Fast T1- and T2-weighted pulmonary MR-imaging in patients with bronchial carcinoma

International Nuclear Information System (INIS)

Both, M.; Schultze, J.; Reuter, M.; Bewig, B.; Hubner, R.; Bobis, I.; Noth, R.; Heller, M.; Biederer, J.

2005-01-01

Purpose: A prospective study to evaluate the diagnostic potential and limitations of three fast MRI sequences in patients with bronchial carcinoma based on the comparison with spiral CT. Material and methods: Three fast chest MRI sequences from 20 patients with central or peripheral bronchial carcinoma were evaluated by two observers for relation of tumour to adjacent structures, lymph node enlargement, additional pulmonary lesions and artefacts. The information from MR-imaging was compared with the results from spiral CT. MRI comprised a T1-3D-GRE breath-hold examination ('VIBE', TR/TE 4.5/1.9 ms, flip-angle 12 deg., matrix 502 x 512, 2.5 mm coronal slices), a breath-hold, T2-HASTE sequence (TR/TE 2000/43 ms, matrix 192 x 256, 10 mm coronal slices) and a respiration-triggered T2-TSE sequence (TR/TE 3000-6000/120 ms, matrix 270 x 512, 6 mm transverse slices). The FOV was adapted individually (380-480 mm). Results: The presence of the primary bronchial carcinoma and infiltration of thoracic structures by tumour tissue could be demonstrated by all sequences. VIBE sequence was more suitable for detecting small pulmonary nodules than the other MRI examinations, but compared to CT still 20% of these lesions were missed. Contrary to VIBE and T2-weighted TSE scans, HASTE sequence was limited in imaging mediastinal lymph nodes due to missing relevant findings in 2/20 patients. HASTE images significantly provided the lowest rate of artefacts in imaging lung parenchyma (P < 0.001 in peripheral parenchyma), but spatial resolution was limited in this sequence. Concerning the differentiation between tumour and adjacent atelectasis (n = 8), T2-weighted TSE imaging was superior to CT and VIBE in all cases and to HASTE sequence in 4/8 patients. Conclusion: The combination of VIBE and HASTE sequence allows for an adequate imaging of thoracic processes in patients with bronchial carcinoma, limited only in visualizing small pulmonary nodules. To obtain more detail resolution and to

T2-weighted fast spin-echo MR imaging of the pelvis

International Nuclear Information System (INIS)

Francis, I.R.; Steiner, R.M.; Herfkens, R.J.; Jain, K.; Glover, G.H.

1991-01-01

A fast Se (FSE) sequence capable of acquiring SE images with a wide range of TRs and TEs in short imaging times has been recently introduced. I this paper, the authors evaluated the value of this technique compared with standard T2-weighted SE imaging. Twenty-five patients were evaluated with T2-weighted SE and FSE images on a 1.5-T GE Signa imager. Imaging times ranged from 3 to 5 minutes for the FSE acquisition and from 12 to 15 minutes for the SE images. Three observers performed a comparison by using a 10-point scale for organ definition and lesion conspicuity, with differences settled by consensus reading. Pelvic organ definition was superior and pelvic tumors and free fluid were also more conspicuous on FSE images. In 2/25 patients ringing artifacts were present

Changes in transport and confinement in the EXTRAP-T2 reversed field pinch

Science.gov (United States)

Sallander, E.; Sallander, J.; Hedqvist, A.

1999-09-01

At the EXTRAP-T2 reversed field pinch a non-intrusive approach has been undertaken to monitor transport driven by magnetic fluctuations. Correlations are presented between fluctuations observed in the core and at the edge of the plasma. The fluctuations are characterized and their effect on the confinement of core electron energy is estimated.

Changes in transport and confinement in the EXTRAP-T2 reversed field pinch

International Nuclear Information System (INIS)

Sallander, E.; Sallander, J.; Hedqvist, A.

1999-01-01

At the EXTRAP-T2 reversed field pinch a non-intrusive approach has been undertaken to monitor transport driven by magnetic fluctuations. Correlations are presented between fluctuations observed in the core and at the edge of the plasma. The fluctuations are characterized and their effect on the confinement of core electron energy is estimated. (author)

Resistive wall instabilities and tearing mode dynamics in the EXTRAP T2R thin shell reversed-field pinch

Science.gov (United States)

Malmberg, J.-A.; Brunsell, P. R.

2002-01-01

Observations of resistive wall instabilities and tearing mode dynamics in the EXTRAP T2R thin shell (τw=6 ms) reversed field pinch are described. A nonresonant mode (m=1,n=-10) with the same handedness as the internal field grows nearly exponentially with an average growth time of about 2.6 ms (less than 1/2 of the shell time) consistent with linear stability theory. The externally nonresonant unstable modes (m=1,n>0), predicted by linear stability theory, are observed to have only low amplitudes (in the normal low-Θ operation mode of the device). The radial field of the dominant internally resonant tearing modes (m=1,n=-15 to n=-12) remain low due to spontaneous fast mode rotation, corresponding to angular phase velocities up to 280 krad/s. Phase aligned mode structures are observed to rotate toroidally with an average angular velocity of 40 krad/s, in the opposite direction of the plasma current. Toward the end of the discharge, the radial field of the internally resonant modes grows as the modes slow down and become wall-locked, in agreement with nonlinear computations. Fast rotation of the internally resonant modes has been observed only recently and is attributed to a change of the front-end system (vacuum vessel, shell, and TF coil) of the device.

Radioimmunoassay method for determination of 3, 3', 5'-triiodothyronine (reverse - T3)

International Nuclear Information System (INIS)

Kosowicz, J.

1979-01-01

To introduce radioimmunoassay, 3, 3', 5'-triiodothyronine (reverse-T 3 ) was coupled to bovine serum albumin by the carbodiimide technique and rabbits were immunized with the conjugates obtained. The immunizations were performed by multiple site intradermal injections at places in which cornynebacterium parvum was previously injected to enhance immunologic reaction. After 3 months the rabbits raised antisera to reverse-T 3 of a high titer and specificity. To obtain labelled 125 I-reverse T 3 , 3,3'-diiodothyronine was used. Iodination was performed by the chloramine T technique and the iodination mixture was subjected to gel filtration on Sephadex G-25 (fine) column. The purified monolabelled 125 I-reverse T 3 had a specific activity of 3,000 milli Curie/mg. The reverse T 3 radioimmunoassay of a high sensitivity (ca 2 pg/tube) was introduced in the clinical studies and facilitated direct determination of reverse T 3 in sera without the need of plasma extractions. The interference of serum proteins (TBG) was avoided by adding 8-anilino-1-naphtalene sulfonic acid to serum samples. Separation of free from antibody bound antigens was achieved by polyethylene glycol precipitation or immunoprecipitation. (author)

Cardiac troponin T and fast skeletal muscle denervation in ageing.

Science.gov (United States)

Xu, Zherong; Feng, Xin; Dong, Juan; Wang, Zhong-Min; Lee, Jingyun; Furdui, Cristina; Files, Daniel Clark; Beavers, Kristen M; Kritchevsky, Stephen; Milligan, Carolanne; Jin, Jian-Ping; Delbono, Osvaldo; Zhang, Tan

2017-10-01

Ageing skeletal muscle undergoes chronic denervation, and the neuromuscular junction (NMJ), the key structure that connects motor neuron nerves with muscle cells, shows increased defects with ageing. Previous studies in various species have shown that with ageing, type II fast-twitch skeletal muscle fibres show more atrophy and NMJ deterioration than type I slow-twitch fibres. However, how this process is regulated is largely unknown. A better understanding of the mechanisms regulating skeletal muscle fibre-type specific denervation at the NMJ could be critical to identifying novel treatments for sarcopenia. Cardiac troponin T (cTnT), the heart muscle-specific isoform of TnT, is a key component of the mechanisms of muscle contraction. It is expressed in skeletal muscle during early development, after acute sciatic nerve denervation, in various neuromuscular diseases and possibly in ageing muscle. Yet the subcellular localization and function of cTnT in skeletal muscle is largely unknown. Studies were carried out on isolated skeletal muscles from mice, vervet monkeys, and humans. Immunoblotting, immunoprecipitation, and mass spectrometry were used to analyse protein expression, real-time reverse transcription polymerase chain reaction was used to measure gene expression, immunofluorescence staining was performed for subcellular distribution assay of proteins, and electromyographic recording was used to analyse neurotransmission at the NMJ. Levels of cTnT expression in skeletal muscle increased with ageing in mice. In addition, cTnT was highly enriched at the NMJ region-but mainly in the fast-twitch, not the slow-twitch, muscle of old mice. We further found that the protein kinase A (PKA) RIα subunit was largely removed from, while PKA RIIα and RIIβ are enriched at, the NMJ-again, preferentially in fast-twitch but not slow-twitch muscle in old mice. Knocking down cTnT in fast skeletal muscle of old mice: (i) increased PKA RIα and reduced PKA RIIα at the NMJ; (ii

Advanced feedback control methods in EXTRAP T2R reversed field pinch

International Nuclear Information System (INIS)

Yadikin, D.; Brunsell, P. R.; Paccagnella, R.

2006-01-01

Previous experiments in the EXTRAP T2R reversed field pinch device have shown the possibility of suppression of multiple resistive wall modes (RWM). A feedback system has been installed in EXTRAP T2R having 100% coverage of the toroidal surface by the active coil array. Predictions based on theory and the previous experimental results show that the number of active coils should be sufficient for independent stabilization of all unstable RWMs in the EXTRAP T2R. Experiments using different feedback schemes are performed, comparing the intelligent shell, the fake rotating shell, and the mode control with complex feedback gains. Stabilization of all unstable RWMs throughout the discharge duration of t d ≅10τ w is seen using the intelligent shell feedback scheme. Mode rotation and the control of selected Fourier harmonics is obtained simultaneously using the mode control scheme with complex gains. Different sensor signals are studied. A feedback system with toroidal magnetic field sensors could have an advantage of lower feedback gain needed for the RWM suppression compared to the system with radial magnetic field sensors. In this study, RWM suppression is demonstrated, using also the toroidal field component as a sensor signal in the feedback system

Focal neuronal loss, reversible subcortical focal T2 hypointensity in seizures with a nonketotic hyperglycemic hyperosmolar state

Energy Technology Data Exchange (ETDEWEB)

Raghavendra, S.; Ashalatha, R.; Thomas, Sanjeev V. [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Department of Neurology, Trivandrum, Kerala (India); Kesavadas, C. [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Department of Imaging Sciences and Interventional Radiology, Trivandrum (India)

2007-04-15

Neuroimaging in seizures associated with nonketotic hyperglycemia (NKH) is considered normal. We report magnetic resonance imaging (MRI) abnormalities in four patients with NKH and seizures. We prospectively evaluated clinical and radiological abnormalities in four patients with NKH during the period March 2004 to December 2005. All patients presented with seizures, either simple or complex partial seizures or epilepsia partialis continua. Two of them had transient hemianopia. MRI showed subcortical T2 hypointensity in the occipital white matter and in or around the central sulcus (two patients each), T2 hyperintensity of the overlying cortex (two patients), focal overlying cortical enhancement (three patients) and bilateral striatal hyperintensity (one patient). Diffusion-weighted imaging (DWI) performed in three patients showed restricted diffusion. The ictal semiology and electroencephalographic (EEG) findings correlated with the MRI abnormalities. On clinical recovery, the subcortical T2 hypointensity and striatal hyperintensity reversed in all patients. The initial cortical change evolved to FLAIR hyperintensity suggestive of focal cortical gliosis. The radiological differential diagnosis considered initially included encephalitis, malignancy and hemorrhagic infarct rendering a diagnostic dilemma. We identified subcortical T2 hypointensity rather than hyperintensity as a characteristic feature of seizures associated with NKH. Only very few similar reports exist in literature. Reversible bilateral striatal T2 hyperintensity in NKH has not been reported to the best of our knowledge. (orig.)

Focal neuronal loss, reversible subcortical focal T2 hypointensity in seizures with a nonketotic hyperglycemic hyperosmolar state

International Nuclear Information System (INIS)

Raghavendra, S.; Ashalatha, R.; Thomas, Sanjeev V.; Kesavadas, C.

2007-01-01

Neuroimaging in seizures associated with nonketotic hyperglycemia (NKH) is considered normal. We report magnetic resonance imaging (MRI) abnormalities in four patients with NKH and seizures. We prospectively evaluated clinical and radiological abnormalities in four patients with NKH during the period March 2004 to December 2005. All patients presented with seizures, either simple or complex partial seizures or epilepsia partialis continua. Two of them had transient hemianopia. MRI showed subcortical T2 hypointensity in the occipital white matter and in or around the central sulcus (two patients each), T2 hyperintensity of the overlying cortex (two patients), focal overlying cortical enhancement (three patients) and bilateral striatal hyperintensity (one patient). Diffusion-weighted imaging (DWI) performed in three patients showed restricted diffusion. The ictal semiology and electroencephalographic (EEG) findings correlated with the MRI abnormalities. On clinical recovery, the subcortical T2 hypointensity and striatal hyperintensity reversed in all patients. The initial cortical change evolved to FLAIR hyperintensity suggestive of focal cortical gliosis. The radiological differential diagnosis considered initially included encephalitis, malignancy and hemorrhagic infarct rendering a diagnostic dilemma. We identified subcortical T2 hypointensity rather than hyperintensity as a characteristic feature of seizures associated with NKH. Only very few similar reports exist in literature. Reversible bilateral striatal T2 hyperintensity in NKH has not been reported to the best of our knowledge. (orig.)

Importance of radial profiles in spectroscopic diagnostics applied to the EXTRAP-T2R reversed-field pinch

OpenAIRE

Gravestijn, Bob

2003-01-01

The determination of the plasma confinement propertiesdemand data as the electron temperature, the ionic and electrondensity profiles and the radiative emissivity profiles. Thefocus of this thesis is the importance of radial profiles inspectroscopic diagnostics applied to the EXTRAP-T2Rreversed-field pinch. EXTRAP-T2R is a resistive shell reversed-field pinch with amagnetic field shell penetration time much longer than therelaxation cycle time scale. Significant improvements inconfinement pro...

NMR relaxation in natural soils: Fast Field Cycling and T1-T2 Determination by IR-MEMS

Science.gov (United States)

Haber-Pohlmeier, S.; Pohlmeier, A.; Stapf, S.; van Dusschoten, D.

2009-04-01

Soils are natural porous media of highest importance for food production and sustainment of water resources. For these functions, prominent properties are their ability of water retainment and transport, which are mainly controlled by pore size distribution. The latter is related to NMR relaxation times of water molecules, of which the longitudinal relaxation time can be determined non-invasively by fast-field cycling relaxometry (FFC) and both are obtainable by inversion recovery - multi-echo- imaging (IR-MEMS) methods. The advantage of the FFC method is the determination of the field dependent dispersion of the spin-lattice relaxation rate, whereas MRI at high field is capable of yielding spatially resolved T1 and T2 times. Here we present results of T1- relaxation time distributions of water in three natural soils, obtained by the analysis of FFC data by means of the inverse Laplace transformation (CONTIN)1. Kaldenkirchen soil shows relatively broad bimodal distribution functions D(T1) which shift to higher relaxation rates with increasing relaxation field. These data are compared to spatially resolved T1- and T2 distributions, obtained by IR-MEMS. The distribution of T1 corresponds well to that obtained by FFC.

Resistive wall modes in the EXTRAP T2R reversed-field pinch

Science.gov (United States)

Brunsell, P. R.; Malmberg, J.-A.; Yadikin, D.; Cecconello, M.

2003-10-01

Resistive wall modes (RWM) in the reversed field pinch are studied and a detailed comparison of experimental growth rates and linear magnetohydrodynamic (MHD) theory is made. RWM growth rates are experimentally measured in the thin shell device EXTRAP T2R [P. R. Brunsell et al., Plasma Phys. Controlled Fusion 43, 1 (2001)]. Linear MHD calculations of RWM growth rates are based on experimental equilibria. Experimental and linear MHD RWM growth rate dependency on the equilibrium profiles is investigated experimentally by varying the pinch parameter Θ=Bθ(a)/ in the range Θ=1.5-1.8. Quantitative agreement between experimental and linear MHD growth rates is seen. The dominating RWMs are the internal on-axis modes (having the same helicity as the central equilibrium field). At high Θ, external nonresonant modes are also observed. For internal modes experimental growth rates decrease with Θ while for external modes, growth rates increase with Θ. The effect of RWMs on the reversed-field pinch plasma performance is discussed.

A reversion of an IL2RG mutation in combined immunodeficiency providing competitive advantage to the majority of CD8+ T cells.

Science.gov (United States)

Kuijpers, Taco W; van Leeuwen, Ester M M; Barendregt, Barbara H; Klarenbeek, Paul; aan de Kerk, Daan J; Baars, Paul A; Jansen, Machiel H; de Vries, Niek; van Lier, René A W; van der Burg, Mirjam

2013-07-01

Mutations in the common gamma chain (γc, CD132, encoded by the IL2RG gene) can lead to B(+)T(-)NK(-) X-linked severe combined immunodeficiency, as a consequence of unresponsiveness to γc-cytokines such as interleukins-2, -7 and -15. Hypomorphic mutations in CD132 may cause combined immunodeficiencies with a variety of clinical presentations. We analyzed peripheral blood mononuclear cells of a 6-year-old boy with normal lymphocyte counts, who suffered from recurrent pneumonia and disseminated mollusca contagiosa. Since proliferative responses of T cells and NK cells to γc -cytokines were severely impaired, we performed IL2RG gene analysis, showing a heterozygous mutation in the presence of a single X-chromosome. Interestingly, an IL2RG reversion to normal predominated in both naïve and antigen-primed CD8(+) T cells and increased over time. Only the revertant CD8(+) T cells showed normal expression of CD132 and the various CD8(+) T cell populations had a different T-cell receptor repertoire. Finally, a fraction of γδ(+) T cells and differentiated CD4(+)CD27(-) effector-memory T cells carried the reversion, whereas NK or B cells were repeatedly negative. In conclusion, in a patient with a novel IL2RG mutation, gene-reverted CD8(+) T cells accumulated over time. Our data indicate that selective outgrowth of particular T-cell subsets may occur following reversion at the level of committed T progenitor cells.

Advanced feedback control methods in EXTRAP T2R reversed field pinch

Science.gov (United States)

Yadikin, D.; Brunsell, P. R.; Paccagnella, R.

