal neurons are degenerated and 80% of content of the striatal dopamine is reduced before the diagnosis can be established according to widely accepted clinical diagnostic criteria. This condition describes a stage of disease called "prodromal", where non-motor symptoms, such as olfactory dysfunction, constipation, rapid eye movement behaviour disorder, depression, precede motor sign of PD. Detection of prodromal phase of PD is becoming an important goal for determining the prognosis and choosing a suitable treatment strategy. In this review, we present some non-invasive instrumental approaches that could be useful to identify patients in the prodromal phase of PD or in an early clinical phase, when the first motor symptoms begin to be apparent. Conventional magnetic resonance imaging (MRI) and advanced MRI techniques, such as magnetic resonance spectroscopy imaging, diffusion-weighted and diffusion tensor imaging and functional MRI, are useful to differentiate early PD with initial motor symptoms from atypical parkinsonian disorders, thus, making easier early diagnosis. Functional MRI and diffusion tensor imaging techniques can show abnormalities in the olfactory system in prodromal PD.

Magnetic study of iron sorbitol

Energy Technology Data Exchange (ETDEWEB)

Lazaro, F.J. E-mail: osoro@posta.unizar.es; Larrea, A.; Abadia, A.R.; Romero, M.S

2002-09-01

A magnetic study of iron sorbitol, an iron-containing drug to treat the iron deficiency anemia is presented. Transmission electron microscopy reveals that the system contains nanometric particles with an average diameter of 3 nm whose composition is close to two-line ferrihydrite. The characterisation by magnetisation and AC susceptibility measurements indicates superparamagnetic behaviour with progressive magnetic blocking starting at 8 K. The quantitative analysis of the magnetic results indicates that the system consists of an assembly of very small magnetic moments, presumably originated by spin uncompensation of the antiferromagnetic nanoparticles, with Arrhenius type magnetic dynamics.

Longitudinal magnetic bistability of electroplated wires

International Nuclear Information System (INIS)

Kurlyandskaya, G.V.; Garcia-Miquel, H.; Vazquez, M.; Svalov, A.V.; Vas'kovskiy, V.O.

2002-01-01

Fe 20 Ni 74 Co 6 and Fe 20 Ni 64 Co 16 1 μm thick magnetic tubes electroplated onto Cu 98 Be 2 conductive wire have been investigated in as-deposited state, after heat treatment under longitudinal magnetic field for 1 h at 330 deg. C, and after rf-sputtering deposition of the additional 2 μm Fe 19 Ni 81 layer. Heat treatments and an additional layer deposition modify the shape of hysteresis loops. Magnetically bistable behaviour, observed after the field annealing at a temperature of 330 deg. C, is studied as a function of the length of the samples. This is the first report by our knowledge on the bistable behaviour of the electroplated wires. The bistability of these wires is promising for applications such as tagging or pulse generator applications

Effects of magnetic core geometry on false detection in residual current sensor

International Nuclear Information System (INIS)

Colin, Bruno; Chillet, Christian; Kedous-Lebouc, Afef; Mas, Patrick

2006-01-01

Under high-supply current, residual circuit breakers are subject to abnormal tripping, caused by false residual currents. Geometric or magnetic anomalies in the circuit breaker ring core seem to be responsible for these abnormal currents. This paper studies a few anomalies (spiral shape effect, conductor eccentricity, lamination effect) and calculates different contributions using the finite element simulations. The results show that the ring core, made of thin wound magnetic tape, is particularly sensitive to primary conductor eccentricity

Investigation of magnetically enhanced swelling behaviour of ...

Indian Academy of Sciences (India)

Keywords. Starch; iron oxide; nanotechnology; nanoparticles; superparamagnetic; drug delivery. Abstract. The present study follows a novel strategy for the preparation of superparamagnetic nanoparticles of cross-linked starch impregnated homogeneously with nanosized iron oxide. The prepared magnetic nanoparticles ...

Malformations and abnormalities of the petrous portion of the temporal bone

International Nuclear Information System (INIS)

Reith, W.; Yilmaz, U.; Heumueller, I.

2014-01-01

High-resolution computed tomography (HRCT) is the procedure of choice in the diagnostics of abnormalities of the middle and inner ear. It allows a detailed presentation of anatomical features and achieves the prerequisites for selection of the various therapeutic options. The highly diverse abnormalities can be described using detailed imaging analyses. Malformations with an abnormally developed modiolus are assumed to be early embryological defects, such as the classical Mondini dysplasia. The essential therapeutic option for middle ear deformities is still a cochlear implant. The domain of magnetic resonance imaging (MRI) is not only in the analysis of the cochlear nerve and for exclusion of fibrosis or ossification of the labyrinth but is also able to visualize details of isolated malformations, such as an extended vestibular aqueduct or subtle alterations to the vestibule or can visualize them better in comparison to CT. Radiological diagnostics are used not only for classification but also to recognize typical clinical problem situations and play a key role in the diagnostics of hearing disorders and selection of the optimal therapeutic procedure. (orig.) [de

Exposure to stressful life events during pregnancy predicts psychotic experiences via behaviour problems in childhood.

Science.gov (United States)

Betts, Kim S; Williams, Gail M; Najman, Jakob M; Scott, James; Alati, Rosa

2014-12-01

Exposure to stressful life events during pregnancy has been associated with later schizophrenia in offspring. We explore how prenatal stress and neurodevelopmental abnormalities in childhood associate to increase the risk of later psychotic experiences. Participants from the Mater University Study of Pregnancy (MUSP), an Australian based, pre-birth cohort study were examined for lifetime DSM-IV positive psychotic experiences at 21 years by a semi-structured interview (n = 2227). Structural equation modelling suggested psychotic experiences were best represented with a bifactor model including a general psychosis factor and two group factors. We tested for an association between prenatal stressful life events with the psychotic experiences, and examined for potential moderation and mediation by behaviour problems and cognitive ability in childhood. Prenatal stressful life events predicted psychotic experiences indirectly via behaviour problems at child age five years, and this relationship was not confounded by maternal stressful life events at child age five. We found no statistical evidence for an interaction between prenatal stressful life events and behaviour problems or cognitive ability. The measurable effect of prenatal stressful life events on later psychotic experiences in offspring manifested as behaviour problems by age 5. By identifying early abnormal behavioural development as an intermediary, this finding further confirms the role of prenatal stress to later psychotic disorders. Copyright © 2014 Elsevier Ltd. All rights reserved.

Investigation of HTSC; influence of microstructure, magnetic and of non-magnetic impurities; synthesis of new systems

International Nuclear Information System (INIS)

Wohlleben, D.

1991-01-01

We have investigated intensively the parameters of preparation of HTSC of the BiCaSrCuO system and could prepare the 2212- and 2232 phases separately in X-ray pure form. Concerning the 123-system the substitution of Cu by 3d-elements changed the superconducting behaviour strongly where as a replacement of Y by other Rare Earth-elements does not influence much the superconducting properties. Fluctuations occur in a wide range around T c . The layered-structure and granular character of the HTSC determine strongly the magnetic behaviour of HTSC especially the so-called Meissnereffect. Our first magnetic data of HTSC showed that even in magnetic fields smaller than Hc 1 (perpendicular) we did not receive 100% fluxexpulsion (Meissner). The fluxexpulsion of most of our samples was only 1/3 of -1/4 π. However in very small fields ( [de

Renormalization of Magnetic Excitations in Praseodymium

DEFF Research Database (Denmark)

Lindgård, Per-Anker

1975-01-01

The magnetic exciton renormalization and soft-mode behaviour as the temperature approaches zero of the singlet-doublet magnet (dhcp)pr are accounted for by a selfconsistent rpa theory with no adjustable parameters. The crystal-field splitting between the ground state and the doublet is d=3.74 mev...

Detailed study of the magnetic behaviour at low scale in La2/3Sr1/3MnO3

Science.gov (United States)

Arango, I. C.; E Ordoñez, J.; Dominguez, C.; Arango, C.; E Gomez, M.

2017-12-01

The La2/3Sr1/3MnO3 (LSMO) with Curie temperature above room temperature is the leading compound of the manganite perovskite family. Therefore, the physical properties are desirable for practical applications as magnetic sensors. However, when the dimensions are reduced the ferromagnetic properties of material are weakened. In this research, we have grown La2/3Sr1/3MnO3/SrTiO3 thin films by sputtering DC at high oxygen pressure at 830°C. X-Ray Diffraction (XRD) analysis reveals that only (0 0 2) LSMO peak are present, indicating a textured growth. The samples morphology was characterized by Atomic Force Microscopy (AFM). Additionally, LSMO microwires were patterned by UV lithography; the devices are a well-defined channel with current and voltage leads enabling four points resistance measurements. Resistivity versus temperature curves displays typical manganite behaviour with metal-insulator transition ∼350K. We study the electric and magnetotransport properties in LSMO film and in wire channel and their dependence with size (width and length) for potential applications like magnetic sensors.

Microwave assisted synthesis of Magnetically responsive composite materials

Czech Academy of Sciences Publication Activity Database

Šafařík, Ivo; Horská, Kateřina; Pospíšková, K.; Maděrová, Zdeňka; Šafaříková, Miroslava

2013-01-01

Roč. 49, č. 1 (2013), s. 213-218 ISSN 0018-9464 R&D Projects: GA ČR(CZ) GAP503/11/2263; GA MŠk LH12190 Institutional support: RVO:67179843 Keywords : magnetic materials * magnetic modification * magnetic separation * microwaves Subject RIV: EH - Ecology, Behaviour Impact factor: 1.213, year: 2013

Structured imaging technique in the gynecologic office for the diagnosis of abnormal uterine bleeding.

Science.gov (United States)

Dueholm, Margit; Hjorth, Ina Marie D

2017-04-01

The aim in the diagnosis of abnormal uterine bleeding (AUB) is to identify the bleeding cause, which can be classified by the PALM-COEIN (Polyp, Adenomyosis, Leiomyoma, Malignancy (and hyperplasia), Coagulopathy, Ovulatory disorders, Endometrial, Iatrogenic and Not otherwise classified) classification system. In a gynecologic setting, the first step is most often to identify structural abnormalities (PALM causes). Common diagnostic options for the identification of the PALM include ultrasonography, endometrial sampling, and hysteroscopy. These options alone or in combination are sufficient for the diagnosis of most women with AUB. Contrast sonography with saline or gel infusion, three-dimensional ultrasonography, and magnetic resonance imaging may be included. The aim of this article is to describe how a simple structured transvaginal ultrasound can be performed and implemented in the common gynecologic practice to simplify the diagnosis of AUB and determine when additional invasive investigations are required. Structured transvaginal ultrasound for the identification of the most common endometrial and myometrial abnormalities and the most common ultrasound features are described. Moreover, situations where magnetic resonance imaging may be included are described. This article proposes a diagnostic setup in premenopausal women for the classification of AUB according to the PALM-COEIN system. Moreover, a future diagnostic setup for fast-track identification of endometrial cancer in postmenopausal women based on a structured evaluation of the endometrium is described. Copyright © 2016. Published by Elsevier Ltd.

The association between reduced knee joint proprioception and medial meniscal abnormalities using MRI in knee osteoarthritis: results from the Amsterdam osteoarthritis cohort.

Science.gov (United States)

van der Esch, M; Knoop, J; Hunter, D J; Klein, J-P; van der Leeden, M; Knol, D L; Reiding, D; Voorneman, R E; Gerritsen, M; Roorda, L D; Lems, W F; Dekker, J

2013-05-01

Osteoarthritis (OA) of the knee is characterized by pain and activity limitations. In knee OA, proprioceptive accuracy is reduced and might be associated with pain and activity limitations. Although causes of reduced proprioceptive accuracy are divergent, medial meniscal abnormalities, which are highly prevalent in knee OA, have been suggested to play an important role. No study has focussed on the association between proprioceptive accuracy and meniscal abnormalities in knee OA. To explore the association between reduced proprioceptive accuracy and medial meniscal abnormalities in a clinical sample of knee OA subjects. Cross-sectional study in 105 subjects with knee OA. Knee proprioceptive accuracy was assessed by determining the joint motion detection threshold in the knee extension direction. The knee was imaged with a 3.0 T magnetic resonance (MR) scanner. Number of regions with medial meniscal abnormalities and the extent of abnormality in the anterior and posterior horn and body were scored according to the Boston-Leeds Osteoarthritis Knee Score (BLOKS) method. Multiple regression analyzes were used to examine whether reduced proprioceptive accuracy was associated with medial meniscal abnormalities in knee OA subjects. Mean proprioceptive accuracy was 2.9° ± 1.9°. Magnetic resonance imaging (MRI)-detected medial meniscal abnormalities were found in the anterior horn (78%), body (80%) and posterior horn (90%). Reduced proprioceptive accuracy was associated with both the number of regions with meniscal abnormalities (P knee complaints. This is the first study showing that reduced proprioceptive accuracy is associated with medial meniscal abnormalities in knee OA. The study highlights the importance of meniscal abnormalities in understanding reduced proprioceptive accuracy in persons with knee OA. Copyright © 2013 Osteoarthritis Research Society International. All rights reserved.

Functional neuroimaging abnormalities in idiopathic generalized epilepsy

Directory of Open Access Journals (Sweden)

Megan L. McGill

2014-01-01

Full Text Available Magnetic resonance imaging (MRI techniques have been used to quantitatively assess focal and network abnormalities. Idiopathic generalized epilepsy (IGE is characterized by bilateral synchronous spike–wave discharges on electroencephalography (EEG but normal clinical MRI. Dysfunctions involving the neocortex, particularly the prefrontal cortex, and thalamus likely contribute to seizure activity. To identify possible morphometric and functional differences in the brains of IGE patients and normal controls, we employed measures of thalamic volumes, cortical thickness, gray–white blurring, fractional anisotropy (FA measures from diffusion tensor imaging (DTI and fractional amplitude of low frequency fluctuations (fALFF in thalamic subregions from resting state functional MRI. Data from 27 patients with IGE and 27 age- and sex-matched controls showed similar thalamic volumes, cortical thickness and gray–white contrast. There were no differences in FA values on DTI in tracts connecting the thalamus and prefrontal cortex. Functional analysis revealed decreased fALFF in the prefrontal cortex (PFC subregion of the thalamus in patients with IGE. We provide minimum detectable effect sizes for each measure used in the study. Our analysis indicates that fMRI-based methods are more sensitive than quantitative structural techniques for characterizing brain abnormalities in IGE.

Brain abnormalities on MRI in non-functioning pituitary adenoma patients treated with or without postoperative radiotherapy

NARCIS (Netherlands)

Sattler, Margriet G. A.; Meiners, Linda C.; Sluiter, Wim J.; van den Berg, Gerrit; Langendijk, Johannes A.; Wolffenbuttel, Bruce H. R.; van den Bergh, Alphons C. M.; van Beek, Andre P.

Background and purpose: To assess and compare brain abnormalities on Magnetic Resonance Imaging (MRI) in non-functioning pituitary macro-adenoma (NFA) patients treated with or without postoperative radiotherapy (RT). Material and methods: In 86 NFA patients, treated between 1987 and 2008 at the

Characteristic Magnetic Resonance Imaging Findings in Rheumatoid Arthritis of the Temporomandibular Joint: Focus on Abnormal Bone Marrow Signal of the Mandibular Condyle, Pannus, and Lymph Node Swelling in the Parotid Glands.

Science.gov (United States)

Hirahara, Naohisa; Kaneda, Takashi; Muraoka, Hirotaka; Fukuda, Taiga; Ito, Kotaro; Kawashima, Yusuke

2017-04-01

The purpose of this study was to determine the characteristic magnetic resonance imaging (MRI) findings indicating bone and soft tissue involvement in patients with rheumatoid arthritis (RA) of the temporomandibular joints (TMJs). Twenty-one patients with RA and TMJ pain who underwent MRI examination of the TMJs at the authors' hospital from August 2006 to December 2014 were included in this study. Twenty-two patients with normal TMJs who underwent MRI examination at the authors' hospital from November to December 2014 were included as controls. MRI findings were compared between the 2 groups. MRI findings of RA in the TMJ included 1) abnormal disc position (95.2%), 2) abnormal disc morphology (83.3%), 3) joint effusion (30.9%), 4) osseous changes in the mandibular condyle (83.3%), 5) synovial proliferation (pannus; 85.7%), 6) erosion of the articular eminence and glenoid fossa (9.52%), 7) deformity of the articular eminence and glenoid fossa (16.6%), 8) abnormal bone marrow signal in the mandibular condyle (83.3%), and 9) swelling of lymph nodes in the parotid glands (78.5%). The abnormal bone marrow signal and pannus in the mandibular condyle and lymph node swelling in the parotid glands were markedly more common in patients with RA than in controls. MRI findings of RA of the TMJs were characterized by bone and soft tissue involvement, including abnormal bone marrow signal of the mandibular condyle, pannus, and swelling of lymph nodes in the parotid glands. These characteristic MRI findings could be useful in detecting RA in the TMJ in a clinical situation. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

MRI appearance of surgically proven abnormal accessory anterior-inferior tibiofibular ligament (Bassett's ligament)

International Nuclear Information System (INIS)

Subhas, Naveen; Vinson, Emily N.; Cothran, R.L.; Helms, Clyde A.; Santangelo, James R.; Nunley, James A.

2008-01-01

A thickened accessory anterior-inferior tibiofibular ligament (Bassett's ligament) of the ankle can be a cause of ankle impingement. Its imaging appearance is not well described. The purpose of this study was to determine if the ligament could be identified on magnetic resonance imaging (MRI), to determine associated abnormalities, and to determine if MRI could be used to differentiate normal from abnormal. Eighteen patients with a preoperative ankle MRI and an abnormal Bassett's ligament reported at surgery were found retrospectively. A separate cohort of 18 patients was selected as a control population. The presence of Bassett's ligament and its thickness were noted. The integrity and appearance of the lateral ankle ligaments, talar dome cartilage, and anterolateral gutter were also noted. In 34 of the 36 cases (94%), Bassett's ligament was identified on MRI. The ligament was seen in all three imaging planes and most frequently in the axial plane. The mean thickness of the ligament in the surgically abnormal cases was 2.37 mm, compared with 1.87 mm in the control with a p value = 0.015 (t test). Nine of the 18 abnormal cases (50%) had talar dome cartilage lesions as a result of contact with the ligament at surgery, with only 3 cases of high-grade defects seen on MRI. Fourteen of the 18 abnormal cases (78%) had of synovitis or scarring in the lateral gutter at surgery, with only 5 cases with scarring seen on MRI. The anterior-inferior tibiofibular ligament was abnormal or torn in 8 of the 18 abnormal cases (44%) by MRI and confirmed in only 3 cases at surgery. Bassett's ligament can be routinely identified on MRI and was significantly thicker in patients who had it resected at surgery. An abnormal Bassett's ligament is often present in the setting of a normal anterior-inferior tibiofibular ligament. The cartilage abnormalities and synovitis associated with an abnormal Bassett's ligament are poorly detected by conventional MRI. (orig.)

Unusual magnetic properties of UGa{sub 3} single crystals

Energy Technology Data Exchange (ETDEWEB)

Kaczorowski, D.; Klamut, P.W.; Czopnik, A.; Jezowski, A. [Polska Akademia Nauk, Wroclaw (Poland). Inst. Niskich Temperatur i Badan Strukturalnych

1998-01-01

The magnetic behaviour of single-crystalline UGa{sub 3} has been studied by means of DC- and AC-magnetic susceptibility and thermal conductivity measurements. As many as three pronounced singularities have been found in both, the {chi}(T) and {kappa}(T) variations. The features at T{sub N} = 65 K are associated with an antiferromagnetic phase transition while those at T{sub 1} = 40 K and T{sub 2} = 8 K have an unknown origin. At low temperatures a significant diamagnetic response is observed in {chi}`(T) accompanied by a rapid rise in {chi}{sup ``}(T). This behaviour of the AC-susceptibility is strongly dependent on the frequency of the alternating magnetic field and on the strength of the external steady magnetic field. (orig.) 7 refs.

Magnetic resonance image abnormality in migraine with aura

Energy Technology Data Exchange (ETDEWEB)

Ziegler, D.K.; Batnitzky, S.; Barter, R.; McMillan, J.H. (Kansas Univ., Kansas City, KS (United States). Medical Center)

1991-07-01

Cerebral magnetic resonance imaging (MRI) was performed on 18 patients with migraine characterized by aura consisting of both visual symtoms and parasthesias. 15 headache-free individuals of the same age range were used as controls. Records were radomized and read in blind fashion by two neuroradiologists. Small subcortical white matter lesions were seen in three migraine cases and two controls. In one migraine case cortical infarctions were seen. In two controls, small areas of increased density similar to those in migraine were seen. No consistent correlation of migraine or its duration with cerebral atrophy was found. It is concluded that identification of both these MRI findings (small subcortical white lesions and cerebral atrophy) as significantly associated with migraine is doubtful. 21 refs., 2 figs.

Magnetic resonance image abnormality in migraine with aura

International Nuclear Information System (INIS)

Ziegler, D.K.; Batnitzky, S.; Barter, R.; McMillan, J.H.

1991-01-01

Cerebral magnetic resonance imaging (MRI) was performed on 18 patients with migraine characterized by aura consisting of both visual symtoms and parasthesias. 15 headache-free individuals of the same age range were used as controls. Records were radomized and read in blind fashion by two neuroradiologists. Small subcortical white matter lesions were seen in three migraine cases and two controls. In one migraine case cortical infarctions were seen. In two controls, small areas of increased density similar to those in migraine were seen. No consistent correlation of migraine or its duration with cerebral atrophy was found. It is concluded that identification of both these MRI findings (small subcortical white lesions and cerebral atrophy) as significantly associated with migraine is doubtful. 21 refs., 2 figs

Magnetic islands modelled by a phase-field-crystal approach

Science.gov (United States)

Faghihi, Niloufar; Mkhonta, Simiso; Elder, Ken R.; Grant, Martin

2018-03-01

Using a minimal model based on the phase-field-crystal formalism, we study the coupling between the density and magnetization in ferromagnetic solids. Analytical calculations for the square phase in two dimensions are presented and the small deformation properties of the system are examined. Furthermore, numerical simulations are conducted to study the influence of an external magnetic field on various phase transitions, the anisotropic properties of the free energy functional, and the scaling behaviour of the growth of the magnetic domains in a crystalline solid. It is shown that the energy of the system can depend on the direction of the magnetic moments, with respect to the crystalline direction. Furthermore, the growth of the magnetic domains in a crystalline solid is studied and is shown that the growth of domains is in agreement with expected behaviour.

The tests at Saclay of the stellarator W7X superconducting magnets

International Nuclear Information System (INIS)

Jacquemet, M.

2000-05-01

The tests on the superconducting magnets should allow to check at ambient or cryogenic temperature, the mechanical behaviour and the lack of leak from the conductor, the correct configuration of the cable in the pipe, the electric insulation, the magnet behaviour during a transition, the buckling and mechanical constraints on the whole. (N.C.)

Thermal relaxation of magnetic clusters in amorphous Hf57Fe43 alloy

International Nuclear Information System (INIS)

Pajic, Damir; Zadro, Kreso; Ristic, Ramir; Zivkovic, Ivica; Skoko, Zeljko; Babic, Emil

2007-01-01

The magnetization processes in binary magnetic/non-magnetic amorphous alloy Hf 57 Fe 43 are investigated by the detailed measurement of magnetic hysteresis loops, temperature dependence of magnetization, relaxation of magnetization and magnetic ac susceptibility, including a nonlinear term. Blocking of magnetic moments at lower temperatures is accompanied by the slow relaxation of magnetization and magnetic hysteresis loops. All of the observed properties are explained by the superparamagnetic behaviour of the single domain magnetic clusters inside the non-magnetic host, their blocking by the anisotropy barriers and thermal fluctuation over the barriers accompanied by relaxation of magnetization. From magnetic viscosity analysis based on thermal relaxation over the anisotropy barriers it is found that magnetic clusters occupy the characteristic volume from 25 up to 200 nm 3 . The validity of the superparamagnetic model of Hf 57 Fe 43 is based on the concentration of iron in the Hf 100-x Fe x system that is just below the threshold for long range magnetic ordering. This work also throws more light on the magnetic behaviour of other amorphous alloys

Magnetoelastic behaviour of Gd sub 5 Ge sub 4

CERN Document Server

Magen, C; Algarabel, P A; Marquina, C; Ibarra, M R

2003-01-01

A complete investigation of the complex magnetic behaviour of Gd sub 5 Ge sub 4 by means of linear thermal expansion and magnetostriction measurements (5-300 K, 0-120 kOe) has been carried out. Our results support the suggested existence in this system of a coupled crystallographic-magnetic transition from a Gd sub 5 Ge sub 4 -type Pnma (antiferromagnetic) to a Gd sub 5 Si sub 4 -type Pnma (ferromagnetic) state. Strong magnetoelastic effects are observed at the field-induced first-order magnetic-martensitic transformation. A revised magnetic and crystallographic H- T phase diagram is proposed.

Striatal morphology correlates with sensory abnormalities in unaffected relatives of cervical dystonia patients.

LENUS (Irish Health Repository)

Walsh, Richard A

2012-02-01

Structural grey matter abnormalities have been described in adult-onset primary torsion dystonia (AOPTD). Altered spatial discrimination thresholds are found in familial and sporadic AOPTD and in some unaffected relatives who may be non-manifesting gene carriers. Our hypothesis was that a subset of unaffected relatives with abnormal spatial acuity would have associated structural abnormalities. Twenty-eight unaffected relatives of patients with familial cervical dystonia, 24 relatives of patients with sporadic cervical dystonia and 27 control subjects were recruited. Spatial discrimination thresholds (SDTs) were determined using a grating orientation task. High-resolution magnetic resonance imaging (MRI) images (1.5 T) were analysed using voxel-based morphometry. Unaffected familial relatives with abnormal SDTs had reduced caudate grey matter volume (GMV) bilaterally relative to those with normal SDTs (right Z = 3.45, left Z = 3.81), where there was a negative correlation between SDTs and GMV (r = -0.76, r(2) = 0.58, p < 0.0001). Familial relatives also had bilateral sensory cortical expansion relative to unrelated controls (right Z = 4.02, left Z = 3.79). Unaffected relatives of patients with sporadic cervical dystonia who had abnormal SDTs had reduced putaminal GMV bilaterally compared with those with normal SDTs (right Z = 3.96, left Z = 3.45). Sensory abnormalities in some unaffected relatives correlate with a striatal substrate and may be a marker of genetic susceptibility in these individuals. Further investigation of grey matter changes as a candidate endophenotype may assist future genetic studies of dystonia.

Implications of white striping and spaghetti meat abnormalities on meat quality and histological features in broilers.

Science.gov (United States)

Baldi, G; Soglia, F; Mazzoni, M; Sirri, F; Canonico, L; Babini, E; Laghi, L; Cavani, C; Petracci, M

2018-01-01

During the past few years, there has been an increasing prevalence of broiler breast muscle abnormalities, such as white striping (WS) and wooden breast conditions. More recently, a new muscular abnormality termed as spaghetti meat (SM) because of the altered structural integrity of the Pectoralis major muscle often associated with WS has emerged. Thus, this study aimed at evaluating the effects of WS and SM conditions, occurring alone or combined within the same P. major muscle, on meat quality traits and muscle histology. In two replications, 96 P. major muscles were classified into four classes: normal (N), WS, SM and WS/SM. The whole fillet was used for weight assessment and morphometric measurements, then each sample was cut in order to separate the superficial layer from the deep one and used to evaluate proximate composition, histological features, nuclear magnetic resonance relaxation times, functional properties and both myofibrillar and sarcoplasmic proteins profile. Fillets affected by WS and SM abnormalities exhibited higher weights and increased thickness and length. SM condition was associated with a relevant decrease in protein content coupled with a significant increase in moisture level, whereas fat content was affected only by the simultaneous presence of WS. Histological evaluations revealed that abnormal samples were characterized by several degenerative aspects that almost completely concerned the superficial layer of the fillets. White striped fillets exhibited necrosis and lysis of fibers, fibrosis, lipidosis, loss of cross striation and vacuolar degeneration. Moreover, SM samples were characterized by poor fiber uniformity and a progressive rarefaction of the endo- and peri-mysial connective tissue, whereas WS/SM fillets showed intermediate histological features. Nuclear magnetic resonance relaxation analysis revealed a higher proportion of extra-myofibrillar water in the superficial section of all the abnormal fillets, especially in SM

A prospective study of diffusion weighted magnetic resonance imaging abnormalities in patients with cluster of seizures and status epilepticus.

Science.gov (United States)

Jabeen, S A; Cherukuri, Pavankumar; Mridula, Rukmini; Harshavardhana, K R; Gaddamanugu, Padmaja; Sarva, Sailaja; Meena, A K; Borgohain, Rupam; Jyotsna Rani, Y

2017-04-01

To study the frequency, imaging characteristics, and clinical predictors for development of periictal diffusion weighted MRI abnormalities. We prospectively analyzed electro clinical and imaging characteristic of adult patients with cluster of seizures or status epilepticus between November 2013 and November 2015, in whom the diffusion weighted imaging was done within 24h after the end of last seizure (clinical or electrographic). There were thirty patients who fulfilled the inclusion and exclusion criteria. Twenty patients (66%) had periictal MRI abnormalities. Nine patients (34%) did not have any MRI abnormality. All the patients with PMA had abnormalities on diffusion weighted imaging (DWI). Hippocampal abnormalities were seen in nine (53%), perisylvian in two (11.7%), thalamic in five (30%), splenium involvement in two (11.7%) and cortical involvement (temporo-occipital, parieto-occipital, temporo-parietal, fronto-parietal and fronto-temporal) in sixteen (94.1%) patients. Complete reversal of DWI changes was noted in sixteen (80%) patients and four (20%) patients showed partial resolution of MRI abnormalities. Mean duration of seizures was significantly higher among patients with PMA (59.11+20.97h) compared to those without MRI changes (27.33+9.33h) (pstatus epilepticus and were highly concordant with clinical semiology and EEG activity. Patients with longer duration of seizures/status were more likely to have PMA. Copyright © 2017 Elsevier B.V. All rights reserved.

Study of the behaviour of magnetic lines after perturbation of a toroidal field with magnetic surfaces

International Nuclear Information System (INIS)

Mercier, C.

1989-02-01

The effect of a perturbing magnetic field on a field whose magnetic surfaces are tori nested around a closed central line is studied. This perturbation effect creates magnetic islands around surfaces with rational rotational transform. These islands are investigated analytically, which makes it possible to evaluate their size. The resulting turbulence of the medium can then be studied by calculating the interaction of two neighbouring islands

Metal magnetic memory technique used to predict the fatigue crack propagation behavior of 0.45%C steel

Energy Technology Data Exchange (ETDEWEB)

Chongchong, Li [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China); National Key Lab for Remanufacturing, Academy of Armored Forces Engineering, Beijing 100072 (China); Lihong, Dong, E-mail: lihong.dong@126.com [National Key Lab for Remanufacturing, Academy of Armored Forces Engineering, Beijing 100072 (China); Haidou, Wang [National Key Lab for Remanufacturing, Academy of Armored Forces Engineering, Beijing 100072 (China); Guolu, Li [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China); Binshi, Xu [National Key Lab for Remanufacturing, Academy of Armored Forces Engineering, Beijing 100072 (China)

2016-05-01

Monitoring fatigue crack propagation behavior of ferromagnetic components is very important. In this paper, the tension–tension fatigue tests of center cracked tension (CCT) specimens were carried out; the variation regularity of both tangential and normal components of magnetic signals during fatigue process were investigated. The results showed that the initial abnormal signals which appeared at the notch were reversed after cyclic loading. The abnormal magnetic signals became more significant with the increase of fatigue cycles and reversed again after failure. The characteristic parameters, i.e., the peak value of tangential component, B{sub tp}, and maximum gradient value of normal component, K{sub m}, showed similar variation trends during the fatigue process, which can be divided into three different stages. An approximate linear relationship was found between the characteristic parameters and fatigue crack length 2a. The feasibility of predicting the fatigue crack propagation using the abnormal magnetic signals was discussed. What's more, the variation and distribution of the magnetic signals were also analyzed based on the theory of magnetic charge. - Highlights: • A novel and passive NDT method, i.e. MMMT method, is proposed. • Both tangential and normal components of magnetic signals were investigated. • The prediction of crack propagation by abnormal magnetic signals was discussed. • A linear relationship was found between the parameters and fatigue crack length 2a. • The parameters can be potentially used to evaluate the crack propagation state.

Musculoskeletal applications of magnetic resonance imaging: Council on Scientific Affairs

International Nuclear Information System (INIS)

Harms, S.E.; Fisher, C.F.; Fulmer, J.M.

1989-01-01

Magnetic resonance imaging provides superior contrast, resolution, and multiplanar imaging capability, allowing excellent definition of soft-tissue and bone marrow abnormalities. For these reasons, magnetic resonance imaging has become a major diagnostic imaging method for the evaluation of many musculoskeletal disorders. The applications of magnetic resonance imaging for musculoskeletal diagnosis are summarized and examples of common clinical situations are given. General guidelines are suggested for the musculoskeletal applications of magnetic resonance imaging

Universal behaviour of magnetoconductance due to week localization in two-dimensional systems - example of GaInAs quantum wells

International Nuclear Information System (INIS)

Zduniak, A.; Dyakonov, M.I.; Litwin-Staszewska, E.; Knap, W.

1995-01-01

Week localization corrections to conductivity of two-dimensional electron gas are studied by measurements of magnetic field dependence of the conductivity in GaInAs quantum wells. We observed that, when presented as a function of the normalized magnetic field (x=B/B tr where B is the magnetic field, B tr =h/4eτD, D is the diffusion constant and τ is momentum relaxation time), different samples show very similar high field behaviour. A theoretical description is developed that allows one to describe in a consistent way and low field behaviour. The theory predicts universal (B -1/2 ) behaviour of the conductivity correction for all 2D systems in high field limit (x>1). Low field behaviour depends strongly on spin and phase relaxation mechanisms. Comparison of the theory with experiment confirms the universal behaviour in the high field limit and allows one to estimate the spin and phase relaxation times for different GaInAs quantum wells. (author)

Two patterns of cerebral metabolite abnormalities are detected on proton magnetic resonance spectroscopy in HIV-infected subjects commencing antiretroviral therapy

International Nuclear Information System (INIS)

Winston, Alan; Taylor-Robinson, Simon D.; Duncombe, Chris; Li, Patrick C.K.; Gill, John M.; Kerr, Stephen J.; Puls, Rebekah L.; Emery, Sean; Cooper, David A.

2012-01-01

Cerebral function impairment remains problematic in subjects with chronic human immunodeficiency virus (HIV) infection despite effective combination antiretroviral therapy (cART). Using cerebral proton magnetic resonance spectroscopy ( 1 H MRS), we aimed to determine if abnormalities could be detected in neurologically asymptomatic HIV-infected subjects electively commencing cART. Therapy-naive, HIV-infected individuals and HIV-uninfected controls underwent 1 H MRS in several anatomical voxels including the mid-frontal grey matter (FGM) and right basal ganglia (RBG). Differences in cerebral metabolite ratios between groups and correlations between immune and virological status were assessed. Forty-six subjects were recruited (26 HIV-infected and 20 control subjects). In the HIV-infected group, mean CD4+ count (SD, cells per microlitre) and plasma HIV RNA (SD, log10 copies per millilitre) were 192 (86) and 4.71 (0.64), respectively. Choline (Cho)/Creatine (Cr) and myoinositol (MI)/Cr ratios were significantly lower in the FGM in HIV-infected subjects compared to controls (0.67 (0.14) versus 0.88 (0.49), p = 0.036, and 0.94 (0.28) and 1.17 (0.26), p = 0.008, for Cho/Cr and MI/Cr, respectively) and Cho/Cr ratio associated with CD4+ lymphocyte count (p = 0.041). N-Acetyl-aspartate (NAA)/Cho ratio was significantly lower in the RBG in HIV-infected subjects compared to controls (2.27 (0.54) versus 2.63 (0.68), p = 0.002), and this was associated with greater plasma HIV RNA load (p = 0.014). Two patterns of cerebral metabolite abnormalities were observed in HIV-infected subjects electively commencing cART. Greater inflammatory metabolite ratios (Cho/Cr and MI/Cr) associated with lower markers of peripheral immune markers (CD4+ lymphocyte count) in the FGM and lower neuronal metabolite ratios (NAA/Cho) associated with greater HIV viraemia in the RBG were present in HIV-infected subjects. (orig.)

Magnetic resonance appearance of monoclonal gammopathies of unknown significance and multiple myeloma. The GRI Study Group.

Science.gov (United States)

Bellaïche, L; Laredo, J D; Lioté, F; Koeger, A C; Hamze, B; Ziza, J M; Pertuiset, E; Bardin, T; Tubiana, J M

1997-11-01

A prospective multicenter study. To evaluate the use of magnetic resonance imaging, in the differentiation between monoclonal gammopathies of unknown significance and multiple myeloma. Although multiple myeloma has been studied extensively with magnetic resonance imaging, to the authors' knowledge, no study has evaluated the clinical interest of magnetic resonance imaging in the differentiation between monoclonal gammopathies of unknown significance and multiple myeloma. The magnetic resonance examinations of the thoracolumbar spine in 24 patients with newly diagnosed monoclonal gammopathies of unknown significance were compared with those performed in 44 patients with newly diagnosed nontreated multiple myeloma. All findings on magnetic resonance examination performed in patients with monoclonal gammopathies of unknown significance were normal, whereas findings on 38 (86%) of the 44 magnetic resonance examinations performed in patients with multiple myeloma were abnormal. Magnetic resonance imaging can be considered as an additional diagnostic tool in differentiating between monoclonal gammopathies of unknown significance and multiple myeloma, which may be helpful when routine criteria are not sufficient. An abnormal finding on magnetic resonance examination in a patient with monoclonal gammopathies of unknown significance should suggest the diagnosis of multiple myeloma after other causes of marrow signal abnormalities are excluded. Magnetic resonance imaging also may be proposed in the long-term follow-up of monoclonal gammopathies of unknown significance when a new biologic or clinical event suggests the diagnosis of malignant monoclonal gammopathy.

Advanced cardiovascular imaging in Williams syndrome: Abnormalities, usefulness, and strategy for use.

Science.gov (United States)

Hills, Jordan A; Zarate, Yuri A; Danylchuk, Noelle R; Lepard, Tiffany; Chen, Jean Chi-Jen; Collins, Ronnie Thomas

2017-05-01

Extracardiac arterial stenoses are not uncommon in Williams syndrome (WS); however, data on the utility of advanced cardiovascular imaging (CVI) to assess these stenoses are lacking. We retrospectively reviewed the frequency, indication, and diagnostic outcomes of CVI modalities performed in patients with WS evaluated at a single institution between 2001 and 2014. Data were collected and analyzed from 34 patients (56% female) who underwent CVI during the study period. The median age was 10 years (range 1.8-33 years). Excluding echocardiograms, 78 CVI studies "advanced" were performed in the 34 patients (mean 2.3 studies/patient). The most common advanced CVI was renal ultrasound with Doppler (29/34, 85%), followed by computed tomographic angiography (13/34, 38%) and magnetic resonance angiography in (9/34, 26%). Abnormalities were detected in 62% of patients (21/34). For the 20 patients in whom advanced CVI were performed for defined clinical indications, the rate of abnormalities were 73, 70, 57, and 100% when performed for anatomic delineation (15 patients), hypertension (10 patients), bruits (7 patients), and/or decreased peripheral pulses (2 patients), respectively. Advanced CVI in patients with WS reveals abnormalities in the majority of cases, and physical exam findings frequently indicate abnormalities on advanced CVI. © 2017 Wiley Periodicals, Inc.

Abnormal uterine bleeding

Science.gov (United States)

Anovulatory bleeding; Abnormal uterine bleeding - hormonal; Polymenorrhea - dysfunctional uterine bleeding ... ACOG committee opinion no. 557: Management of acute abnormal uterine bleeding in nonpregnant reproductive-aged women. Reaffirmed 2015. www. ...

High resolution magnetic force microscopy: instrumentation and application for recording media

NARCIS (Netherlands)

Porthun, Steffen; Porthun, S.

This thesis describes aspects of the use of magnetic force microscopy for the study of magnetic recording media. The maximum achievable storage density in magnetic recording is limited by the magnetic reversal behaviour of the medium and by the stability of the written information. The shape and

Grey matter abnormalities in children and adolescents with functional neurological symptom disorder.

Science.gov (United States)

Kozlowska, Kasia; Griffiths, Kristi R; Foster, Sheryl L; Linton, James; Williams, Leanne M; Korgaonkar, Mayuresh S

2017-01-01

Functional neurological symptom disorder refers to the presence of neurological symptoms not explained by neurological disease. Although this disorder is presumed to reflect abnormal function of the brain, recent studies in adults show neuroanatomical abnormalities in brain structure . These structural brain abnormalities have been presumed to reflect long-term adaptations to the disorder, and it is unknown whether child and adolescent patients, with illness that is typically of shorter duration, show similar deficits or have normal brain structure. High-resolution, three-dimensional T1-weighted magnetic resonance images (MRIs) were acquired in 25 patients (aged 10-18 years) and 24 healthy controls. Structure was quantified in terms of grey matter volume using voxel-based morphometry. Post hoc, we examined whether regions of structural difference related to a measure of motor readiness to emotional signals and to clinical measures of illness duration, illness severity, and anxiety/depression. Patients showed greater volumes in the left supplementary motor area (SMA) and right superior temporal gyrus (STG) and dorsomedial prefrontal cortex (DMPFC) (corrected p disorder.

Investigation of magnetically enhanced swelling behaviour of ...

Indian Academy of Sciences (India)

mer produced by many plants as a source of stored energy. (Corre et al 2010). It is an .... A vibrating-sample magnetometer (VSM) was used to study the magnetic ... were prepared: saline water (0·9 g NaCl), synthetic urine. (0·8 g NaCl, 0·10 g ...

Controlling the competing magnetic anisotropy energies in FineMET amorphous thin films with ultra-soft magnetic properties

Directory of Open Access Journals (Sweden)

Ansar Masood

2017-05-01

Full Text Available Thickness dependent competing magnetic anisotropy energies were investigated to explore the global magnetic behaviours of FineMET amorphous thin films. A dominant perpendicular magnetization component in the as-deposited state of thinner films was observed due to high magnetoelastic anisotropy energy which arises from stresses induced at the substrate-film interface. This perpendicular magnetization component decreases with increasing film thickness. Thermal annealing at elevated temperature revealed a significant influence on the magnetization state of the FineMET thin films and controlled annealing steps leads to ultra-soft magnetic properties, making these thin films alloys ideal for a wide range of applications.

Urine - abnormal color

Science.gov (United States)

... medlineplus.gov/ency/article/003139.htm Urine - abnormal color To use the sharing features on this page, please enable JavaScript. The usual color of urine is straw-yellow. Abnormally colored urine ...

Tooth - abnormal colors

Science.gov (United States)

... medlineplus.gov/ency/article/003065.htm Tooth - abnormal colors To use the sharing features on this page, please enable JavaScript. Abnormal tooth color is any color other than white to yellowish- ...

Influence of MRI abnormality in skull base bone on prognosis of nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Jin-Cheng, Lu; Qing, Wei; Yi-Qin, Zhang; Feng, Li

2004-01-01

Purpose. To evaluate the influence of skull base bone (SBB) abnormality showed by MRI on prognosis of nasopharyngeal carcinoma (NPC). Patients and methods. From March 1993 to December 1998, 122 NPC patients received prime radiotherapy treatment. All of them were proved pathologically and checked by magnetic resonance imaging (MRI). Every patient received radiation through conjoint facio-cervical field and conventional dose-fractionation schedules. The total dose to the primary tumor was 60 5 Gy (median, 70 Gy). The Kaplan Meier method, the Log-rank test and the Cox regression model were used to evaluate the significance of prognostic factors on NPC patient survival. Results. The overall median survival period was 50 (6 2) months, and the 1, 3 and 5 year-survival rates were, respectively, 99.2%, 87.9%, and 73.3%. The 1, 3, and 5 year-survival rates of abnormality and normality of the SBB on MRI were 98.9%, 87.2%, 71.9%, and 100.0%, 89.8%, 77.0%, respectively (P 0.4233). Gender, age, head pain, SBB abnormality, cranial nerve palsy, cervical lymphadenopathy and primary tumor extent were analyzed with the Cox regression model and SBB abnormality on MRI did not prove to have statistical significance (P = 0.6934). According to the analysis of regrouping, patients with SBB abnormalities ≥ sites have a worse prognosis (P = 0.0427). Then. the above seven factors are analyzed by Cox regression model and the result had statistical significance (P = 0.0385). Conclusion. The SBB abnormality on MRI is of no obvious influence on prognosis of NPC. However, when SBB abnormality sites were ≥ 2, there is obvious statistical significance on the prognosis. (author)

Conductivity, dielectric behaviour and magnetoelectric effect in ...

Indian Academy of Sciences (India)

intensity of the magnetic field. The maximum value of ME coefficient was observed for 75% ferroelectric phase composite. Keywords. Conductivity; dielectric behaviour; magnetoelectric effect; CuFe2O4; BaTiO3. 1. Introduction. Magnetoelectric composites consist of two phases viz. piezoelectric and piezomagnetic. The ME ...

Magnetic hysteresis effects in superconducting coplanar microwave resonators

Energy Technology Data Exchange (ETDEWEB)

Bothner, D.; Gaber, T.; Kemmler, M.; Gruenzweig, M.; Ferdinand, B.; Koelle, D.; Kleiner, R. [Universitaet Tuebingen (Germany); Wuensch, S.; Siegel, M. [Karlsruher Institut fuer Technologie (Germany); Mikheenko, P.; Johansen, T.H. [University of Oslo (Norway)

2013-07-01

We present experimental data regarding the impact of external magnetic fields on quality factor and resonance frequency of superconducting microwave resonators in a coplanar waveguide geometry. In particular we focus on the influence of magnetic history and show with the assistance of numerical calculations that the found hysteretic behaviour can be well understood with a highly inhomogeneous microwave current density in combination with established field penetration models for type-II superconducting thin films. Furthermore we have used magneto-optical imaging techniques to check the field distribution which we have assumed in our calculations. Finally, we demonstrate that and how the observed hysteretic behaviour can be used to optimize and tune the resonator performance for possible hybrid quantum sytems in magnetic fields.

Abnormal room temperature ferromagnetism in CuO/ZnO nanocomposites via hydrothermal method

Energy Technology Data Exchange (ETDEWEB)

Lu, Ping; Zhou, Wei; Li, Ying; Wang, Jianchun; Wu, Ping, E-mail: pingwu@tju.edu.cn

2017-03-31

Highlights: • CuO/ZnO nanocomposites have been synthesized by a one-step hydrothermal method. • The interaction between ZnO and CuO causes a modification of electronic structure. • The abnormal RTFM is discovered at the interface of CuO/ZnO. • The M{sub S} can be tuned by changing the phase ratios of the CuO and ZnO. • The indirect double-exchange model was employed to explain the origin of magnetism. - Abstract: CuO/ZnO nanocomposites have been successfully synthesized by a one-step hydrothermal method with different phase ratios. Field emission scanning electron microscopy and transmission electron microscopy results show that the obtained products of nanosheets are composed of small primary particles with an average size of about 20 nm. With the increasing proportion of CuO phase, nanosheets have significant collapse and the amount of small sheets increases obviously. The abnormal room temperature ferromagnetism was discovered at the interface between diamagnetic ZnO and antiferromagnetic CuO, which can be tuned by changing the phase ratios. Optical spectra indicate that the interaction between ZnO and CuO modifies the electronic structure of nanocomposites. XPS results verify the valence change of Cu ions and the presence of oxygen vacancies, which are ultimately responsible for the observed ferromagnetism. The indirect double-exchange model was employed to explain the origin of magnetism. Our study suggests that magnetically functional interfaces exhibit very appealing properties for novel devices.

Basal ganglia dysfunction in idiopathic REM sleep behaviour disorder parallels that in early Parkinson's disease.

Science.gov (United States)

Rolinski, Michal; Griffanti, Ludovica; Piccini, Paola; Roussakis, Andreas A; Szewczyk-Krolikowski, Konrad; Menke, Ricarda A; Quinnell, Timothy; Zaiwalla, Zenobia; Klein, Johannes C; Mackay, Clare E; Hu, Michele T M

2016-08-01

SEE POSTUMA DOI101093/AWW131 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Resting state functional magnetic resonance imaging dysfunction within the basal ganglia network is a feature of early Parkinson's disease and may be a diagnostic biomarker of basal ganglia dysfunction. Currently, it is unclear whether these changes are present in so-called idiopathic rapid eye movement sleep behaviour disorder, a condition associated with a high rate of future conversion to Parkinson's disease. In this study, we explore the utility of resting state functional magnetic resonance imaging to detect basal ganglia network dysfunction in rapid eye movement sleep behaviour disorder. We compare these data to a set of healthy control subjects, and to a set of patients with established early Parkinson's disease. Furthermore, we explore the relationship between resting state functional magnetic resonance imaging basal ganglia network dysfunction and loss of dopaminergic neurons assessed with dopamine transporter single photon emission computerized tomography, and perform morphometric analyses to assess grey matter loss. Twenty-six patients with polysomnographically-established rapid eye movement sleep behaviour disorder, 48 patients with Parkinson's disease and 23 healthy control subjects were included in this study. Resting state networks were isolated from task-free functional magnetic resonance imaging data using dual regression with a template derived from a separate cohort of 80 elderly healthy control participants. Resting state functional magnetic resonance imaging parameter estimates were extracted from the study subjects in the basal ganglia network. In addition, eight patients with rapid eye movement sleep behaviour disorder, 10 with Parkinson's disease and 10 control subjects received (123)I-ioflupane single photon emission computerized tomography. We tested for reduction of basal ganglia network connectivity, and for loss of tracer uptake in rapid eye movement sleep

Electrodynamics in cylindrical symmetry in the magnetic plasma state

Science.gov (United States)

López-Bara, F. I.; López-Aguilar, F.

2018-05-01

Excited states in magnetic structures of the so-called spin-ices and in some artificial magnetic materials present a behaviour as being a magnetic neutral plasma. In this state the electromagnetic waves in confined systems (waveguides) filled with materials with magnetic charges are able to transmit information and energy. In the natural spin-ices, the difficulty is the very low temperature for which these magnetic entities appear, whose phenomenology under the electromagnetic interaction is that of solids containing magnetic charges. However, similar behaviour may be present in other compounds at higher temperatures, even at room temperature and they are named artificial spin-ice compounds. This analysis is addressed to obtain theoretical results about magnetic responses and frequency-dependent magnetricity. The key physical magnitudes are the plasmon frequency () which is related to the cut-off frequency in a wave guide and the effective inertial masses () of these magnetic charges. All properties of the electromagnetic propagation in these compounds with effective magnetic monopoles depend on and m. This is carried out including the dissipative forces among magnetic charges which give new characteristic features to the electromagnetic propagation. The main goal of this work is the analysis of these electromagnetic properties in order to find possible circuital applications of these materials to be utilized by devices.

Electromagnetic behaviour of the earth and planets

International Nuclear Information System (INIS)

McCarthy, A.J.

2002-01-01

Forecast problems of global warming, rising sea-levels, UV enhancement, and solar disruptions of power grids and satellite communications, have been widely discussed. Added to these calamities is the steady decay of the Earth's magnetic radiation shield against high energy particles. A system of solar-induced aperiodic electromagnetic resonances, referred to here as the Debye resonances, is resurrected as the preferred basis for describing the electromagnetic behaviour of the Earth and planets. Debye's two basic solutions to the spherical vector wave equation provide foundations for electromagnetic modes of the terrestrial and gaseous planets respectively in contrast with the separate electric and magnetic approaches usually taken. For those engaged in radiation protection issues, this paper provides the first published account of how the Sun apparently triggers an Earth magnetic shield against its own harmful radiation. Disturbances from the Sun - which are random in terms of polarity, polarisation, amplitude, and occurrence - are considered here to trigger the Debye modes and generate observed planetary electric and magnetic fields. Snapping or reconnection of solar or interplanetary field lines, acting together with the newly conceived magnetospheric transmission lines of recent literature, is suspected as the excitation mechanism. Virtual replacement of free space by plasma, places the electromagnetic behaviour of the Earth and planets under greatly enhanced control from the Sun. From a radiation protection viewpoint, modal theory based on solar-terrestrial coupling provides a new insight into the origin of the Earth's magnetic radiation shield, greater understanding of which is essential to development of global cosmic radiation protection strategies. Should man-made influences unduly increase conductivities of the Earth's magnetosphere, planet Earth could be left with no magnetic radiation shield whatsoever. Copyright (2002) Australasian Radiation Protection

Plant abnormality inspection device

International Nuclear Information System (INIS)

Takenaka, Toshio.