2006-07-01

Previous experiments in the EXTRAP T2R reversed field pinch device have shown the possibility of suppression of multiple resistive wall modes (RWM). A feedback system has been installed in EXTRAP T2R having 100% coverage of the toroidal surface by the active coil array. Predictions based on theory and the previous experimental results show that the number of active coils should be sufficient for independent stabilization of all unstable RWMs in the EXTRAP T2R. Experiments using different feedback schemes are performed, comparing the intelligent shell, the fake rotating shell, and the mode control with complex feedback gains. Stabilization of all unstable RWMs throughout the discharge duration of td≈10τw is seen using the intelligent shell feedback scheme. Mode rotation and the control of selected Fourier harmonics is obtained simultaneously using the mode control scheme with complex gains. Different sensor signals are studied. A feedback system with toroidal magnetic field sensors could have an advantage of lower feedback gain needed for the RWM suppression compared to the system with radial magnetic field sensors. In this study, RWM suppression is demonstrated, using also the toroidal field component as a sensor signal in the feedback system.

I + (H2O)2 → HI + (H2O)OH Forward and Reverse Reactions. CCSD(T) Studies Including Spin-Orbit Coupling.

Science.gov (United States)

Wang, Hui; Li, Guoliang; Li, Qian-Shu; Xie, Yaoming; Schaefer, Henry F

2016-03-03

The potential energy profile for the atomic iodine plus water dimer reaction I + (H2O)2 → HI + (H2O)OH has been explored using the "Gold Standard" CCSD(T) method with quadruple-ζ correlation-consistent basis sets. The corresponding information for the reverse reaction HI + (H2O)OH → I + (H2O)2 is also derived. Both zero-point vibrational energies (ZPVEs) and spin-orbit (SO) coupling are considered, and these notably alter the classical energetics. On the basis of the CCSD(T)/cc-pVQZ-PP results, including ZPVE and SO coupling, the forward reaction is found to be endothermic by 47.4 kcal/mol, implying a significant exothermicity for the reverse reaction. The entrance complex I···(H2O)2 is bound by 1.8 kcal/mol, and this dissociation energy is significantly affected by SO coupling. The reaction barrier lies 45.1 kcal/mol higher than the reactants. The exit complex HI···(H2O)OH is bound by 3.0 kcal/mol relative to the asymptotic limit. At every level of theory, the reverse reaction HI + (H2O)OH → I + (H2O)2 proceeds without a barrier. Compared with the analogous water monomer reaction I + H2O → HI + OH, the additional water molecule reduces the relative energies of the entrance stationary point, transition state, and exit complex by 3-5 kcal/mol. The I + (H2O)2 reaction is related to the valence isoelectronic bromine and chlorine reactions but is distinctly different from the F + (H2O)2 system.

Reversal of human allergen-specific CRTH2+ T(H)2 cells by IL-12 or the PS-DSP30 oligodeoxynucleotide.

Science.gov (United States)

Annunziato, F; Cosmi, L; Manetti, R; Brugnolo, F; Parronchi, P; Maggi, E; Nagata, K; Romagnani, S

2001-11-01

The chemoattractant receptor homologous molecule expressed on T(H)2 cells (CRTH2) is a receptor for prostaglandin D(2), which among human T cells is selectively expressed by T(H)2 and type 2 cytotoxic effectors. Our purpose was to assess whether the cytokine production profile of T(H)2 effectors could be reversed by exploiting their selective expression of CRTH2. CRTH2(+) T cells were purified from the blood of allergic subjects, stimulated with the specific allergen in the absence or presence of IL-12, and assessed by flow cytometry at the single-cell level for their ability to produce IL-4 and/or IFN-gamma after antigen or polyclonal stimulation. Both IL-12 and the PS-DSP30 oligodeoxynucleotide enabled CRTH2(+) allergen-stimulated T(H)2 cells to produce IFN-gamma. This change in the profile of cytokine production by T(H)2 cells from allergic subjects was related to the upregulation of IL-12 receptor beta2 chain and was associated with the loss of CRTH2. These data demonstrate that the cytokine production pattern of fully differentiated T(H)2 effectors can be changed to a less polarized profile, thus providing the physiologic basis for new immunotherapeutic strategies in allergic disorders.

Fast algorithms for coordinate processors in Galois field for multiplicity t = 4.5 and t > 5

International Nuclear Information System (INIS)

Nikityuk, N.M.

1989-01-01

Fast algorithms for solving the coordinate equations for special-purpose processors at multiplicity t = 4.5 and t > 5 are described. Block diagrams of coordinate processor for t 4 in Galois field GF(2 m ) is presented which is solved by a table method. Economical algorithms for solving the coordinate equations by serial methods at t > 5 are described. The algorithms and devices proposed could be applied when creating fast processors in high energy physics spectrometers. 9 refs.; 3 figs

Comparison of single-shot fast spin-echo sequence and T2-weighted fast spin-echo sequence in MR imaging of the brain

International Nuclear Information System (INIS)

Cha, Sung Ho; Seo, Jeong Jin; Jeong, Gwang Woo; Kim, Jae Kyu; Kim, Yun Hyeon; Jeong, Yong Yeon; Kang, Heoung Keun; Oh, Hee Yeon; Yoon, Jong Hoon

1998-01-01

The purpose of this study was to evaluate the usefulness of the single-shot fast spinecho (SS-FSE) sequence in comparison with the T2-weighted fast spin-echo (T2-FSE) sequence in brain MR imaging. In 41 patients aged 15-75 years with intracranial lesion, both SS-FSE and T2-FES images were obtained using a 1.5-T MR system. Lesions included cerebral ischemia or infarcts (n=3D23), tumors (n=3D10), hemorrhages (n=3D3), inflammatory diseases (n=3D2), arachnoid cysts(n=3D2), and vascular disease (n=3D1), and the MR images were retrospectively evaluated. To calculate contrast-to-noise ratio (CNR), percentage contrast, and signal-to-noise ratio (SNR)-and thus make a quantitative comparison-the mean signal intensities of lesions, normal brain tissue, and noise out-side the patient were measured. For qualitative comparison, the visibility, margin, and extent of the lesions were rated using a five-grade system, and the degree of MR artifacts was also evaluated. Wilcoxon's signed ranks test was used for statistical analysis. The mean CNR of lesions was significantly higher on SS-FSE (31.3) than on T2-FSE images (27.5) (p=3D0.0131). Mean percentage contrast was also higher on SS-FSE (159.0) than on T2-FSE images (108.5) (p=3D0.0222), but mean SNR was higher on T2-FSE (80.3) than on SS-FSE images (53.5) (p=3D0.0000). No significant differences in lesion visibility were observed between the two imaging sequences, though margin and extent of the lesion were worse on SS-FSE images. For MR artifacts, no significant differences were demonstrated. For the evaluation of most intracranial lesions, MR imaging using the SS-FSE sequence appears to be slightly inferior to the T2-FSE sequence, but may be useful where patients are ill or uncooperative, or where children require sedation.=20

Fast mapping of the T2 relaxation time of cerebral metabolites using proton echo-planar spectroscopic imaging (PEPSI).

Science.gov (United States)

Tsai, Shang-Yueh; Posse, Stefan; Lin, Yi-Ru; Ko, Cheng-Wen; Otazo, Ricardo; Chung, Hsiao-Wen; Lin, Fa-Hsuan

2007-05-01

Metabolite T2 is necessary for accurate quantification of the absolute concentration of metabolites using long-echo-time (TE) acquisition schemes. However, lengthy data acquisition times pose a major challenge to mapping metabolite T2. In this study we used proton echo-planar spectroscopic imaging (PEPSI) at 3T to obtain fast T2 maps of three major cerebral metabolites: N-acetyl-aspartate (NAA), creatine (Cre), and choline (Cho). We showed that PEPSI spectra matched T2 values obtained using single-voxel spectroscopy (SVS). Data acquisition for 2D metabolite maps with a voxel volume of 0.95 ml (32 x 32 image matrix) can be completed in 25 min using five TEs and eight averages. A sufficient spectral signal-to-noise ratio (SNR) for T2 estimation was validated by high Pearson's correlation coefficients between logarithmic MR signals and TEs (R2 = 0.98, 0.97, and 0.95 for NAA, Cre, and Cho, respectively). In agreement with previous studies, we found that the T2 values of NAA, but not Cre and Cho, were significantly different between gray matter (GM) and white matter (WM; P PEPSI and SVS scans was less than 9%. Consistent spatial distributions of T2 were found in six healthy subjects, and disagreement among subjects was less than 10%. In summary, the PEPSI technique is a robust method to obtain fast mapping of metabolite T2. (c) 2007 Wiley-Liss, Inc.

Evaluation of lorcaserin on progression of prediabetes to type 2 diabetes and reversion to euglycemia.

Science.gov (United States)

Nesto, Richard; Fain, Randi; Li, Yuhan; Shanahan, William

2016-05-01

Lorcaserin is a selective 5-HT2C (5-hydroxytryptamine 2C) receptor agonist indicated for weight management. Here, we assess the impact of lorcaserin on progression from prediabetes to type 2 diabetes (T2D) and on reversion from prediabetes to euglycemia. This is a post hoc analysis of pooled data from two Phase 3 studies, BLOOM and BLOSSOM (N = 6136), evaluating the impact of lorcaserin on weight and glycemic parameters over 52 weeks in the subpopulation of obese/overweight subjects with prediabetes, alternately defined by fasting plasma glucose (FPG) 100-125 mg/dl or glycated hemoglobin (HbA1c) 5.7-6.4% at baseline. At Week 52, in the subpopulation with prediabetes, nearly twice as many lorcaserin-treated subjects achieved ≥5% weight loss versus placebo (HbA1c: 55.6% vs. 27.5%, p prediabetes, lorcaserin may contribute to weight loss and improve glycemic parameters, and thus may help with preventing progression to T2D and promoting reversion to euglycemia. www.clinicaltrials.gov identifiers are NCT00395135 (BLOOM) and NCT00603902 (BLOSSOM).

Application of fast spin-echo T[sub 2]-weighted imaging for examination of the neurocranium. Comparison with the conventional T[sub 2]-weighted spin-echo sequence. Die Anwendung der T[sub 2]-gewichteten Turbo-Spin-Echo-Sequenz zur Untersuchung des Neurokraniums. Vergleich mit der konventionellen T[sub 2]-gewichteten Spin-Echo-Sequenz

Energy Technology Data Exchange (ETDEWEB)

Siewert, C. (Strahlenklinik und Poliklinik, Universitaets-Klinikum Rudolf Virchow, Standort Wedding, Freie Univ. Berlin (Germany)); Hosten, N. (Strahlenklinik und Poliklinik, Universitaets-Klinikum Rudolf Virchow, Standort Wedding, Freie Univ. Berlin (Germany)); Felix, R. (Strahlenklinik und Poliklinik, Universitaets-Klinikum Rudolf Virchow, Standort Wedding, Freie Univ. Berlin (Germany))

1994-07-01

T[sub 2]-weighted spin-echo imaging is the standard screening procedure in MR imaging of the neutrocranium. We evaluated fast spin-echo T[sub 2]-weighted imaging (TT[sub 2]) of the neurocranium in comparison to conventional spin-echo T[sub 2]-weighted imaging (T[sub 2]). Signal-to-noise and contrast-to-noise ratio of normal brain tissues (basal ganglia, grey and white matter, CSF fluid) and different pathologies were calculated. Signal-to-noise ratio and contrast-to-noise ratio were significantly higher than TT[sub 2] than in T[sub 2] (with the exception of grey-to-white matter contrast). Tissues with increased content of water protons (mobile protons) showed the highest contrast to surrounding tissues. The increased signal intensity of fat must be given due attention in fatty lesions. Because the contrast-to-noise ratio between white matter and basal ganglia is less in TT[sub 2], Parkinson patients have to be examined by conventional T[sub 2]. If these limitations are taken into account, fast spin-echo T[sub 2]-weighted imaging is well appropriate for MR imaging of the neurocranium, resulting in heavy T[sub 2]-weighting achieved in a short acquisition time. (orig.)

Evaluation with fat-suppression fast spin-echo T2-weighted images for bone and soft tissue disorders

International Nuclear Information System (INIS)

Kakitsubata, Yousuke; Watanabe, Katsushi; Kakitsubata, Sachiko; Shimizu, Tokiyoshi.

1997-01-01

One hundred and sixty-four magnetic resonance (MR) studies of bone or soft tissue disorders were evaluated with T2-weighted fast spin echo (FSE) imaging and T2-weighted fat-suppressed FSE (FS-FSE) imaging. Fifty-two patients with bone contusion of the knee were also evaluated with conventional T2-weighted SE imaging and T2-weighted FS-FSE imaging. In 50 of 71 patients (70.4%), areas of high signal intensity in bone marrow were more clearly demonstrated on T2-weighted FS-FSE images than on T2-weighted FSE image. Edema or inflammation of soft tissues were also clearly revealed on T2-weighted FS-FSE images. In 27 of 32 patients (84%), bone contusions were more apparently shown on T2-weighted FS-FSE images than on conventional T2-weighted SE image. T2-weighted FS-FSE imaging is a sensitive method of evaluating the long T2 lesions of bone or soft tissue disorders. (author)

Assessment of the image quality and tumor detectability of breath-hold T2-weighted imaging of liver tumors using a fast gradient MR system

International Nuclear Information System (INIS)

Yoshida, Kotaro; Suto, Yuji; Sugihara, Shuji; Tokuda, Yukiko

1996-01-01

Fourteen patients with various types of focal liver tumors were imaged with turbo spin-echo (TSE), breath-hold TSE (BH-TSE) and half-Fourier single-shot TSE (HASTE) pulse sequences using a fast gradient magnetic resonance imaging (MRI) system. We compared the T2-weighted images of the liver with the TSE, BH-TSE, HASTE and conventional spin-echo (SE) pulse sequences in order to determine whether those fast T2-weighted images, including fat suppressed images, could replace SE images. In quantitative and qualitative analysis, the fast T2-weighted images were slightly superior to the SE images, but they were inferior in the conspicuousness of liver tumor to the SE images. These findings suggest that the fast T2-weighted images can shorten the examination time of the liver MRI, but cannot replace the T2-weighted SE images because of the low conspicuousness. (author)

Properties of the edge plasma in the rebuilt Extrap-T2R reversed field pinch experiment

International Nuclear Information System (INIS)

Vianello, N; Spolaore, M; Serianni, G; Bergsaker, H; Antoni, V; Drake, J R

2002-01-01

The edge region of the rebuilt Extrap-T2R reversed field pinch experiment has been investigated using Langmuir probes. Radial profiles of main plasma parameters are obtained and compared with those of the previous device Extrap-T2. The spontaneous setting up of a double shear layer of ExB toroidal velocity is confirmed. The particle flux induced by electrostatic fluctuations is calculated and the resulting effective diffusion coefficient is consistent with the Bohm estimate. A close relationship between electrostatic fluctuations at the edge and non-linear coupling of MHD modes in the core is found

Properties of the edge plasma in the rebuilt Extrap-T2R reversed field pinch experiment

Science.gov (United States)

Vianello, N.; Spolaore, M.; Serianni, G.; Bergsåker, H.; Antoni, V.; Drake, J. R.

2002-12-01

The edge region of the rebuilt Extrap-T2R reversed field pinch experiment has been investigated using Langmuir probes. Radial profiles of main plasma parameters are obtained and compared with those of the previous device Extrap-T2. The spontaneous setting up of a double shear layer of E×B toroidal velocity is confirmed. The particle flux induced by electrostatic fluctuations is calculated and the resulting effective diffusion coefficient is consistent with the Bohm estimate. A close relationship between electrostatic fluctuations at the edge and non-linear coupling of MHD modes in the core is found.

Fast damage imaging using the time-reversal technique in the frequency–wavenumber domain

International Nuclear Information System (INIS)

Zhu, R; Huang, G L; Yuan, F G

2013-01-01

The time-reversal technique has been successfully used in structural health monitoring (SHM) for quantitative imaging of damage. However, the technique is very time-consuming when it is implemented in the time domain. In this paper, we study the technique in the frequency–wavenumber (f–k) domain for fast real-time imaging of multiple damage sites in plates using scattered flexural plate waves. Based on Mindlin plate theory, the time reversibility of dispersive flexural waves in an isotropic plate is theoretically investigated in the f–k domain. A fast damage imaging technique is developed by using the cross-correlation between the back-propagated scattered wavefield and the incident wavefield in the frequency domain. Numerical simulations demonstrate that the proposed technique cannot only localize multiple damage sites but also potentially identify their sizes. Moreover, the time-reversal technique in the f–k domain is about two orders of magnitude faster than the method in the time domain. Finally, experimental testing of an on-line SHM system with a sparse piezoelectric sensor array is conducted for fast multiple damage identification using the proposed technique. (paper)

Cardiac T2-mapping using a fast gradient echo spin echo sequence - first in vitro and in vivo experience

OpenAIRE

Baessler, Bettina; Schaarschmidt, Frank; Stehning, Christian; Schnackenburg, Bernhard; Maintz, David; Bunck, Alexander C.

2015-01-01

Background: The aim of this study was the evaluation of a fast Gradient Spin Echo Technique (GraSE) for cardiac T2-mapping, combining a robust estimation of T2 relaxation times with short acquisition times. The sequence was compared against two previously introduced T2-mapping techniques in a phantom and in vivo. Methods: Phantom experiments were performed at 1.5 T using a commercially available cylindrical gel phantom. Three different T2-mapping techniques were compared: a Multi Echo Spin Ec...

MUSIC. a fast T2* - sensitive MRI technique with enhanced volume coverage

International Nuclear Information System (INIS)

Loenneker, Thomas; Hennig, Juergen

1994-01-01

A fast imaging method based on gradient-recalled echoes and echo time inter-leaved multi-slice excitation is presented. This method maintains the sensitivity of T 2 * by using a long echo time of at least 35 milliseconds. Bipolar gradients are used to shift the gradient echoes in order to ensure constant TE for each slab and prevent ghost-artefacts within the images caused by spin- or stimulated echoes. This method enhances the total imaging time of a conventional multi-slice gradient echo technique, while maintaining the high volume coverage. Thus, stimulated human cortical activation maps can be detected on standard clinical MR instruments at several planes within measuring times of a few seconds. The efficiency of the technique is demonstrated in the detection of temporary changes in T 2 * in functional MRI experiments of the human visual cortex at a magnetic field strength of 2 tesla. (author). 18 refs., 6 figs

Iminoboronate Formation Leads to Fast and Reversible Conjugation Chemistry of α-Nucleophiles at Neutral pH.