1990-01-01

The present invention concerns a plant abnormality inspection device for conducting remote or automatic patrolling inspection in a plant and, more particularly, relates to such a device as capable of detecting abnormal odors. That is, the device comprises a moving device for moving to a predetermined position in the plant, a plurality of gas sensors for different kind of gases to be inspected mounted thereon, a comparator for comparing the concentration of a gas detected by the gas sensor with the normal gas concentration at the predetermined position and a judging means for judging the absence or presence of abnormality depending on the combination of the result of the comparison and deliverying a signal if the state is abnormal. As a result, a slight amount of gas responsible to odors released upon abnormality of the plant can be detected by a plurality of gas sensors for different kinds gases to rapidly and easily find abnormal portions in the plant. (I.S.)

Polarization and magnetization of electronic matter

International Nuclear Information System (INIS)

Beck, G.

1979-01-01

The behaviour of a system of spin-electrons in a weak external electric or magnetic field is studied. Already in the case of a single free electron classical and quantum theory lead to different results concerning the Lorentz transformation of the magnetic moment (Thomas factor of spin-orbit coupling). The separation of the current into a convection and a spin part can be performed in a covariant way. While the convection current is responsible for the diamagnetism of a system, the spin current accounts for paramagnetic behaviour. After a Lorentz transformation of a diamagnetic system paraelectric components appear, while a paramagnetic system, after rransformation, exhibits dia-electric properties, epsilon 1) after a Lorentz transformation shows diamagnetic components, while a diaelectric system would acquire paramagnetic behaviour. Quantum electrodynamics leads to the result, that Dirac's electron vacuum behaves like a paramagnetic medium. It follows from this result, that the electron vacuum in a weak external electric field represents a diaelectric system. (Author) [pt

Magnetic resonance imaging of muscle tears

International Nuclear Information System (INIS)

De Smet, A.A.; Fisher, D.R.; Heiner, J.P.; Keene, J.S.

1990-01-01

Magnetic resonance scans were obtained on 17 patients with acute, subacute, or chronic muscle tears. These patients presented with complaints of persistent pain or a palpable mass. Magnetic resonance findings were characterized according to alterations in muscle shape and the presence of abnormal high signal within the injured muscle. These areas of high signal were noted on both T1-weighted and T2-weighted scans and were presumed to represent areas of intramuscular hemorrhage. (orig.)

Magnetic Resonance Imaging of Patients With Chronic Lateral Epicondylitis: Is There a Relationship Between Magnetic Resonance Imaging Abnormalities of the Common Extensor Tendon and the Patient's Clinical Symptom?

Science.gov (United States)

Qi, Liang; Zhang, Yu-Dong; Yu, Rong-Bin; Shi, Hai-Bin

2016-02-01

The aim of the study is to determine the inter-reliability and intra-observer reliability of magnetic resonance imaging (MRI) for lateral epicondylitis and investigate whether there is a potential relationship between MRI abnormalities of the common extensor tendon (CET) and its clinical symptom.The study group comprised 96 consecutive patients (46 men and 50 women) with a clinical diagnosis of chronic lateral epicondylitis, which were examined on 3.0 T MR. An MRI scoring system was used to grade the degree of tendinopahty. Three independent musculoskeletal radiologists, who were blinded to the patients' clinical information, scored images separately. Clinical symptoms were assessed using the Patient-Rated Tennis Elbow Evaluation (PRTEE).Of all the patients, total 96 elbows had MRI-assessed tendinopathy, including 38 (39.6%) with grade 1, 31 (32.3%) with grade 2, and 27 (28.1%) with grade 3. Inter-observer reliability and intra-observer agreement for MRI interpretation of the grades of tendinopathy was good, and a positive correlation between the grades of tendinopathy and PRTEE was determined.MRI is a reliable tool in determining radiological severity of chronical lateral epicondylitis. The severity of MR signal changes positively correlate with the patient's clinical symptom.

Magnetic levitation by induced eddy currents in non-magnetic conductors and conductivity measurements

International Nuclear Information System (INIS)

Iniguez, J; Raposo, V; Flores, A G; Zazo, M; Hernandez-Lopez, A

2005-01-01

We report a study on magnetic levitation by induced ac currents in non-magnetic conductors at low frequencies. Our discussion, based on Faraday's induction law, allows us to distinguish the two components of the current responsible for levitation and heating, respectively. The experimental evaluation of the levitation force in a copper ring revealed the accuracy of our analysis, clearly illustrating its asymptotic behaviour versus frequency, and validating it for the qualitative analysis of magnetic levitation and heating in conductors of different shapes such as tubes and discs, composed of collections of conductive loops. The analysis of the results allows precise values of its electrical conductivity to be found. With the help of a simulation technique, this work also reveals the progressive deformation undergone by magnetic induction lines due to magnetic screening when frequency increases

Computation of the magnetic field of a spectrometer in detectors region

International Nuclear Information System (INIS)

Zhidkov, E.P.; Yuldasheva, M.B.; Yudin, I.P.; Yuldashev, O.I.

1995-01-01

Computed results of the 3D magnetic field of a spectrometer intended for investigation of hadron production of charmed particles and the indication of the narrow resonances in neutron-nucleus interactions are presented. The methods used in computations: finite element method and finite element method with suggested new infinite elements are described. For accuracy control the computations were carried out on a sequence of three-dimensional meshes. Special attention is devoted to behaviour of the magnetic field in the basic detector (proportional chambers) region. The performed results can be used for the field behaviour estimate of similar spectrometer magnets. (orig.)

Conducting single-molecule magnet materials.

Science.gov (United States)

Cosquer, Goulven; Shen, Yongbing; Almeida, Manuel; Yamashita, Masahiro

2018-05-11

Multifunctional molecular materials exhibiting electrical conductivity and single-molecule magnet (SMM) behaviour are particularly attractive for electronic devices and related applications owing to the interaction between electronic conduction and magnetization of unimolecular units. The preparation of such materials remains a challenge that has been pursued by a bi-component approach of combination of SMM cationic (or anionic) units with conducting networks made of partially oxidized (or reduced) donor (or acceptor) molecules. The present status of the research concerning the preparation of molecular materials exhibiting SMM behaviour and electrical conductivity is reviewed, describing the few molecular compounds where both SMM properties and electrical conductivity have been observed. The evolution of this research field through the years is discussed. The first reported compounds are semiconductors in spite being able to present relatively high electrical conductivity, and the SMM behaviour is observed at low temperatures where the electrical conductivity of the materials is similar to that of an insulator. During the recent years, a breakthrough has been achieved with the coexistence of high electrical conductivity and SMM behaviour in a molecular compound at the same temperature range, but so far without evidence of a synergy between these properties. The combination of high electrical conductivity with SMM behaviour requires not only SMM units but also the regular and as far as possible uniform packing of partially oxidized molecules, which are able to provide a conducting network.

Magnetic resonance imaging of knee osteonecrosis: a study of 19 cases

Energy Technology Data Exchange (ETDEWEB)

Cunha, Daniel Leme da; Ribeiro, Elisio Jose Salgado; Domingues, Romeu Cortes, E-mail: danielc@predialnet.com.b [Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro, RJ (Brazil); Pires Carvalho, Antonio Carlos [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Faculdade de Medicina

2010-04-15

Objective: to describe epidemiological, clinical and magnetic resonance imaging findings of osteonecrosis in the distal femur and proximal tibia. Materials and methods: evaluation of 19 patients (12 women and 7 men), with no previous history of causative factors, with magnetic resonance imaging findings suggestive of osteonecrosis in the tibial plateau or femoral condyle. Results: osteochondral abnormalities were observed in 63.1% of the cases; in 73.6% of them, such abnormality was associated with ipsilateral meniscal lesion. Also, a significant association with bone marrow edema (grade III in 16 cases) was observed. Conclusion: magnetic resonance imaging has demonstrated to be a noninvasive method with good sensitivity in the diagnosis of knee osteonecrosis as well as of associated lesions which are most frequently found in women (63% of cases). (author)

Abnormal Functional Connectivity Density in Post-traumatic Stress Disorder.

Science.gov (United States)

Zhang, Youxue; Xie, Bing; Chen, Heng; Li, Meiling; Liu, Feng; Chen, Huafu

2016-05-01

Post-traumatic stress disorder (PTSD) is a psychiatric disorder that occurs in individuals who have experienced life-threatening mental traumas. Previous neuroimaging studies have indicated that the pathology of PTSD may be associated with the abnormal functional integration among brain regions. In the current study, we used functional connectivity density (FCD) mapping, a novel voxel-wise data-driven approach based on graph theory, to explore aberrant FC through the resting-state functional magnetic resonance imaging of the PTSD. We calculated both short- and long-range FCD in PTSD patients and healthy controls (HCs). Compared with HCs, PTSD patients showed significantly increased long-range FCD in the left dorsolateral prefrontal cortex (DLPFC), but no abnormal short-range FCD was found in PTSD. Furthermore, seed-based FC analysis of the left DLPFC showed increased connectivity in the left superior parietal lobe and visual cortex of PTSD patients. The results suggested that PTSD patients experienced a disruption of intrinsic long-range functional connections in the fronto-parietal network and visual cortex, which are associated with attention control and visual information processing.

Magnetic resonance imaging of bone marrow disease in children

International Nuclear Information System (INIS)

Cohen, M.D.; Klatte, E.C.; Baehner, R.

1984-01-01

Seven children underwent magnetic resonance imaging (MRI) of the bone marrow: results showed that it is technically feasible to obtain good MR images of marrow in children. MR has detected abnormality in the bone marrow of a child who had metastatic neuroblastoma. The extent of abnormality in the femur correlated well with findings of a bone marrow isotope scan. In one child who had idiopathic aplastic anemia, diseased marrow could not be distinguished from normal marrow on MR images. MRI identified abnormality of the marrow in osteogenic sarcoma, and demonstrated change in response to chemotherapy. It displayed marrow spread of tumors as well as CT. MRI showed marrow abnormality in four children who had leukemia

The need for a behavioural science focus in research on mental health and mental disorders

DEFF Research Database (Denmark)

Wittchen, Hans-Ulrich; Knappe, Susanne; Andersson, Gerhard

2014-01-01

of patients who already have developed a disease to improve medical treatment, the proposed framework model, linked to a concerted funding programme of the "Science of Behaviour Change", carries the promise of improved diagnosis, treatment and prevention of health-risk behaviour constellations as well......Psychology as a science offers an enormous diversity of theories, principles, and methodological approaches to understand mental health, abnormal functions and behaviours and mental disorders. A selected overview of the scope, current topics as well as strength and gaps in Psychological Science may...... help to depict the advances needed to inform future research agendas specifically on mental health and mental disorders. From an integrative psychological perspective, most maladaptive health behaviours and mental disorders can be conceptualized as the result of developmental dysfunctions...

Early MR abnormality indicating functional recovery from spontaneous intracerebral hemorrhage

Energy Technology Data Exchange (ETDEWEB)

Fumeya, Hiroshi; Hideshima, Hiroshi [Hideshima Hospital, Musashino, Tokyo (Japan)

1991-10-01

Magnetic resonance (MR) imaging as an indicator of recovery from hemiparesis was evaluated in 60 patients with spontaneous intracerebral hemorrhage. T{sub 2}-weighted MR images revealed early MR abnormality (EMA) of the corticospinal tract within 1 week of ictus. Most patients without EMA recovered beyond Brunnstrom's Recovery Stage 3 while only a few patients with EMA did so. Patients with EMA cannot regain motor function because EMA is almost always followed by complete tract degeneration. EMA in the brainstem and poor motor function recovery are closely correlated. (author).

Early MR abnormality indicating functional recovery from spontaneous intracerebral hemorrhage

Energy Technology Data Exchange (ETDEWEB)

Fumeya, Hiroshi; Hideshima, Hiroshi (Hideshima Hospital, Musashino, Tokyo (Japan))

1991-10-01

Magnetic resonance (MR) imaging as an indicator of recovery from hemiparesis was evaluated in 60 patients with spontaneous intracerebral hemorrhage. T{sub 2}-weighted MR images revealed early MR abnormality (EMA) of the corticospinal tract within 1 week of ictus. Most patients without EMA recovered beyond Brunnstrom's Recovery Stage 3 while only a few patients with EMA did so. Patients with EMA cannot regain motor function because EMA is almost always followed by complete tract degeneration. EMA in the brainstem and poor motor function recovery are closely correlated. (author).

Abnormal pressures as hydrodynamic phenomena

Science.gov (United States)

Neuzil, C.E.

1995-01-01

So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually plays an important role. This paper develops the theoretical framework for abnormal pressures as hydrodynamic phenomena, shows that it explains the manifold occurrences of abnormal pressures, and examines the implications of this approach. -from Author

Safety of implantable pacemakers and cardioverter defibrillators in the magnetic field of a novel remote magnetic navigation system.

Science.gov (United States)

Jilek, Clemens; Tzeis, Stylianos; Reents, Tilko; Estner, Heidi-Luise; Fichtner, Stephanie; Ammar, Sonia; Wu, Jinjin; Hessling, Gabriele; Deisenhofer, Isabel; Kolb, Christof

2010-10-01

Electromagnetic interference with pacemaker and implantable cardioverter defibrillator (ICD) systems may cause temporary or permanent system malfunction of implanted devices. The aim of this study was to evaluate potential interference of a novel magnetic navigation system with implantable rhythm devices. A total of 121 devices (77 pacemakers, 44 ICDs) were exposed to an activated NIOBE II® Magnetic Navigation System (Stereotaxis, St. Louis, MO, USA) at the maximal magnetic field strength of 0.1 Tesla and evaluated in vitro with respect to changes in parameter settings of the device, changes of the battery status/detection of elective replacement indication, or alterations of data stored in the device. A total of 115 out of 121 (95%) devices were free of changes in parameter settings, battery status, and internally stored data after repeated exposition to the electromagnetic field of the remote magnetic navigation system. Interference with the magnetic navigation field was observed in 6 pacemakers, resulting in reprogramming to a power-on-reset mode with or without detection of the elective replacement indication in 5 devices and abnormal variance of battery status in one device. All pacemakers could be reprogrammed to the initial modes and the battery status proved to be normal some minutes after the pacemakers had been removed from the magnetic field. Interference of a remote magnetic navigation system (at maximal field strength) with pacemakers and ICDs not connected to leads with antitachycardic detection and therapies turned off is rare. Occurring functional abnormalities could be reprogrammed in our sample. An in vitro study will give information about interference of devices connected to leads. © 2010 Wiley Periodicals, Inc.

Universal behaviour of magnetoconductance due to week localization in two-dimensional systems - example of GaInAs quantum wells

Energy Technology Data Exchange (ETDEWEB)

Zduniak, A.; Dyakonov, M.I.; Litwin-Staszewska, E.; Knap, W. [Groupe d`Etudes des Semiconducteurs, Universite de Montpellier II, Montpellier (France)

1995-12-31

Week localization corrections to conductivity of two-dimensional electron gas are studied by measurements of magnetic field dependence of the conductivity in GaInAs quantum wells. We observed that, when presented as a function of the normalized magnetic field (x=B/B{sub tr} where B is the magnetic field, B{sub tr}=h/4e{tau}D, D is the diffusion constant and {tau} is momentum relaxation time), different samples show very similar high field behaviour. A theoretical description is developed that allows one to describe in a consistent way and low field behaviour. The theory predicts universal (B{sup -1/2}) behaviour of the conductivity correction for all 2D systems in high field limit (x>1). Low field behaviour depends strongly on spin and phase relaxation mechanisms. Comparison of the theory with experiment confirms the universal behaviour in the high field limit and allows one to estimate the spin and phase relaxation times for different GaInAs quantum wells. (author). 5 refs, 2 figs.

Abnormal functional motor lateralization in healthy siblings of patients with schizophrenia.

Science.gov (United States)

Altamura, Mario; Fazio, Leonardo; De Salvia, Michela; Petito, Annamaria; Blasi, Giuseppe; Taurisano, Paolo; Romano, Raffaella; Gelao, Barbara; Bellomo, Antonello; Bertolino, Alessandro

2012-07-30

Earlier neuroimaging studies of motor function in schizophrenia have demonstrated reduced functional lateralization in the motor network during motor tasks. Here, we used event-related functional magnetic resonance imaging during a visually guided motor task in 18 clinically unaffected siblings of patients with schizophrenia and 24 matched controls to investigate if abnormal functional lateralization is related to genetic risk for this brain disorder. Whereas activity associated with motor task performance was mainly contralateral with only a marginal ipsilateral component in healthy participants, unaffected siblings had strong bilateral activity with significantly greater response in ipsilateral and contralateral premotor areas as well as in contralateral subcortical motor regions relative to controls. Reduced lateralization in siblings was also identified with a measure of laterality quotient. These findings suggest that abnormal functional lateralization of motor circuitry is related to genetic risk of schizophrenia. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

[Behaviour problems of children with Down syndrome in preschool-age - Results from the Heidelberg Down syndrome study].

Science.gov (United States)

Sarimski, Klaus

2018-05-01

We report on the frequency and the correlations of behaviour problems among children with Down syndrome in preschool-age. As part of a longitudinal study 48 mothers of children with Down syndrome completed the German version of the “Strengths and Difficulties Questionnaire” (SDQ-D) and the Parenting Stress Inventory (PSI). The mothers were asked to fill out the questionnaires when the children had a mean age of five years. The results were compared to norms from children with typical development. Thirty per cent of the children with Down syndrome were rated as abnormal. Specifically, mean scores indicating problems with children of the same age and hyperactivity were elevated. A regression analysis predicting the total problem score of the SDQ-D revealed maternal educational level, optimistic attitude, and subjective parental stress at the age of one year and the degree of behavioural abnormalities at the age of three years as significant influential factors. Early intervention for Down syndrome children should include supporting parenting competence and coping skills in order to prevent behaviour problems.

Cyclic deformation behaviour of austenitic steels at ambient and ...

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

Fatigue; cyclic deformation behaviour; metastable austenitic steel; .... Figure 4 shows a sequence of the basic diagrams which can be used to assess the fatigue .... well as the change of temperature and the development of the magnetic ...

The need for a behavioural science focus in research on mental health and mental disorders

NARCIS (Netherlands)

Wittchen, H.U.; Knappe, S.; Andersson, G.; Araya, R.; Banos Rivera, R.M.; Barkham, M.; Bech, P.; Beckers, T.; Berger, T.; Berking, M.; Berrocal, C.; Botella, C.; Carlbring, P.; Chouinard, G.; Colom, F.; Csillag, C.; Cuijpers, P.; David, D.; Emmelkamp, P.M.G; Essau, C.A.; Fava, G.A.; Goschke, T.; Hermans, D.; Hofmann, S.G.; Lutz, W.; Muris, P.; Ollendick, T.H.; Raes, F.; Rief, W.; Riper, H.; Tossani, E.; van der Oord, S.; Vervliet, B.; Haro, J.M.; Schumann, G.

2014-01-01

Psychology as a science offers an enormous diversity of theories, principles, and methodological approaches to understand mental health, abnormal functions and behaviours and mental disorders. A selected overview of the scope, current topics as well as strength and gaps in Psychological Science may

Osteoarthritis of the knee: correlation of subchondral MR signal abnormalities with histopathologic and radiographic features

International Nuclear Information System (INIS)

Bergman, A.G.; Willen, H.K.; Lindstrand, A.L.; Pettersson, H.T.A.

1994-01-01

Subchondral signal abnormalities are often present on magnetic resonance (MR) images of patients with osteoarthritis, but no study correlating these changes with histopathology has been published. We selected nine consecutive patients with clinical and radiographic diagnosis of moderate to severe osteoarthritis of the knee scheduled to under go joint replacement surgery, and performed MR imaging and conventional radiographs pre-operatively. After surgery, the resected portions of the femur and tibia underwent gross and microscopic examination, and the findings were correlated with the corresponding findings on the imaging studies. Subchondral MR signal abnormalities of the femur or tibia were present in seven of the nine patients, with intermediate signal on T1-weighted images and low or isointense signal on T2-weighted images. The subchondral signal abnormalities were hemispherical in configuration and corresponded predominantly to fibrous tissue replacing the fatty marrow. A component of trabecular thickening was also present. (orig.)

Magnetic behaviour in metal–organic frameworks—Some recent ...

Indian Academy of Sciences (India)

Administrator

e-mail: snatarajan@sscu.iisc.ernet.in. Abstract. ... compounds to probe the nature of the magnetic species and their interactions with them. Keywords. .... selected under a polarizing microscope and glued to ..... out any center of inversion.

Can abnormal returns be earned on bandwidth-bounded currencies? Evidence from a genetic algorithm

OpenAIRE

Pedro Godinho

2012-01-01

Most of the studies about the Foreign Exchange market (Forex) analyse the behaviour of currencies that are allowed to float freely (or almost freely), but some currencies are still bounded by bandwidths (either disclosed or undisclosed). In this paper, I try to find out whether two bandwidth-bounded currencies, the Hong Kong dollar (HKD) and the Singapore dollar (SGD), present opportunities for abnormal returns. I consider a set of trading rules, and I use a genetic algorithm to optimise both...

Comparison of brain volume abnormalities between ADHD and conduct disorder in adolescence

Science.gov (United States)

Stevens, Michael C.; Haney-Caron, Emily

2012-01-01

associated with numerous frontal lobe structural deficits, a conclusion that is not strongly supported following direct comparison of diagnostically pure groups. The results are important for future etiological studies, particularly those seeking to identify how early expression of specific brain structure abnormalities could potentiate the risk for antisocial behaviour. PMID:22663946

Microclump effects in magnetically-immersed electron diodes

International Nuclear Information System (INIS)

Olson, C.L.

1998-01-01

Magnetically-immersed electron diodes are being developed to produce needle-like, high-current, electron beams for radiography applications. An immersed diode consists of a needle cathode and a planar anode/bremmstrahlung converter which are both immersed in a strong solenoidal magnetic field (12--50 T); nominal parameters are 10 MV, 40 kA, 0.5 mm radius cathode, and 5--35 cm anode-cathode gaps. A physical picture of normal and abnormal diode behavior is emerging. Normal diode behavior occurs for times 0 ≤ t ≤ τ, where the transition time τ is typically 30 ns; during this time, bipolar space-charge limited flow occurs, which scales well to desired radiography parameters of high dose and small spot size. Abnormal diode behavior occurs for t ≥ τ, which results in substantial increases in spot size and current (impedance reduction). This abnormal behavior appears to be caused by an increase in ion charge in the gap, which may result from poor vacuum, impurity ions undergoing ion-ion stripping collisions during transit, or microclumps undergoing stripping collisions during transit. The potential effects of microclumps on diode behavior are reported here

Structural Brain Abnormalities of Attention-Deficit/Hyperactivity Disorder With Oppositional Defiant Disorder.

Science.gov (United States)

Noordermeer, Siri D S; Luman, Marjolein; Greven, Corina U; Veroude, Kim; Faraone, Stephen V; Hartman, Catharina A; Hoekstra, Pieter J; Franke, Barbara; Buitelaar, Jan K; Heslenfeld, Dirk J; Oosterlaan, Jaap

2017-11-01

Attention-deficit/hyperactivity disorder (ADHD) is associated with structural abnormalities in total gray matter, basal ganglia, and cerebellum. Findings of structural abnormalities in frontal and temporal lobes, amygdala, and insula are less consistent. Remarkably, the impact of comorbid oppositional defiant disorder (ODD) (comorbidity rates up to 60%) on these neuroanatomical differences is scarcely studied, while ODD (in combination with conduct disorder) has been associated with structural abnormalities of the frontal lobe, amygdala, and insula. The aim of this study was to investigate the effect of comorbid ODD on cerebral volume and cortical thickness in ADHD. Three groups, 16 ± 3.5 years of age (mean ± SD; range 7-29 years), were studied on volumetric and cortical thickness characteristics using structural magnetic resonance imaging (surface-based morphometry): ADHD+ODD (n = 67), ADHD-only (n = 243), and control subjects (n = 233). Analyses included the moderators age, gender, IQ, and scan site. ADHD+ODD and ADHD-only showed volumetric reductions in total gray matter and (mainly) frontal brain areas. Stepwise volumetric reductions (ADHD+ODD attention, (working) memory, and decision-making. Volumetric reductions of frontal lobes were largest in the ADHD+ODD group, possibly underlying observed larger impairments in neurocognitive functions. Previously reported striatal abnormalities in ADHD may be caused by comorbid conduct disorder rather than ODD. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Behavioural disturbances in a temperate fish exposed to sustained high-CO2 levels.

Directory of Open Access Journals (Sweden)

Fredrik Jutfelt

Full Text Available As atmospheric CO2 levels rise, the CO2 concentration in ocean surface waters increases through a process commonly referred to as ocean acidification. Recently, surprising behavioural modifications has been detected in the early life stages of tropical coral reef fish exposed to ocean acidification-relevant CO2 concentrations, but it has been unclear if this effect could occur in temperate waters. Here we show several severe behavioural disturbances, including effects on boldness, exploratory behaviour, lateralisation, and learning in a temperate fish, the three-spined stickleback (Gasterosteus aculeatus. The behavioural effects were consistent throughout the exposure period and increased in effect size with exposure time. We observed the effects on adult sticklebacks, a species known to be tolerant to other environmental stressors. Our findings suggest that behavioural abnormalities that stem from CO2 exposure are not restricted to sensitive tropical species or early life stages and may therefore affect fish on a global scale. The severity of disturbances and the possibility of a serious behavioural problem for fish across the globe is cause for concern.

Magnetic resonance imaging and peripheral blood abnormalities in experimental allergic encephalomyelitis

International Nuclear Information System (INIS)

Rose, L.M.; Alvord, E.C. Jr.; Richards, T.L.

1989-01-01

Experimental allergic encephalomyelitis (EAE) was induced in twelve cynomologous macaques (Macaca fascicularis) by sensitization to autologous myelin basic protein (BP) in complete Freund's adjuvant (CFA). The white blood cell (WBC) count, absolute number of lymphocytes and absolute numbers of CD4 + and CD8 + T-cell subsets were measured weekly. Using magnetic resonance imaging (MRI), the animals were monitored twice weekly for the development of central nervous system (CNS) lesions. Conventional spin-warp imaging was performed using a General Electric CSI-II NMR imager/spectrometer (2 Tesla magnet). CNS lesions were detected by MRI in all of the animals sensitized to myelin BP. Longitudinal analysis of their peripheral blood leukocytes revealed a progressive leukocytosis and lymphopenia, which always preceded the onset of clinical signs and almost always also preceded the formation of detectable CNS lesions. These results suggest that frequent analysis of T-cell subsets may provide a more accurate means of predicting episodes of disease activity than clinical or MRI evaluation

Visual pathway abnormalities were found in most multiple sclerosis patients despite history of previous optic neuritis

Directory of Open Access Journals (Sweden)

Stella Maris Costa Castro

2013-07-01

Full Text Available Objective It was to investigate visual field (VF abnormalities in a group of multiple sclerosis (MS patients in the remission phase and the presence of magnetic resonance imaging (MRI lesions in the optic radiations. Methods VF was assessed in 60 participants (age range 20-51 years: 35 relapsing-remitting MS patients [20 optic neuritis (+, 15 optic neuritis (-] and 25 controls. MRI (3-Tesla was obtained in all patients. Results Visual parameters were abnormal in MS patients as compared to controls. The majority of VF defects were diffuse. All patients except one had posterior visual pathways lesions. No significant difference in lesion number, length and distribution was noted between patients with and without history of optic neuritis. One patient presented homonymous hemianopsia. Conclusion Posterior visual pathway abnormalities were found in most MS patients despite history of previous optic neuritis.

Basal ganglia dysfunction in idiopathic REM sleep behaviour disorder parallels that in early Parkinson’s disease

Science.gov (United States)

Rolinski, Michal; Griffanti, Ludovica; Piccini, Paola; Roussakis, Andreas A.; Szewczyk-Krolikowski, Konrad; Menke, Ricarda A.; Quinnell, Timothy; Zaiwalla, Zenobia; Klein, Johannes C.; Mackay, Clare E.

2016-01-01

Abstract See Postuma (doi:10.1093/aww131) for a scientific commentary on this article. Resting state functional magnetic resonance imaging dysfunction within the basal ganglia network is a feature of early Parkinson’s disease and may be a diagnostic biomarker of basal ganglia dysfunction. Currently, it is unclear whether these changes are present in so-called idiopathic rapid eye movement sleep behaviour disorder, a condition associated with a high rate of future conversion to Parkinson’s disease. In this study, we explore the utility of resting state functional magnetic resonance imaging to detect basal ganglia network dysfunction in rapid eye movement sleep behaviour disorder. We compare these data to a set of healthy control subjects, and to a set of patients with established early Parkinson’s disease. Furthermore, we explore the relationship between resting state functional magnetic resonance imaging basal ganglia network dysfunction and loss of dopaminergic neurons assessed with dopamine transporter single photon emission computerized tomography, and perform morphometric analyses to assess grey matter loss. Twenty-six patients with polysomnographically-established rapid eye movement sleep behaviour disorder, 48 patients with Parkinson’s disease and 23 healthy control subjects were included in this study. Resting state networks were isolated from task-free functional magnetic resonance imaging data using dual regression with a template derived from a separate cohort of 80 elderly healthy control participants. Resting state functional magnetic resonance imaging parameter estimates were extracted from the study subjects in the basal ganglia network. In addition, eight patients with rapid eye movement sleep behaviour disorder, 10 with Parkinson’s disease and 10 control subjects received 123I-ioflupane single photon emission computerized tomography. We tested for reduction of basal ganglia network connectivity, and for loss of tracer uptake in rapid eye

Frequency of brain MRI abnormalities in neuromyelitis optica spectrum disorder at presentation: A cohort of Latin American patients.

Science.gov (United States)

Carnero Contentti, Edgar; Daccach Marques, Vanessa; Soto de Castillo, Ibis; Tkachuk, Veronica; Antunes Barreira, Amilton; Armas, Elizabeth; Chiganer, Edson; de Aquino Cruz, Camila; Di Pace, José Luis; Hryb, Javier Pablo; Lavigne Moreira, Carolina; Lessa, Carmen; Molina, Omaira; Perassolo, Monica; Soto, Arnoldo; Caride, Alejandro

2018-01-01

Brain magnetic resonance imaging (BMRI) lesions were classically not reported in neuromyelitis optica (NMO). However, BMRI lesions are not uncommon in NMO spectrum disorder (NMOSD) patients. To report BMRI characteristic abnormalities (location and configuration) in NMOSD patients at presentation. Medical records and BMRI characteristics of 79 patients with NMOSD (during the first documented attack) in Argentina, Brazil and Venezuela were reviewed retrospectively. BMRI abnormalities were observed in 81.02% of NMOSD patients at presentation. Forty-two patients (53.1%) showed typical-NMOSD abnormalities. We found BMRI abnormalities at presentation in the brainstem/cerebellum (n = 26; 32.9%), optic chiasm (n = 16; 20.2%), area postrema (n = 13; 16.4%), thalamus/hypothalamus (n = 11; 13.9%), corpus callosum (n = 11; 13.9%), periependymal-third ventricle (n = 9; 11.3%), corticospinal tract (n = 7; 8.8%), hemispheric white matter (n = 1; 1.2%) and nonspecific areas (n = 49; 62.03%). Asymptomatic BMRI lesions were more common. The frequency of brain MRI abnormalities did not differ between patients who were positive and negative for aquaporin 4 antibodies at presentation. Typical brain MRI abnormalities are frequent in NMOSD at disease onset. Copyright © 2017 Elsevier B.V. All rights reserved.

Functional and structural abnormalities associated with empathy in patients with schizophrenia: An fMRI and VBM study.

Science.gov (United States)

Singh, Sadhana; Modi, Shilpi; Goyal, Satnam; Kaur, Prabhjot; Singh, Namita; Bhatia, Triptish; Deshpande, Smita N; Khushu, Subash

2015-06-01

Empathy deficit is a core feature of schizophrenia which may lead to social dysfunction. The present study was carried out to investigate functional and structural abnormalities associated with empathy in patients with schizophrenia using functional magnetic resonance imaging (fMRI) and voxel-based morphometry (VBM). A sample of 14 schizophrenia patients and 14 healthy control subjects matched for age, sex and education were examined with structural highresolution T1-weighted MRI; fMRI images were obtained during empathy task in the same session. The analysis was carried out using SPM8 software. On behavioural assessment, schizophrenic patients (83.00+-29.04) showed less scores for sadness compared to healthy controls (128.70+-22.26) (p less than 0.001). fMRI results also showed reduced clusters of activation in the bilateral fusiform gyrus, left lingual gyrus, left middle and inferior occipital gyrus in schizophrenic subjects as compared to controls during empathy task. In the same brain areas, VBM results also showed reduced grey and white matter volumes. The present study provides an evidence for an association between structural alterations and disturbed functional brain activation during empathy task in persons affected with schizophrenia. These findings suggest a biological basis for social cognition deficits in schizophrenics.

Interhemispheric motor networks are abnormal in patients with Gilles de la Tourette syndrome

DEFF Research Database (Denmark)

Bäumer, Tobias; Thomalla, Götz; Kroeger, Johan

2010-01-01

Brain imaging has shown altered corpus callosum (CC) morphology in patients with Gilles de la Tourette syndrome (GTS). Yet it is unclear whether these morphological changes are associated with altered interhemispheric interactions. Here, we combined transcranial magnetic stimulation (TMS) with di...... in control subjects but not in patients. Our combined TMS-DTI approach demonstrates abnormal functional interhemispheric connectivity in GTS accompanied by an altered structure-function relationship in the motor CC....

Evolution of Diffusion-Weighted Magnetic Resonance Imaging Signal Abnormality in Sporadic Creutzfeldt-Jakob Disease, With Histopathological Correlation.

Science.gov (United States)

Eisenmenger, Laura; Porter, Marie-Claire; Carswell, Christopher J; Thompson, Andrew; Mead, Simon; Rudge, Peter; Collinge, John; Brandner, Sebastian; Jäger, Hans R; Hyare, Harpreet

2016-01-01

Prion diseases represent the archetype of brain diseases caused by protein misfolding, with the most common subtype being sporadic Creutzfeldt-Jakob disease (sCJD), a rapidly progressive dementia. Diffusion-weighted imaging (DWI) has emerged as the most sensitive magnetic resonance imaging (MRI) sequence for the diagnosis of sCJD, but few studies have assessed the evolution of MRI signal as the disease progresses. To assess the natural history of the MRI signal abnormalities on DWI in sCJD to improve our understanding of the pathogenesis and to investigate the potential of DWI as a biomarker of disease progression, with histopathological correlation. Gray matter involvement on DWI was assessed among 37 patients with sCJD in 26 cortical and 5 subcortical subdivisions per hemisphere using a semiquantitative scoring system of 0 to 2 at baseline and follow-up. A total brain score was calculated as the summed scores in the individual regions. In 7 patients, serial mean diffusivity measurements were obtained. Age at baseline MRI, disease duration, atrophy, codon 129 methionine valine polymorphism, Medical Research Council Rating Scale score, and histopathological findings were documented. The study setting was the National Prion Clinic, London, England. All participants had a probable or definite diagnosis of sCJD and had at least 2 MRI studies performed during the course of their illness. The study dates were October 1, 2008 to April 1, 2012. The dates of our analysis were January 19 to April 20, 2012. Correlation of regional and total brain scores with disease duration. Among the 37 patients with sCJD in this study there was a significant increase in the number of regions demonstrating signal abnormality during the study period, with 59 of 62 regions showing increased signal intensity (SI) at follow-up, most substantially in the caudate and putamen (P disease duration (r = 0.47, P = .003 at baseline and r = 0.35, P = .03 at follow-up), and the left

Caroli's disease: magnetic resonance imaging features

Energy Technology Data Exchange (ETDEWEB)

Guy, France; Cognet, Francois; Dranssart, Marie; Cercueil, Jean-Pierre; Conciatori, Laurent; Krause, Denis [Department of Radiology and Imaging, Dijon Le Bocage University Hospital, 2 Blvd. Marechal de Lattre de Tassigny, BP 1542, 21034 Dijon Cedex (France)

2002-11-01

Our objective was to describe the main aspects of MR imaging in Caroli's disease. Magnetic resonance cholangiography with a dynamic contrast-enhanced study was performed in nine patients with Caroli's disease. Bile duct abnormalities, lithiasis, dot signs, hepatic enhancement, renal abnormalities, and evidence of portal hypertension were evaluated. Three MR imaging patterns of Caroli's disease were found. In all but two patients, MR imaging findings were sufficient to confirm the diagnosis. Moreover, MR imaging provided information about the severity, location, and extent of liver involvement. This information was useful in planning the best therapeutic strategy. Magnetic resonance cholangiography with a dynamic contrast-enhanced study is a good screening tool for Caroli's disease. Direct cholangiography should be reserved for confirming doubtful cases. (orig.)

Clinical, functional, behavioural and epigenomic biomarkers of obesity.

Science.gov (United States)

Lafortuna, Claudio L; Tovar, Armando R; Rastelli, Fabio; Tabozzi, Sarah A; Caramenti, Martina; Orozco-Ruiz, Ximena; Aguilar-Lopez, Miriam; Guevara-Cruz, Martha; Avila-Nava, Azalia; Torres, Nimbe; Bertoli, Gloria

2017-06-01

Overweight and obesity are highly prevalent conditions worldwide, linked to an increased risk for death, disability and disease due to metabolic and biochemical abnormalities affecting the biological human system throughout different domains. Biomarkers, defined as indicators of biological processes in health and disease, relevant for body mass excess management have been identified according to different criteria, including anthropometric and molecular indexes, as well as physiological and behavioural aspects. Analysing these different biomarkers, we identified their potential role in diagnosis, prognosis and treatment. Epigenetic biomarkers, cellular mediators of inflammation and factors related to microbiota-host interactions may be considered to have a theranostic value. Though, the molecular processes responsible for the biological phenomenology detected by the other analysed markers, is not clear yet. Nevertheless, these biomarkers possess valuable diagnostic and prognostic power. A new frontier for theranostic biomarkers can be foreseen in the exploitation of parameters defining behaviours and lifestyles linked to the risk of obesity, capable to describe the effects of interventions for obesity prevention and treatment which include also behaviour change strategies.

Spin-glass-like behaviour in IrSr2RECu2O8 (RE=Sm and Eu)

International Nuclear Information System (INIS)

Santos-Garcia, A.J. dos; Duijn, J. van; Alario-Franco, M.A.

2008-01-01

We report the results of magnetic and specific heat measurements on the 1212-type compounds IrSr 2 RECu 2 O 8 with RE=Sm and Eu, prepared by high-pressure and high-temperature synthesis. The magnetic susceptibility of these compounds shows a large difference in the temperature dependence of the magnetization measured under zero-field-cooled and field-cooled conditions below 87 and 71 K, respectively, and upon further cooling below ∼10 K substantial maxima are observed too. Further AC susceptibility measurements support a glassy behaviour in lower magnetic transitions whereas the specific heat measurements do not show the typical long-range ordering commonly displayed in ferro, ferri or antiferromagnetic transitions. Hysteresis loops suggest the presence of magnetic clusters in the otherwise paramagnetic zone, indicating that these compounds probably display a reentrant spin-glass transition. Results are presented and discussed. - Graphical abstract: IrSr 2 RECu 2 O 8 with RE=Sm and Eu were prepared by high-pressure and high-temperature synthesis. Both samples adopt a M-1212-type perovskite structure and a microdomain texturing of the long c-axis is observed by TEM. A very interesting magnetic behaviour is observed in these materials. A 'cluster by cluster freezing' model is proposed, instead of the classical individual spin freezing one to explain the spin-glass-like behaviour that seems to coexist with weak ferromagnetism in both compounds

Energy dump of the ATLAS superconducting system simulations of electrical and thermal behaviour of magnet system at slow- and fast dump

CERN Document Server

van Beek, Martijn; Dudarev, A

During the slow dump (discharge) of the Barrel Toroidal (superconducting) magnet of the ATLAS detector, the control system gave an alarm that the differences between the voltages over the conductors were too high. The alarm was not due to any danger, because of some sort of phenomenon observed in the first few seconds after start of the discharge. A possible explanation of the differences of the coil voltages is that the changing current through the conductors may cause induced currents in the coil casing around. The goal was to make a simulation of the electrical behaviour of the magnet system during a slow dump. In this way, an explanation can be found for the start phenomenon of the slow dump of the Barrel Toroid. Some extra analyses on the measurements were performed to describe the energy dissipation during a fast dump. This is done by calculating the resistance of the coils during the dump. With the maximum resistance, the maximum temperature can be estimated, which says something about the enthalpy of ...

Stochastic behaviour of particle orbits in field reversed geometries

International Nuclear Information System (INIS)

Finn, J.M.

1979-01-01

Studies of stochastic or ergodic behaviour of beam particle orbits in axisymmetric systems with field reversal produced by ion rings or by neutral injection are presented. In the former case a large class of orbits is ergodic, whereas in the latter most are integrable. Effects of ergodic behaviour on particle confinement, equilibrium, magnetic compression, and stability are discussed. The modification, due to ergodic orbits of the stability criterion for low frequency (ω << ωsub(ci)) resonant instabilities is presented. (author)

A dynamic macromodel for distributed parameter magnetic microactuators

International Nuclear Information System (INIS)

Fang Yuming; Huang Qingan; Li Weihua

2008-01-01

This paper presents a reduced-order model to describe the mechanical behaviour of microbeam-based magnetic devices. The integration for magnetic force is calculated by dividing the microbeam into several segments, and the nonlinear equation set has been developed based on the magnetic circuit principle. In comparison with previous models, the present macromodel accounts for both the micro-magnetic-core reluctance and the coupling between the beam deflection and magnetic force. This macromodel is validated by comparing with the experimental results available in some papers and finite-element solutions

Magnetic levitation by induced eddy currents in non-magnetic conductors and conductivity measurements

Energy Technology Data Exchange (ETDEWEB)

Iniguez, J; Raposo, V; Flores, A G; Zazo, M; Hernandez-Lopez, A [Departamento de Fisica Aplicada, Universidad de Salamanca, E-37071, Salamanca (Spain)

2005-11-01

We report a study on magnetic levitation by induced ac currents in non-magnetic conductors at low frequencies. Our discussion, based on Faraday's induction law, allows us to distinguish the two components of the current responsible for levitation and heating, respectively. The experimental evaluation of the levitation force in a copper ring revealed the accuracy of our analysis, clearly illustrating its asymptotic behaviour versus frequency, and validating it for the qualitative analysis of magnetic levitation and heating in conductors of different shapes such as tubes and discs, composed of collections of conductive loops. The analysis of the results allows precise values of its electrical conductivity to be found. With the help of a simulation technique, this work also reveals the progressive deformation undergone by magnetic induction lines due to magnetic screening when frequency increases.

Abnormal sound detection device

International Nuclear Information System (INIS)

Yamada, Izumi; Matsui, Yuji.

1995-01-01

Only components synchronized with rotation of pumps are sampled from detected acoustic sounds, to judge the presence or absence of abnormality based on the magnitude of the synchronized components. A synchronized component sampling means can remove resonance sounds and other acoustic sounds generated at a synchronously with the rotation based on the knowledge that generated acoustic components in a normal state are a sort of resonance sounds and are not precisely synchronized with the number of rotation. On the other hand, abnormal sounds of a rotating body are often caused by compulsory force accompanying the rotation as a generation source, and the abnormal sounds can be detected by extracting only the rotation-synchronized components. Since components of normal acoustic sounds generated at present are discriminated from the detected sounds, reduction of the abnormal sounds due to a signal processing can be avoided and, as a result, abnormal sound detection sensitivity can be improved. Further, since it is adapted to discriminate the occurrence of the abnormal sound from the actually detected sounds, the other frequency components which are forecast but not generated actually are not removed, so that it is further effective for the improvement of detection sensitivity. (N.H.)

Triple-q, Modulated Magnetic Structure and Critical Behaviour of Neodymium

DEFF Research Database (Denmark)

Lebech, Bente; Bak, Poul Erik

1978-01-01

In order to study the magnetic structure of neodymium, the authors have performed neutron scattering measurements on single crystals. The results of these measurements are combined with the results of renormalisation-group theory and Landau symmetry arguments. Below the Neel temperature......, the magnetic structure was found to be a unique two-dimensional ordered structure, accompanied by a similarly patterned lattice distortion...

Brief Report: Exploring the Relationship between Sensory Processing and Repetitive Behaviours in Williams Syndrome

Science.gov (United States)

Riby, Deborah M.; Janes, Emily; Rodgers, Jacqui

2013-01-01

This study explored the relationship between sensory processing abnormalities and repetitive behaviours in children with Williams Syndrome (WS; n = 21). This is a novel investigation bringing together two clinical phenomena for the first time in this neuro-developmental disorder. Parents completed the Sensory Profile (Short Form; Dunn in The…

Modern permanent magnetic materials - preparation and properties

International Nuclear Information System (INIS)

Rodewald, W.

1989-01-01

First of all, the basic properties of the classical (steel, AlNiCo) permanent magnetic materials and the modern rare-earth (RE) permanent magnetic materials are compared. Since the properties of RE permanent magnets depend on the particular production process, the fundamentals of the main industrial processes (powder metallurgy, rapid-solidification technique) are described and the typical properties are explained. Furthermore the production processes in development such as mechanical alloying, melt spinning technique and extrusion upsetting are briefly outlined. For applying the permanent magnets, they have to be completely magnetized. The magnetization behaviour of the various RE permanent magnets is discussed by means of the internal demagnetization curve. Finally the various influences on the temperature stability of RE permanent magnets are compiled. (orig./MM) [de

Temperature-dependent magnetism of Fe thin films on ZnSe(0 0 1)

International Nuclear Information System (INIS)

Cantoni, M.; Bertacco, R.; Ciccacci, F.; Puppin, E.; Pinotti, E.; Brenna, M.; Marangolo, M.; Eddrieff, M.; Torelli, P.; Maccherozzi, F.; Fujii, J.; Panaccione, G.

2007-01-01

We present X-ray magnetic circular dichroism (XMCD) and magneto-optical Kerr effect (MOKE) data on the magnetic properties of Fe/ZnSe(0 0 1) thin films at increasing Fe coverage. The magnetic behaviour of the Fe overlayer is superparamagnetic for a coverage up to 6 monolayers whereas, above this threshold, a truly ferromagnetic phase shows up. XMCD and MOKE data show that this behaviour is substantially unchanged in the temperature range 10-300 K for all the investigated coverages: these findings imply that the blocking temperature is definitely below 10 K

Computation of the Magnetic Field of a Spectrometer in Detectors Region

International Nuclear Information System (INIS)

Zhidkov, E.P.; Yuldasheva, M.B.; Yudin, I.P.; Yuldashev, O.I.

1994-01-01

Computed results of the 3D magnetic field of a spectrometer intended for investigation of hadron production of charmed particles and the indication of the narrow resonances in neutron-nucleus interaction are presented. The methods, used in computations - finite element method and finite element method with suggested new infinite elements are described. For accuracy control the computations were carried out on a sequence of three-dimensional meshes. Special attention is devoted to the behaviour of the magnetic field in the basic detectors (proportional chambers) region. The performed results can be used for the field behaviour estimate of similar spectrometer magnets. 12 refs., 16 figs

Atomoxetine reduces hyperactive/impulsive behaviours in neurokinin-1 receptor 'knockout' mice.

Science.gov (United States)

Pillidge, Katharine; Porter, Ashley J; Vasili, Temis; Heal, David J; Stanford, S Clare

2014-12-01

Mice with functional ablation of the neurokinin-1 receptor gene (NK1R(-/-)) display behavioural abnormalities which resemble the hyperactivity, inattention and impulsivity seen in Attention Deficit Hyperactivity Disorder (ADHD). Here, we investigated whether the established ADHD treatment, atomoxetine, alleviates these abnormalities when tested in the light/dark exploration box (LDEB) and 5-Choice Serial Reaction-Time Task (5-CSRTT). Separate cohorts of mice were tested in the 5-CSRTT and LDEB after treatment with no injection, vehicle or atomoxetine (5-CSRTT: 0.3, 3 or 10mg/kg; LDEB: 1, 3 or 10mg/kg). Atomoxetine reduced the hyperactivity displayed by NK1R(-/-) mice in the LDEB at a dose (3mg/kg) which did not affect the locomotor activity of wildtypes. Atomoxetine (10mg/kg) also reduced impulsivity in NK1R(-/-) mice, but not wildtypes, in the 5-CSRTT. No dose of drug affected attention in either genotype. This evidence that atomoxetine reduces hyperactive/impulsive behaviours in NK1R(-/-) mice consolidates the validity of using NK1R(-/-) mice in research of the aetiology and treatment of ADHD. Copyright © 2014. Published by Elsevier Inc.

Critical dynamics of an interacting magnetic nanoparticle system

DEFF Research Database (Denmark)

Hansen, Mikkel Fougt; Jonsson, P.E.; Nordblad, P.

2002-01-01

Effects of dipole-dipole interactions on the magnetic relaxation have been investigated for three Fe-C nanoparticle samples with volume concentrations of 0.06, 5 and 17 vol%. While both the 5 and 17 vol% samples exhibit collective behaviour due to dipolar interactions, only the 17 vol% sample dis...... displays critical behaviour close to its transition temperature. The behaviour of the 5 vol% sample can be attributed to a mixture of collective and single-particle dynamics....

Importance of matrix inelastic deformations in the initial response of magnetic elastomers.

Science.gov (United States)

Sánchez, Pedro A; Gundermann, Thomas; Dobroserdova, Alla; Kantorovich, Sofia S; Odenbach, Stefan

2018-03-14

Being able to predict and understand the behaviour of soft magnetic materials paves the way to their technological applications. In this study we analyse the magnetic response of soft magnetic elastomers (SMEs) with magnetically hard particles. We present experimental evidence of a difference between the first and next magnetisation loops exhibited by these SMEs, which depends non-monotonically on the interplay between the rigidity of the polymer matrix, its mechanical coupling with the particles, and the magnetic interactions in the system. In order to explain the microstructural mechanism behind this behaviour, we used a minimal computer simulation model whose results evidence the importance of irreversible matrix deformations due to both translations and rotations of the particles. To confirm the simulation findings, computed tomography (CT) was used. We conclude that the initial exposure to the field triggers the inelastic matrix relaxation in the SMEs, as particles attempt to reorient. However, once the necessary degree of freedom is achieved, both the rotations and the magnetisation behaviour become stationary. We expect this scenario not only to be limited to the materials studied here, but also to apply to a broader class of hybrid SMEs.

Magnetic properties of natural pyrrhotite Part I: Behaviour

NARCIS (Netherlands)

Dekkers, M.J.

1988-01-01

The grain-size dependence of the initial susceptibility (X 1~),saturation magnetization (.1,), saturation remanence (J~),coercive force (He), remanent coercive force (Hcr) and remanent acquisition coercive force (Hcr’), is reported for four natural pyrrhotites in a grain-size range from 250

Charged particle confinement in magnetic mirror

International Nuclear Information System (INIS)

Bora, D.; John, P.I.; Saxena, Y.C.; Varma, R.K.

1982-01-01

The behaviour of single charged particle trapped in a magnetic mirror has been investigated experimentally. The particle injected off axis and trapped in a magnetic mirror, leak out of the mirror with the leakage characterized by multiple decay times. The observed decay times are in good agreement with predictions of a ''wave mechanical like'' model by Varma, over a large range of relevant parameters. (author)

Macroscopic simulation of isotropic permanent magnets

International Nuclear Information System (INIS)

Bruckner, Florian; Abert, Claas; Vogler, Christoph; Heinrichs, Frank; Satz, Armin; Ausserlechner, Udo; Binder, Gernot; Koeck, Helmut; Suess, Dieter

2016-01-01

Accurate simulations of isotropic permanent magnets require to take the magnetization process into account and consider the anisotropic, nonlinear, and hysteretic material behaviour near the saturation configuration. An efficient method for the solution of the magnetostatic Maxwell equations including the description of isotropic permanent magnets is presented. The algorithm can easily be implemented on top of existing finite element methods and does not require a full characterization of the hysteresis of the magnetic material. Strayfield measurements of an isotropic permanent magnet and simulation results are in good agreement and highlight the importance of a proper description of the isotropic material. - Highlights: • Simulations of isotropic permanent magnets. • Accurate calculation of remanence magnetization and strayfield. • Comparison with strayfield measurements and anisotropic magnet simulations. • Efficient 3D FEM–BEM coupling for solution of Maxwell equations.