Science.gov (United States)

Bandyopadhyay, Anupam; Gao, Jianmin

2015-10-12

Bioorthogonal reactions that are fast and reversible under physiological conditions are in high demand for biological applications. Herein, it is shown that an ortho boronic acid substituent makes aryl ketones rapidly conjugate with α-nucleophiles at neutral pH. Specifically, 2-acetylphenylboronic acid and derivatives were found to conjugate with phenylhydrazine with rate constants of 10(2) to 10(3) M(-1) s(-1) , comparable to the fastest bioorthogonal conjugations known to date. (11) B NMR analysis revealed the varied extent of iminoboronate formation of the conjugates, in which the imine nitrogen forms a dative bond with boron. The iminoboronate formation activates the imines for hydrolysis and exchange, rendering these oxime/hydrazone conjugations reversible and dynamic under physiological conditions. The fast and dynamic nature of the iminoboronate chemistry should find wide applications in biology. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photoinduced local heating in silica photonic crystals for fast and reversible switching.

Science.gov (United States)

Gallego-Gómez, Francisco; Blanco, Alvaro; López, Cefe

2012-12-04

Fast and reversible photonic-bandgap tunability is achieved in silica artificial opals by local heating. The effect is fully reversible as heat rapidly dissipates through the non-irradiated structure without active cooling and water is readsorbed. The performance is strongly enhanced by decreasing the photoirradiated opal volume, allowing bandgap shifts of 12 nm and response times of 20 ms. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fast MR Imaging of the Paediatric Abdomen with CAIPIRINHA-Accelerated T1w 3D FLASH and with High-Resolution T2w HASTE: A Study on Image Quality

Directory of Open Access Journals (Sweden)

Mengxia Li

2015-01-01

Full Text Available The aim of this study was to explore the applicability of fast MR techniques to routine paediatric abdominopelvic MRI at 1.5 Tesla. “Controlled Aliasing in Parallel Imaging Results in Higher Acceleration-” (CAIPIRINHA- accelerated contrast-enhanced-T1w 3D FLASH imaging was compared to standard T1w 2D FLASH imaging with breath-holding in 40 paediatric patients and to respiratory-triggered T1w TSE imaging in 10 sedated young children. In 20 nonsedated patients, we compared T2w TIRM to fat-saturated T2w HASTE imaging. Two observers performed an independent and blinded assessment of overall image quality. Acquisition time was reduced by the factor of 15 with CAIPIRINHA-accelerated T1w FLASH and by 7 with T2w HASTE. With CAIPIRINHA and with HASTE, there were significantly less motion artefacts in nonsedated patients. In sedated patients, respiratory-triggered T1w imaging in general showed better image quality. However, satisfactory image quality was achieved with CAIPIRINHA in two sedated patients where respiratory triggering failed. In summary, fast scanning with CAIPIRINHA and HASTE presents a reliable high quality alternative to standard sequences in paediatric abdominal MRI. Paediatric patients, in particular, benefit greatly from fast image acquisition with less breath-hold cycles or shorter sedation.

Spontaneous quasi single helicity regimes in EXTRAP T2R reversed-field pinch

Science.gov (United States)

Frassinetti, L.; Brunsell, P. R.; Drake, J. R.; Menmuir, S.; Cecconello, M.

2007-11-01

In recent years, good progress toward a better understanding and control of the plasma performance in reversed-field pinch devices has been made. These improvements consist both of the discovery of spontaneous plasma regimes, termed the quasi single helicity (QSH) regime, in which part of the plasma core is no longer stochastic, and of the development of techniques for active control of plasma instabilities. In this paper, a systematic study of spontaneous QSH in the EXTRAP T2R device [P. R. Brunsell, H. Bergsaker, M. Cecconello et al., Plasma Phys. Control. Fusion 43, 1457 (2001)] is presented. In this device, QSH states can occur spontaneously and it is associated with magnetic and thermal structures. A statistical analysis to determine the most favorable experimental conditions to have a transition to the QSH regime will be presented. The results described here are useful to understand the underlying properties of QSH regimes in view of future applications of the QSH active control in EXTRAP T2R; they are also important to have a comparison with the QSH studied in other devices.

Fast T1 mapping of the brain at high field using Look-Locker and fast imaging.

Science.gov (United States)

Jiang, Ke; Zhu, Yanjie; Jia, Sen; Wu, Yin; Liu, Xin; Chung, Yiu-Cho

2017-02-01

This study aims to develop and evaluate a new method for fast high resolution T1 mapping of the brain based on the Look-Locker technique. Single-shot turboflash sequence with high temporal acceleration is used to sample the recovery of inverted magnetization. Multi-slice interleaved acquisition within one inversion slab is used to reduce the number of inversion pulses and hence SAR. Accuracy of the proposed method was studied using simulation and validated in phantoms. It was then evaluated in healthy volunteers and stroke patients. In-vivo results were compared to values obtained by inversion recovery fast spin echo (IR-FSE) and literatures. With the new method, T 1 values in phantom experiments agreed with reference values with median error map was acquired in 3.35s and the T1 maps of the whole brain were acquired in 2min with two-slice interleaving, with a spatial resolution of 1.1×1.1×4mm 3 . The T 1 values obtained were comparable to those measured with IR-FSE and those reported in literatures. These results demonstrated the feasibility of the proposed method for fast T1 mapping of the brain in both healthy volunteers and stroke patients at 3T. Copyright © 2016 Elsevier Inc. All rights reserved.

Laser heating of field-reversed configurations

International Nuclear Information System (INIS)

Carson, R.S.; Vlases, G.C.

1983-01-01

The experimental facility is a 21-cm-long solenoid with a 5.5-cm bore. The 4-cm ID quartz tube is filled with slowly flowing H 2 to 0.5-3.0 torr. Fields up to 6.5 T in 3.7 μsec are produced, with reverse-bias fields up -1.9 T. Preionization is by 40kA axial discharge 4.5 μsec before field-reversal is begun. The CO 2 laser used produces 300 to 400 J in 2 μsec, in an annular beam that can be defocused for preheating the outer edges of the plasma, or focused tightly for central-column heating and beam propagation during formation. The focusing system includes a return mirror for multiple passing of the laser energy. Diagnostics include compensated, diamagnetic flux loops, internal field probes, cross-tube and axial interferometers, fast photography, and spectroscopy

Comparison of two-dimensional fast spin echo T2 weighted sequences and three-dimensional volume isotropic T2 weighted fast spin echo (VISTA) MRI in the evaluation of triangular fibrocartilage of the wrist.

Science.gov (United States)

Park, Hee Jin; Lee, So Yeon; Kang, Kyung A; Kim, Eun Young; Shin, Hun Kyu; Park, Se Jin; Park, Jai Hyung; Kim, Eugene

2018-04-01

To compare image quality of three-dimensional volume isotropic T 2 weighted fast spin echo (3D VISTA) and two-dimensional (2D) T 2 weighted images (T2WI) for evaluation of triangular fibrocartilage (TFC) and to investigate whether 3D VISTA can replace 2D T 2 WI in evaluating TFC injury. This retrospective study included 69 patients who received wrist MRIs using both 2D T 2 WI and 3D VISTA techniques for assessment of wrist pathology, including TFC injury. Two radiologists measured the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) of the two sequences. The anatomical identification score and diagnostic performance were independently assessed by two interpreters. The diagnostic abilities of 3D VISTA and 2D T 2 WI were analysed by sensitivity, specificity and accuracy for diagnosing TFC injury using surgically or clinically confirmed diagnostic reference standards. 17 cases (25%) were classified as having TFC injury. 2 cases (12%) were diagnosed surgically, and 15 cases (88%) were diagnosed by physical examination. 52 cases (75%) were diagnosed as having intact TFC. 8 of these cases (15%) were surgically confirmed, while the others were diagnosed by physical examination and clinical findings. The 3D VISTA images had significantly higher SNR and CNR values for the TFC than 2D T 2 WI images. The scores of 3D VISTA's total length, full width and sharpness were similar to those of 2D T 2 WI. We were unable to find a significant difference between 3D VISTA and 2D T 2 WI in the ability to diagnose TFC injury. 3D VISTA image quality is similar to that of 2D T 2 WI for TFC evaluation and is also excellent for tissue contrast. 3D VISTA can replace 2D images in TFC injury assessment. Advances in knowledge: 3D VISTA image quality is similar to that of 2D T 2 WI for TFC evaluation and is also excellent for tissue contrast. 3D VISTA can replace 2D images in TFC injury assessment.

Impurity profiles and radial transport in the EXTRAP-T2 reversed field pinch

International Nuclear Information System (INIS)

Sallander, J.

1999-01-01

Radially resolved spectroscopy has been used to measure the radial distribution of impurity ions (O III-O V and C III-CVI) in the EXTRAP-T2 reversed field pinch (RFP). The radial profile of the emission is reconstructed from line emission measured along five lines of sight. The ion density profile is the fitted quantity in the reconstruction of the brightness profile and is thus obtained directly in this process. These measurements are then used to adjust the parameters in transport calculations in order to obtain consistency with the observed ion density profiles. Comparison between model and measurements show that a radial dependence in the diffusion is needed to explain the measured ion densities. (author)

Impurity profiles and radial transport in the EXTRAP-T2 reversed field pinch

Science.gov (United States)

Sallander, J.

1999-05-01

Radially resolved spectroscopy has been used to measure the radial distribution of impurity ions (O III-O V and C III-CVI) in the EXTRAP-T2 reversed field pinch (RFP). The radial profile of the emission is reconstructed from line emission measured along five lines of sight. The ion density profile is the fitted quantity in the reconstruction of the brightness profile and is thus obtained directly in this process. These measurements are then used to adjust the parameters in transport calculations in order to obtain consistency with the observed ion density profiles. Comparison between model and measurements show that a radial dependence in the diffusion is needed to explain the measured ion densities.

Metalized T graphene: A reversible hydrogen storage material at room temperature

International Nuclear Information System (INIS)

Ye, Xiao-Juan; Zhong, Wei; Du, You-Wei; Liu, Chun-Sheng; Zeng, Zhi

2014-01-01

Lithium (Li)-decorated graphene is a promising hydrogen storage medium due to its high capacity. However, homogeneous mono-layer coating graphene with lithium atoms is metastable and the lithium atoms would cluster on the surface, resulting in the poor reversibility. Using van der Waals-corrected density functional theory, we demonstrated that lithium atoms can be homogeneously dispersed on T graphene due to a nonuniform charge distribution in T graphene and strong hybridizations between the C-2p and Li-2p orbitals. Thus, Li atoms are not likely to form clusters, indicating a good reversible hydrogen storage. Both the polarization mechanism and the orbital hybridizations contribute to the adsorption of hydrogen molecules (storage capacity of 7.7 wt. %) with an optimal adsorption energy of 0.19 eV/H 2 . The adsorption/desorption of H 2 at ambient temperature and pressure is also discussed. Our results can serve as a guide in the design of new hydrogen storage materials based on non-hexagonal graphenes.

Nano-functionalized filamentous fungus hyphae with fast reversible macroscopic assembly & disassembly features.

Science.gov (United States)

Wang, Haiying; Li, Xiaorui; Chai, Liyuan; Zhang, Liyuan

2015-05-18

A uniform decoration of hyphae by polyaniline nanoparticles (PANI NPs) was achieved here. This novel hybrid structure can be effectively assembled into a film by filtration and disassembled in water by shaking. This reversible process is very fast, which promises applications in nanomaterials including adsorption.

Application of three-dimensional fast spin-echo T2-weighted image in lesions of the inner ear

International Nuclear Information System (INIS)

Xian Junfang; Wang Zhenchang; Yan Fei; Niu Yantao; Zhu Ye; Wang Yan; Tian Qichang; Lan Baosen

1999-01-01

Objective: To investigate the advantage of three-dimensional fast spin-echo T 2 -weighted image (3D FSE T 2 WI) in depicting normal structures and lesions of the inner ear. Methods: 3D FSE T 2 WI and 2D FSE T 2 WI were performed in 10 healthy volunteers and 20 cases with inner ear diseases. Advantages and disadvantages of the two techniques were compared. CT was performed in 6 cases with enlarged endo-lymphatic sac and 1 cases of Mondini malformation. Results: 3D FSE T 2 WI enabled visualization of detailed anatomic structures. Enlarged endo-lymphatic sacs were clearly revealed in 9 cases on 16 sides by 3D FSE T 2 WI, while only a part but not the whole of the enlarged endo-lymphatic sac could be shown on 2D FSE T 2 WI. In 6 cases, 3D FSE T 2 WI displayed enlarged endo-lymphatic sac on 11 sides and normal on 1 side; however, CT revealed enlarged vestibular aqueduct on all 12 sides. One case with small acoustic neuroma (only 4 mm in diameter) was clearly demonstrated on 3D FSE T 2 WI but not well shown on 2D FSE T 2 WI. One case with cochlear Mondini malformation associated with dysplasia of vestibule and semicircular canals was displayed more clearly on 3D FSE T 2 WI than on 2D FSE T 2 WI. Conclusions: 3D FSE T 2 WI can clearly display normal structures and lesions of the inner ear

Fast imaging diagnostics on the C-2U advanced beam-driven field-reversed configuration device

Energy Technology Data Exchange (ETDEWEB)

Granstedt, E. M., E-mail: egranstedt@trialphaenergy.com; Petrov, P.; Knapp, K.; Cordero, M.; Patel, V. [Tri Alpha Energy, P.O. Box 7010, Rancho Santa Margarita, California 92688 (United States)

2016-11-15

The C-2U device employed neutral beam injection, end-biasing, and various particle fueling techniques to sustain a Field-Reversed Configuration (FRC) plasma. As part of the diagnostic suite, two fast imaging instruments with radial and nearly axial plasma views were developed using a common camera platform. To achieve the necessary viewing geometry, imaging lenses were mounted behind re-entrant viewports attached to welded bellows. During gettering, the vacuum optics were retracted and isolated behind a gate valve permitting their removal if cleaning was necessary. The axial view incorporated a stainless-steel mirror in a protective cap assembly attached to the vacuum-side of the viewport. For each system, a custom lens-based, high-throughput optical periscope was designed to relay the plasma image about half a meter to a high-speed camera. Each instrument also contained a remote-controlled filter wheel, set between shots to isolate a particular hydrogen or impurity emission line. The design of the camera platform, imaging performance, and sample data for each view is presented.

Impact of Ramadan Intermittent Fasting on Oxidative Stress Measured by Urinary 15-F2t-Isoprostane

Directory of Open Access Journals (Sweden)

Mo'ez Al-Islam Ezzat Faris

2012-01-01

fast Ramadan were recruited. Urine and serum sampling and anthropometric and dietary assessments were conducted one week before Ramadan (T0, at the end of the third week of Ramadan (T1, and one month after Ramadan (T2. Biochemical measurements included urinary 15FIP, creatinine, and hematological indices. Results revealed that the urinary level of 15FIP measured at T0 was normal, while they showed a significantly (P<0.05 higher level when measured at T1 concomitant with a significant (P<0.05 increase in the body weight and total body fat percent. In conclusion, results suggest that increased body weight is associated with increased lipid peroxidation and oxidative stress, and the impact of RIF on oxidative stress is mediated by the changes in body weight at the end of the month.

Fast T1-weighted imaging using GRASE sequence for the female pelvis

International Nuclear Information System (INIS)

Dohke, Masako; Watanabe, Yuji; Kumashiro, Masayuki; Amoh, Yoshiki; Ishimori, Takayoshi; Oda, Kazushige; Okumura, Akira; Koike, Shinji; Dodo, Yoshihiro

1998-01-01

GRASE sequence, a combination of TSE and gradient echo, has been developed as a fast T 2 -weighted imaging technique. We have modified the GRASE sequence to be used for fast T 1 -weighted imaging of the female pelvis. In this article, we compared image quality and incidence of artifacts between T 1 -weighted GRASE images and conventional T 1 -weighted SE images. In a phantom study, signal-to-noise ratio was inferior in the GRASE images relative to corresponding on SE images. Susceptibility and chemical shift artifacts seen in GRASE images were seen with almost equal incidence in SE and TSE images. In a clinical study, we compared GRASE images with SE images in six patients with endometrial cysts and four patients with dermoid cysts. The overall image quality obtained with GRASE sequence was satisfactory in all patients and was almost identical with that obtained with SE sequence. GRASE images demonstrated endometrial cysts and dermoid cysts as clearly as did SE images. T 1 -weighted GRASE imaging, however, has a relatively long TE (35 ms) for T 1 -weighted images, which makes the signal intensity of urine and uterine endometrium with long T 2 values higher than in SE images. In conclusion, GRASE sequence can be used for fast T 1 -weighted imaging of the female pelvis because of short imaging time. (author)

Basic evaluation of the new pulse sequence for simultaneous acquisition of T1- and T2-weighted images

International Nuclear Information System (INIS)

Kurose, Atsunari; Takahashi, Tohru; Ohishi, Tae; Ishikawa, Akihiro

2006-01-01

A novel pulse sequence that enables simultaneous acquisition of T1-weighted (T1W) and T2-weighted (T2W) images is presented. In this new technique, the inversion recovery (IR) pulse of conventional fast inversion recovery (Fast IR) is replaced with a pulse train that consists of a fast spin echo (FSE) and 180(y)+90(x) for driven inversion (DI). By using a shorter T1 and independent k-space ordering, the first part of the sequence provides T2W images and the second part provides T1W images, thereby enabling simultaneous acquisition in a single scan time comparable to that of Fast IR. Signal simulation also was conducted, and this was compared with conventional scanning techniques using normal volunteers. In the human studies, both T1W and T2W images showed the same image quality as conventional images, suggesting the potential for this technique to replace the combination of Fast IR and T2W FSE for scan-time reduction. (author)

Reynolds and Maxwell stress measurements in the reversed field pinch experiment Extrap-T2R

Science.gov (United States)

Vianello, N.; Antoni, V.; Spada, E.; Spolaore, M.; Serianni, G.; Cavazzana, R.; Bergsåker, H.; Cecconello, M.; Drake, J. R.

2005-08-01

The complete Reynolds stress (RS) has been measured in the edge region of the Extrap-T2R reversed field pinch experiment. The RS exhibits a strong gradient in the region where a high E × B shear takes place. Experimental results show this gradient to be almost entirely due to the electrostatic contribution. This has been interpreted as experimental evidence of flow generation via turbulence mechanism. The scales involved in flow generation are deduced from the frequency decomposition of RS tensor. They are found related to magnetohydrodynamic activity but are different with respect to the scales responsible for turbulent transport.