Fast reactor operating experience gained in Russia: Analysis of anomalies and abnormal operation cases

International Nuclear Information System (INIS)

Ashurko, Y.M.; Baklushin, R.P.; Zagorulko, Y.I.; Ivanenko, V.N.; Matveyev, V.P.; Vasilyev, B.A.

2000-01-01

Review of various anomalous events and abnormal operation experience gained in the process of Russian fast reactors operation is given in the paper. The main information refers to the BN-600 demonstration reactor operation. Statistical data on sodium leaks and steam generator failures are presented, and sources of these events and countermeasures taken to avoid their appearance on the operating reactors as well as related changes made in the BN-800 reactor design are considered. In the paper, some features of impurities behaviour are considered in various modes of the BN-600 reactor operation. Information is given on the impurities ingress into the circuits, on abnormal situation emerged in the process of the BN-600 reactor operation and its probable cause. Information is presented on the event related to the increased torque of the BN-600 reactor central rotating column and repair works performed. (author)

Morphostructural MRI Abnormalities Related to Neuropsychiatric Disorders Associated to Multiple Sclerosis

Directory of Open Access Journals (Sweden)

Simona Bonavita

2013-01-01

Full Text Available Multiple Sclerosis associated neuropsychiatric disorders include major depression (MD, obsessive-compulsive disorder (OCD, bipolar affective disorder, euphoria, pseudobulbar affect, psychosis, and personality change. Magnetic Resonance Imaging (MRI studies focused mainly on identifying morphostructural correlates of MD; only a few anecdotal cases on OCD associated to MS (OCD-MS, euphoria, pseudobulbar affect, psychosis, personality change, and one research article on MRI abnormalities in OCD-MS have been published. Therefore, in the present review we will report mainly on neuroimaging abnormalities found in MS patients with MD and OCD. All together, the studies on MD associated to MS suggest that, in this disease, depression is linked to a damage involving mainly frontotemporal regions either with discrete lesions (with those visible in T1 weighted images playing a more significant role or subtle normal appearing white matter abnormalities. Hippocampal atrophy, as well, seems to be involved in MS related depression. It is conceivable that grey matter pathology (i.e., global and regional atrophy, cortical lesions, which occurs early in the course of disease, may involve several areas including the dorsolateral prefrontal cortex, the orbitofrontal cortex, and the anterior cingulate cortex whose disruption is currently thought to explain late-life depression. Further MRI studies are necessary to better elucidate OCD pathogenesis in MS.

Behavioural and physiological responses of shelter dogs to long-term confinement

Directory of Open Access Journals (Sweden)

Paolo Dalla Villa

2013-06-01

Full Text Available In Italy, National Law (281/1991 prohibits euthanasia of shelter dogs if they are not dangerous or suffering seriously. Adoption rates in rescue shelters are often lower than entrance rates, leading inevitably to overcrowded facilities where animals are likely to spend the rest of their lives in kennels. In this situation, housing conditions (i.e. space provided, environmental, and social stimulation may have an impact on canine welfare. In this research project, the effects of two different forms of housing (group- and pair housing on long-term shelter dogs were compared using behavioural and physiological parameters. Observational data and saliva samples were collected from dogs exposed to both experimental settings; behaviour and cortisol concentration levels were used as welfare indicators. Pair housing offered fewer social and environmental stimuli and behavioural analysis showed a significant decrease in locomotor, exploratory, and social behaviour. Cortisol levels show that this parameter varied independently of housing conditions. Although this study found no evidence suggesting that one form of confinement reduced animal welfare more than the other (e.g. in terms of abnormal behaviour, or higher cortisol concentrations, the type of confinement did affect the expression of a variety of behaviours and these variations should not be ignored with respect to housing decisions for long-term shelter dogs.

Magnetic and structural characterization of the semiconductor FeIn2Se4

International Nuclear Information System (INIS)

Torres, T.; Sagredo, V.; Chalbaud, L.M. de; Attolini, G.; Bolzoni, F.

2006-01-01

Plate-like single crystals of magnetic semiconductor FeIn 2 Se 4 were grown with a chemical vapour transport technique. The X-ray powder diffraction analyses suggest that the compound crystallize in the hexagonal structure with space group P3m1. We have performed dc magnetization measurements at different magnetic fields on the diluted magnetic semiconductor FeIn 2 Se 4 . Low field magnetizations measurements shows irreversibility in the DC magnetization, as evidenced by field cooled and zero field cooled measurements below 17 K, suggesting a spin-glass like behaviour. The high-temperature susceptibility data follow a typical Curie-Weiss law with θ=-183±2 K which suggest the presence of predominant antiferromagnetic interactions with high degree of frustration. The randomness and frustration necessary for spin-glass behaviour are explained in a manner compatible with the cation and charge ordering present in the material

Birth origin differentially affects depressive-like behaviours: are captive-born cynomolgus monkeys more vulnerable to depression than their wild-born counterparts?

Directory of Open Access Journals (Sweden)

Sandrine M J Camus

Full Text Available BACKGROUND: Adverse early-life experience might lead to the expression of abnormal behaviours in animals and the predisposition to psychiatric disorder (e.g. major depressive disorder in Humans. Common breeding processes employ weaning and housing conditions different from what happens in the wild. METHODS: The present study, therefore, investigated whether birth origin impacts the possible existence of spontaneous atypical/abnormal behaviours displayed by 40 captive-born and 40 wild-born socially-housed cynomolgus macaques in farming conditions using an unbiased ethological scan-sampling analysis followed by multifactorial correspondence and hierarchical clustering analyses. RESULTS: We identified 10 distinct profiles (groups A to J that significantly differed on several behaviours, body postures, body orientations, distances between individuals and locations in the cage. Data suggest that 4 captive-born and 1 wild-born animals (groups G and J present depressive-like symptoms, unnatural early life events thereby increasing the risk of developing pathological symptoms. General differences were also highlighted between the captive- and wild-born populations, implying the expression of differential coping mechanisms in response to the same captive environment. CONCLUSIONS: Birth origin thus impacts the development of atypical ethologically-defined behavioural profiles, reminiscent of certain depressive-like symptoms. The use of unbiased behavioural observations might allow the identification of animal models of human mental/behavioural disorders and their most appropriate control groups.

Autistic-like behavioural and neurochemical changes in a mouse model of food allergy.

Science.gov (United States)

de Theije, Caroline G M; Wu, Jiangbo; Koelink, Pim J; Korte-Bouws, Gerdien A H; Borre, Yuliya; Kas, Martien J H; Lopes da Silva, Sofia; Korte, S Mechiel; Olivier, Berend; Garssen, Johan; Kraneveld, Aletta D

2014-03-15

Food allergy has been suggested to contribute to the expression of psychological and psychiatric traits, including disturbed social behaviour and repetitive behaviour inherent in autism spectrum disorders (ASD). Most research in this field receives little attention, since fundamental evidence showing direct effects of food allergic immune responses on social behaviour is very limited. In the present study, we show that a food allergic reaction to cow's milk protein, induced shortly after weaning, reduced social behaviour and increased repetitive behaviour in mice. This food allergic reaction increased levels of serotonin (5-hydroxytryptamine; 5-HT) and the number of 5-HT positive cells, and decreased levels of 5-hydroxyindoleacetic acid (5-HIAA) in the intestine. Behavioural changes in food allergic mice were accompanied by reduced dopaminergic activity in the prefrontal cortex. Furthermore, neuronal activation (c-Fos expression) was increased in the prefrontal cortex and reduced in the paraventricular nucleus of the hypothalamus after exposure to a social target. We hypothesize that an intestinal allergic response regulates complex, but critical, neuroimmune interactions, thereby affecting brain circuits involved in social interaction, repetitive behaviour and cognition. Together with a genetic predisposition and multiple environmental factors, these effects of allergic immune activation may exacerbate behavioural abnormalities in patients with ASD. Copyright © 2013 Elsevier B.V. All rights reserved.

Two patterns of cerebral metabolite abnormalities are detected on proton magnetic resonance spectroscopy in HIV-infected subjects commencing antiretroviral therapy

Energy Technology Data Exchange (ETDEWEB)

Winston, Alan; Taylor-Robinson, Simon D. [Imperial College London, St. Mary' s Hospital, London (United Kingdom); Duncombe, Chris [HIV-NAT, Thai Red Cross AIDS Research Centre, Bangkok (Thailand); Li, Patrick C.K. [Queen Elizabeth Hospital, Hong Kong (China); Gill, John M. [Calgary Regional Health Authority, Calgary (Canada); Kerr, Stephen J. [HIV-NAT, Thai Red Cross AIDS Research Centre, Bangkok (Thailand); University of New South Wales, National Centre in HIV Epidemiology and Clinical Research, Sydney, NSW (Australia); Puls, Rebekah L.; Emery, Sean; Cooper, David A. [University of New South Wales, National Centre in HIV Epidemiology and Clinical Research, Sydney, NSW (Australia); Collaboration: for the Altair Study Group

2012-12-15

Cerebral function impairment remains problematic in subjects with chronic human immunodeficiency virus (HIV) infection despite effective combination antiretroviral therapy (cART). Using cerebral proton magnetic resonance spectroscopy ({sup 1}H MRS), we aimed to determine if abnormalities could be detected in neurologically asymptomatic HIV-infected subjects electively commencing cART. Therapy-naive, HIV-infected individuals and HIV-uninfected controls underwent {sup 1}H MRS in several anatomical voxels including the mid-frontal grey matter (FGM) and right basal ganglia (RBG). Differences in cerebral metabolite ratios between groups and correlations between immune and virological status were assessed. Forty-six subjects were recruited (26 HIV-infected and 20 control subjects). In the HIV-infected group, mean CD4+ count (SD, cells per microlitre) and plasma HIV RNA (SD, log10 copies per millilitre) were 192 (86) and 4.71 (0.64), respectively. Choline (Cho)/Creatine (Cr) and myoinositol (MI)/Cr ratios were significantly lower in the FGM in HIV-infected subjects compared to controls (0.67 (0.14) versus 0.88 (0.49), p = 0.036, and 0.94 (0.28) and 1.17 (0.26), p = 0.008, for Cho/Cr and MI/Cr, respectively) and Cho/Cr ratio associated with CD4+ lymphocyte count (p = 0.041). N-Acetyl-aspartate (NAA)/Cho ratio was significantly lower in the RBG in HIV-infected subjects compared to controls (2.27 (0.54) versus 2.63 (0.68), p = 0.002), and this was associated with greater plasma HIV RNA load (p = 0.014). Two patterns of cerebral metabolite abnormalities were observed in HIV-infected subjects electively commencing cART. Greater inflammatory metabolite ratios (Cho/Cr and MI/Cr) associated with lower markers of peripheral immune markers (CD4+ lymphocyte count) in the FGM and lower neuronal metabolite ratios (NAA/Cho) associated with greater HIV viraemia in the RBG were present in HIV-infected subjects. (orig.)

Long term delivery of pulsed magnetic fields does not alter visual discrimination learning or dendritic spine density in the mouse CA1 pyramidal or dentate gyrus neurons [v2; ref status: indexed, http://f1000r.es/2gk

Directory of Open Access Journals (Sweden)

Matthew Sykes

2013-12-01

Full Text Available Repetitive transcranial magnetic stimulation (rTMS is thought to facilitate brain plasticity. However, few studies address anatomical changes following rTMS in relation to behaviour. We delivered 5 weeks of daily pulsed rTMS stimulation to adult ephrin-A2-/- and wildtype (C57BI/6j mice (n=10 per genotype undergoing a visual learning task and analysed learning performance, as well as spine density, in the dentate gyrus molecular and CA1 pyramidal cell layers in Golgi-stained brain sections. We found that neither learning behaviour, nor hippocampal spine density was affected by long term rTMS. Our negative results highlight the lack of deleterious side effects in normal subjects and are consistent with previous studies suggesting that rTMS has a bigger effect on abnormal or injured brain substrates than on normal/control structures.

Electrocardiographic abnormalities in opiate addicts.

Science.gov (United States)

Wallner, Christina; Stöllberger, Claudia; Hlavin, Anton; Finsterer, Josef; Hager, Isabella; Hermann, Peter

2008-12-01

To determine in a cross-sectional study the prevalence of electrocardiographic (ECG) abnormalities in opiate addicts who were therapy-seeking and its association with demographic, clinical and drug-specific parameters. In consecutive therapy-seeking opiate addicts, a 12-lead ECG was registered within 24 hours after admission and evaluated according to a pre-set protocol between October 2004 and August 2006. Additionally, demographic, clinical and drug-specific parameters were recorded. Included were 511 opiate-addicts, 25% female, with a mean age of 29 years (range 17-59 years). One or more ECG abnormalities were found in 314 patients (61%). In the 511 patients we found most commonly ST abnormalities (19%), QTc prolongation (13%), tall R- and/or S-waves (11%) and missing R progression (10%). ECG abnormalities were more common in males than in females (64 versus 54%, P seizures less often (16 versus 27%, P opiate addicts. The most frequent ECG abnormalities are ST abnormalities, QTc prolongation and tall R- and/or S-waves. ST abnormalities are associated with cannabis, and QTc prolongation with methadone and benzodiazepines.

Nuclear magnetic resonance imaging of the thorax

International Nuclear Information System (INIS)

Gamsu, G.; Webb, W.R.; Sheldon, P.; Kaufman, L.; Crooks, L.E.; Birnberg, F.A.; Goodman, P.; Hinchcliffe, W.A.; Hedgecock, M.

1983-01-01

Nuclear magnetic resonance (NMR) images of the thorax were obtained in ten normal volunteers, nine patients with advanced bronchogenic carcinoma, and three patients with benign thoracic abnormalities. In normal volunteers, mediastinal and hilar structures were seen with equal frequency on NMR images and computed tomographic scans. The hila were especially well displayed on spin-echo images. Spin-echo images showed mediastinal invasion by tumor, vascular and bronchial compression and invasion, and hilar and mediastinal adenopathy. Tumor and benign abnormalities could be separated from mediastinal and hilar fat because of their longer T1 times. Lung masses and nodules as small as 1.5 cm could be seen on the spin-echo images. NMR imaging shows promise for assessment of benign and malignant mediastinal, hilar, and lung abnormalities

Roentgenologic abnormalities in Down's syndrome

Energy Technology Data Exchange (ETDEWEB)

Higuchi, Takehiko; Russell, W J; Komatsuda, Michio; Neriishi, Shotaro

1968-07-25

Roentgenograms of 28 patients with Down's syndrome were reviewed with emphasis on all previously reported abnormalities and any possible additional ones. Most of the abnormalities occurred with the same frequency as previously reported, but some less frequently reported findings were also seen. One abnormal vertebral measurement found in this series may be an additional stigma of Down's syndrome. All of the 27 cases studied cytogenetically had chromosomal abnormalities consistent with this disease. This study emphasizes the need for roentgenologic norms for the Japanese, and the desirability of combining chromosome studies with roentgenological abnormalities and clinical observations in diagnosing Down's syndrome. 19 references, 2 figures, 5 tables.

Magnetic and magneto-elastic properties of a single crystal of TbB{sub 6}

Energy Technology Data Exchange (ETDEWEB)

Granovsky, S.A.; Amara, M.; Galera, R.M. [Laboratoire Louis Neel, CNRS, BP 166, Grenoble (France); Kunii, S. [Department of Physics, Faculty of Science, Tohoku University, Aramaki, Aoba-ku, Sendai (Japan)

2001-07-23

The magnetic and magneto-elastic properties of a single crystal of TbB{sub 6} are studied. In the ordered range metamagnetic behaviours are observed and complex phase diagrams are determined for magnetic fields along fourfold and threefold directions. In the paramagnetic phase the third-order magnetic susceptibilities and the parastriction curves show anisotropic behaviour which could be accounted for by crystalline electric field (CEF) effects. A set of CEF parameters is proposed on the basis of the analysis of the experimental magnetic and quadrupolar susceptibilities. Though non-negligible, the deduced quadrupolar couplings are weak in comparison with those previously determined in PrB{sub 6}. (author)

CT and MR imaging of odontoid abnormalities: A pictorial review

Directory of Open Access Journals (Sweden)

Nishchint Jain

2016-01-01

Full Text Available Odontoid process is the central pillar of the craniovertebral junction. Imaging of this small structure continues to be a challenge for the radiologists due to complex bony and ligamentous anatomy. A wide range of developmental and acquired abnormalities of odontoid have been identified. Their accurate radiologic evaluation is important as different lesions have markedly different clinical course, patient management, and prognosis. This article seeks to provide knowledge for interpreting appearances of odontoid on computed tomography (CT and magnetic resonance imaging (MRI with respect to various disease processes, along with providing a quick review of the embryology and relevant anatomy.

Latent and Abnormal Functional Connectivity Circuits in Autism Spectrum Disorder.

Science.gov (United States)

Chen, Shuo; Xing, Yishi; Kang, Jian

2017-01-01

Autism spectrum disorder (ASD) is associated with disrupted brain networks. Neuroimaging techniques provide noninvasive methods of investigating abnormal connectivity patterns in ASD. In the present study, we compare functional connectivity networks in people with ASD with those in typical controls, using neuroimaging data from the Autism Brain Imaging Data Exchange (ABIDE) project. Specifically, we focus on the characteristics of intrinsic functional connectivity based on data collected by resting-state functional magnetic resonance imaging (rs-fMRI). Our aim was to identify disrupted brain connectivity patterns across all networks, instead of in individual edges, by using advanced statistical methods. Unlike many brain connectome studies, in which networks are prespecified before the edge connectivity in each network is compared between clinical groups, we detected the latent differentially expressed networks automatically. Our network-level analysis identified abnormal connectome networks that (i) included a high proportion of edges that were differentially expressed between people with ASD and typical controls; and (ii) showed highly-organized graph topology. These findings provide new insight into the study of the underlying neuropsychiatric mechanism of ASD.

Cognitive dysfunction and functional magnetic resonance imaging in systemic lupus erythematosus.

Science.gov (United States)

Barraclough, M; Elliott, R; McKie, S; Parker, B; Bruce, I N

2015-10-01

Cognitive dysfunction is a common aspect of systemic lupus erythematosus (SLE) and is increasingly reported as a problem by patients. In many cases the exact cause is unclear. Limited correlations between specific autoantibodies or structural brain abnormalities and cognitive dysfunction in SLE have been reported. It may be that the most appropriate biomarkers have yet to be found. Functional magnetic resonance imaging (fMRI) is a technique used in many other conditions and provides sensitive measures of brain functionality during cognitive tasks. It is now beginning to be employed in SLE studies. These studies have shown that patients with SLE often perform similarly to healthy controls in terms of behavioural measures on cognitive tasks. However, SLE patients appear to employ compensatory brain mechanisms, such as increased response in fronto-parietal regions, to maintain adequate cognitive performance. As there have been only a few studies using fMRI in SLE to investigate cognitive dysfunction, many questions remain unanswered. Further research could, however, help to identify biomarkers for cognitive dysfunction in SLE. © The Author(s) 2015.

Amplitude of low frequency fluctuation abnormalities in adolescents with online gaming addiction.

Science.gov (United States)

Yuan, Kai; Jin, Chenwang; Cheng, Ping; Yang, Xuejuan; Dong, Tao; Bi, Yanzhi; Xing, Lihong; von Deneen, Karen M; Yu, Dahua; Liu, Junyu; Liang, Jun; Cheng, Tingting; Qin, Wei; Tian, Jie

2013-01-01

The majority of previous neuroimaging studies have demonstrated both structural and task-related functional abnormalities in adolescents with online gaming addiction (OGA). However, few functional magnetic resonance imaging (fMRI) studies focused on the regional intensity of spontaneous fluctuations in blood oxygen level-dependent (BOLD) during the resting state and fewer studies investigated the relationship between the abnormal resting-state properties and the impaired cognitive control ability. In the present study, we employed the amplitude of low frequency fluctuation (ALFF) method to explore the local features of spontaneous brain activity in adolescents with OGA and healthy controls during resting-state. Eighteen adolescents with OGA and 18 age-, education- and gender-matched healthy volunteers participated in this study. Compared with healthy controls, adolescents with OGA showed a significant increase in ALFF values in the left medial orbitofrontal cortex (OFC), the left precuneus, the left supplementary motor area (SMA), the right parahippocampal gyrus (PHG) and the bilateral middle cingulate cortex (MCC). The abnormalities of these regions were also detected in previous addiction studies. More importantly, we found that ALFF values of the left medial OFC and left precuneus were positively correlated with the duration of OGA in adolescents with OGA. The ALFF values of the left medial OFC were also correlated with the color-word Stroop test performance. Our results suggested that the abnormal spontaneous neuronal activity of these regions may be implicated in the underlying pathophysiology of OGA.

Amplitude of low frequency fluctuation abnormalities in adolescents with online gaming addiction.

Directory of Open Access Journals (Sweden)

Kai Yuan

Full Text Available The majority of previous neuroimaging studies have demonstrated both structural and task-related functional abnormalities in adolescents with online gaming addiction (OGA. However, few functional magnetic resonance imaging (fMRI studies focused on the regional intensity of spontaneous fluctuations in blood oxygen level-dependent (BOLD during the resting state and fewer studies investigated the relationship between the abnormal resting-state properties and the impaired cognitive control ability. In the present study, we employed the amplitude of low frequency fluctuation (ALFF method to explore the local features of spontaneous brain activity in adolescents with OGA and healthy controls during resting-state. Eighteen adolescents with OGA and 18 age-, education- and gender-matched healthy volunteers participated in this study. Compared with healthy controls, adolescents with OGA showed a significant increase in ALFF values in the left medial orbitofrontal cortex (OFC, the left precuneus, the left supplementary motor area (SMA, the right parahippocampal gyrus (PHG and the bilateral middle cingulate cortex (MCC. The abnormalities of these regions were also detected in previous addiction studies. More importantly, we found that ALFF values of the left medial OFC and left precuneus were positively correlated with the duration of OGA in adolescents with OGA. The ALFF values of the left medial OFC were also correlated with the color-word Stroop test performance. Our results suggested that the abnormal spontaneous neuronal activity of these regions may be implicated in the underlying pathophysiology of OGA.

Magnetic resonance imaging of transfusional hemosiderosis complicating thalassemia major

International Nuclear Information System (INIS)

Brasch, R.C.; Wesbey, G.E.; Gooding, C.A.; Koerper, M.A.

1984-01-01

Tissue deposits of hemosiderin, a paramagnetic iron-protein complex, resulted in marked abnormalities of magnetic resonance (MR) spin-echo signal intensity within the viscera of three children with transfusional hemosiderosis and thalassemia major. In all patients the liver and bone marrow demonstrated abnormally low spin-echo intensities and the kidneys and muscles had abnormally high intensities. These observations correlate with in vitro MR observation of ferric (Fe +3 ) solutions, in which concentrations of ferric salts greater than 20 mmol yielded higher intensities than did water alone. MR imaging is sensitive to the tissue deposition of hemosiderin, and MR intensity appears to provide a rough measure of the amount of iron deposited

Abnormality diagnosis device for nuclear reactor

Energy Technology Data Exchange (ETDEWEB)

Utsunomiya, Kazuhiro; Oyama, Shinmi; Sakaba, Hideo

1989-02-21

According to the present invention, abnormality such as abnormal increase of temperature in a nuclear reactor is detected to send a signal to control rod drives, etc. thereby stopping the operation of the nuclear reactor. Receiving/transmission device transmits a signal for conducting normal operation of an abnormality information section, as well as receives an echo signal from the abnormality information section to transmit an abnormal signal to a reactor protection system. The abnormality information section is disposed to fuel assemblies, receives a signal from the receiving/transmission device for conducting the normal operation to transmit a normal echo signal, as well as changes the echo signal when detecting the nuclear reactor abnormality. By the foregoing method, since the abnormality information section is disposed to the fuel assemblies, various effects can be attained such as: (1) there is no response delay from the occurrence of abnormality to emergency counter measure after detection, (2) high burnup degree for fuels can thus be possible to improve the economical property, (3) the abnormality information section can be taken out from the reactor container together with fuel assemablies by an existent take-out mechanism and (4) since wireless transmission and reception are established between the receiving/transmission device and the abnormality information section, cables are not required in the container. (K.M.).

Magnetic memory of a single-molecule quantum magnet wired to a gold surface.

Science.gov (United States)

Mannini, Matteo; Pineider, Francesco; Sainctavit, Philippe; Danieli, Chiara; Otero, Edwige; Sciancalepore, Corrado; Talarico, Anna Maria; Arrio, Marie-Anne; Cornia, Andrea; Gatteschi, Dante; Sessoli, Roberta

2009-03-01

In the field of molecular spintronics, the use of magnetic molecules for information technology is a main target and the observation of magnetic hysteresis on individual molecules organized on surfaces is a necessary step to develop molecular memory arrays. Although simple paramagnetic molecules can show surface-induced magnetic ordering and hysteresis when deposited on ferromagnetic surfaces, information storage at the molecular level requires molecules exhibiting an intrinsic remnant magnetization, like the so-called single-molecule magnets (SMMs). These have been intensively investigated for their rich quantum behaviour but no magnetic hysteresis has been so far reported for monolayers of SMMs on various non-magnetic substrates, most probably owing to the chemical instability of clusters on surfaces. Using X-ray absorption spectroscopy and X-ray magnetic circular dichroism synchrotron-based techniques, pushed to the limits in sensitivity and operated at sub-kelvin temperatures, we have now found that robust, tailor-made Fe(4) complexes retain magnetic hysteresis at gold surfaces. Our results demonstrate that isolated SMMs can be used for storing information. The road is now open to address individual molecules wired to a conducting surface in their blocked magnetization state, thereby enabling investigation of the elementary interactions between electron transport and magnetism degrees of freedom at the molecular scale.

Structural magnetic resonance imaging can identify trigeminal system abnormalities in classical trigeminal neuralgia

Directory of Open Access Journals (Sweden)

Danielle DeSouza

2016-10-01

Full Text Available Classical trigeminal neuralgia (TN is a chronic pain disorder that has been described as one ofthe most severe pains one can suffer. The most prevalent theory of TN etiology is that the trigeminal nerve is compressed at the root entry zone (REZ by blood vessels. However, there is significant evidence showing a lack of neurovascular compression (NVC for many cases of classical TN. Furthermore, a considerable number of patients who are asymptomatic have MR evidence of NVC. Since there is no validated animal model that reproduces the clinical features of TN, our understanding of TN pathology mainly comes from biopsy studies that have limitations. Sophisticated structural MRI techniques including diffusion tensor imaging provide new opportunities to assess the trigeminal nerves and CNS to provide insight into TN etiology and pathogenesis. Specifically, studies have used high-resolution structural MRI methods to visualize patterns of trigeminal nerve-vessel relationships and to detect subtle pathological features at the trigeminal REZ. Structural MRI has also identified CNS abnormalities in cortical and subcortical gray matter and white matter and demonstrated that effective neurosurgical treatment for TN is associated with a reversal of specific nerve and brain abnormalities. In conclusion, this review highlights the advanced structural neuroimaging methods that are valuable tools to assess the trigeminal system in TN and may inform our current understanding of TN pathology. These methods may in the future have clinical utility for the development of neuroimaging-based biomarkers of TN.

A survey on abnormal uterine bleeding among radiographers with frequent MRI exposure using intrauterine contraceptive devices.

Science.gov (United States)

Huss, A; Schaap, K; Kromhout, H

2018-02-01

Based on a previous case report of menometrorrhagia (prolonged/excessive uterine bleeding, occurring at irregular and/or frequent intervals) in MRI workers with intrauterine devices (IUDs), it was evaluated whether this association could be confirmed. A survey was performed among 381 female radiographers registered with their national association. Logistic regression was used to analyze associations of abnormal uterine bleeding with the frequency of working with MRI scanners, presence near the scanner/in the scanner room during image acquisition, and with scanner strength or type. A total of 68 women reported using IUDs, and 72 reported abnormal uterine bleeding. Compared with unexposed women not using IUDs, the odds ratio in women with IUDs working with MRI scanners was 2.09 (95% confidence interval 0.83-3.66). Associations were stronger if women working with MRI reported being present during image acquisition (odds ratio 3.43, 95% CI 1.26-9.34). Associations with scanner strength or type were not consistent. Radiographers using IUDs who are occupationally exposed to stray fields from MRI scanners report abnormal uterine bleeding more often than their co-workers without an IUD, or nonexposed co-workers with an IUD. In particular, radiographers present inside the scanner room during image acquisition showed an increased risk. Magn Reson Med 79:1083-1089, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Avoiding shame: young LGBT people, homophobia and self-destructive behaviours.

Science.gov (United States)

McDermott, Elizabeth; Roen, Katrina; Scourfield, Jonathan

2008-11-01

This paper reports on findings from qualitative research conducted in the UK that sought to explore the connections between sexual identities and self-destructive behaviours in young people. International evidence demonstrates that there are elevated rates of suicide and alcohol abuse amongst lesbian, gay, bisexual and transgender (LGBT) youth. Rarely included in this body of research are investigations into young LGBT people's views and experiences of self-destructive behaviours. Data from interviews and focus groups with young LGBT participants suggest a strong link between homophobia and self-destructive behaviours. Utilising a discourse analytic approach, we argue that homophobia works to punish at a deep individual level and requires young LGBT people to manage being positioned, because of their sexual desire or gendered ways of being, as abnormal, dirty and disgusting. At the centre of the complex and multiple ways in which young LGBT people negotiate homophobia are 'modalities of shame-avoidance' such as: the routinization and minimizing of homophobia; maintaining individual 'adult' responsibility; and constructing 'proud' identities. The paper argues that these strategies of shame-avoidance suggest young LGBT people manage homophobia individually, without expectation of support and, as such, may make them vulnerable to self-destructive behaviours.

Atomoxetine reduces hyperactive/impulsive behaviours in neurokinin-1 receptor ‘knockout’ mice

Science.gov (United States)

Pillidge, Katharine; Porter, Ashley J.; Vasili, Temis; Heal, David J.; Stanford, S. Clare

2014-01-01

Background Mice with functional ablation of the neurokinin-1 receptor gene (NK1R−/−) display behavioural abnormalities which resemble the hyperactivity, inattention and impulsivity seen in Attention Deficit Hyperactivity Disorder (ADHD). Here, we investigated whether the established ADHD treatment, atomoxetine, alleviates these abnormalities when tested in the light/dark exploration box (LDEB) and 5-Choice Serial Reaction-Time Task (5-CSRTT). Methods Separate cohorts of mice were tested in the 5-CSRTT and LDEB after treatment with no injection, vehicle or atomoxetine (5-CSRTT: 0.3, 3 or 10 mg/kg; LDEB: 1, 3 or 10 mg/kg). Results Atomoxetine reduced the hyperactivity displayed by NK1R−/− mice in the LDEB at a dose (3 mg/kg) which did not affect the locomotor activity of wildtypes. Atomoxetine (10 mg/kg) also reduced impulsivity in NK1R−/− mice, but not wildtypes, in the 5-CSRTT. No dose of drug affected attention in either genotype. Conclusions This evidence that atomoxetine reduces hyperactive/impulsive behaviours in NK1R−/− mice consolidates the validity of using NK1R−/− mice in research of the aetiology and treatment of ADHD. PMID:25450119

Unstable magnetic moments in Ce compounds

International Nuclear Information System (INIS)

Aarts, J.

1984-01-01

The problems which are connected with the appearance or disappearance of local moments in metals are well reflected in the magnetic behaviour of Ce intermetallic compounds. This work describes experiments on two Ce compounds which are typical examples of unstable moment systems. The first of these is CeAl 2 which at low temperatures, shows coexistence of antiferromagnetic order and the Kondo effect. Measurements are presented of the magnetization and the susceptibility in different magnetic field and temperature regions. An analysis of these measurements, using a model for the crystal field effects, shows the agreement between the measurements and the calculations to be reasonably good for CeAl 2 , but this agreement becomes worse upon decreasing Ce concentration. A phenomenological description of the observations is given. The second compound reported on is CeCu 2 Si 2 , the first 'heavy-fermion' superconductor to be investigated. The superconducting state is possibly formed by the quasi-particles of a non-magnetic many body singlet state, and not simply by the (sd) conduction electrons. This being a novel phenomenon, a number of experiments were performed to test this picture and to obtain a detailed description of the behaviour of CeCu 2 Si 2 . Measurements of the Meissner volume, confirmed the superconductivity to be intrinsic. (Auth.)

Micromagnetic simulation of the influence of grain boundary on cerium substituted Nd-Fe-B magnets

Directory of Open Access Journals (Sweden)

D. Liu

2017-05-01

Full Text Available A three-dimensional finite element model was performed to study the magnetization reversal of (CexNd1-x2Fe14B nanocomposite permanent magnets. The influences of volume fraction, width and performance parameters of the grain boundary (GB composition on the coercivity were analyzed by the method of micromagnetic simulation. The calculation results indicate that the structure and chemistry of GB phase play important roles in Nd2Fe14B-based magnets. An abnormal increase in the value of coercivity is found to be connected with the GB phase, approximately when the percentage of doped cerium is between 20% and 30%. While the coercivity decreases directly with the increase in cerium content instead of being abnormal when there is no GB phase in magnets at all or the value of magnetocrystalline anisotropy or exchange integral is too large.

Abnormalities of Object Visual Processing in Body Dysmorphic Disorder

Science.gov (United States)

Feusner, Jamie D.; Hembacher, Emily; Moller, Hayley; Moody, Teena D.

2013-01-01

Background Individuals with body dysmorphic disorder may have perceptual distortions for their appearance. Previous studies suggest imbalances in detailed relative to configural/holistic visual processing when viewing faces. No study has investigated the neural correlates of processing non-symptom-related stimuli. The objective of this study was to determine whether individuals with body dysmorphic disorder have abnormal patterns of brain activation when viewing non-face/non-body object stimuli. Methods Fourteen medication-free participants with DSM-IV body dysmorphic disorder and 14 healthy controls participated. We performed functional magnetic resonance imaging while participants matched photographs of houses that were unaltered, contained only high spatial frequency (high detail) information, or only low spatial frequency (low detail) information. The primary outcome was group differences in blood oxygen level-dependent signal changes. Results The body dysmorphic disorder group showed lesser activity in the parahippocampal gyrus, lingual gyrus, and precuneus for low spatial frequency images. There were greater activations in medial prefrontal regions for high spatial frequency images, although no significant differences when compared to a low-level baseline. Greater symptom severity was associated with lesser activity in dorsal occipital cortex and ventrolateral prefrontal cortex for normal and high spatial frequency images. Conclusions Individuals with body dysmorphic disorder have abnormal brain activation patterns when viewing objects. Hypoactivity in visual association areas for configural and holistic (low detail) elements and abnormal allocation of prefrontal systems for details is consistent with a model of imbalances in global vs. local processing. This may occur not only for appearance but also for general stimuli unrelated to their symptoms. PMID:21557897

Electrolytic tiltmeters inside magnetic fields: Some observations

International Nuclear Information System (INIS)

Alberdi, J.; Arce, P.; Barcala, J.M.; Calvo, E.; Ferrando, A.; Josa, M.I.; Luque, J.M.; Molinero, A.; Navarrete, J.; Oller, J.C.; Yuste, C.; Calderon, A.; Garcia-Moral, L.A.; Gomez, G.; Gonzalez-Sanchez, F.J.; Martinez-Rivero, C.; Matorras, F.; Rodrigo, T.; Ruiz-Arbol, P.; Scodellaro, L.; Sobron, M.; Vila, I.; Virto, A.L.

2007-01-01

We present observations of the electrolytic clinometers behaviour inside magnetic field environments introducing phenomenological expressions to account for the measured output voltage variations as functions of field gradients and field strengths

Electrolytic tiltmeters inside magnetic fields: Some observations

Energy Technology Data Exchange (ETDEWEB)

Alberdi, J. [CIEMAT, Madrid (Spain); Arce, P. [CIEMAT, Madrid (Spain); Barcala, J.M. [CIEMAT, Madrid (Spain); Calvo, E. [CIEMAT, Madrid (Spain); Ferrando, A. [CIEMAT, Madrid (Spain)]. E-mail: antonio.ferrando@ciemat.es; Josa, M.I. [CIEMAT, Madrid (Spain); Luque, J.M. [CIEMAT, Madrid (Spain); Molinero, A. [CIEMAT, Madrid (Spain); Navarrete, J. [CIEMAT, Madrid (Spain); Oller, J.C. [CIEMAT, Madrid (Spain); Yuste, C. [CIEMAT, Madrid (Spain); Calderon, A. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Garcia-Moral, L.A. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Gomez, G. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Gonzalez-Sanchez, F.J. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Martinez-Rivero, C. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Matorras, F. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Rodrigo, T. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Ruiz-Arbol, P. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Scodellaro, L. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Sobron, M. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Vila, I. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain); Virto, A.L. [Instituto de Fisica de Cantabria, CSIC-University of Cantabria, Santander (Spain)

2007-04-21

We present observations of the electrolytic clinometers behaviour inside magnetic field environments introducing phenomenological expressions to account for the measured output voltage variations as functions of field gradients and field strengths.

Ising model on tangled chain - 2: Magnetization and susceptibility

International Nuclear Information System (INIS)

Mejdani, R.

1993-05-01

In the preceding paper we have considered an Ising model defined on tangled chain to study the behaviour of the free energy and entropy, particularly in the zero-field and zero-temperature limit. In this paper, following the main line and basing on some results of the previous work, we shall study in the ''language'' of state configurations the behaviour of the magnetization and the susceptibility for different conditions of the model, to understand better the competition between the ferromagnetic bonds along the chain and the antiferromagnetic additional bonds across the chain. Particularly interesting is the behaviour of the susceptibility in the zero-field and zero-temperature limit. Exact solutions for the magnetization and susceptibility, generated by analytical calculations and iterative algorithms, are described. The additional bonds, introduced as a form of perfectly disorder, indicate a particular effect on the spin correlation. We found that the condition J=-J' between the ferromagnetic interaction J along the chain and the antiferromagnetic interaction J' across the chain is somewhat as a ''transition-region'' condition for this behaviour. (author). 16 refs, 14 figs

Quantum circuit behaviour

International Nuclear Information System (INIS)

Poulton, D.

1989-09-01

Single electron tunnelling in multiply connected weak link systems is considered. Using a second quantised approach the tunnel current, in both normal and superconducting systems, using perturbation theory, is derived. The tunnel currents are determined as a function of an Aharanov-Bohm phase (acquired by the electrons). Using these results, the multiply connected system is then discussed when coupled to a resonant LC circuit. The resulting dynamics of this composite system are then determined. In the superconducting case the results are compared and contrasted with flux mode behaviour seen in large superconducting weak link rings. Systems in which the predicted dynamics may be seen are also discussed. In analogy to the electron tunnelling analysis, the tunnelling of magnetic flux quanta through the weak link is also considered. Here, the voltage across the weak link, due to flux tunnelling, is determined as a function of an externally applied current. This is done for both singly and multiply connected flux systems. The results are compared and contrasted with charge mode behaviour seen in superconducting weak link systems. Finally, the behaviour of simple quantum fluids is considered when subject to an external rotation. Using a microscopic analysis it is found that the microscopic quantum behaviour of the particles is manifest on a macroscopic level. Results are derived for bosonic, fermionic and BCS pair-type systems. The connection between flux quantisation in electromagnetic systems is also made. Using these results, the dynamics of such a quantum fluid is considered when coupled to a rotating torsional oscillator. The results are compared with those found in SQUID devices. A model is also presented which discusses the possible excited state dynamics of such a fluid. (author)

Correlation between magnetostriction and magnetic structure in pseudobinary compounds Tb(Co1-xFex2

Directory of Open Access Journals (Sweden)

Yue Wang

2017-07-01

Full Text Available Giant low-field magnetostriction has been achieved in pseudobinary Laves phase compounds RR’T2 (R and R’: rare earth elements; T: transition metal elements around the ferromagnetic - ferromagnetic (ferro.-ferro. transition temperature. Evolution of the magnetic structure across such transition requires comprehensive investigation. In this work, pseudobinary system Tb(Co1-xFex2 is selected to investigate the evolution of local magnetic moment, for which two end terminals TbCo2 and TbFe2 possess the rhombohedral (R structure at the ferromagnetic state but with different magnetic ordering temperatures (TC. Magnetometry measurements reveal that a composition independent ferromagnetic - ferromagnetic transition occurs at ∼100 K despite the increased Curie temperature TC with raised Fe concentration in the Tb(Co1-xFex2. Synchrotron XRD data reveal that both the lattice parameter and the lattice strain along the direction are abnormally temperature dependent, accompanied with experimentally observed magnetostriction abnormality at 100 K. In-situ neutron powder diffraction (NPD results show that the local magnetic moments of T2 (9e site atoms are also abnormally temperature dependent, which is larger at 100 K than that at a lower temperature 50 K. Such findings indicate close correlations between the magnetic structure and the magnetostrictive effect in the pseudobinary RT2 compounds.

Strain-tuning of edge magnetism in zigzag graphene nanoribbons.

Science.gov (United States)

Yang, Guang; Li, Baoyue; Zhang, Wei; Ye, Miao; Ma, Tianxing

2017-09-13

Using the determinant quantum Monte-Carlo method, we elucidate the strain tuning of edge magnetism in zigzag graphene nanoribbons. Our intensive numerical results show that a relatively weak Coulomb interaction may induce a ferromagnetic-like behaviour with a proper strain, and the edge magnetism can be enhanced greatly as the strain along the zigzag edge increases, which provides another way to control graphene magnetism even at room temperature.

Magnetic resonance imaging abnormalities in multiple sclerosis: A review

International Nuclear Information System (INIS)

Saharian, M. A.; Shakaouri Rad, A.; Motamedi, M.; Pakdaman, H.; Radue, E. W.

2007-01-01

:During the last two decades, magnetic resonance imaging has been widely used In the diagnosis and treatment monitoring of multiple sclerosis. MRI, both conventional and non conventional methods, has transformed all aspects of M S research and clinical practice in recent years. Although advanced imaging methods have added much more to our knowledge about pathogenesis and natural history of the disease but their cost, availability, complexity and lack of validation have limited their use in routine clinical practice. Conventional MR techniques including proton density, T1/T2-Weighted images and fluid- attenuated inversion recovery sequences are now accepted in standard protocols for diagnosis and treatment outcome measures in clinical trials of multiple sclerosis. This review will focus on the type, morphology and evolution of M S lesions regarding conventional MRI and their use for treatment monitoring in daily clinical practice

ETGAR - Information system for abnormal occurrences in nuclear power plants

International Nuclear Information System (INIS)

Baram, J.; Nagar, M.; Pultorak, G.

1975-01-01

The need for extensive information on systems and components arises early in the planning stage of a nuclear power plant. This information is equally necessary during the building of the plant and during the licensing process. Another type of information helps preventive maintenance during the operating life of the plant. In the case of abnormal occurrences additional information on their possible consequences and on possible ways of handling them, is essential. To cover these four needs, the ETGAR system, which at present covers mostly PWR and BWR type nuclear power plants, collects and evaluates information on abnormal occurrences in nuclear power plants. The information is coded, using a three-level coding scheme for systems and components, and put on magnetic tape. A search program enables the retrieval of any pertinent information from the data base. The sources for the ETGAR data base are reports on abnormal occurrences in nuclear power plants. Most of them are USAEC dockets, originated at U.S.A. power plants. The relevant documents are accessible through a standard query run for ETGAR in the INIS data base which is maintained by the INIS centre in Israel. This query retrieves every two weeks all the documents which come under the ETGAR scope and these are handed as microfiches to the ETGAR evaluators after each INIS run. The evaluation and coding of the documents, the ETGAR coding scheme and the computer programs are described. (B.G.)

Improvement of the microstructure and magnetic properties of sintered NdFeB permant magnets

International Nuclear Information System (INIS)

Vial, F.; Rozendaal, E.; Sagawa, M.

1998-01-01

A correlation between sintered NdFeB process, microstructure of the products at each step of the process and magnetic properties has been established. To increase (BH) max of sintered NdFeB magnets, the total rare-earth content in the alloy has to be decreased and to keep coercivity as high as possible, the unavoidable oxygen pick-up has to be substantially reduced. The composition improvements tend to create a high sensitivity to form abnormal grain growth which can potentially occur during the sintering operation. Special attention has been given to characterising, understanding the mechanisms and solving this defect which could affect the magnetic properties. In addition, the composition and each step of the process have been optimised to improve magnetic properties, thermal stability and corrosion resistance of the NdFeB permanent magnets. These collaborative studies have resulted in a significant improvement of both remanence and coercivity of the sintered NdFeB permanent magnets, covering a wide coercivity range from 800 to 2500 kA/m (10 to 35 kOe) with respective associated energy products of 400 to 270 kJ/m3 (52 to 35 MGOe). (orig.)

On the influence of mechanical and magnetic characteristics on the field quality of superconducting magnets

International Nuclear Information System (INIS)

Abramov, A.G.; Ershov, S.Yu.; Daikovsky, A.G.; Ryabov, A.D.; Tkachenko, N.P.

1992-01-01

The paper presents a numerical analysis of the effect of mechanical processes in a superconducting magnet, beginning with the coil assembly fabrication and ending with energizing it. The purpose of our work was to find the correlations between the harmonics and mechanical behaviour of the design and hence, to detect possible defects in the production technology and show the possible ways of solving the problems. The effects related to the saturation of the magnetic shield are analysed as well. (Author)

Children with Congenital Hypothyroidism Have Similar Neuroradiological Abnormal Findings as Healthy Ones

Directory of Open Access Journals (Sweden)

Marianna Rachmiel

2013-01-01

Full Text Available Objective. To assess the neuroradiological findings of children with congenital hypothyroidism (CHT compared to healthy controls (HC. Patients and Methods. Thirty children with CHT, mean age 12.5 ± 1.6 years, 14 (44.8% males, were compared with 38 HC mean age 11.7 ± 1.7 years, 16 (45.7% males. Clinical data were collected from medical charts and questionnaires seeking information on family history, birth and perinatal period events, medications, and overall health history. Neurocognitive function was assessed for global intelligence, visual and verbal memory, and executive functioning using standardized tests. Neuroimaging was performed using 1.5 T magnetic resonance imaging and assessed by two pediatric radiologists. Results. Children with CHT had a similar proportion of incidental findings as did the children in the HC group, at 43.3% and 39.5%, respectively, . Abnormalities of the sellar region were reported in 13.3% of CHT group and 7.9% of HC group, . Other incidental findings included cerebellar ectopia, choroidal fissure and pineal cysts, and multiple increased signal intensity foci. Neuroradiological findings were not associated with clinical and neurocognitive abnormalities. Conclusion. Neuroimaging of children with CHT demonstrated a similar incidence of structural abnormalities as in the healthy population. There is no association between those findings and neurocognitive function.

Dynamic behaviour of the high confinement mode of fusion plasmas

International Nuclear Information System (INIS)

Zohm, H.

1995-05-01

This paper describes the dynamic behaviour of the High Confinement mode (H-mode) of fusion plasmas, which is one of the most promising regimes of enhanced energy confinement in magnetic fusion research. The physics of the H-mode is not yet fully understood, and the detailed behaviour is complex. However, we establish a simple physics picture of the phenomenon. Although a first principles theory of the anomalous transport processes in a fusion plasma has not yet been given, we show that within the picture developed here, it is possible to describe the dynamic behaviour of the H-mode, namely the dynamics of the L-H transition and the occurrence of edge localized modes (ELMs). (orig.)

Neutron depolarization study of static and dynamic magnetic properties of ferromagnets

International Nuclear Information System (INIS)

Stuesser, N.

1986-01-01

In this thesis neutron depolarization experiments are performed on amorphous and crystalline ferromagnetic materials. The subjects studied are concerned with 'domain structure in magnetically weak uniaxial amorphous ferromagnetic ribbons', 'static critical behaviour at the ferromagnetic-paramagnetic phase transition', 'small magnetic anisotropy in nickel near T c ', and 'magnetization reversal in conducting ferromagnets'. 87 refs.; 37 figs.; 3 tabs

Impaired affective and cognitive theory of mind and behavioural change in amyotrophic lateral sclerosis.

Science.gov (United States)

van der Hulst, Egberdina-Józefa; Bak, Thomas H; Abrahams, Sharon

2015-11-01

Executive and behavioural changes are well-recognised in classical amyotrophic lateral sclerosis (ALS), indicating a subclinical behavioural-variant frontotemporal dementia (bvFTD) in some patients. Social cognitive deficits in ALS have been recently described and an impairment was identified on a simple Theory of Mind (ToM) test, which assesses the judgement of the preference of another through direction of eye gaze. The present study further delineated this deficit, by distinguishing between Affective and Cognitive subcomponents, and determining the relationship to behavioural change, levels of empathy and self-awareness. The Cognitive-Affective Judgement of Preference Test was administered to 33 patients with ALS and 26 controls. Furthermore, a comprehensive neuropsychological battery and detailed behavioural assessment, with measures of empathy and awareness, were included. Patients with ALS showed a significant impairment in Affective ToM only when compared with healthy controls, with a deficit in 36% of patients; 12% showed an isolated Affective ToM deficit while 24% showed more generic ToM dysfunction. A Cognitive ToM deficit was found in 27% of patients, with 3% showing an isolated Cognitive ToM deficit. The patients with ALS showed reduced empathy (Fantasy scale) and increased behavioural dysfunction with high levels of apathy. In addition, patients with either an Affective and/or Cognitive ToM deficit exhibited poor self-awareness of their performance and abnormalities on verbal fluency, while those with an Affective ToM deficit also displayed higher levels of apathy and a naming deficit. Dysfunctional ToM is a prominent feature of the cognitive profile of ALS. This specific difficulty in identifying and distinguishing the feelings and thoughts of another from a self-perspective may underpin the social behavioural abnormalities present in some patients with ALS, manifest as apathy and loss of awareness. Published by the BMJ Publishing Group Limited. For

Nonlinear nuclear magnetic resonance in ferromagnets

International Nuclear Information System (INIS)

Nurgaliev, T.

1988-01-01

The properties of nonlinear nuclear magnetic resonance (NMR) have been studied theoretically by taking into account the interaction between NMR and FMR in the ferromagnets. The Landau-Lifshitz-Bloch equations, describing the electron and nuclear magnetization behaviour in ferromagnets are presented in an integral form for a weakly excited electronic system. The stationary solution of these equations has been analysed in the case of equal NMR and FMR frequencies: the criteria for the appearance of two stable dynamic states is found and the high-frequency magnetic susceptibility for these systems is investigated. 2 figs., 8 refs

Comparative study of magnetic ordering in bulk and nanoparticles of Sm0.65Ca0.35MnO3: Magnetization and electron magnetic resonance measurements

Science.gov (United States)

Goveas, Lora Rita; Anuradha, K. N.; Bhagyashree, K. S.; Bhat, S. V.

2015-05-01

To explore the effect of size reduction to nanoscale on the hole doped Sm0.65Ca0.35MnO3 compound, dc magnetic measurements and electron magnetic resonance (EMR) were done on bulk and nanoparticle samples in the temperature range 10 ≤ T ≤ 300 K. Magnetization measurement showed that the bulk sample undergoes a charge ordering transition at 240 K and shows a mixed magnetic phase at low temperature. However, the nanosample underwent a ferromagnetic transition at 75 K, and the charge ordered state was destabilized on size reduction down to nanoscale. The low-temperature ferromagnetic component is found to be enhanced in nanoparticles as compared to their bulk counterpart. Interestingly around room temperature, bulk particles show higher magnetization where as at low temperature nanoparticles show higher magnetization. Ferromagnetism in the bulk is due to super exchange where as ferromagnetism in nanoparticles is due to uncompensated spins of the surface layer. Temperature variation of EMR parameters correlates well with the results of magnetic measurements. The magnetic behaviour of the nanoparticles is understood in terms of the core shell scenario.

Normal and abnormal growth plate

International Nuclear Information System (INIS)

Kumar, R.; Madewell, J.E.; Swischuk, L.E.