Reynolds and Maxwell stress measurements in the reversed field pinch experiment Extrap-T2R

International Nuclear Information System (INIS)

Vianello, N.; Antoni, V.; Spada, E.; Spolaore, M.; Serianni, G.; Cavazzana, R.; Bergsaaker, H.; Cecconello, M.; Drake, J.R.

2005-01-01

The complete Reynolds stress (RS) has been measured in the edge region of the Extrap-T2R reversed field pinch experiment. The RS exhibits a strong gradient in the region where a high E x B shear takes place. Experimental results show this gradient to be almost entirely due to the electrostatic contribution. This has been interpreted as experimental evidence of flow generation via turbulence mechanism. The scales involved in flow generation are deduced from the frequency decomposition of RS tensor. They are found related to magnetohydrodynamic activity but are different with respect to the scales responsible for turbulent transport

tRNA modification profiles of the fast-proliferating cancer cells

Energy Technology Data Exchange (ETDEWEB)

Dong, Chao; Niu, Leilei; Song, Wei [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Department of Obstetrics and Gynecology, Peking University Third Hospital, Peking University, Beijing 100191 (China); Xiong, Xin; Zhang, Xianhua [Departmentof Pharmacy, Peking University Third Hospital, Peking University, Beijing 100191 (China); Zhang, Zhenxi; Yang, Yi; Yi, Fan [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Department of Obstetrics and Gynecology, Peking University Third Hospital, Peking University, Beijing 100191 (China); Zhan, Jun; Zhang, Hongquan [Department of Anatomy, Histology and Embryology, Laboratory of Molecular Cell Biology and Tumor Biology, Peking University, Beijing 100191 (China); Yang, Zhenjun; Zhang, Li-He [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Department of Obstetrics and Gynecology, Peking University Third Hospital, Peking University, Beijing 100191 (China); Zhai, Suodi [Departmentof Pharmacy, Peking University Third Hospital, Peking University, Beijing 100191 (China); Li, Hua, E-mail: huali88@sina.com [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Department of Obstetrics and Gynecology, Peking University Third Hospital, Peking University, Beijing 100191 (China); Ye, Min, E-mail: yemin@bjmu.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Department of Obstetrics and Gynecology, Peking University Third Hospital, Peking University, Beijing 100191 (China); Du, Quan, E-mail: quan.du@pku.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Department of Obstetrics and Gynecology, Peking University Third Hospital, Peking University, Beijing 100191 (China)

2016-08-05

Despite the recent progress in RNA modification study, a comprehensive modification profile is still lacking for mammalian cells. Using a quantitative HPLC/MS/MS assay, we present here a study where RNA modifications are examined in term of the major RNA species. With paired slow- and fast-proliferating cell lines, distinct RNA modification profiles are first revealed for diverse RNA species. Compared to mRNAs, increased ribose and nucleobase modifications are shown for the highly-structured tRNAs and rRNAs, lending support to their contribution to the formation of high-order structures. This study also reveals a dynamic tRNA modification profile in the fast-proliferating cells. In addition to cultured cells, this unique tRNA profile has been further confirmed with endometrial cancers and their adjacent normal tissues. Taken together, the results indicate that tRNA is a actively regulated RNA species in the fast-proliferating cancer cells, and suggest that they may play a more active role in biological process than expected. -- Highlights: •RNA modifications were first examined in term of the major RNA species. •A dynamic tRNA modifications was characterized for the fast-proliferating cells. •The unique tRNA profile was confirmed with endometrial cancers and their adjacent normal tissues. •tRNA was predicted as an actively regulated RNA species in the fast-proliferating cancer cells.

tRNA modification profiles of the fast-proliferating cancer cells

International Nuclear Information System (INIS)

Dong, Chao; Niu, Leilei; Song, Wei; Xiong, Xin; Zhang, Xianhua; Zhang, Zhenxi; Yang, Yi; Yi, Fan; Zhan, Jun; Zhang, Hongquan; Yang, Zhenjun; Zhang, Li-He; Zhai, Suodi; Li, Hua; Ye, Min; Du, Quan

2016-01-01

Despite the recent progress in RNA modification study, a comprehensive modification profile is still lacking for mammalian cells. Using a quantitative HPLC/MS/MS assay, we present here a study where RNA modifications are examined in term of the major RNA species. With paired slow- and fast-proliferating cell lines, distinct RNA modification profiles are first revealed for diverse RNA species. Compared to mRNAs, increased ribose and nucleobase modifications are shown for the highly-structured tRNAs and rRNAs, lending support to their contribution to the formation of high-order structures. This study also reveals a dynamic tRNA modification profile in the fast-proliferating cells. In addition to cultured cells, this unique tRNA profile has been further confirmed with endometrial cancers and their adjacent normal tissues. Taken together, the results indicate that tRNA is a actively regulated RNA species in the fast-proliferating cancer cells, and suggest that they may play a more active role in biological process than expected. -- Highlights: •RNA modifications were first examined in term of the major RNA species. •A dynamic tRNA modifications was characterized for the fast-proliferating cells. •The unique tRNA profile was confirmed with endometrial cancers and their adjacent normal tissues. •tRNA was predicted as an actively regulated RNA species in the fast-proliferating cancer cells.

T2 mapping of muscle activity using ultrafast imaging

International Nuclear Information System (INIS)

Tawara, Noriyuki; Nitta, Osamu; Kuruma, Hironobu; Niitsu, Mamoru; Itoh, Akiyoshi

2011-01-01

Measuring exercise-induced muscle activity is essential in sports medicine. Previous studies proposed measuring transverse relaxation time (T 2 ) using muscle functional magnetic resonance imaging (mfMRI) to map muscle activity. However, mfMRI uses a spin-echo (SE) sequence that requires several minutes for acquisition. We evaluated the feasibility of T 2 mapping of muscle activity using ultrafast imaging, called fast-acquired mfMRI (fast-mfMRI), to reduce image acquisition time. The current method uses 2 pulse sequences, spin-echo echo-planar imaging (SE-EPI) and true fast imaging with steady precession (TrueFISP). SE-EPI images are used to calculate T 2 , and TrueFISP images are used to obtain morphological information. The functional image is produced by subtracting the image of muscle activity obtained using T 2 at rest from that produced after exercise. Final fast-mfMRI images are produced by fusing the functional images with the morphologic images. Ten subjects repeated ankle plantar flexion 200 times. In the fused images, the areas of activated muscle in the fast-mfMRI and SE-EPI images were identical. The geometric location of the fast-mfMRI did not differ between the morphologic and functional images. Morphological and functional information from fast-mfMRI can be applied to the human trunk, which requires limited scan duration. The difference obtained by subtracting T 2 at rest from T 2 after exercise can be used as a functional image of muscle activity. (author)

Increased reverse T3 concentration in patients with anorexia nerrosa

International Nuclear Information System (INIS)

Baranowska, B.; Kaniewski, M.; Zgliczynski, S.

1980-01-01

In 20 female patients with anorexia nervosa, aging 16 - 26 years, the thyroid function was estimated by +- determining TSH secretion in response to TRH, and serum thyroxine (T 4 ), 3,5,3'L-triiodothyronine (T 3 ) and 3,3',5'L-triiodothyronine (reverse T 3 ) concentrations. 14 healthy women of the same age were included into the control group. If compared with control group, a marked supression of TRH stimulated TSH secretion and a lowering of serum T 3 concentration was found in patients with anorexia nervosa. On the other hand, serum reverse T 3 concentration was markedly higher in patients with anorexia nervosa than in control ones. Gain of body weight leads to normalization of thyroid hormones level in the serum. Obtained results show for peripheral mechanism of described hormonal disorders. (author)

Use of high flip angle in T1-prepared FAST sequences for myocardial perfusion quantification

International Nuclear Information System (INIS)

Vallee, Jean-Paul; Ivancevic, Marko; Lazeyras, Francois; Didier, Dominique; Kasuboski, Larry; Chatelain, Pascal; Righetti, Alberto

2003-01-01

This study reports on the first use of high flip angle and radio-frequency (RF) spoiling in T1-prepared fast acquisition in steady state (FAST) sequence for myocardial perfusion in patients. T1 dynamic range was measured in vitro with a FAST, an RF FAST and a snapshot fast low-angle shot (FLASH) sequences with a 90 flip angle. Myocardial perfusion was then measured twice in 6 patients during the same MR session. The RF FAST and FLASH, but not the FAST sequence, demonstrated an extended T1 dynamic range; however, the FLASH images were degraded by artifacts not present on the RF FAST images. The myocardial perfusion indices K1 (first-order transfer constant from the blood to the myocardium for the Gd-DTPA) and Vd (distribution volume of Gd-DTPA in myocardium) did not differ significantly between the two injections. K1 was 0.48±0.12 ml/min g -1 and Vd was 12.5±2.9%. With an extended T1 dynamic range and the sensitivity required for myocardial perfusion quantification, the RF FAST sequence with a 90 flip angle outperformed the snapshot FLASH sequence in terms of image quality and the FAST sequence in terms of contrast dynamic range. (orig.)

Preparation of metastable CoFeNi alloys with ultra-high magnetic saturation (Bs = 2.4-2.59 T) by reverse pulse electrodeposition

Science.gov (United States)

Tabakovic, Ibro; Venkatasamy, Venkatram

2018-04-01

The results of reverse pulse electrodeposition of CoFeNi films with ultra-high magnetic saturation, i.e. Bs values between 2.4 and 2.59 T, are presented in this work. Based on valence-bond theory (Hund's rule) it was assumed that the electronic configuration of MOH obtained by one electron reduction of electroactive intermediate (MOH+ads + e → MOHads) or oxidation of metal (M - e + HOH → MOH + H+) would result with larger number of spins per atom for each of transition metals in MOH-precipitated in CoFeNi deposit- with one more spin than their respective neutral metal in the order: Fe > Co > Ni. The experimental results showed that the increase of Bs value above Slater-Pauling curve was not observed for CoFe alloys, thus FeOH and CoOH compounds were not present in deposit. However, the increase of the Bs values above the Slater-Pauling curve (Bs = 2.4-2.59 T) was observed, for CoFeNi films obtained by reverse pulse electrodeposition. Therefore, NiOH as a stable compound is probably formed in a one-electron oxidation step during anodic pulse oxidation reaction precipitated presumably at the grain boundaries, giving rise to the ultra-high magnetic saturation of CoFeNi films. The effects of experimental conditions on elemental composition, magnetic properties, crystal structure, and thermal stability of CoFeNi films were studied.

Scaling of confinement and profiles in the EXTRAP T2 reversed-field pinch

International Nuclear Information System (INIS)

Welander, A.

1999-01-01

In the Extrap T2 reversed-field pinch the diagnostic techniques for the measurement of electron density and temperature include; Thomson scattering which gives values at three radial positions in the core (r/a=0, 0.28, 0.56), Langmuir probes which give values at the edge (r/a>0.9) and interferometry which gives a line-averaged density. The empirical scaling of electron density and temperature including profile information with global plasma parameters has been studied. The density profile is subject to large variations, with an average parabolic shape when the density is low and flatter shapes when the density is increased. The change in the profile shape can be attributed to a shift in the penetration length of neutrals from the vicinity of the wall. The temperature scales roughly as I/n 1/2 where I is the plasma current and n is the density. The temperature profile is always quite flat with lower variations and there is a tendency for a flatter profile at higher temperatures. (author)

Scaling of confinement and profiles in the EXTRAP T2 reversed-field pinch

Science.gov (United States)

Welander, A.

1999-01-01

In the EXTRAP T2 reversed-field pinch the diagnostic techniques for the measurement of electron density and temperature include; Thomson scattering which gives values at three radial positions in the core (r/a = 0, 0.28, 0.56), Langmuir probes which give values at the edge (r/a > 0.9) and interferometry which gives a line-averaged density. The empirical scaling of electron density and temperature including profile information with global plasma parameters has been studied. The density profile is subject to large variations, with an average parabolic shape when the density is low and flatter shapes when the density is increased. The change in the profile shape can be attributed to a shift in the penetration length of neutrals from the vicinity of the wall. The temperature scales roughly as I/n1/2 where I is the plasma current and n is the density. The temperature profile is always quite flat with lower variations and there is a tendency for a flatter profile at higher temperatures.

Losses of neutral injected fast ions due to adiabaticity breaking processes in a field-reversed configuration

International Nuclear Information System (INIS)

Takahashi, Toshiki; Inoue, Koji; Ishizuka, Takashi; Kondoh, Yoshiomi; Iwasawa, Naotaka

2004-02-01

Losses of neutral beam (NB) injected fast ions from the confinement region of a Field-Reversed Configuration (FRC) with a strong magnetic mirror are numerically analyzed for parameters relevant to NB injection experiments on the FIX (FRC injection experiment) device [T. Asai et al., Phys. Plasmas 7, 2294 (2000)]. Ionization processes of beam particles are calculated by the Monte Carlo method. The confinement of beam ions is discussed with the concept of accessible regions that restrict the ion excursion and are determined from two constants of motion, the kinetic energy and canonical angular momentum, in the case of an axisymmetric and a steady state FRC without an electrostatic field. From the calculation of the accessible regions, it is found that all the fast ions suffer from the orbit loss on the wall surface and/or the end loss. Single particle orbits are also calculated to find a difference of confinement properties from the results by employing the accessible regions. The magnetic moment is observed to show non-adiabatic motions of the beam ions, which cause a gradual orbit loss on the wall even in a case that a strong magnetic mirror is applied. The results show that the correlation of the magnetic moment disappears as the fast ions experience the density gradient around the separatrix surface and the field-null points. (author)

Moessbauer study of the fast magnetization reversal forced in permalloy and invar by an external rf magnetic field

International Nuclear Information System (INIS)

Kopcewicz, M.

1978-01-01

The effect of fast magnetization reversal leading to fast relaxation of the hyperfine field (collapse effect) forced by an external rf magnetic field is studied using the Moessbauer technique for permalloy and invar. The rf collapse and sideband effects are investigated as a function of external rf field, frequency, and intensity. The collapse of the hfs spectrum through unresolved hfs spectrum, triangular shape to a single line, as well as the formation of sidebands is observed. The rf collapse effect is attributed to the rf forced uniform rotation of internal magnetization which causes fast magnetization reversal leading to fast relaxation of the hyperfine field as a result of which the average field at the Moessbauer nuclei is reduced to zero. The difference of the magnetization reversal process in permalloy and invar are discussed. It is shown that the origin of collapse and sideband effects is totaly different: the collapse effect being of purely magnetic origin while the formation of sidebands is due to the rf induced mechanical vibrations of iron atoms within the sample. It is possible to damp sidebands without affecting the collapse effect. The results obtained show that the application of the rf field to ferromagnetic materials gives a unique possibility to force, simulate, and control the relaxation effects in ferromagnetic materials. (author)

Reversed-field pinch experiments in EXTRAP T2R with a resistive shell boundary

International Nuclear Information System (INIS)

Malmberg, J.-A.; Cecconello, M.; Brunsell, P.R.; Yadikin, D.; Drake, J.R.

2003-01-01

The EXTRAP T2R reversed-field pinch has a resistive shell with a magnetic penetration time of 6 ms. This time is intermediate between the dynamo/relaxation cycle time scale (<2ms) and the pulse length (∼20ms). The resonant tearing modes do not wall-lock. They rotate with angular phase velocities in the range of 20 to 600 krad/s. As a result of the rotation the radial component of the perturbations at the shell from the resonant modes is suppressed. Non-resonant (resistive-wall) kink modes are unstable and their linear growth rates have been measured. The measured growth rates follow the trend expected from theoretical estimates for a range of equilibrium parameters. Furthermore, when the resonant modes are rotating, the loop voltage and confinement parameters have values comparable to those of a conducting shell RFP. The poloidal beta is around 10% for a range of current and density. (author)

Energetic electron measurements in the edge of a reversed-field pinch

International Nuclear Information System (INIS)

Ingraham, J.C.; Ellis, R.F.; Downing, J.N.; Munson, C.P.; Weber, P.G.; Wurden, G.A.

1990-01-01

The edge plasma of the ZT-40M [Fusion Technol. 8, 1571 (1985)] reversed-field pinch has been studied using a combination of three different plasma probes: a double-swept Langmuir probe, an electrostatic energy analyzer, and a calorimeter--Langmuir probe. The edge plasma has been measured both with and without a movable graphite tile limiter present nearby in the plasma. Without a limiter a fast nonthermal tail of electrons (T congruent 350 eV) is detected in the edge plasma with nearly unidirectional flow along B and having a density between 2% and 10% of the cold edge plasma (T congruent 20 eV). The toroidal sense of this fast electron flow is against the force of the applied electric field. A large power flux along B is measured flowing in the same direction as the fast electrons and is apparently carried by the fast electrons. With the limiter present the fast electrons are still detected in the plasma, but are strongly attenuated in the shadow of the limiter. The measured scrape-off lengths for both the fast electrons and the cold plasma indicate cross-field transport at the rate of, or less than, Bohm diffusion. Estimates indicate that the fast electrons could carry the reversed-field pinch current density at the edge and, from the measured transverse diffusion rates, could also account for the electron energy loss channel in ZT-40 M. The long mean-free-path kinetic nature of these fast electrons suggests that a kinetic process, rather than a magnetohydrodynamic process that is based upon a local Ohm's law formulation, is responsible for their generation

Fast T1 and T2 mapping methods: the zoomed U-FLARE sequence compared with EPI and snapshot-FLASH for abdominal imaging at 11.7 Tesla.

Science.gov (United States)

Pastor, Géraldine; Jiménez-González, María; Plaza-García, Sandra; Beraza, Marta; Reese, Torsten

2017-06-01

A newly adapted zoomed ultrafast low-angle RARE (U-FLARE) sequence is described for abdominal imaging applications at 11.7 Tesla and compared with the standard echo-plannar imaging (EPI) and snapshot fast low angle shot (FLASH) methods. Ultrafast EPI and snapshot-FLASH protocols were evaluated to determine relaxation times in phantoms and in the mouse kidney in vivo. Owing to their apparent shortcomings, imaging artefacts, signal-to-noise ratio (SNR), and variability in the determination of relaxation times, these methods are compared with the newly implemented zoomed U-FLARE sequence. Snapshot-FLASH has a lower SNR when compared with the zoomed U-FLARE sequence and EPI. The variability in the measurement of relaxation times is higher in the Look-Locker sequences than in inversion recovery experiments. Respectively, the average T1 and T2 values at 11.7 Tesla are as follows: kidney cortex, 1810 and 29 ms; kidney medulla, 2100 and 25 ms; subcutaneous tumour, 2365 and 28 ms. This study demonstrates that the zoomed U-FLARE sequence yields single-shot single-slice images with good anatomical resolution and high SNR at 11.7 Tesla. Thus, it offers a viable alternative to standard protocols for mapping very fast parameters, such as T1 and T2, or dynamic processes in vivo at high field.