1987-01-01

Skeletal growth is a dynamic process. A knowledge of the structure and function of the normal growth plate is essential in order to understand the pathophysiology of abnormal skeletal growth in various diseases. In this well-illustrated article, the authors provide a radiographic classification of abnormal growth plates and discuss mechanisms that lead to growth plate abnormalities

Magnetic resonance imaging in clinically-definite multiple sclerosis

International Nuclear Information System (INIS)

Noakes, J.B.; Herkes, G.K.; Frith, J.A.

1990-01-01

Forty-two patients with clinically-definite multiple sclerosis were examined by magnetic resonance imaging using a 1.5-T instrument. Magnetic resonance imaging detected an abnormality in 90% of patients. In four patients, no lesions were demonstrated. The number, size and site of the lesions by magnetic resonance imaging were compared with the patients' clinical status and other variables. The Kurtzke disability status scale score increased in patients with corpus callosum atrophy, brainstem and basal ganglia lesions, and correlated with the total number of lesions. No correlation was shown between the findings of magnetic resonance imaging and disease duration, age, sex or pattern-reversal visual-evoked potentials. The variety of magnetic resonance images that could be obtained in patients with clinically-definite multiple sclerosis is highlighted. 24 refs., 8 figs., 1 tab

Structural and magnetic properties of Fe60Al40 alloys prepared by means of a magnetic mill

International Nuclear Information System (INIS)

Bernal-Correa, R.; Rosales-Rivera, A.; Pineda-Gomez, P.; Salazar, N.A.

2010-01-01

A study on synthesis, structural and magnetic characterization of Fe 60 Al 40 (at.%) alloys prepared by means of mechanical alloying process is presented. The mechanical alloying was performed using a milling device with magnetically controlled ball movement (Uni-Ball-Mill 5 equipment) at several milling times. The characterization was carried out via X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The effects of milling time on the structural state, morphological evolution and magnetic behaviour of the Fe 60 Al 40 (at.%) alloys are discussed. Besides, in this current study we emphasize the result that indicating a ferro-para-ferromagnetic transition from a correlation between X-ray diffraction and magnetization data.

Abnormal thermal expansion properties of cubic NaZn13-type La(Fe,Al)13 compounds.

Science.gov (United States)

Li, Wen; Huang, Rongjin; Wang, Wei; Zhao, Yuqiang; Li, Shaopeng; Huang, Chuanjun; Li, Laifeng

2015-02-28

The cubic NaZn13-type La(Fe,Al)13 compounds were synthesized, and their linear thermal expansion properties were investigated in the temperature range of 4.2-300 K. It was found that these compounds exhibit abnormal thermal expansion behavior, i.e., pronounced negative thermal expansion (NTE) or zero thermal expansion (ZTE) behavior, below the Curie temperature due to the magnetovolume effect (MVE). Moreover, in the La(Fe,Al)13 compounds, the modification of the coefficient of thermal expansion (CTE) as well as the abnormal thermal expansion (ATE) temperature-window is achieved through optimizing the proportion of Fe and Al. Typically, the average CTE of the LaFe13-xAlx compounds with x = 1.8 reaches as large as -10.47 × 10(-6) K(-1) between 100 and 225 K (ΔT = 125 K). Also, the ZTE temperature-window of the LaFe13-xAlx compounds with x = 2.5 and x = 2.7 could be broadened to 245 K (from 5 to 250 K). Besides, the magnetic properties of these compounds were measured and correlated with the abnormal thermal expansion behavior. The present results highlight the potential application of such La(Fe,Al)13 compounds with abnormal thermal expansion properties in cryogenic engineering.

Switch-shock wave structure in a magnetized partly-ionized gas

International Nuclear Information System (INIS)

Cramer, N.F.

1975-01-01

The effect of the interaction of plasma and neutral gas on the structure of switch-type shock waves propagating in a partly-ionized gas is studied. These shocks, in which the magnetic field is perpendicular to the shock front either upstream or downstream, exhibit a spiralling behaviour of the magnetic field in the shock transition region, if the Hall term is important in the Ohm's law. Observations of this behaviour for shocks propagating into a plasma with a residual neutral content of about 15% has implied an anomalously high resistivity of the plasma. We show that this can be partly explained by considering the collisions of ions with the neutral atoms in a magnetic field. We show that the extra dissipation due to the increase in resistivity goes primarily to the ions and neutrals. Thus even in the absence of viscous dissipation within each species, the heavy particles can be appreciably heated in a shock propagating into a partly-ionized gas in a magnetic field. (author)

Magnetic resonance in neuroborreliosis

International Nuclear Information System (INIS)

Ustymowicz, A.; Zajkowska, J.

2003-01-01

Magnetic resonance (MR) is commonly used in diagnosing infections of the central nervous system. The aim of the study is to evaluate central nervous system changes in neuroborreliosis patients. MR examinations were performed in 44 patients with clinical symptoms, epidemiology and laboratory tests results of neuroborreliosis. Abnormalities were detected in 22 patients. Most of them presented cortico-subcortical atrophy (86%). In 9 cases foci of increased signal in T2-weighted and FLAIR images were observed in white matter. They were single or multiple, located subcorticaly and paraventriculary. In 2 subjects areas of increased signal were found in the brain stem. Central nervous system abnormalities detected with MR are not specific for Lyme disease. They can suggest demyelinating lesions and/or gliosis observed in many nervous system disorders (SM, ADEM, lacunar infarcts). (author)

Critical behaviour in very pure Ni-Ta systems

International Nuclear Information System (INIS)

Oddou, J.L.; Berthier, J.; Peretto, P.

1978-01-01

The authors use the perturbed angular correlation technique to follow the behaviour of the magnetic hyperfine field on 181 Ta in nickel in the critical region of the matrix. Contrary to what is expected, it is observed that the critical exponent associated to the hyperfine field is different from the critical exponent associated to the bulk magnetization. Because the concentrations of the various impurities are very low, the authors think that the explanation of the phenomenon is to be found in the framework of a one-impurity model interacting with the surrounding spins via an isotropic exchange energy

Abnormal findings of magnetic resonance imaging (MRI) in patients with systemic lupus erythematosus involving the brain

Energy Technology Data Exchange (ETDEWEB)

Ishikawa, Akira; Okada, Jun; Kondo, Hirobumi (Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Medicine); Kashiwazaki, Sadao

1992-06-01

To elucidate the clinical significance of MRI on central nervous system systemic lupus erythematosus (CNS-SLE), MRI and CT scans were performed in 35 patients with SLE, of 18 patients who had CNS manifestations at the time of MRI examinations. The investigations were also carried out in 17 patients without CNS-SLE. The rate of detection of abnormal findings on MRI in patients with CNS-SLE was 77.2% (14/18), which was high, as compared with the rate of those on CT scans (50%: 9/18). Especially, all of 4 patients with seizure and 3 patients with encephalopathy showed abnormal MRI findings, although respectively 50% and 33.3% of them had abnormal CT scan findings. MRI findings were classified into 4 groups below: (1) Large focal are as increased signal intensity at T2 weighted image. These were observed in 2 of 4 patients with seizure and 1 of 3 patients with encephalopathy, which were completely resolved after treatment. (2) Patchy subcortical foci of increased signal intensity at T2 weighted image. These were observed in 11 of 18 CNS-SLE and 7 of 17 without CNS-SLE, which were not detected by CT scan. (3) All of six patients with cerebral infarctions showed high signal intensity areas at T2 weighted image and low signal intensity areas at T1 weighted image. (4) Normal findings were observed in 4 of 18 CNS-SLE (22.2%). We concluded that MRI is useful for the evaluation of CNS-SLE and provides more information than CT scan. (author).

Abnormal findings of magnetic resonance imaging (MRI) in patients with systemic lupus erythematosus involving the brain

International Nuclear Information System (INIS)

Ishikawa, Akira; Okada, Jun; Kondo, Hirobumi; Kashiwazaki, Sadao.

1992-01-01

To elucidate the clinical significance of MRI on central nervous system systemic lupus erythematosus (CNS-SLE), MRI and CT scans were performed in 35 patients with SLE, of 18 patients who had CNS manifestations at the time of MRI examinations. The investigations were also carried out in 17 patients without CNS-SLE. The rate of detection of abnormal findings on MRI in patients with CNS-SLE was 77.2% (14/18), which was high, as compared with the rate of those on CT scans (50%: 9/18). Especially, all of 4 patients with seizure and 3 patients with encephalopathy showed abnormal MRI findings, although respectively 50% and 33.3% of them had abnormal CT scan findings. MRI findings were classified into 4 groups below: 1) Large focal are as increased signal intensity at T2 weighted image. These were observed in 2 of 4 patients with seizure and 1 of 3 patients with encephalopathy, which were completely resolved after treatment. 2) Patchy subcortical foci of increased signal intensity at T2 weighted image. These were observed in 11 of 18 CNS-SLE and 7 of 17 without CNS-SLE, which were not detected by CT scan. 3) All of six patients with cerebral infarctions showed high signal intensity areas at T2 weighted image and low signal intensity areas at T1 weighted image. 4) Normal findings were observed in 4 of 18 CNS-SLE (22.2%). We concluded that MRI is useful for the evaluation of CNS-SLE and provides more information than CT scan. (author)

Magnetic soft mode behaviour investigated via multi-spin flip Raman spectroscopy on near surface Cd{sub 1-x}Mn{sub x}Te/Cd{sub 1-y}Mg{sub y}Te quantum wells

Energy Technology Data Exchange (ETDEWEB)

Kehl, Christian

2011-03-28

The main motivation for this thesis was the experimental confirmation of the theoretically predicted magnetic soft mode and the analysis of its dependence on the hole-concentration and external B-field, as well as its disappearance with increasing sample temperature. For that purpose, CdMnTe/CdMgTe QWs (Mn: 0.6%, 1.0%) positioned close to the sample surface (13-19 nm) were investigated in an in-plane applied external magnetic field (up to 4.5 T in Voigt-geometry) via a two-colour experiment i.e. using two light sources. This allows the spin excitation of Mn-ions by simultaneously tuning the hole-concentration towards the ferromagnetic phase transition by photo-generated carriers. Thus, one tuneable laser is responsible for resonant below-barrier excitation as a probe for Multi-SF Raman scattering. The other laser excites photo-generated carriers from above barrier (2.41 eV) for tuning the hole concentration in the QW. Positioning the QW close to the sample surface causes a surface-induced p-doping of the QW (intrinsic hole concentration in the QW) and enables the active tuning of the hole concentration by photo-generated carriers due to different tunnelling behaviour of electrons and holes from the QW to the surface. The Mn-g-factor was decreased by quasi-continuously increasing the above-barrier illumination, while the below-barrier excitation was kept at a constant low power. This results in a Mn-g-factor reduction starting from its atomic value g=2.01 to lowest evaluated Mn-g-factor in this thesis g=1.77. This is a magnetic softening of 12%. Apart from the general magnetic soft mode behaviour at low temperatures, one of the main experimental results in this thesis is the confirmation of the theoretical prediction that the magnetic soft mode behaviour in the external B-field does not only depend on the carrier concentration but also on the B-field strength itself. An additional aspect is the temperature dependence of the magnetic soft mode. The Mn

Relationship of Hypertension, Blood Pressure, and Blood Pressure Control With White Matter Abnormalities in the Women’s Health Initiative Memory Study (WHIMS)—MRI Trial

OpenAIRE

Kuller, Lewis H.; Margolis, Karen L.; Gaussoin, Sarah A.; Bryan, Nick R.; Kerwin, Diana; Limacher, Marian; Wassertheil-Smoller, Sylvia; Williamson, Jeff; Robinson, Jennifer G.

2010-01-01

This paper evaluates the relationship of blood pressure (BP) levels at Women’s Health Initiative (WHI) baseline, treatment of hypertension, and white matter abnormalities among women in conjugated equine estrogen (CEE) and medroxyprogesterone acetate and CEE-alone arms. The WHI Memory Study—Magnetic Resonance Imaging (WHIMS-MRI) trial scanned 1424 participants. BP levels at baseline were significantly positively related to abnormal white matter lesion (WML) volumes. Participants treated for h...

Periventricular Nodular Heterotopia: Detection of Abnormal Microanatomic Fiber Structures with Whole-Brain Diffusion MR Imaging Tractography.

Science.gov (United States)

Farquharson, Shawna; Tournier, J-Donald; Calamante, Fernando; Mandelstam, Simone; Burgess, Rosemary; Schneider, Michal E; Berkovic, Samuel F; Scheffer, Ingrid E; Jackson, Graeme D; Connelly, Alan

2016-12-01

Purpose To investigate whether it is possible in patients with periventricular nodular heterotopia (PVNH) to detect abnormal fiber projections that have only previously been reported in the histopathology literature. Materials and Methods Whole-brain diffusion-weighted (DW) imaging data from 14 patients with bilateral PVNH and 14 age- and sex-matched healthy control subjects were prospectively acquired by using 3.0-T magnetic resonance (MR) imaging between August 1, 2008, and December 5, 2012. All participants provided written informed consent. The DW imaging data were processed to generate whole-brain constrained spherical deconvolution (CSD)-based tractography data and super-resolution track-density imaging (TDI) maps. The tractography data were overlaid on coregistered three-dimensional T1-weighted images to visually assess regions of heterotopia. A panel of MR imaging researchers independently assessed each case and indicated numerically (no = 1, yes = 2) as to the presence of abnormal fiber tracks in nodular tissue. The Fleiss κ statistical measure was applied to assess the reader agreement. Results Abnormal fiber tracks emanating from one or more regions of heterotopia were reported by all four readers in all 14 patients with PVNH (Fleiss κ = 1). These abnormal structures were not visible on the tractography data from any of the control subjects and were not discernable on the conventional T1-weighted images of the patients with PVNH. Conclusion Whole-brain CSD-based fiber tractography and super-resolution TDI mapping reveals abnormal fiber projections in nodular tissue suggestive of abnormal organization of white matter (with abnormal fibers both within nodules and projecting to the surrounding white matter) in patients with bilateral PVNH. © RSNA, 2016.

Clinically relevant magnetic resonance imaging (MRI) findings in ...

African Journals Online (AJOL)

Background: Shoulder pain is the most common and well-documented site of musculoskeletal pain in elite swimmers. Structural abnormalities on magnetic resonance imaging (MRI) of elite swimmers' symptomatic shoulders are common. Little has been documented about the association between MRI findings in the ...

The Association of PTSD Symptom Severity with Localized Hippocampus and Amygdala Abnormalities

Science.gov (United States)

Akiki, Teddy J.; Averill, Christopher L.; Wrocklage, Kristen M.; Schweinsburg, Brian; Scott, J. Cobb; Martini, Brenda; Averill, Lynnette A.; Southwick, Steven M.; Krystal, John H.; Abdallah, Chadi G.

2017-01-01

Background The hippocampus and amygdala have been repeatedly implicated in the psychopathology of posttraumatic stress disorder (PTSD). While numerous structural neuroimaging studies examined these two structures in PTSD, these analyses have largely been limited to volumetric measures. Recent advances in vertex-based neuroimaging methods have made it possible to identify specific locations of subtle morphometric changes within a structure of interest. Methods In this cross-sectional study, we used high-resolution magnetic resonance imaging to examine the relationship between PTSD symptomatology, as measured using the Clinician Administered PTSD Scale for the DSM-IV (CAPS), and structural shape of the hippocampus and amygdala using vertex-wise shape analyses in a group of combat-exposed US Veterans (N = 69). Results Following correction for multiple comparisons and controlling for age and cranial volume, we found that participants with more severe PTSD symptoms showed an indentation in the anterior half of the right hippocampus and an indentation in the dorsal region of the right amygdala (corresponding to the centromedial amygdala). Post hoc analysis using stepwise regression suggest that among PTSD symptom clusters, arousal symptoms explain most of the variance in the hippocampal abnormality, whereas re-experiencing symptoms explain most of the variance in the amygdala abnormality. Conclusion The results provide evidence of localized abnormalities in the anterior hippocampus and centromedial amygdala in combat-exposed US Veterans suffering from PTSD symptoms. This novel finding provides a more fine-grained analysis of structural abnormalities in PTSD and may be informative for understanding the neurobiology of the disorder. PMID:28825050

Fractures of the distal phalanx and associated soft tissue and osseous abnormalities in 22 horses with ossified sclerotic ungual cartilages diagnosed with magnetic resonance imaging.

Science.gov (United States)

Selberg, Kurt; Werpy, Natasha

2011-01-01

Ungual cartilage ossification in the forelimb is a common finding in horses. Subtle abnormalities associated with the ungual cartilages can be difficult to identify on radiographs. Magnetic resonance (MR) imaging findings of 22 horses (23 forelimbs) with a fracture of the distal phalanx and ossified ungual cartilage were characterized and graded. All horses had a forelimb fracture. Eleven involved a left forelimb (seven medial; four lateral), and 12 involved a right forelimb (five medial; seven lateral). All fractures were nonarticular, simple in configuration, and nondisplaced. The fractures were oriented in an axial proximal to abaxial distal and palmar to dorsal direction, and extended from the base of the ossified ungual cartilage into the distal phalanx. The fracture involved the fossa of the collateral ligament on the distal phalanx in 17 of 23 limbs. The palmar process and ossified ungual cartilage was abnormally mineralized in all horses. Ligaments and soft tissues adjacent to the ossified ungual cartilages were affected in all horses. The routine site of fracture in this study at the base of the ossified ungual cartilage extending into the distal phalanx suggests a biomechanical cause or focal stress point from cycling. The ligamentous structures associated with the ungual cartilages were often affected, showed altered signal intensity as well as enlargement and were thought to be contributing to the lameness. In conclusion, ossified ungual cartilages may lead to fracture of the palmar process of the distal phalanx and injury of the ungual cartilage ligaments. © 2011 Veterinary Radiology & Ultrasound.

Abnormal neuronal migration: radiologic-clinic study. Alteraciones en la migracion neural: estudio clinico-radiologico

Energy Technology Data Exchange (ETDEWEB)

Martinez Fernandez, M.; Menor Serrano, F.; Bordon Ferre, F.; Garcia Tena, J.; Esteban Hernandez, E.; Sanguesa Nebot, C.; Marti Bonnati, L. (Hospital Infantil La Fe, Valencia (Spain))

1994-01-01

We present our experience in 18 pediatric patients with abnormal neuronal migration. Seven cases of heterotopia of the gray matter, 7 agyria-pachygyria complexes, 1 case of polymicrogyria, 2 cases of schizencephaly and 1 case of hemimegalencephaly were diagnosed by means of ultrasonography, computed tomography and magnetic resonance. The clinical picture was reviewed in each case, with special attention to the occurrence of convulsions, psycho motor development and visual changes. In general, the greater the morphological change, the greater the neurological involvement in these patients. However, the two cases of schizencephaly presented mild clinical expression. Magnetic resonance increases the diagnostic yield in neuronal migration disorders. Nevertheless, either ultrasonography or, especially, computed tomography is useful as a first diagnostic approach in these malformative disorders. (Author)

Prenatal stress produces anxiety prone female offspring and impaired maternal behaviour in the domestic pig.

Science.gov (United States)

Rutherford, Kenneth M D; Piastowska-Ciesielska, Agnieszka; Donald, Ramona D; Robson, Sheena K; Ison, Sarah H; Jarvis, Susan; Brunton, Paula J; Russell, John A; Lawrence, Alistair B

2014-04-22

Numerous studies have shown that prenatal stress (PNS) can have profound effects on postnatal well-being. Here, the domestic pig (Sus scrofa) was used to investigate PNS effects owing to the direct relevance for farm animal welfare and the developing status of the pig as a large animal model in translational research. Pregnant primiparous sows were exposed, in mid-gestation, to either a social stressor (mixing with unfamiliar conspecifics) or were kept in stable social groups. The ratio of levels of mRNAs for corticotropin releasing hormone (CRH) receptors 1 and 2 in the amygdala, measured for the first time in the pig, was substantially increased in 10-week-old female, but not male, PNS progeny indicating a neurobiological propensity for anxiety-related behaviour. Mature female offspring were observed at parturition in either a behaviourally restrictive crate or open pen. Such PNS sows showed abnormal maternal behaviour in either environment, following the birth of their first piglet. They spent more time lying ventrally, more time standing and showed a higher frequency of posture changes. They were also more reactive towards their piglets, and spent longer visually attending to their piglets compared to controls. Associated with this abnormal maternal care, piglet mortality was increased in the open pen environment, where protection for piglets is reduced. Overall, these data indicate that PNS females have their brain development shifted towards a pro-anxiety phenotype and that PNS can be causally related to subsequent impaired maternal behaviour in adult female offspring. Copyright © 2014 Elsevier Inc. All rights reserved.

Development and validation of a behavioural assay to measure the tolerance of Hediste diversicolor to copper

International Nuclear Information System (INIS)

Burlinson, Frazer C.; Lawrence, Andrew J.

2007-01-01

The behaviour of Hediste diversicolor from the Humber was investigated under different concentrations of copper sulphate. A range of behaviours were indicative of metal-stress. These included consistent attempts at burrowing, eversion of the proboscis and abnormal crawling. The bioassay itself consisted of exposing worms to increasing concentrations of copper sulphate and recording the concentration at which a stress response was elicited. The behavioural end-points were shown to be a good predictor of time of death of Fal estuary worms under acutely toxic conditions. The bioassay would therefore allow the separation of tolerance phenotypes without mortality to the worm. Worms were not affected by consecutive bioassays and it was proposed that tolerance to more than one metal could be determined for individual worms. - A non-destructive behavioural bioassay is developed to determine the copper tolerance of ragworms

Development of advanced biorefinery concepts using magnetically responsive materials

Czech Academy of Sciences Publication Activity Database

Šafařík, Ivo; Pospišková, K.; Baldíková, E.; Šafaříková, Miroslava

2016-01-01

Roč. 116, DEC (2016), s. 17-26 ISSN 1369-703X R&D Projects: GA ČR GA13-13709S Institutional support: RVO:67179843 Keywords : saccharomyces-cerevisiae cells * solid acid catalysts * Separation * Biocatalysis * Immobilization * Bioconversion * Magnetic particles * Magnetic enzymes and cells Subject RIV: EH - Ecology, Behaviour Impact factor: 2.892, year: 2016

A mononuclear uranium(IV) single-molecule magnet with an azobenzene radical ligand

Energy Technology Data Exchange (ETDEWEB)

Antunes, Maria A.; Coutinho, Joana T.; Santos, Isabel C.; Marcalo, Joaquim; Almeida, Manuel; Pereira, Laura C.J. [C" 2TN, Instituto Superior Tecnico, Universidade de Lisboa, Bobadela (Portugal); Baldovi, Jose J.; Gaita-Arino, Alejandro; Coronado, Eugenio [Instituto de Ciencia Molecular, Universitat de Valencia, Paterna (Spain)

2015-12-01

A tetravalent uranium compound with a radical azobenzene ligand, namely, [{(SiMe_2NPh)_3-tacn}U{sup IV}(η{sup 2}-N{sub 2}Ph{sub 2{sup .}})] (2), was obtained by one-electron reduction of azobenzene by the trivalent uranium compound [U{sup III}{(SiMe_2NPh)_3-tacn}] (1). Compound 2 was characterized by single-crystal X-ray diffraction and {sup 1}H NMR, IR, and UV/Vis/NIR spectroscopy. The magnetic properties of 2 and precursor 1 were studied by static magnetization and ac susceptibility measurements, which for the former revealed single-molecule magnet behaviour for the first time in a mononuclear U{sup IV} compound, whereas trivalent uranium compound 1 does not exhibit slow relaxation of the magnetization at low temperatures. A first approximation to the magnetic behaviour of these compounds was attempted by combining an effective electrostatic model with a phenomenological approach using the full single-ion Hamiltonian. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Magnetic dynamic properties of electron-doped La(0.23)Ca(0.77)MnO3 nanoparticles.

Science.gov (United States)

Dolgin, B; Puzniak, R; Mogilyansky, D; Wisniewski, A; Markovich, V; Jung, G

2013-02-20

Magnetic properties of basically antiferromagnetic La(0.23)Ca(0.77)MnO(3) particles with average sizes of 12 and 60 nm have been investigated in a wide range of magnetic fields and temperature. Particular attention has been paid to magnetization dynamics through measurements of the temperature dependence of ac-susceptibility at various frequencies, the temperature and field dependence of thermoremanent and isothermoremanent magnetization originating from nanoparticles shells, and the time decay of the remanent magnetization. Experimental results and their analysis reveal the major role in magnetic behaviour of investigated antiferromagnetic nanoparticles played by the glassy component, associated mainly with the formation of the collective state formed by ferromagnetic clusters in frustrated coordination at the surfaces of interacting antiferromagnetic nanoparticles. Magnetic behaviour of nanoparticles has been ascribed to a core-shell scenario. Magnetic transitions have been found to play an important role in determining the dynamic properties of the phase separated state of coexisting different magnetic phases.

Magnetic dynamic properties of electron-doped La0.23Ca0.77MnO3 nanoparticles

International Nuclear Information System (INIS)

Dolgin, B; Markovich, V; Jung, G; Puzniak, R; Wisniewski, A; Mogilyansky, D

2013-01-01

Magnetic properties of basically antiferromagnetic La 0.23 Ca 0.77 MnO 3 particles with average sizes of 12 and 60 nm have been investigated in a wide range of magnetic fields and temperature. Particular attention has been paid to magnetization dynamics through measurements of the temperature dependence of ac-susceptibility at various frequencies, the temperature and field dependence of thermoremanent and isothermoremanent magnetization originating from nanoparticles shells, and the time decay of the remanent magnetization. Experimental results and their analysis reveal the major role in magnetic behaviour of investigated antiferromagnetic nanoparticles played by the glassy component, associated mainly with the formation of the collective state formed by ferromagnetic clusters in frustrated coordination at the surfaces of interacting antiferromagnetic nanoparticles. Magnetic behaviour of nanoparticles has been ascribed to a core–shell scenario. Magnetic transitions have been found to play an important role in determining the dynamic properties of the phase separated state of coexisting different magnetic phases. (paper)

Investigation of Thermal and Vacuum Transients on the LHC Prototype Magnet String

CERN Document Server

Cruikshank, P; Riddone, G; Tavian, L

1996-01-01

The prototype magnet string, described in a companion paper, is a full-scale working model of a 50-m length of the future Large Hadron Collider (LHC), CERN's new accelerator project, which will use high-field superconducting magnets operating below 2 K in superfluid helium. As such, it provides an excellent test bed for practising standard operating modes of LHC insulation vacuum and cryogenics, as well as for experimentally assessing accidental behaviour and failure modes, and thus verifying design calculations. We present experimental investigation of insulation vacuum pumpdown, magnet forced-flow cooldown and warmup, and evolution of residual vacuum pressures and temperatures in natural warmup, as well as catastrophic loss of insulation vacuum. In all these transient modes, experimental results are compared with simulated behaviour, using a non-linear, one-dimensional thermal model of the magnet string.