Increased reverse T/sub 3/ concentration in patients with anorexia nervosa

Energy Technology Data Exchange (ETDEWEB)

Baranowska, B.; Kaniewski, M.; Zgliczynski, S. (Centrum Medyczne Ksztalcenia Podyplomowego, Warsaw (Poland))

1980-01-01

In 20 female patients with anorexia nervosa, aging 16 - 26 years, the thyroid function was estimated by +- determining TSH secretion in response to TRH, and serum thyroxine (T/sub 4/), 3,5,3'L-triiodothyronine (T/sub 3/) and 3,3',5'L-triiodothyronine (reverse T/sub 3/) concentrations. 14 healthy women of the same age were included into the control group. If compared with control group, a marked supression of TRH stimulated TSH secretion and a lowering of serum T/sub 3/ concentration was found in patients with anorexia nervosa. On the other hand, serum reverse T/sub 3/ concentration was markedly higher in patients with anorexia nervosa than in control ones. Gain of body weight leads to normalization of thyroid hormones level in the serum. Obtained results show for peripheral mechanism of described hormonal disorders.

Proton T2 relaxation effect of superparamagnetic iron oxide. Comparison between fast spin echo and conventional spin echo sequence

International Nuclear Information System (INIS)

Tanimoto, Akihiro; Satoh, Yoshinori; Higuchi, Nobuya; Izutsu, Mutsumu; Yuasa, Yuji; Hiramatsu, Kyoichi

1995-01-01

Superparamagnetic iron oxide (SPIO) particles have been known to show a great T 2 relaxation effect in the liver, which contributes to significant liver signal decrease and detection of hepatic neoplasms. Recently, fast spin echo (FSE) sequence with less scanning time than conventional spin echo (SE) sequence has been rapidly introduced in clinical MR imaging. To investigate whether SPIO would show decreased T 2 relaxation effect on FSE, we obtained T 2 relaxivity (R2) of SPIO in vitro and liver signal decrease caused by SPIO in vivo. SPIO showed 20% less R2 on Carr-Purcell-Meiboom-Gill (CPMG) sequence than on SE. Relative liver signal-to-noise ratio (SNR) decrease caused by SPIO was significantly smaller (p 2 relaxation effect on FSE than on SE. However, further studies will be required to assess the diagnostic capability of SPIO on FSE, in the detection of hepatic neoplasms. (author)

Fast spin-echo T2-weighted MR imaging of tongue cancer; the value of fat-suppression

International Nuclear Information System (INIS)

Kim, Zu Byoung; Na, Dong Gyu; Ryoo, Jae Wook; Kim, Kyeong Ah; Byun, Hong Sik; Baek, Chung Whan; Son, Yong Ik

2000-01-01

To compare the diagnostic efficacy of fast spin-echo (FSE) T2-weighted MR imaging with and without fat suppression. Twelve patients (7 men and 5 women; mean age, 48 years) with pathologically proven cancer of the tongue were included in this study. In all of these, FSE T2-weighted MR images with and without fat suppression were obtained in the same imaging planes before surgery or biopsy. Two radiologists visually compared the images thus obtained in terms of detection, extent, and conspicuity of the tumor, and the contrast-to-noise ratio (CNR) of each tumor was also calculated. In all patients, both imaging modalities were equal in terms of tumor detection. In 4 of 12(33%), the extent of the tumor was greater with fat suppression, while in eight (67%), it was almost the same both with and without. In ten patients (83%), the tumor was more conspicuous with fat suppression, and percentage CNRs were significantly higher with fat suppression than without (180±70% and 113±61%, respectively; p=0.02). For the evaluation of patients with tongue cancer, fat-suppressed FSE T2-weighted MR imaging is superior to its conventional equivalent

Type 2 iodothyronine deiodinase in skeletal muscle: effects of hypothyroidism and fasting.

Science.gov (United States)

Heemstra, Karen A; Soeters, Maarten R; Fliers, Eric; Serlie, Mireille J; Burggraaf, Jacobus; van Doorn, Martijn B; van der Klaauw, Agatha A; Romijn, Johannes A; Smit, Johannes W; Corssmit, Eleonora P; Visser, Theo J

2009-06-01

The iodothyronine deiodinases D1, D2, and D3 enable tissue-specific adaptation of thyroid hormone levels in response to various conditions, such as hypothyroidism or fasting. The possible expression of D2 mRNA in skeletal muscle is intriguing because this enzyme could play a role in systemic as well as local T3 production. We determined D2 activity and D2 mRNA expression in human skeletal muscle biopsies under control conditions and during hypothyroidism, fasting, and hyperinsulinemia. This was a prospective study. The study was conducted at a university hospital. We studied 11 thyroidectomized patients with differentiated thyroid carcinoma (DTC) on and after 4 wk off T4( replacement and six healthy lean subjects in the fasting state and during hyperinsulinemia after both 14 and 62 h of fasting. D2 activity and D2 mRNA levels were measured in skeletal muscle samples. No differences were observed in muscle D2 mRNA levels in DTC patients on and off T4 replacement therapy. In healthy subjects, muscle D2 mRNA levels were lower after 62 h compared to 14 h of fasting. Insulin increased mRNA expression after 62 h, but not after 14 h of fasting. Skeletal muscle D2 activities were very low and not influenced by hypothyroidism and fasting. Human skeletal muscle D2 mRNA expression is modulated by fasting and insulin, but not by hypothyroidism. The lack of a clear effect of D2 mRNA modulation on the observed low D2 activities questions the physiological relevance of D2 activity in human skeletal muscle.

BLADE acquisition method improves T2-weighted MR images of the female pelvis compared with a standard fast spin-echo sequence

International Nuclear Information System (INIS)

Fujimoto, Koji; Koyama, Takashi; Tamai, Ken; Morisawa, Nobuko; Okada, Tomohisa; Togashi, Kaori

2011-01-01

Purpose: To investigate feasibility of the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER or BLADE) T2-weighted imaging (T2WI) of the female pelvis by comparing it with standard fast spin-echo T2WI (STD-T2WI). Materials and methods: Sagittal STD-T2WI and BLADE-T2WI of the female pelvis were performed with (36 patients) or without (15 patients) administration of butylscopolamine on a 1.5 T MR unit. Two radiologists independently rated depiction of the uterus, ovary, intestines, bladder, gynecological lesions, overall quality, and artifacts using a four-point scale. Results were compared between STD-T2WI vs. BLADE-T2WI either with (B+) or without (B−) administration of butylscopolamine, BLADE-T2WI (B−) vs. BLADE-T2WI (B+), and STD-T2WI (B+) vs. BLADE-T2WI (B−). Results: When butylscopolamine was administrated, depiction of the uterus, ovary, intestines, gynecological lesions, and overall image quality was rated higher and artifacts were rated fewer for BLADE-T2WI with significance compared with STD-T2WI. When the drug was not administrated, significant difference was observed in depiction of the lesion, overall quality, and artifacts. Depiction of the uterus, gynecological lesion, and overall quality was rated significantly higher and artifacts were fewer in BLADE-T2WI (B+) than in BLADE-T2WI (B−). Conclusion: BLADE method was feasible for female pelvic MRI, with best image quality in BLADE-T2WI (B+).

Hormonal changes associated with the transition between nursing and natural fasting in northern elephant seals (Mirounga angustirostris)

Science.gov (United States)

Ortiz, Rudy M.; Houser, Dorian S.; Wade, Charles E.; Ortiz, C. Leo

2003-01-01

To better interpret previously described hormonal changes observed during the natural postweaning fast (2-3 months) endured by pups of the northern elephant seal (Mirounga angustirostris), we compared plasma cortisol, thyroid hormones, and leptin in pups (n=5) measured during nursing and fasting periods. Blood samples were taken at four times; early (9 days postpartum) and late (18-22 days postpartum) nursing, and early (second week postweaning) and late (eighth week postweaning) fasting. Plasma cortisol increased 39% between early and late nursing and almost 4-fold by late fasting. After the early nursing period, cortisol and body mass were negatively correlated (y=28.3-0.19 x; R=0.569; p=0.027). Total thyroxine (tT(4)), free T(4) (fT(4)), total triiodothyronine (tT3) and reverse T(3) (rT(3)) were greatest at early nursing and reduced by late nursing and remained so throughout the fast, with the exception of tT(4), which increased between late nursing (17.7+/-2.1 ng mL(-1)) and late fasting (30.1+/-2.8 ng mL(-1)) periods. Leptin remained unaltered among the four sampling periods and was not correlated with body mass. Pups appear to exhibit a shift in the relationship between cortisol and body mass suggesting a potential role for cortisol in the regulation of body fat. The higher concentrations of tT(3) and tT(4) during early nursing may reflect enhanced growth and development during this period, however the increase late in fasting is likely physiologically insignificant and an artifact of reduced metabolic clearance of these hormones. Transition of the pups from nursing to fasting states is characterized by a striking lack of change in cortisol, thyroid hormones, and leptin suggesting that any metabolic alterations associated with this transition may occur independent of these hormones.

Time reversal in polarized neutron decay: the emiT experiment

CERN Document Server

Jones, G L; Anaya, J M; Bowles, T J; Chupp, T E; Coulter, K P; Dewey, M S; Freedman, S J; Fujikawa, B K; García, A; Greene, G L; Hwang, S R; Lising, L J; Mumm, H P; Nico, J S; Robertson, R G H; Steiger, T D; Teasdale, W A; Thompson, A K; Wasserman, E G; Wietfeldt, F E; Wilkerson, J F

2000-01-01

The standard electro-weak model predicts negligible violation of time-reversal invariance in light quark processes. We report on an experimental test of time-reversal invariance in the beta decay of polarized neutrons as a search for physics beyond the standard model. The emiT collaboration has measured the time-reversal-violating triple-correlation in neutron beta decay between the neutron spin, electron momentum, and neutrino momentum often referred to as the D coefficient. The first run of the experiment produced 14 million events which are currently being analyzed. However, a second run with improved detectors should provide greater statistical precision and reduced systematic uncertainties.

Power deposition by neutral beam injected fast ions in field-reversed configurations

International Nuclear Information System (INIS)

Takahashi, Toshiki; Kato, Takayuki; Kondoh, Yoshiomi; Iwasaka, Naotaka

2004-04-01

Effects of Coulomb collisions on neutral beam (NB) injected fast ions into Field-Reversed Configuration (FRC) plasmas are investigated by calculating the single particle orbits, where the ions are subject to the slowing down and pitch angle collisions. The Monte-Carlo method is used for the pitch angle scattering, and the friction term is added to the equation of motion to show effects of slowing down collision such as the deposited power profile. Calculation parameters used are relevant to the NB injection on the FRC Injection Experiment (FIX) device. It is found that the dominant local power deposition occurs in the open field region between the X-point and the mirror point because of a concentration of fast ions and a longer duration travel at the mirror reflection point. In the present calculation, the maximum deposited power to the FRC plasma is about 10% of the injected power. Although the pitch angle scattering by Coulomb collision destroys the mirror confinement of NB injected fast ions, this effect is found negligible. The loss mechanism due to non-adiabatic fast ion motion, which is intrinsic in non-uniform FRC plasmas, affects much greater than the pitch angle scattering by Coulomb collision. (author)

Thomson scattering in the EXTRAP-T2 reversed-field pinch

International Nuclear Information System (INIS)

Welander, A.

1996-11-01

A Thomson scattering system has been installed on the EXTRAP-T2 RFP experiment. The system measures the electron density and temperature in three radial points using three spectral channels. A description of the system, the calibration techniques and examples of data obtained are given. The error bars for the electron temperature measurements are estimated to be < 10% for typical T2-plasmas. 4 refs

Model for Simulating Fasting Glucose in Type 2 Diabetes and the Effect of Adherence to Treatment

DEFF Research Database (Denmark)

Aradóttir, Tinna Björk; Boiroux, Dimitri; Bengtsson, Henrik

2017-01-01

trial results where a dose guidance algorithm was used. We investigate sources of variance and through simulations evaluate the contribution of adherence to variance and dose guidance quality. The results suggest that the model for simulation of T2D patients is sufficient for simulating fasting glucose......The primary goal of this paper is to predict fasting glucose levels in type 2 diabetes (T2D) in long-acting insulin treatment. The paper presents a model for simulating insulin-glucose dynamics in T2D patients. The model combines a physiological model of type 1 diabetes (T1D) and an endogenous...... insulin production model in T2D. We include a review of sources of variance in fasting glucose values in long-acting insulin treatment, with respect to dose guidance algorithms. We use the model to simulate fasting glucose levels in T2D long-acting insulin treatment and compare the results with clinical...

Positive and negative sudden impulses caused by fast forward and reverse interplanetary shocks

Energy Technology Data Exchange (ETDEWEB)

Andrioli, Vania Fatima; Savian, Jairo Francisco, E-mail: vaniafatima@gmail.com, E-mail: savian@lacesm.ufsm.br [Space Science Laboratory of Santa Maria - LACESM/CT - UFSM, Universidade Federal de Santa Maria - UFSM, Centro Tecnologico, Santa Maria, RS (Brazil); Echer, Ezequiel, E-mail: eecher@dge.inpe.br [National Institute for Space Research - INPE - MCT, Sao Jose dos Campos, SP (Brazil); Schuch, Nelson Jorge, E-mail: njschuch@lacesm.ufsm.br [Southern Regional Space Research Center - CRSPE/INPE - MCT, Universidade Federal de Santa Maria - UFSM, Santa Maria, RS (Brazil)

2007-07-01

Fast forward interplanetary shocks (FFS) are characterized by positive jump in all interplanetary plasma parameters (solar wind speed, temperature and density) and interplanetary magnetic field. However the fast reverse interplanetary shocks (FRS) are characterized by negative jump in all mentioned parameters except solar wind speed. Observations show that FFS cause positive sudden impulses (SI) while FRS cause negative SI in the H-component of the geomagnetic field. In this work we investigate the SI caused by interplanetary shocks. We use the observed plasma parameters, upstream and downstream, to calculate the variation of dynamic pressure. We observe that the SI amplitude is larger for positive SI than for negative ones, as a consequence of the fact that FFS have larger dynamic pressure variations as compared to FRS. (author)

The magnetization reversal in CoFe{sub 2}O{sub 4}/CoFe{sub 2} granular systems

Energy Technology Data Exchange (ETDEWEB)

Jin, J.; Sun, X.; Wang, M.; Ding, Z.L.; Ma, Y.Q., E-mail: yqma@ahu.edu.cn [Anhui University, Anhui Key Laboratory of Information Materials and Devices, School of Physics and Materials Science (China)

2016-12-15

The temperature-dependent field cooling (FC) and zero-field cooling (ZFC) magnetizations, i.e., M{sub FC} and M{sub ZFC}, measured under different magnetic fields from 500 Oe to 20 kOe have been investigated on two exchange–spring CoFe{sub 2}O{sub 4}/CoFe{sub 2} composites with different relative content of CoFe{sub 2}. Two samples exhibit different magnetization reversal behaviors. With decreasing temperature, a progressive freezing of the moments in two composites occurs at a field-dependent irreversible temperature T{sub irr}. For the sample with less CoFe{sub 2}, the curves of −d(M{sub FC} − M{sub ZFC})/dT versus temperature T exhibit a broad peak at an intermediate temperature T{sub 2} below T{sub irr}, and the moments are suggested not to fully freeze till the lowest measuring temperature 10 K. However, for the −d(M{sub FC} − M{sub ZFC})/dT curves of the sample with more CoFe{sub 2}, besides a broad peat at an intermediate temperature T{sub 2}, a rapid rise around the low temperature T{sub 1}~15 K is observed, below which the moments are suggested to fully freeze. Increase of magnetic field from 2 kOe leads to the shift of T{sub 2} and T{sub irr} towards a lower temperature, and the shift of T{sub 2} is attributable to the moment reversal of CoFe{sub 2}O{sub 4}.

Reverse bistable effect in ferroelectric liquid crystal devices with ultra-fast switching at low driving voltage.

Science.gov (United States)

Guo, Qi; Zhao, Xiaojin; Zhao, Huijie; Chigrinov, V G

2015-05-15

In this Letter, reverse bistable effect with deep-sub-millisecond switching time is first reported in ferroelectric liquid crystal (FLC) devices using a homogeneous photo-alignment technique. It is indicated by our experimental results that both the anchoring energy and the dielectric property of the FLC's alignment layer is critical for the existence of the reverse bistable effect. In addition, with the derived criteria of the reverse bistable effect, we quantitatively analyze the switching dynamics of the reverse bistable FLC and the transition condition between the traditional bistability and our presented reverse bistability. Moreover, the fabricated FLC device exhibits an ultra-fast switching of ∼160  μs and a high contrast ratio of 1000:1, both of which were measured at a low driving voltage of 11 V. The featured deep-sub-millisecond switching time is really advantageous for our presented reverse bistable FLC devices, which enables a significant quality improvement of the existing optical devices, as well as a wide range of new applications in photonics and display areas.

Perspectives and experiences of patients with type 2 diabetes observing the Ramadan fast.

Science.gov (United States)

Almansour, Hadi A; Chaar, Betty; Saini, Bandana

2018-05-01

Diabetes is a common chronic disease among Australians. Culturally and linguistically diverse groups are observed to have higher prevalence rates of diabetes. Continuing management needs adherence to medication and diet regimens. Religious practices such as fasting can affect diabetes management and medication use. Pharmacists as medication specialists have a significant role in helping people observing religious practices such as the Ramadan fast, which involves month-long absolute abstinence from food during daylight hours, to maintain good control over their condition. This study investigated the perspective of patients with type 2 diabetes (T2D) who undertake the fast of Ramadan, to understand their experiences, health-related needs and service preferences regarding diabetes management. A qualitative, exploratory design was used in this study. Data collection comprised the conduct of semi-structured interviews with a purposive convenient sample of patients in areas of ethnic diversity in Sydney, using a standardised interview guide. Interview data were transcribed verbatim and thematically analysed. Twenty-five semi-structured interviews (68% males) among a heterogeneous sample of fasting T2D patients were conducted. Themes emerging from analysis of transcripts included issues relating to sociocultural pressure for T2D patients to fast; lack of awareness about the role of pharmacists and, most importantly, the need to train pharmacists in cultural sensitivity and clinical implications thereof. Community awareness about the role of the pharmacists in assisting medication use and adjustment during fasting periods should be enhanced. Furthermore, community pharmacists need to be trained about the unique religious and sociocultural issues of patients with diabetes opting to observe spiritual rituals such as the Ramadan fast. Clinical education in this area should up-skill pharmacists to inculcate self-management behaviours in fasting T2D patients.

Therapeutic fasting as a potential effective treatment for type 2 diabetes: A 4-month case study

Directory of Open Access Journals (Sweden)

Michael Ku

2017-12-01

Full Text Available Lifestyle therapy is an integral part of type 2 diabetes (T2D management, but there remains no consensus on an optimal diet. The objective of this study is to evaluate the efficacy of therapeutic fasting as a treatment for T2D. This case follows a male T2D patient treated at the Intensive Dietary Management Clinic in Scarborough, Ontario, over a 4-month period. The patient’s initial fasting regimen consisted of a 24-h fast, three times a week. Over the course of treatment, the patient gradually extended his fasting period, eventually fasting for 42 h, two to three times a week. By the end of treatment, the patient’s weight was reduced by 17.8% and his waist circumference was reduced by 11.0%. In addition, the patient’s glycated haemoglobin levels decreased from 7.7% to 7.2%, and he was able to completely discontinue his insulin treatment, despite over a decade of insulin usage. The patient did not find it difficult to adhere to the fasting schedule and did not experience any hypoglycaemic episodes or other significant adverse effects. These observations suggest that therapeutic fasting may be a viable treatment option for T2D patients.

Effect of Ramadan Fasting on Serum Glucose and Lipid Profile Among Algerian Type 2 Diabetes Patients

Directory of Open Access Journals (Sweden)

Tiboura Ghania

2015-12-01

Full Text Available Background and aims: We designed this study to assess the effect of Ramadan fasting on serum lipid profile among type 2 diabetic patients. Material and Methods: The study was carried out in July 2014 (Ramadan 1421. The total duration of fasting was 17 hours a day. The investigation involved 80 patients. The mean age of the patients was 56± 8 years. The dietary survey lasting three days was recorded. The anthropometric and the biochemical parameters were measured in all subjects before (T1 and during (T2 the fasting month of Ramadan and results were compared using student t-test. Results: There was a significant decrease in high density lipoprotein cholesterol (HDL-c levels during T2 (0.35±0,08 g/L compared to T1 (0.38±0,11 g/L. Apolipoprotein A1 (Apo A1 decreased significantly during fasting compared to pre-fasting days while apo B increased during T2 (p˂0.05. The dietary fat consumption increased during Ramadan; especially for the saturated one (p<0.05. Conclusion: The present study suggests that fasting month of Ramadan could be beneficial for some patients with type 2 diabetes who are well controlled and balanced. However, some of them may be at risk of cardiovascular complications in which dyslipidemia can be the leading cause.

Prolonged fasting reduces IGF-1/PKA to promote hematopoietic-stem-cell-based regeneration and reverse immunosuppression.

Science.gov (United States)

Cheng, Chia-Wei; Adams, Gregor B; Perin, Laura; Wei, Min; Zhou, Xiaoying; Lam, Ben S; Da Sacco, Stefano; Mirisola, Mario; Quinn, David I; Dorff, Tanya B; Kopchick, John J; Longo, Valter D

2014-06-05

Immune system defects are at the center of aging and a range of diseases. Here, we show that prolonged fasting reduces circulating IGF-1 levels and PKA activity in various cell populations, leading to signal transduction changes in long-term hematopoietic stem cells (LT-HSCs) and niche cells that promote stress resistance, self-renewal, and lineage-balanced regeneration. Multiple cycles of fasting abated the immunosuppression and mortality caused by chemotherapy and reversed age-dependent myeloid-bias in mice, in agreement with preliminary data on the protection of lymphocytes from chemotoxicity in fasting patients. The proregenerative effects of fasting on stem cells were recapitulated by deficiencies in either IGF-1 or PKA and blunted by exogenous IGF-1. These findings link the reduced levels of IGF-1 caused by fasting to PKA signaling and establish their crucial role in regulating hematopoietic stem cell protection, self-renewal, and regeneration. Copyright © 2014 Elsevier Inc. All rights reserved.

Evaluation of pneumonia in children: comparison of MRI with fast imaging sequences at 1.5T with chest radiographs

Energy Technology Data Exchange (ETDEWEB)

Yikilmaz, Ali; Koc, Ali; Coskun, Abdulhakim (Dept. of Radiology, Erciyes Medical School, Kayseri (Turkey)); Ozturk, Mustafa K (Dept. of Pediatric Infectious Diseases, Erciyes Medical School, Kayseri (Turkey)); Mulkern, Robert V; Lee, Edward Y (Dept. of Radiology and Dept. of Medicine, Pulmonary Div., Children' s Hospital Boston and Harvard Medical School, Boston (United States)), email: Edward.lee@childrens.harvard.edu

2011-10-15

Background Although there has been a study aimed at magnetic resonance imaging (MRI) evaluation of pneumonia in children at a low magnetic field (0.2T), there is no study which assessed the efficacy of MRI, particularly with fast imaging sequences at 1.5T, for evaluating pneumonia in children. Purpose To investigate the efficacy of chest MRI with fast imaging sequences at 1.5T for evaluating pneumonia in children by comparing MRI findings with those of chest radiographs. Material and Methods This was an Institutional Review Board-approved, HIPPA-compliant prospective study of 40 consecutive pediatric patients (24 boys, 16 girls; mean age 7.3 years +- 6.6 years) with pneumonia, who underwent PA and lateral chest radiographs followed by MRI within 24 h. All MRI studies were obtained in axial and coronal planes with two different fast imaging sequences: T1-weighted FFE (Fast Field Echo) (TR/TE: 83/4.6) and T2-weighted B-FFE M2D (Balanced Fast Field Echo Multiple 2D Dimensional) (TR/TE: 3.2/1.6). Two experienced pediatric radiologists reviewed each chest radiograph and MRI for the presence of consolidation, necrosis/abscess, bronchiectasis, and pleural effusion. Chest radiograph and MRI findings were compared with Kappa statistics. Results All consolidation, lung necrosis/abscess, bronchiectasis, and pleural effusion detected with chest radiographs were also detected with MRI. There was statistically substantial agreement between chest radiographs and MRI in detecting consolidation (k = 0.78) and bronchiectasis (k = 0.72) in children with pneumonia. The agreement between chest radiographs and MRI was moderate for detecting necrosis/abscess (k = 0.49) and fair for detecting pleural effusion (k = 0.30). Conclusion MRI with fast imaging sequences is comparable to chest radiographs for evaluating underlying pulmonary consolidation, bronchiectasis, necrosis/abscess, and pleural effusion often associated with pneumonia in children

Self-organisation and intermittent coherent oscillations in the EXTRAP T2 reversed field pinch

International Nuclear Information System (INIS)

Cecconello, M.; Malmberg, J.A.; Sallander, E.; Drake, J.R.

2002-01-01

Many reversed-field pinch (RFP) experiments exhibit a coherent oscillatory behaviour that is characteristic of discrete dynamo events and is associated with intermittent current profile self-organisation phenomena. However, in the vast majority of the discharges in the resistive shell RFP experiment EXTRAP T2, the dynamo activity does not show global, coherent oscillatory behaviour. The internally resonant tearing modes are phase-aligned and wall-locked resulting in a large localised magnetic perturbation. Equilibrium and plasma parameters have a level of high frequency fluctuations but the average values are quasi-steady. For some discharges, however, the equilibrium parameters exhibit the oscillatory behaviour characteristic of the discrete dynamo events. For these discharges, the trend observed in the tearing mode spectra, associated with the onset of the discrete relaxation event behaviour, is a relative higher amplitude of m = 0 mode activity and relative lower amplitude of the m = 1 mode activity compared with their average values. Global plasma parameters and model profile calculations for sample discharges representing the two types of relaxation dynamics are presented

Self-Organisation and Intermittent Coherent Oscillations in the EXTRAP T2 Reversed Field Pinch

Science.gov (United States)

Cecconello, M.; Malmberg, J.-A.; Sallander, E.; Drake, J. R.

Many reversed-field pinch (RFP) experiments exhibit a coherent oscillatory behaviour that is characteristic of discrete dynamo events and is associated with intermittent current profile self-organisation phenomena. However, in the vast majority of the discharges in the resistive shell RFP experiment EXTRAP T2, the dynamo activity does not show global, coherent oscillatory behaviour. The internally resonant tearing modes are phase-aligned and wall-locked resulting in a large localised magnetic perturbation. Equilibrium and plasma parameters have a level of high frequency fluctuations but the average values are quasi-steady. For some discharges, however, the equilibrium parameters exhibit the oscillatory behaviour characteristic of the discrete dynamo events. For these discharges, the trend observed in the tearing mode spectra, associated with the onset of the discrete relaxation event behaviour, is a relative higher amplitude of m = 0 mode activity and relative lower amplitude of the m = 1 mode activity compared with their average values. Global plasma parameters and model profile calculations for sample discharges representing the two types of relaxation dynamics are presented.

Moderately T2-weighted images obtained with the single-shot fast spin-echo technique. Differentiating between malignant and benign urinary obstructions

International Nuclear Information System (INIS)

Obuchi, Masao; Sugimoto, Hideharu; Kubota, Hayato; Yamamoto, Wakako; Kinebuchi, Yuko; Honda, Minoru; Takahara, Taro

2002-01-01

The purpose of this study was to determine whether a distinction could be made between benign and malignant urinary obstructions in moderately T 2 -weighted images obtained with the single-shot fast spin-echo technique. Forty-four lesions in 39 patients with urinary obstruction were evaluated with the single-shot fast spin-echo (SSFSE) technique with an effective TE of 90-100 ms and without fat saturation. Benign and malignant lesions were compared for the presence of ureteral wall thickening and a signal intensity relative to the proximal ureteral wall. Statistically significant differences were found between benign and malignant lesions in both morphologic change (P 2 -weighted SSFSE technique without fat saturation can accurately distinguish between benign and malignant urinary obstructions. (author)

SULF2 strongly prediposes to fasting and postprandial triglycerides in patients with obesity and type 2 diabetes mellitus.

Science.gov (United States)

Hassing, H Carlijne; Surendran, R Preethi; Derudas, Bruno; Verrijken, An; Francque, Sven M; Mooij, Hans L; Bernelot Moens, Sophie J; Hart, Leen M 't; Nijpels, Giel; Dekker, Jacqueline M; Williams, Kevin Jon; Stroes, Erik S G; Van Gaal, Luc F; Staels, Bart; Nieuwdorp, Max; Dallinga-Thie, Geesje M

2014-05-01

Hepatic overexpression of sulfatase-2 (SULF2), a heparan sulfate remodeling enzyme, strongly contributes to high triglyceride (TG) levels in obese, type 2 diabetic (T2DM) db/db mice. Nevertheless, data in humans are lacking. Here, the association of human hepatic SULF2 expression and SULF2 gene variants with TG metabolism in patients with obesity and/or T2DM was investigated. Liver biopsies from 121 obese subjects were analyzed for relations between hepatic SULF2 mRNA levels and plasma TG. Associations between seven SULF2 tagSNPs and TG levels were assessed in 210 obese T2DM subjects with dyslipidemia. Replication of positive findings was performed in 1,316 independent obese T2DM patients. Postprandial TRL clearance was evaluated in 29 obese T2DM subjects stratified by SULF2 genotype. Liver SULF2 expression was significantly associated with fasting plasma TG (r = 0.271; P = 0.003) in obese subjects. The SULF2 rs2281279(A>G) SNP was reproducibly associated with lower fasting plasma TG levels in obese T2DM subjects (P obesity and T2DM. Copyright © 2013 The Obesity Society.

Fast, non-competitive and reversible inhibition of NMDA-activated currents by 2-BFI confers neuroprotection.

Directory of Open Access Journals (Sweden)

Zhao Han

Full Text Available Excessive activation of the N-methyl-D-aspartic acid (NMDA type glutamate receptors (NMDARs causes excitotoxicity, a process important in stroke-induced neuronal death. Drugs that inhibit NMDA receptor-mediated [Ca(2+]i influx are potential leads for development to treat excitotoxicity-induced brain damage. Our previous studies showed that 2-(2-benzofu-ranyl-2-imidazoline (2-BFI, an immidazoline receptor ligand, dose-dependently protects rodent brains from cerebral ischemia injury. However, the molecular mechanisms remain unclear. In this study, we found that 2-BFI transiently and reversibly inhibits NMDA, but not AMPA currents, in a dose-dependent manner in cultured rat cortical neurons. The mechanism of 2-BFI inhibition of NMDAR is through a noncompetitive fashion with a faster on (Kon = 2.19±0.33×10(-9 M(-1 sec(-1 and off rate (Koff = 0.67±0.02 sec(-1 than those of memantine, a gold standard for therapeutic inhibition NMDAR-induced excitotoxicity. 2-BFI also transiently and reversibly blocked NMDA receptor-mediated calcium entry to cultured neurons and provided long-term neuroprotection against NMDA toxicity in vitro. Collectively, these studies demonstrated a potential mechanism of 2-BFI-mediated neuroprotection and indicated that 2-BFI is an excellent candidate for repositioning as a drug for stroke treatment.

Mechanistic Aspects of the Reversible Binding of SO2 on Arylplatinum Complexes: Experimental and ab Initio Studies

NARCIS (Netherlands)

Koten, G. van; Albrecht, M.A.; Gossage, R.A.; Frey, H.; Ehlers, A.W.; Baerends, E.J.; Merbach, A.E.

2001-01-01

The detailed mechanism of the reversible binding and fast exchange of SO2 on the organoplatinum(II) complex [PtI(NCN)], 1, has been studied experimentally in solution (C2F4Br2) using low-temperature NMR spectroscopy and theoretically by ab initio calculations. Direct bonding of SO2 and formation of

Stability of the phenotypic reversion of x-ray transformed C3H/10T1/2 cells depends on cellular proliferation after subcultivation at low cell density

International Nuclear Information System (INIS)

Brouty-Boye, D.; Gresser, I.; Bandu, M.T.

1982-01-01

Reversion from the transformed to the non-transformed phenotype could be obtained by seeding X-ray transformed C3H/10T1/2 cells at low cell density. Cloned revertant cells of varying degrees of reversion were obtained depending on the time they were isolated after one subculture at low cell density. Most of the revertants isolated 7 and 10 days after seeding at very low cell density eventually returned to the transformed phenotype when passaged serially at high cell density. In contrast, 25-35% of the revertants isolated 17-20 days after seeding at low cell density maintained the non-transformed phenotype despite subsequent serial passages at high cell density. The finding that there was a direct relationship between the time during which transformed cells seeded at low cell density multiplied and the number of stable revertant clones obtained, suggests the possibility that reversion from the transformed to the non-transformed phenotype may be a multistep process. Revertant cells displayed a chromosomal pattern characteristic of the transformed cells rather than that of the parental non-transformed 10T1/2 cells. (author)

Measurements of neutral hydrogen profiles on the EXTRAP-T2 reversed-field pinch from time-resolved ? line emission

Science.gov (United States)

Sallander, J.; Hedqvist, A.; Rachlew-Källne, E.

1998-09-01

The investigations of the radial distributions of 0953-4075/31/17/015/img2 emission from the EXTRAP-T2 reversed-field pinch (RFP) plasma show that the emission profile varies a lot, even during one plasma discharge. At central electron temperatures of about 150 eV it was expected that the 0953-4075/31/17/015/img2 emission should emerge from the plasma centre. In comparison, 0953-4075/31/17/015/img4 is always observed to radiate from the centre. Our measurements of 0953-4075/31/17/015/img2 emission have, however, shown that this is not always the case, the emission often comes from the plasma edge. The analysis of the measurements has led us to conclude that the edge emission comes from charge-exchange recombination with neutral hydrogen near the carbon first wall. These observations provide a way to estimate the change in neutral hydrogen density during local plasma-wall interaction.

Reversed-field pinch experiments in EXTRAP T2R with a resistive shell boundary

International Nuclear Information System (INIS)

Drake, J.R.

2002-01-01

The EXTRAP T2R reversed-field pinch is operated with a resistive shell with a magnetic penetration time of 6 ms. This time is intermediate between the dynamo/relaxation cycle time scale (<1 ms) and the pulse length (= 20 ms). The internally-resonant tearing modes do not wall lock and exhibit natural rotation with velocities in the range of 20 to 600 krad/s. Under these conditions the radial component of the tearing mode perturbation at the shell is suppressed. Therefore the linear growth rates of the unstable, non-resonant, ideal (resistive-wall) kink modes can be observed even at very low amplitudes (0.01% of the equilibrium field). Both internally-non-resonant and externally non-resonant RW mode types are observed. The growth rates have been measured for a range of equilibrium current profile parameters and are compared with theoretical estimates. Previous observations and simulations for the resistive-shell RFP have shown an increased loop voltage associated with altered dynamo dynamics. When the tearing modes are rotating, the loop voltage and confinement parameters have values comparable to those of a conducting-shell RFP. (author)

MRI of the anterior talofibular ligament, talar cartilage and os subfibulare: Comparison of isotropic resolution 3D and conventional 2D T2-weighted fast spin-echo sequences at 3.0 T

Energy Technology Data Exchange (ETDEWEB)

Yi, Jisook; Cha, Jang Gyu [Soonchunhyang University Bucheon Hospital, Department of Radiology, Wonmi-gu, Bucheon-si (Korea, Republic of); Lee, Young Koo [Soonchunhyang University Bucheon Hospital, Department of Orthopedics, Wonmi-gu, Bucheon-si (Korea, Republic of); Lee, Bo Ra [Soonchunhyang University Bucheon Hospital, Department of Biomedical Statistics, Wonmi-gu, Bucheon-si (Korea, Republic of); Jeon, Chan Hong [Soonchunhyang University Bucheon Hospital, Division of Rheumatology, Department of Internal Medicine, Wonmi-gu, Bucheon-si (Korea, Republic of)

2016-07-15

To determine the accuracy of a three-dimensional (3D) T2-weighted fast spin-echo (FSE) magnetic resonance (MR) sequence compared with two-dimensional (2D) sequence for diagnosing anterior talofibular ligament (ATFL) tears, chondral lesion of the talus (CLT) and os subfibulare/avulsion fracture of the distal fibula (OSF). Thirty-five patients were included, who had undergone ankle MRI with 3D T2-weighted FSE and 2D T2-weighted FSE sequences, as well as subsequent ankle arthroscopy, between November 2013 and July 2014. Each MR imaging sequence was independently scored by two readers retrospectively for the presence of ATFL tears, CLT and OSF. The area under the receiver operating curve (AUC) was compared to determine the discriminatory power of the two image sequences. Interobserver agreement was expressed as unweighted kappa value. Arthroscopic findings confirmed 21 complete tears of the ATFL, 14 partial tears of the ATFL, 17 CLTs and 7 OSFs. There were no significant differences in the diagnoses of ATFL tears (p = 0.074-0.501), CLT (p = 0.090-0.450) and OSF (p = 0.317) obtained from the 2D and 3D sequences by either reader. The interobserver agreement rates between two readers using the 3D T2-weighted FSE sequence versus those obtained with the 2D sequence were substantial (κ = 0.659) versus moderate (κ = 0.553) for ATFL tears, moderate (κ = 0.499) versus substantial (κ = 0.676) for CLT and substantial (κ = 0.621) versus substantial (κ = 0.689) for OSF. Three-dimensional isotropic T2-weighted FSE MRI of the ankle resulted in no statistically significant difference in diagnostic performance compared to two-dimensional T2-weighted FSE MRI in the evaluation of ATFL tears, CLTs and OSFs. (orig.)