Relationship between magnetism and prion protein

Directory of Open Access Journals (Sweden)

F. Balzano

2010-01-01

Full Text Available The mechanism of conversion of the normal prion protein (PrPC into aggregates of its pathological conformer (PrPSc reamins unclear. The aim of this study was to evaluate the effects induced by exposure of biological samples containing PrPSC to a magnetic field induced prominent molecular changes of samples indicated by the IR spectra located in the region that contains contribution primarily from absorption of amides. This finding suggests the existence of a strong correlation between magnetism and PrPsc and supports a new hypothesis that explains the conversion of normal PrPc to abnormal isoform PrPsc.

Physics and measurements of magnetic materials

CERN Document Server

Sgobba, S

2010-01-01

Magnetic materials, both hard and soft, are used extensively in several components of particle accelerators. Magnetically soft iron-nickel alloys are used as shields for the vacuum chambers of accelerator injection and extraction septa; Fe-based material is widely employed for cores of accelerator and experiment magnets; soft spinel ferrites are used in collimators to damp trapped modes; innovative materials such as amorphous or nanocrystalline core materials are envisaged in transformers for high-frequency polyphase resonant convertors for application to the International Linear Collider (ILC). In the field of fusion, for induction cores of the linac of heavy-ion inertial fusion energy accelerators, based on induction accelerators requiring some 107 kg of magnetic materials, nanocrystalline materials would show the best performance in terms of core losses for magnetization rates as high as 105 T/s to 107 T/s. After a review of the magnetic properties of materials and the different types of magnetic behaviour...

Defining Abnormally Low Tenders

DEFF Research Database (Denmark)

Ølykke, Grith Skovgaard; Nyström, Johan

2017-01-01

The concept of an abnormally low tender is not defined in EU public procurement law. This article takes an interdisciplinary law and economics approach to examine a dataset consisting of Swedish and Danish judgments and verdicts concerning the concept of an abnormally low tender. The purpose...

MOKE study of Co/Ti/(Gd-Co) multilayers near the magnetic compensation state

International Nuclear Information System (INIS)

Svalov, A.V.; Fernandez, A.; Vas'kovskiy, V.O.; Kurlyandskaya, G.V.; Barandiaran, J.M.; Anton, R. Lopez; Tejedor, M.

2006-01-01

The magnetic behaviour of [Co/Ti/a-Gd 0.36 Co 0.64 /Ti] 4 /Co layered structures was studied by means of the transversal magneto-optic Kerr effect, with Ti spacers of different thicknesses. Within the Gd 0.36 Co 0.64 amorphous layer, the Gd magnetic sub-lattice dominates at all investigated temperatures. The strong exchange interaction at the interfaces causes 'macroscopic ferrimagnetic behaviour' in the whole system. The existence of a magnetic compensation state in the complete multilayer system was manifested by the change of sign in the magneto-optic hysteresis loops and the increase of coercivity. The evolution of the critical field for a spin-orientation transition leading to a non-collinear magnetic state near the 'compensation temperature' can be described within molecular field theory. The influence of the non-magnetic spacer thickness on the characteristics of the compensation state is also discussed

Magnetization transfer imaging identifies basal ganglia abnormalities in adult ADHD that are invisible to conventional T1 weighted voxel-based morphometry

Directory of Open Access Journals (Sweden)

Arjun Sethi

2017-01-01

Full Text Available In childhood, Attention Deficit Hyperactivity Disorder (ADHD is reliably associated with reduced volume of the striatum. In contrast, striatal abnormalities are infrequently detected in voxel-based morphometry (VBM neuroimaging studies of adults with ADHD. This discrepancy has been suggested to reflect normalisation of striatal morphology with age and prolonged treatment of symptoms. If so, this would indicate that while striatal abnormalities are linked to symptom expression in childhood, they cannot explain the persistence of these symptoms in adulthood. However, this may not be case. Instead, we hypothesized that the lack of evidence for striatal abnormalities in adult ADHD may reflect poor sensitivity of typical (T1-weighted neuroimaging to detect subcortical differences. To address this, we acquired both magnetisation transfer (MT saturation maps optimised for subcortical contrast, and conventional T1-weighted images in 30 adults with ADHD and 30 age, IQ, gender and handedness-matched controls. Using VBM of both datasets, we demonstrate volumetric reductions within the left ventral striatum on MT that are not observed on identically pre-processed T1-weighted images from the same participants. Nevertheless, both techniques reported similar sensitivity to cortical abnormalities in the right inferior parietal lobe. Additionally, we show that differences in striatal iron may potentially explain this reduced sensitivity of T1-weighted images in adults. Together, these findings indicate that prior VBM studies reporting no abnormalities in striatal volume in adult ADHD might have been compromised by the methodological insensitivity of T1-weighted VBM to subcortical differences, and that structural abnormalities of the striatum in ADHD do indeed persist into adulthood.

MAGNETIC ARC WELDING STABILIZATION USING NON-CONSUMABLE ELECTRODE

Directory of Open Access Journals (Sweden)

Павло Юрійович Сидоренко

2017-06-01

Full Text Available Results of development torch to magnetically operated   welding arc are defined. Changing the design of the electrode unit is provided the ability to create within the area of the arc magnetic field and induction given configuration without additional equipment. The features of the arc in an axial magnetic field which make it possible to avoid the welding process of unsteady abnormalities resulted in the inappropriate formation of defects in welds. Significant increase in the depth of  weld penetration is connected with the more concentrated magnetically operated   welding arc transmission energy to the product. It is concluded about the feasibility of using a designed torch for the implementation of modern technological processes non-consumable electrode welding.

Alexithymia and illness behaviour among female Indian outpatients with multiple somatic symptoms

OpenAIRE

Sarkar, Jaydip; Chandra, Prabha

2003-01-01

Sixty Indian muslim women outpatients with multiple somatic complaints of nonorganic origin were assessed for alexithymia and abnormal illness behavior using the Toronto Alexithymia Scale (TAS) and the Illness Behaviour Assessment Schedule (IBAS). Alexithymia represented by TAS scores correlated best with the IBAS variables of communication of affect, somatic illness causal beliefs and denial. Correlation with other IBAS variables was modest to poor.There was no correlation of IBAS variables ...

Magnetic after-effect in manganite films

International Nuclear Information System (INIS)

Sirena, M.; Steren, L.B.; Guimpel, J.

2001-01-01

The time dependence of the magnetic and transport properties on La 0.6 Sr 0.4 MnO 3 films and bulk samples has been studied through magnetization and resistivity measurements. A magnetic after-effect has been observed in all samples. At low temperatures, the low-field magnetization, can be described by the function M(t)=M c +M d exp(-t/τ)+S(H,T)ln(t). The resistivity increases logarithmically in the same temperature range, indicating the evolution of the sample to a more disordered state. Above a characteristic temperature, this behaviour is reversed and an increase of the magnetization with time is observed. The relaxation parameters depend on the bulk or films character of the samples. In the latter case, a dependence on the film thickness was found. A direct correlation between the time dependence of the resistivity and magnetization curves in manganite compounds was found

MR imaging of abnormal synovial processes

International Nuclear Information System (INIS)

Quinn, S.F.; Sanchez, R.; Murray, W.T.; Silbiger, M.L.; Ogden, J.; Cochran, C.

1987-01-01

MR imaging can directly image abnormal synovium. The authors reviewed over 50 cases with abnormal synovial processes. The abnormalities include Baker cysts, semimembranous bursitis, chronic shoulder bursitis, peroneal tendon ganglion cyst, periarticular abscesses, thickened synovium from rheumatoid and septic arthritis, and synovial hypertrophy secondary to Legg-Calve-Perthes disease. MR imaging has proved invaluable in identifying abnormal synovium, defining the extent and, to a limited degree, characterizing its makeup

Regional gray matter abnormalities in patients with schizophrenia determined with optimized voxel-based morphometry

Science.gov (United States)

Guo, XiaoJuan; Yao, Li; Jin, Zhen; Chen, Kewei

2006-03-01

This study examined regional gray matter abnormalities across the whole brain in 19 patients with schizophrenia (12 males and 7 females), comparing with 11 normal volunteers (7 males and 4 females). The customized brain templates were created in order to improve spatial normalization and segmentation. Then automated preprocessing of magnetic resonance imaging (MRI) data was conducted using optimized voxel-based morphometry (VBM). The statistical voxel based analysis was implemented in terms of two-sample t-test model. Compared with normal controls, regional gray matter concentration in patients with schizophrenia was significantly reduced in the bilateral superior temporal gyrus, bilateral middle frontal and inferior frontal gyrus, right insula, precentral and parahippocampal areas, left thalamus and hypothalamus as well as, however, significant increases in gray matter concentration were not observed across the whole brain in the patients. This study confirms and extends some earlier findings on gray matter abnormalities in schizophrenic patients. Previous behavior and fMRI researches on schizophrenia have suggested that cognitive capacity decreased and self-conscious weakened in schizophrenic patients. These regional gray matter abnormalities determined through structural MRI with optimized VBM may be potential anatomic underpinnings of schizophrenia.

Tumor disease and associated congenital abnormalities on prenatal MRI.

Science.gov (United States)

Nemec, Stefan F; Horcher, Ernst; Kasprian, Gregor; Brugger, Peter C; Bettelheim, Dieter; Amann, Gabriele; Nemec, Ursula; Rotmensch, Siegfried; Rimoin, David L; Graham, John M; Prayer, Daniela

2012-02-01

Fetal tumors can have a devastating effect on the fetus, and may occur in association with congenital malformations. In view of the increasing role of fetal magnetic resonance imaging (MRI) as an adjunct to prenatal ultrasonography (US), we sought to demonstrate the visualization of fetal tumors, with regard to congenital abnormalities, on MRI. This retrospective study included 18 fetuses with tumors depicted on fetal MRI after suspicious US findings. An MRI standard protocol was used to diagnose tumors judged as benign or malignant. All organ systems were assessed for tumor-related complications and other congenital malformations. Available US results and histopathology were compared with MRI. There were 13/18 (72.2%) benign and 5/18 (27.8%) malignant tumors diagnosed: a cerebral primitive neuroectodermal tumor in 1/18, head-neck teratomas in 4/18; ventricular rhabdomyomas in 4/18; a cardiac teratoma in 1/18; a hepatoblastoma in 1/18; neuroblastomas in 2/18; a cystic hemorrhagic adrenal hyperplasia in 1/18; a pelvic leiomyoma in 1/18; sacrococcygeal teratomas in 3/18. Tumor-related complications were present in 13/18 (72.2%) cases; other congenital abnormalities in 3/18 (16.7%). MRI diagnosis and histology were concordant in 8/11 (72.7%) cases. In 6/12 (50%) cases, US and MRI diagnoses were concordant, and, in 6/12 (50%) cases, additional MRI findings changed the US diagnosis. Our MRI results demonstrate the visualization of fetal tumors, with frequently encountered tumor-related complications, and other exceptional congenital abnormalities, which may provide important information for perinatal management. Compared to prenatal US, MRI may add important findings in certain cases. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Tumor disease and associated congenital abnormalities on prenatal MRI

International Nuclear Information System (INIS)

Nemec, Stefan F.; Horcher, Ernst; Kasprian, Gregor; Brugger, Peter C.; Bettelheim, Dieter; Amann, Gabriele; Nemec, Ursula; Rotmensch, Siegfried; Rimoin, David L.; Graham, John M. Jr.; Prayer, Daniela

2012-01-01

Objective: Fetal tumors can have a devastating effect on the fetus, and may occur in association with congenital malformations. In view of the increasing role of fetal magnetic resonance imaging (MRI) as an adjunct to prenatal ultrasonography (US), we sought to demonstrate the visualization of fetal tumors, with regard to congenital abnormalities, on MRI. Materials and methods: This retrospective study included 18 fetuses with tumors depicted on fetal MRI after suspicious US findings. An MRI standard protocol was used to diagnose tumors judged as benign or malignant. All organ systems were assessed for tumor-related complications and other congenital malformations. Available US results and histopathology were compared with MRI. Results: There were 13/18 (72.2%) benign and 5/18 (27.8%) malignant tumors diagnosed: a cerebral primitive neuroectodermal tumor in 1/18, head–neck teratomas in 4/18; ventricular rhabdomyomas in 4/18; a cardiac teratoma in 1/18; a hepatoblastoma in 1/18; neuroblastomas in 2/18; a cystic hemorrhagic adrenal hyperplasia in 1/18; a pelvic leiomyoma in 1/18; sacrococcygeal teratomas in 3/18. Tumor-related complications were present in 13/18 (72.2%) cases; other congenital abnormalities in 3/18 (16.7%). MRI diagnosis and histology were concordant in 8/11 (72.7%) cases. In 6/12 (50%) cases, US and MRI diagnoses were concordant, and, in 6/12 (50%) cases, additional MRI findings changed the US diagnosis. Conclusion: Our MRI results demonstrate the visualization of fetal tumors, with frequently encountered tumor-related complications, and other exceptional congenital abnormalities, which may provide important information for perinatal management. Compared to prenatal US, MRI may add important findings in certain cases.

Calculation of the magnetic anisotropy energy and finite-temperature magnetic properties of transition-metal films

International Nuclear Information System (INIS)

Garibay-Alonso, R; Villasenor-Gonzalez, P; Dorantes-Davila, J; Pastor, G M

2004-01-01

The magnetic anisotropy energy at the interface (IMAE) of Co films deposited on the Pd(111) surface are determined in the framework of a self-consistent, real-space tight-binding method at zero temperature. Significant spin moments are induced at the Pd atoms at the interface which have an important influence on the observed reorientation transitions as a function of Co film thickness. Film-substrate hybridizations are therefore crucial for the magneto-anisotropic behaviour of thin transition-metal films deposited on metallic non-magnetic substrates. Furthermore, using a real-space recursive expansion of the local Green function and within the virtual-crystal approximation we calculate the magnetization curves and the Curie temperature T C for free-standing Fe films

Giant magnetic anisotropy and tunnelling of the magnetization in Li2(Li1-xFex)N

Energy Technology Data Exchange (ETDEWEB)

Jesche, A.; McCallum, R. W.; Thimmaiah, S.; Jacobs, J. L.; Taufour, V.; Kreyssig, A.; Houk, R. S.; Bud’ko, S. L.; Canfield, P. C.

2014-02-25

Large magnetic anisotropy and coercivity are key properties of functional magnetic materials and are generally associated with rare earth elements. Here we show an extreme, uniaxial magnetic anisotropy and the emergence of magnetic hysteresis in Li2(Li_1-xFe_x)N. An extrapolated, magnetic anisotropy field of 220 T and a coercivity field of over 11 T at 2 K outperform all known hard ferromagnets and single-molecular magnets. Steps in the hysteresis loops and relaxation phenomena in striking similarity to single-molecular magnets are particularly pronounced for x<<1 and indicate the presence of nanoscale magnetic centres. Quantum tunnelling, in the form of temperature-independent relaxation and coercivity, deviation from Arrhenius behaviour and blocking of the relaxation, dominates the magnetic properties up to 10 K. The simple crystal structure, the availability of large single crystals and the ability to vary the Fe concentration make Li2(Li_1-xFe_x)N an ideal model system to study macroscopic quantum effects at elevated temperatures and also a basis for novel functional magnetic materials.

Comparison of properties of Nd-Fe-B and Sm-Co permanent magnets

International Nuclear Information System (INIS)

Ervens, W.

1985-01-01

In this paper permanent magnet materials on the basis of RECo and NdFeB are compared in terms of manufacturing processes, magnetic values at ambient and elevated temperatures, maximum operating temperatures and magnetization behaviour. At the present stage of development NdFeB-magnets are superior to the high coercivity RECo-magnets in their B/sub r/ - and (BH)/sub ma//sup -/ values at room temperature but are inferior to them at temperatures higher than 120 0 C

High levels of maternally transferred mercury disrupt magnetic responses of snapping turtle hatchlings (Chelydra serpentina).

Science.gov (United States)

Landler, Lukas; Painter, Michael S; Coe, Brittney Hopkins; Youmans, Paul W; Hopkins, William A; Phillips, John B

2017-09-01

The Earth's magnetic field is involved in spatial behaviours ranging from long-distance migration to non-goal directed behaviours, such as spontaneous magnetic alignment (SMA). Mercury is a harmful pollutant most often generated from anthropogenic sources that can bio-accumulate in animal tissue over a lifetime. We compared SMA of hatchling snapping turtles from mothers captured at reference (i.e., low mercury) and mercury contaminated sites. Reference turtles showed radio frequency-dependent SMA along the north-south axis, consistent with previous studies of SMA, while turtles with high levels of maternally inherited mercury failed to show consistent magnetic alignment. In contrast, there was no difference between reference and mercury exposed turtles on standard performance measures. The magnetic field plays an important role in animal orientation behaviour and may also help to integrate spatial information from a variety of sensory modalities. As a consequence, mercury may compromise the performance of turtles in a wide variety of spatial tasks. Future research is needed to determine the threshold for mercury effects on snapping turtles, whether mercury exposure compromises spatial behaviour of adult turtles, and whether mercury has a direct effect on the magnetoreception mechanism(s) that mediate SMA or a more general effect on the nervous system. Copyright © 2017 Elsevier Ltd. All rights reserved.

Concerning the study of the irreversible magnetic behaviour of superconductivity; Contribution a l'etude du comportement magnetique irreversible des supraconducteurs

Energy Technology Data Exchange (ETDEWEB)

Kuhn, G [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1965-03-01

The influence of the presence of extended lattice defects on the magnetic behaviour has been studied for the case of type I superconductors, such as Re and Ta, and in a more quantitative manner for the type II superconductor niobium. In this case, measurements of the thermal conductivity have given an estimate of the relative concentration of lattice defects in each specimen. These measurements show that the larger the number of lattice defects, the more irreversible becomes the magnetization curve, and the larger becomes the values of the critical current, which is related by a simple model to the magnetization values. Finally, a study by transmission electron microscopy has confirmed on the one hand the diversity of the extended lattice defects and on the other hand has allowed the formulation of several hypothesis on their respective influence. [French] L'influence de la presence de defauts etendus sur le comportement magnetique a ete etudie pour des supraconducteurs de premiere espece, tels que le rhenium et le tantale, et plus quantitativement pour un supraconducteur de deuxieme espece, le niobium. Dans ce cas, des mesures de conductibilite thermique ont permis d'estimer la concentration relative des defauts du reseau dans chaque echantillon. Ces mesures montrent que plus les defauts du reseau sont nombreux, plus la courbe d'aimantation est irreversible, et plus les valeurs du courant critique, reliees par un modele simple aux valeurs de l'aimantation, sont elevees. Enfin une etude par microscopie electronique en transmission - a permis d'une part de constater la diversite des defauts etendus et d'autre part de formuler quelques hypotheses sur leurs influences respectives.

Magnetization relaxation in spin glasses above transition point

International Nuclear Information System (INIS)

Zajtsev, I.A.; Minakov, A.A.; Galonzka, R.R.

1988-01-01

Magnetization relaxation of Cd 0.6 Zn 0.4 Cr 2 Se 4 and Cd 0.6 Mn 0.4 Te monocrystalline samples with T g =21 K and T g =12 K respectively and magnetic colloid is investigated. It is shown that magnetization inexponential relaxation detected experimentally in spin and dipole glasses is essentially higher than T g temperature transition. It is found that at temperatures higher than T g the essential difference is observed in behaviour of spin glasses with different Z and disorder types

A neutron depolarization study of magnetic inhomogeneities in weak-link superconductors

International Nuclear Information System (INIS)

Zhuchenko, N.K.; Yagud, R.Z.

1993-01-01

Neutron depolarization measurements in the mixed state of both high-T c and low-T c weak-link superconductors have been carried out. Samples of YBCO, BSCCO, SnMo 6 S 8 and 0.5 Nb-0.5 Ti of different magnetic prehistory were analyzed at temperatures T 4.2 K under applied magnetic fields II <= 16.5 kOe. We ascribe the appearance of magnetic inhomogeneities and their hysteresis behaviour to the interaction between dipole magnetic fields (diamagnetic and paramagnetic ones) and applied magnetic fields

Magnetic materials research with polarized neutrons

International Nuclear Information System (INIS)

Hammer, J.; Rauch, H.; Badurek, G.

1980-01-01

In order to study the mechanisms of time dependent effects in magnetic materials with superparamagnetic or spinglass behaviour as well as in ferromagnetic materials a 'dynamic neutron depolarization' system has been developed as a beam hole experiment at the TRIGA Mark II Reactor in Vienna. In the course of this experiment an increasing or decreasing polarization can be observed as a consequence of the interaction between spins of the polarized neutron beam and the magnetic structure if the magnetic clusters in the sample are stimulated by a short magnetic pulse, lasting up to a few seconds. In accordance with numerical calculations and theoretical considerations we can draw conclusions from dynamics in the range of 10 ms to 1 h within magnetic materials which give us additional information that cannot be obtained from experiments used so far

Magnetic operations: a little fuzzy mechanics?

International Nuclear Information System (INIS)

Mielnik, B; RamIrez, A

2011-01-01

We examine the behaviour of charged particles in homogeneous, constant and/or oscillating magnetic fields in the non-relativistic approximation. A special role of the geometric centre of the particle trajectory is elucidated. In the quantum case, it becomes a 'fuzzy point' with non-commuting coordinates, an element of non-commutative geometry that enters into the traditional control problems. We show that its application extends beyond the usually considered time-independent magnetic fields of the quantum Hall effect. Some simple cases of magnetic control by oscillating fields cause the stability maps to differ from the traditional Strutt diagram. The elementary mathematical results help explain the structure of the obtained solutions.

Methods to detect faulty splices in the superconducting magnet system of the LHC

CERN Document Server

Bailey, R; Catalan Lasheras, N; Dahlerup-Petersen, K; Denz, R; Robles, C; Koratzinos, M; Pojer, M; Ponce, L; Saban, R; Schmidt, R; Siemko, A; Solfaroli Camillocci, M; Thiesen, H; Vergara Fernandez, A; Flora, R H; Charifoulline, Z; Bednarek, M; Górnicki, E; Jurkiewicz, P; Kapusta, P; Strait, J

2010-01-01

The incident of 19 September 2008 at the LHC was caused by a faulty inter-magnet splice of about 200 nΩ resistance. Cryogenic and electrical techniques have been developed to detect other abnormal splices, either between or inside the magnets. The existing quench protection system can be used to detect internal splices with R>20 nΩ. Since this system does not cover the bus between magnets, the cryogenic system is used to measure the rate of temperature rise due to ohmic heating. Accuracy of a few mK/h, corresponding to a few Watts, has been achieved, allowing detection of excess resistance, if it is more than 40 nΩ in a cryogenic subsector (two optical cells). Follow-up electrical measurements are made in regions identified by the cryogenic system. These techniques have detected two abnormal internal magnet splices of 100 nΩ and 50 nΩ respectively. In 2009, this ad hoc system will be replaced with a permanent one to monitor all splices at the nΩ level.

Methods to detect faulty splices in the superconducting magnet system of the LHC

International Nuclear Information System (INIS)

Bailey, R.; Bellesia, B.; Lasheras, N.Catalan; Dahlerup-Petersen, K.; Denz, R.; Robles, C.; Koratzinos, M.; Pojer, M.; Ponce, L.; Saban, R.; Schmidt, R.

2009-01-01

The incident of 19 September 2008 at the LHC was caused by a faulty inter-magnet splice of about 200 n(Omega) resistance. Cryogenic and electrical techniques have been developed to detect other abnormal splices, either between or inside the magnets. The existing quench protection system can be used to detect internal splices with R > 20 n(Omega). Since this system does not cover the bus between magnets, the cryogenic system is used to measure the rate of temperature rise due to ohmic heating. Accuracy of a few mK/h, corresponding to a few Watts, has been achieved, allowing detection of excess resistance, if it is more than 40 n(Omega) in a cryogenic subsector (two optical cells). Follow-up electrical measurements are made in regions identified by the cryogenic system. These techniques have detected two abnormal internal magnet splices of 100 n(Omega) and 50 n(Omega) respectively. In 2009, this ad hoc system will be replaced with a permanent one to monitor all splices at the n(Omega) level

Diagnostic accuracy of post-mortem MRI for thoracic abnormalities in fetuses and children

International Nuclear Information System (INIS)

Arthurs, Owen J.; Thayyil, Sudhin; Addison, Shea; Olsen, Oystein E.; Wade, Angie; Jones, Rod; Norman, Wendy; Taylor, Andrew M.; Scott, Rosemary J.; Robertson, Nicola J.; Chitty, Lyn S.; Sebire, Neil J.; Owens, Catherine M.

2014-01-01

To compare the diagnostic accuracy of post-mortem magnetic resonance imaging (PMMR) specifically for non-cardiac thoracic pathology in fetuses and children, compared with conventional autopsy. Institutional ethics approval and parental consent was obtained. A total of 400 unselected fetuses and children underwent PMMR before conventional autopsy, reported blinded to the other dataset. Of 400 non-cardiac thoracic abnormalities, 113 (28 %) were found at autopsy. Overall sensitivity and specificity (95 % confidence interval) of PMMR for any thoracic pathology was poor at 39.6 % (31.0, 48.9) and 85.5 % (80.7, 89.2) respectively, with positive predictive value (PPV) 53.7 % (42.9, 64.0) and negative predictive value (NPV) 77.0 % (71.8, 81.4). Overall agreement was 71.8 % (67.1, 76.2). PMMR was most sensitive at detecting anatomical abnormalities, including pleural effusions and lung or thoracic hypoplasia, but particularly poor at detecting infection. PMMR currently has relatively poor diagnostic detection rates for the commonest intra-thoracic pathologies identified at autopsy in fetuses and children, including respiratory tract infection and diffuse alveolar haemorrhage. The reasonable NPV suggests that normal thoracic appearances at PMMR exclude the majority of important thoracic lesions at autopsy, and so could be useful in the context of minimally invasive autopsy for detecting non-cardiac thoracic abnormalities. (orig.)