MRI of the anterior talofibular ligament, talar cartilage and os subfibulare: Comparison of isotropic resolution 3D and conventional 2D T2-weighted fast spin-echo sequences at 3.0 T

International Nuclear Information System (INIS)

Yi, Jisook; Cha, Jang Gyu; Lee, Young Koo; Lee, Bo Ra; Jeon, Chan Hong

2016-01-01

To determine the accuracy of a three-dimensional (3D) T2-weighted fast spin-echo (FSE) magnetic resonance (MR) sequence compared with two-dimensional (2D) sequence for diagnosing anterior talofibular ligament (ATFL) tears, chondral lesion of the talus (CLT) and os subfibulare/avulsion fracture of the distal fibula (OSF). Thirty-five patients were included, who had undergone ankle MRI with 3D T2-weighted FSE and 2D T2-weighted FSE sequences, as well as subsequent ankle arthroscopy, between November 2013 and July 2014. Each MR imaging sequence was independently scored by two readers retrospectively for the presence of ATFL tears, CLT and OSF. The area under the receiver operating curve (AUC) was compared to determine the discriminatory power of the two image sequences. Interobserver agreement was expressed as unweighted kappa value. Arthroscopic findings confirmed 21 complete tears of the ATFL, 14 partial tears of the ATFL, 17 CLTs and 7 OSFs. There were no significant differences in the diagnoses of ATFL tears (p = 0.074-0.501), CLT (p = 0.090-0.450) and OSF (p = 0.317) obtained from the 2D and 3D sequences by either reader. The interobserver agreement rates between two readers using the 3D T2-weighted FSE sequence versus those obtained with the 2D sequence were substantial (κ = 0.659) versus moderate (κ = 0.553) for ATFL tears, moderate (κ = 0.499) versus substantial (κ = 0.676) for CLT and substantial (κ = 0.621) versus substantial (κ = 0.689) for OSF. Three-dimensional isotropic T2-weighted FSE MRI of the ankle resulted in no statistically significant difference in diagnostic performance compared to two-dimensional T2-weighted FSE MRI in the evaluation of ATFL tears, CLTs and OSFs. (orig.)

Vibrational dynamics of ice in reverse micelles

NARCIS (Netherlands)

Dokter, A.M.; Petersen, C.; Woutersen, S.; Bakker, H.J.

2008-01-01

he ultrafast vibrational dynamics of HDO:D2O ice at 180 K in anionic reverse micelles is studied by midinfrared femtosecond pump-probe spectroscopy. Solutions containing reverse micelles are cooled to low temperatures by a fast-freezing procedure. The heating dynamics of the micellar solutions is

Low-Field NMR Spectrometry of Chalk and Argillaceous Sandstones: Rock-Fluid Affinity Assessed from T-1/T-2 Ratio

DEFF Research Database (Denmark)

Katika, Konstantina; Saidian, Milad; Prasad, Manika

2017-01-01

greensand shows different behavior for small and large pores. Small pores (fast-relaxing components) have T-1/T-2 = 2.0 when water saturated, but T-1/T-2 = 3.8 when oil saturated, indicating oil-affinity of chlorite. By contrast, large pores (slow-relaxing components) have significant preference for water...

Energetic-particle-driven instabilities and induced fast-ion transport in a reversed field pinch

International Nuclear Information System (INIS)

Lin, L.; Brower, D. L.; Ding, W. X.; Anderson, J. K.; Capecchi, W.; Eilerman, S.; Forest, C. B.; Koliner, J. J.; Nornberg, M. D.; Reusch, J.; Sarff, J. S.; Liu, D.

2014-01-01

Multiple bursty energetic-particle (EP) driven modes with fishbone-like structure are observed during 1 MW tangential neutral-beam injection in a reversed field pinch (RFP) device. The distinguishing features of the RFP, including large magnetic shear (tending to add stability) and weak toroidal magnetic field (leading to stronger drive), provide a complementary environment to tokamak and stellarator configurations for exploring basic understanding of EP instabilities. Detailed measurements of the EP mode characteristics and temporal-spatial dynamics reveal their influence on fast ion transport. Density fluctuations exhibit a dynamically evolving, inboard-outboard asymmetric spatial structure that peaks in the core where fast ions reside. The measured mode frequencies are close to the computed shear Alfvén frequency, a feature consistent with continuum modes destabilized by strong drive. The frequency pattern of the dominant mode depends on the fast-ion species. Multiple frequencies occur with deuterium fast ions compared to single frequency for hydrogen fast ions. Furthermore, as the safety factor (q) decreases, the toroidal mode number of the dominant EP mode transits from n=5 to n=6 while retaining the same poloidal mode number m=1. The transition occurs when the m=1, n=5 wave-particle resonance condition cannot be satisfied as the fast-ion safety factor (q fi ) decreases. The fast-ion temporal dynamics, measured by a neutral particle analyzer, resemble a classical predator-prey relaxation oscillation. It contains a slow-growth phase arising from the beam fueling followed by a rapid drop when the EP modes peak, indicating that the fluctuation-induced transport maintains a stiff fast-ion density profile. The inferred transport rate is strongly enhanced with the onset of multiple EP modes

C-Cbl reverses HER2-mediated tamoxifen resistance in human breast cancer cells.

Science.gov (United States)

Li, Wei; Xu, Ling; Che, Xiaofang; Li, Haizhou; Zhang, Ye; Song, Na; Wen, Ti; Hou, Kezuo; Yang, Yi; Zhou, Lu; Xin, Xing; Xu, Lu; Zeng, Xue; Shi, Sha; Liu, Yunpeng; Qu, Xiujuan; Teng, Yuee

2018-05-02

Tamoxifen is a frontline therapy for estrogen receptor (ER)-positive breast cancer in premenopausal women. However, many patients develop resistance to tamoxifen, and the mechanism underlying tamoxifen resistance is not well understood. Here we examined whether ER-c-Src-HER2 complex formation is involved in tamoxifen resistance. MTT and colony formation assays were used to measure cell viability and proliferation. Western blot was used to detect protein expression and protein complex formations were detected by immunoprecipitation and immunofluorescence. SiRNA was used to examine the function of HER2 in of BT474 cells. An in vivo xenograft animal model was established to examine the role of c-Cbl in tumor growth. MTT and colony formation assay showed that BT474 cells are resistant to tamoxifen and T47D cells are sensitive to tamoxifen. Immunoprecipitation experiments revealed ER-c-Src-HER2 complex formation in BT474 cells but not in T47D cells. However, ER-c-Src-HER2 complex formation was detected after overexpressing HER2 in T47D cells and these cells were more resistant to tamoxifen. HER2 knockdown by siRNA in BT474 cells reduced ER-c-Src-HER2 complex formation and reversed tamoxifen resistance. ER-c-Src-HER2 complex formation was also disrupted and tamoxifen resistance was reversed in BT474 cells by the c-Src inhibitor PP2 and HER2 antibody trastuzumab. Nystatin, a lipid raft inhibitor, reduced ER-c-Src-HER2 complex formation and partially reversed tamoxifen resistance. ER-c-Src-HER2 complex formation was disrupted by overexpression of c-Cbl but not by the c-Cbl ubiquitin ligase mutant. In addition, c-Cbl could reverse tamoxifen resistance in BT474 cells, but the ubiquitin ligase mutant had no effect. The effect of c-Cbl was validated in BT474 tumor-bearing nude mice in vivo. Immunofluorescence also revealed ER-c-Src-HER2 complex formation was reduced in tumor tissues of nude mice with c-Cbl overexpression. Our results suggested that c-Cbl can reverse tamoxifen

[The use of the T2-weighted turbo-spin-echo sequence in studying the neurocranium. A comparison with the conventional T2-weighted spin-echo sequence].

Science.gov (United States)

Siewert, C; Hosten, N; Felix, R

1994-07-01

T2-weighted spin-echo imaging is the standard screening procedure in MR imaging of the neurocranium. We evaluated fast spin-echo T2-weighted imaging (TT2) of the neurocranium in comparison to conventional spin-echo T2-weighted imaging (T2). Signal-to-noise and contrast-to-noise ratio of normal brain tissues (basal ganglia, grey and white matter, CSF fluid) and different pathologies were calculated. Signal-to-noise ratio and contrast-to-noise ratio were significantly higher in TT2 than in T2 (with the exception of gray-to-white matter contrast). Tissues with increased content of water protons (mobile protons) showed the highest contrast to surrounding tissues. The increased signal intensity of fat must be given due attention in fatty lesions. Because the contrast-to-noise ratio between white matter and basal ganglia is less in TT2, Parkinson patients have to be examined by conventional T2. If these limitations are taken into account, fast spin-echo T2-weighted imaging is well appropriate for MR imaging of the neurocranium, resulting in heavy T2-weighting achieved in a short acquisition time.

Anteroinferior tears of the glenoid labrum: fat-suppressed fast spin-echo T2 versus gradient-recalled echo MR images

Energy Technology Data Exchange (ETDEWEB)

Tuite, M J [Department of Radiology, University of Wisconsin Hospital and Clinics, 600 Highland Avenue, Madison, WI 53792 (United States); De Smet, A A [Department of Radiology, University of Wisconsin Hospital and Clinics, 600 Highland Avenue, Madison, WI 53792 (United States); Norris, M A [Department of Radiology, University of Wisconsin Hospital and Clinics, 600 Highland Avenue, Madison, WI 53792 (United States); Orwin, J F [Department of Orthopedic Surgery, University of Wisconsin Hospital and Clinics, 600 Highland Avenue, Madison, WI 53792 (United States)

1997-05-01

Objective. To compare fat-suppressed fast spin-echo (FSE) T2-weighted images with gradient-recalled echo (GRE) T2*-weighted images in the evaluation of anteroinferior labral tears. Design. MR images were retrospectively reviewed by two radiologists masked to the history and arthroscopic findings. They separately interpreted the anteroinferior labrum as torn or intact, first on one pulse sequence and then, 4 weeks later, on the other sequence. The MR interpretations were correlated with the arthroscopic findings. Patients. Nine patients with anteroinferior labral tears, and nine similarly-aged patients with normal, labra were studied. Results and conclusions. Observer 1 had a sensitivity of 0.56 on the GRE images and 0.67 on the FSE images (P>0.5), with a specificity of 1.0 for both sequences. Observer 2 had a sensitivity of 0.78 and a specificity of 0.89 for both sequences. In this small study there is no significant difference between GRE and fat-suppressed FSE images in their ability to diagnose anteroinferior labral tears. When evaluating the labrum with conventional MRI, axial fat-suppressed FSE T2-weighted images can be used in place of GRE images without a loss of accuracy. (orig.). With 3 figs., 1 tab.

Postprandial Triglyceride Is Associated with Fasting Triglyceride and HOMA-IR in Korean Subjects with Type 2 Diabetes

Directory of Open Access Journals (Sweden)

Seo Hee Lee

2011-08-01

Full Text Available BackgroundRecent studies indicate postprandial triglyceride (TG had a better association with cardiovascular events and metabolic syndrome than fasting TG. The authors of the present study investigated the metabolic and clinical relevance of postprandial TG.MethodsIn a cross-sectional retrospective study, the authors of the present study compared fasting and postprandial TG and analyzed the relationship between postprandial TG and various demographic and metabolic parameters in 639 Korean subjects with type 2 diabetes (T2D, group I, n=539 and impaired fasting glucose (IFG, group II, n=100 after ingestion of a standardized liquid meal (total 500 kcal, 17.5 g fat, 68.5 g carbohydrate, and 17.5 g protein.ResultsFasting and postprandial TG were significantly correlated (r=0.973, r=0.937, P<0.001 in group I and II, respectively. Of the variables, total cholesterol, waist circumference and body mass index were significantly correlated with fasting and postprandial TG in both groups. Only postprandial TG showed a significant correlation with glucose metabolic parameters (e.g., postprandial glucose, homeostatic model assessment of insulin resistance [HOMA-IR], and fasting C-peptide in subjects with T2D. Multiple regression analysis showed fasting TG and HOMA-IR could be predictable variables for postprandial TG in subjects with T2D.ConclusionPostprandial TG was very strongly correlated with fasting TG. The authors of the present study suggest insulin resistance may be more associated with postprandial TG than fasting TG in Korean T2D patients on a low-fat diet.

Measurements and modeling of transport and impurity radial profiles in the EXTRAP T2R reversed field pinch

Science.gov (United States)

Kuldkepp, M.; Brunsell, P. R.; Cecconello, M.; Dux, R.; Menmuir, S.; Rachlew, E.

2006-09-01

Radial impurity profiles of oxygen in the rebuilt reversed field pinch EXTRAP T2R [P. R. Brunsell et al., Plasma Phys. Control. Fusion 43, 1457 (2001)] have been measured with a multichannel spectrometer. Absolute ion densities for oxygen peak between 1-4×1010cm-3 for a central electron density of 1×1013cm-3. Transport simulations with the one-dimensional transport code STRAHL with a diffusion coefficient of 20m2 s-1 yield density profiles similar to those measured. Direct measurement of the ion profile evolution during pulsed poloidal current drive suggests that the diffusion coefficient is reduced by a factor ˜2 in the core but remains unaffected toward the edge. Core transport is not significantly affected by the radial magnetic field growth seen at the edge in discharges without feedback control. This indicates that the mode core amplitude remains the same while the mode eigenfunction increases at the edge.

Measurements and modeling of transport and impurity radial profiles in the EXTRAP T2R reversed field pinch

International Nuclear Information System (INIS)

Kuldkepp, M.; Brunsell, P. R.; Cecconello, M.; Dux, R.; Menmuir, S.; Rachlew, E.

2006-01-01

Radial impurity profiles of oxygen in the rebuilt reversed field pinch EXTRAP T2R [P. R. Brunsell et al., Plasma Phys. Control. Fusion 43, 1457 (2001)] have been measured with a multichannel spectrometer. Absolute ion densities for oxygen peak between 1-4x10 10 cm -3 for a central electron density of 1x10 13 cm -3 . Transport simulations with the one-dimensional transport code STRAHL with a diffusion coefficient of 20 m 2 s -1 yield density profiles similar to those measured. Direct measurement of the ion profile evolution during pulsed poloidal current drive suggests that the diffusion coefficient is reduced by a factor ∼2 in the core but remains unaffected toward the edge. Core transport is not significantly affected by the radial magnetic field growth seen at the edge in discharges without feedback control. This indicates that the mode core amplitude remains the same while the mode eigenfunction increases at the edge

Fusion proton diagnostic for the C-2 field reversed configurationa)

Science.gov (United States)

Magee, R. M.; Clary, R.; Korepanov, S.; Smirnov, A.; Garate, E.; Knapp, K.; Tkachev, A.

2014-11-01

Measurements of the flux of fusion products from high temperature plasmas provide valuable insights into the ion energy distribution, as the fusion reaction rate is a very sensitive function of ion energy. In C-2, where field reversed configuration plasmas are formed by the collision of two compact toroids and partially sustained by high power neutral beam injection [M. Binderbauer et al., Phys. Rev. Lett. 105, 045003 (2010); M. Tuszewski et al., Phys. Rev. Lett. 108, 255008 (2012)], measurements of DD fusion neutron flux are used to diagnose ion temperature and study fast ion confinement and dynamics. In this paper, we will describe the development of a new 3 MeV proton detector that will complement existing neutron detectors. The detector is a large area (50 cm2), partially depleted, ion implanted silicon diode operated in a pulse counting regime. While the scintillator-based neutron detectors allow for high time resolution measurements (˜100 kHz), they have no spatial or energy resolution. The proton detector will provide 10 cm spatial resolution, allowing us to determine if the axial distribution of fast ions is consistent with classical fast ion theory or whether anomalous scattering mechanisms are active. We will describe in detail the diagnostic design and present initial data from a neutral beam test chamber.

Time reversibility of quantum diffusion in small-world networks

Science.gov (United States)

Han, Sung-Guk; Kim, Beom Jun

2012-02-01

We study the time-reversal dynamics of a tight-binding electron in the Watts-Strogatz (WS) small-world networks. The localized initial wave packet at time t = 0 diffuses as time proceeds until the time-reversal operation, together with the momentum perturbation of the strength η, is made at the reversal time T. The time irreversibility is measured by I = |Π( t = 2 T) - Π( t = 0)|, where Π is the participation ratio gauging the extendedness of the wavefunction and for convenience, t is measured forward even after the time reversal. When η = 0, the time evolution after T makes the wavefunction at t = 2 T identical to the one at t = 0, and we find I = 0, implying a null irreversibility or a complete reversibility. On the other hand, as η is increased from zero, the reversibility becomes weaker, and we observe enhancement of the irreversibility. We find that I linearly increases with increasing η in the weakly-perturbed region, and that the irreversibility is much stronger in the WS network than in the local regular network.

31P T2s of phosphomonoesters, phosphodiesters, and inorganic phosphate in the human brain at 7T

Science.gov (United States)

Klomp, Dennis W.J.; Wijnen, Jannie P.

2017-01-01

Purpose To determine the phosphorus‐31 T2s of phosphomonoesters, phosphodiesters, and inorganic phosphate in the healthy human brain at 7T. Methods A 3D chemical shift imaging multi‐echo sequence with composite block pulses for refocusing was used to measure one free induction decay (FID) and seven full echoes with an echo spacing of 45 ms on the brain of nine healthy volunteers (age range 22–45 years; average age 27 ± 8 years). Spectral fitting was used to determine the change in metabolic signal amplitude with echo time. Results The average apparent T2s with their standard deviation were 202 ± 6 ms, 129 ± 6 ms, 86 ± 2 ms, 214 ± 10 ms, and 213 ± 11 ms for phosphoethanolamine, phosphocholine, inorganic phosphate, glycerophosphoethanolamine, and glycerophosphocholine, respectively. Conclusion The determined apparent T2 for phosphoethanolamine, glycerophosphocholine, and glycerophosphoethanolamine is approximately 200 ms. The lower apparent T2 value for phosphocholine is attributed to the overlap of this resonance with the 3‐phosphorous resonance of 2,3‐diphosphoglycerate from blood, with an apparent shorter T2. Omitting the FID signal and the first echo of phosphocholine leads to a T2 of 182 ± 7 ms, whereas a biexponential analysis leads to 203 ± 4 ms. These values are more in line with phosphoethanolamine and the phosphodiesters. The short T2 of inorganic phosphate is subscribed to the fast reversible exchange with γ‐adenosine triphosphate, which is mediated by glyceraldehyde‐3‐phosphate dehydrogenase and phosphoglycerate kinase within the glycolytic pathway. Magn Reson Med 80:29–35, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any

Reversal of rocuronium-induced (1.2 mg kg-1) profound neuromuscular block by accidental high dose of sugammadex (40 mg kg-1).

NARCIS (Netherlands)

Molina, A.L.; Boer, H.D. de; Klimek, M.; Heeringa, M.; Klein, J.

2007-01-01

Sugammadex is the first selective relaxant binding agent and reverses rocuronium-induced neuromuscular block. A case is reported in which a patient accidentally received a high dose of sugammadex (40 mg kg-1) to reverse a rocuronium-induced (1.2 mg kg-1) profound neuromuscular block. A fast and

Predictor-based multivariable closed-loop system identification of the EXTRAP T2R reversed field pinch external plasma response

Energy Technology Data Exchange (ETDEWEB)

Olofsson, K Erik J; Brunsell, Per R; Drake, James R [Fusion Plasma Physics, School of Electrical Engineering, Royal Institute of Technology (KTH Stockholm), Sweden (Association EURATOM-VR) (Sweden); Rojas, Cristian R; Hjalmarsson, Haakan, E-mail: erik.olofsson@ee.kth.se [Automatic Control, School of Electrical Engineering, KTH Stockholm (Sweden)

2011-08-15

The usage of computationally feasible overparametrized and nonregularized system identification signal processing methods is assessed for automated determination of the full reversed-field pinch external plasma response spectrum for the experiment EXTRAP T2R. No assumptions on the geometry of eigenmodes are imposed. The attempted approach consists of high-order autoregressive exogenous estimation followed by Markov block coefficient construction and Hankel matrix singular value decomposition. It is seen that the obtained 'black-box' state-space models indeed can be compared with the commonplace ideal magnetohydrodynamics (MHD) resistive thin-shell model in cylindrical geometry. It is possible to directly map the most unstable autodetected empirical system pole to the corresponding theoretical resistive shell MHD eigenmode.

Predictor-based multivariable closed-loop system identification of the EXTRAP T2R reversed field pinch external plasma response

Science.gov (United States)

Olofsson, K. Erik J.; Brunsell, Per R.; Rojas, Cristian R.; Drake, James R.; Hjalmarsson, Håkan

2011-08-01

The usage of computationally feasible overparametrized and nonregularized system identification signal processing methods is assessed for automated determination of the full reversed-field pinch external plasma response spectrum for the experiment EXTRAP T2R. No assumptions on the geometry of eigenmodes are imposed. The attempted approach consists of high-order autoregressive exogenous estimation followed by Markov block coefficient construction and Hankel matrix singular value decomposition. It is seen that the obtained 'black-box' state-space models indeed can be compared with the commonplace ideal magnetohydrodynamics (MHD) resistive thin-shell model in cylindrical geometry. It is possible to directly map the most unstable autodetected empirical system pole to the corresponding theoretical resistive shell MHD eigenmode.

Evaluation of shoulder pathology: three-dimensional enhanced T1 high-resolution isotropic volume excitation MR vs two-dimensional fast spin echo T2 fat saturation MR.

Science.gov (United States)

Park, H J; Lee, S Y; Kim, M S; Choi, S H; Chung, E C; Kook, S H; Kim, E

2015-03-01

To evaluate the diagnostic accuracy of three-dimensional (3D) enhanced T1 high-resolution isotropic volume excitation (eTHRIVE) shoulder MR for the detection of rotator cuff tears, labral lesions and calcific tendonitis of the rotator cuff in comparison with two-dimensional (2D) fast spin echo T2 fat saturation (FS) MR. This retrospective study included 73 patients who underwent shoulder MRI using the eTHRIVE technique. Shoulder MR images were interpreted separately by two radiologists. They evaluated anatomic identification and image quality of the shoulder joint on routine MRI sequences (axial and oblique coronal T2 FS images) and compared them with the reformatted eTHRIVE images. The images were scored on a four-point scale (0, poor; 1, questionable; 2, adequate; 3, excellent) according to the degree of homogeneous and sufficient fat saturation to penetrate bone and soft tissue, visualization of the glenoid labrum and distinction of the supraspinatus tendon (SST). The diagnostic accuracy of eTHRIVE images compared with routine MRI sequences was evaluated in the setting of rotator cuff tears, glenoid labral injuries and calcific tendonitis of the SST. Fat saturation scores for eTHRIVE were significantly higher than those of the T2 FS for both radiologists. The sensitivity and accuracy of the T2 FS in diagnosing rotor cuff tears were >90%, whereas sensitivity and accuracy of the eTHRIVE method were significantly lower. The sensitivity, specificity and accuracy of both images in diagnosing labral injuries and calcific tendonitis were similar and showed no significant differences. The specificity of both images for the diagnosis of labral injuries and calcific tendonitis was higher than the sensitivities. The accuracy of 3D eTHRIVE imaging was comparable to that of 2D FSE T2 FS for the diagnosis of glenoid labral injury and calcific tendonitis of SST. The 3D eTHRIVE technique was superior to 2D FSE T2 FS in terms of fat saturation. Overall, 3D eTHRIVE was inferior

Automated T2 relaxometry of the hippocampus for temporal lobe epilepsy.

Science.gov (United States)

Winston, Gavin P; Vos, Sjoerd B; Burdett, Jane L; Cardoso, M Jorge; Ourselin, Sebastien; Duncan, John S

2017-09-01

Hippocampal sclerosis (HS), the most common cause of refractory temporal lobe epilepsy, is associated with hippocampal volume loss and increased T2 signal. These can be identified on quantitative imaging with hippocampal volumetry and T2 relaxometry. Although hippocampal segmentation for volumetry has been automated, T2 relaxometry currently involves subjective and time-consuming manual delineation of regions of interest. In this work, we develop and validate an automated technique for hippocampal T2 relaxometry. Fifty patients with unilateral or bilateral HS and 50 healthy controls underwent T 1 -weighted and dual-echo fast recovery fast spin echo scans. Hippocampi were automatically segmented using a multi-atlas-based segmentation algorithm (STEPS) and a template database. Voxelwise T2 maps were determined using a monoexponential fit. The hippocampal segmentations were registered to the T2 maps and eroded to reduce partial volume effect. Voxels with T2 >170 msec excluded to minimize cerebrospinal fluid (CSF) contamination. Manual determination of T2 values was performed twice in each subject. Twenty controls underwent repeat scans to assess interscan reproducibility. Hippocampal T2 values were reliably determined using the automated method. There was a significant ipsilateral increase in T2 values in HS (p epilepsy. © 2017 The Authors. Epilepsia published by Wiley Periodicals, Inc. on behalf of International League Against Epilepsy.

Articular Cartilage of the Human Knee Joint: In Vivo Multicomponent T2 Analysis at 3.0 T

Science.gov (United States)

Choi, Kwang Won; Samsonov, Alexey; Spencer, Richard G.; Wilson, John J.; Block, Walter F.; Kijowski, Richard

2015-01-01

Purpose To compare multicomponent T2 parameters of the articular cartilage of the knee joint measured by using multicomponent driven equilibrium single-shot observation of T1 and T2 (mcDESPOT) in asymptomatic volunteers and patients with osteoarthritis. Materials and Methods This prospective study was performed with institutional review board approval and with written informed consent from all subjects. The mcDESPOT sequence was performed in the knee joint of 13 asymptomatic volunteers and 14 patients with osteoarthritis of the knee. Single-component T2 (T2Single), T2 of the fast-relaxing water component (T2F) and of the slow-relaxing water component (T2S), and the fraction of the fast-relaxing water component (FF) of cartilage were measured. Wilcoxon rank-sum tests and multivariate linear regression models were used to compare mcDESPOT parameters between volunteers and patients with osteoarthritis. Receiver operating characteristic analysis was used to assess diagnostic performance with mcDESPOT parameters for distinguishing morphologically normal cartilage from morphologically degenerative cartilage identified at magnetic resonance imaging in eight cartilage subsections of the knee joint. Results Higher cartilage T2Single (P cartilage FF (P cartilage T2F (P = .079) and T2S (P = .124) values were seen in patients with osteoarthritis compared with those in asymptomatic volunteers. Differences in T2Single and FF remained significant (P cartilage (P cartilage T2Single and significantly lower cartilage FF than did asymptomatic volunteers, and receiver operating characteristic analysis results suggested that FF may allow greater diagnostic performance than that with T2Single for distinguishing between normal and degenerative cartilage. © RSNA, 2015 Online supplemental material is available for this article. PMID:26024307

SULF2 Strongly Prediposes to Fasting and Postprandial Triglycerides in Patients with Obesity and Type 2 Diabetes Mellitus

Science.gov (United States)

Hassing, H. Carlijne; Surendran, R. Preethi; Derudas, Bruno; Verrijken, An; Francque, Sven M.; Mooij, Hans L.; Bernelot Moens, Sophie J.; ’t Hart, Leen M.; Nijpels, Giel; Dekker, Jacqueline M.; Williams, Kevin Jon; Stroes, Erik S. G.; Van Gaal, Luc F.; Staels, Bart; Nieuwdorp, Max; Dallinga-Thie, Geesje M.

2014-01-01

Objective Hepatic overexpression of sulfatase-2 (SULF2), a heparan sulfate remodelling enzyme, strongly contributes to high triglyceride (TG) levels in obese, type 2 diabetic (T2DM) db/db mice. Nevertheless, data in humans are lacking. Here we sought to investigate the association of human hepatic SULF2 expression and SULF2 gene variants with TG metabolism in patients with obesity and/or T2DM. Design and Methods Liver biopsies from 121 obese subjects were analyzed for relations between hepatic SULF2 mRNA levels and plasma TG. Associations between seven SULF2 tagSNPs and TG levels were assessed in 210 obese T2DM subjects with dyslipidemia. Replication of positive findings was performed in 1316 independent obese T2DM patients. Postprandial TRL clearance was evaluated in 29 obese T2DM subjects stratified by SULF2 genotype. Results Liver SULF2 expression was significantly associated with fasting plasma TG (r = 0.271; p=0.003) in obese subjects. The SULF2 rs2281279(A>G) SNP was reproducibly associated with lower fasting plasma TG levels in obese T2DM subjects (p<0.05). Carriership of the minor G allele was associated with lower levels of postprandial plasma TG (P<0.05) and retinyl esters (RE) levels (P<0.001). Conclusions These findings implicate SULF2 as potential therapeutic target in the atherogenic dyslipidemia of obesity and T2DM. PMID:24339435

Comparison of T1-weighted fast spin-echo and T1-weighted fluid-attenuated inversion recovery images of the lumbar spine at 3.0 Tesla

International Nuclear Information System (INIS)

Lavdas, Eleftherios; Vlychou, Marianna; Arikidis, Nikos; Kapsalaki, Eftychia; Roka, Violetta; Fezoulidis, Ioannis V.

2010-01-01

Background: T1-weighted fluid-attenuated inversion recovery (FLAIR) sequence has been reported to provide improved contrast between lesions and normal anatomical structures compared to T1-weighted fast spin-echo (FSE) imaging at 1.5T regarding imaging of the lumbar spine. Purpose: To compare T1-weighted FSE and fast T1-weighted FLAIR imaging in normal anatomic structures and degenerative and metastatic lesions of the lumbar spine at 3.0T. Material and Methods: Thirty-two consecutive patients (19 females, 13 males; mean age 44 years, range 30-67 years) with lesions of the lumbar spine were prospectively evaluated. Sagittal images of the lumbar spine were obtained using T1-weighted FSE and fast T1-weighted FLAIR sequences. Both qualitative and quantitative analyses measuring the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and relative contrast (ReCon) between degenerative and metastatic lesions and normal anatomic structures were conducted, comparing these sequences. Results: On quantitative evaluation, SNRs of cerebrospinal fluid (CSF), nerve root, and fat around the root of fast T1-weighted FLAIR imaging were significantly lower than those of T1-weighted FSE images (P<0.001). CNRs of normal spinal cord/CSF and disc herniation/ CSF for fast T1-weighted FLAIR images were significantly higher than those for T1-weighted FSE images (P<0.001). ReCon of normal spinal cord/CSF, disc herniation/CSF, and vertebral lesions/CSF for fast T1-weighted FLAIR images were significantly higher than those for T1-weighted FSE images (P<0.001). On qualitative evaluation, it was found that CSF nulling and contrast at the spinal cord (cauda equina)/CSF interface for T1-weighted FLAIR images were significantly superior compared to those for T1-weighted FSE images (P<0.001), and the disc/spinal cord (cauda equina) interface was better for T1-weighted FLAIR images (P<0.05). Conclusion: The T1-weighted FLAIR sequence may be considered as the preferred lumbar spine imaging

Association between impaired fasting glycaemia in pediatric obesity and type 2 diabetes in young adulthood.

Science.gov (United States)

Hagman, E; Danielsson, P; Brandt, L; Ekbom, A; Marcus, C

2016-08-22

In adults, impaired fasting glycemia (IFG) increases the risk for type 2 diabetes mellitus (T2DM). This study aimed to investigate to which extent children with obesity develop T2DM during early adulthood, and to determine whether IFG and elevated hemoglobin A1c (HbA1c) in obese children are risk markers for early development of T2DM. In this prospective cohort study, 1620 subjects from the Swedish Childhood Obesity Treatment Registry - BORIS who were ⩾18 years at follow-up and 8046 individuals in a population-based comparison group, matched on gender age and living area, were included. IFG was defined according to both ADA (cut-off 5.6 mmol l(-1)) and WHO (6.1 mmol l(-1)). Elevated HbA1c was defined according to ADA (cut-off 39 mmol l(-1)). Main outcome was T2DM medication, as a proxy for T2DM. Data on medications were retrieved from a national registry. The childhood obesity cohort were 24 times more likely to receive T2DM medications in early adulthood compared with the comparison group (95% confidence interval (CI): 12.52-46). WHO-defined IFG predicted future use of T2DM medication with an adjusted hazard ratio (HR) of 3.73 (95% CI: 1.87-7.45) compared with those who had fasting glucose levels fasting glucose level of 5.6-6.0 mmol l(-1), that is, the IFG-interval added by American Diabetes Association (ADA), did not increase the use of T2DM medication more than pediatric obesity itself, adjusted HR=1.72 (0.84-3.52). Elevated levels of HbA1c resulted in an adjusted HR=3.12 (1.50-6.52). More severe degree of obesity also increased the future T2DM risk. IFG according to WHO and elevated HbA1c (39-48 mmol l(-1)), but not the additional fasting glucose interval added by ADA (5.6-6.0 mmol l(-1)), can be considered as prediabetes in the obese pediatric population in Sweden.

Structural requirements for the binding of tRNA Lys3 to reverse transcriptase of the human immunodeficiency virus type 1

NARCIS (Netherlands)

Oude Essink, B. B.; Das, A. T.; Berkhout, B.

1995-01-01

Reverse transcription of the human immunodeficiency virus type 1 (HIV-1) RNA genome is primed by the cellular tRNA Lys3 molecule. Packaging of this tRNA primer during virion assembly is thought to be mediated by specific interactions with the reverse transcriptase (RT) protein. Portions of the tRNA

MHD control experiments in the Extrap T2R Reversed Field Pinch

Science.gov (United States)

Marrelli, L.; Bolzonella, T.; Brunsell, P.; Cecconello, M.; Drake, J.; Franz, P.; Gregoratto, D.; Manduchi, G.; Martin, P.; Ortolani, S.; Paccagnella, R.; Piovesan, P.; Spizzo, G.; Yadikin, D.; Zanca, P.

2004-11-01

We report here on MHD active control experiments performed in the Extrap T2R device, which has been recently equipped with a set of 32 feedback controlled saddle coils couples. Experiments aiming at selectively exciting a resonant resistive instability in order to actively induce Quasi Single Helicity states will be presented. Open loop experiments have in fact shown that a spectrum with one dominant mode can be excited in a high aspect ratio device like T2R. In addition, evidences of controlled braking of tearing modes, which spontaneously rotate in T2R, have been gathered, allowing the determination of a threshold for mode wall locking. Different feedback control schemes have been implemented. In particular, mode suppression schemes proved successful in delaying resistive wall modes growth and in increasing the discharge duration: this suggests a hybrid mode control scenario, in which RWM are suppressed and QSH is induced. Radiation imaging and internal magnetic field reconstructions performed with the ORBIT code will be presented.

Fasting Serum Taurine-Conjugated Bile Acids Are Elevated in Type 2 Diabetes and Do Not Change With Intensification of Insulin

Science.gov (United States)

Wewalka, Marlene; Patti, Mary-Elizabeth; Barbato, Corinne; Houten, Sander M.

2014-01-01

Context: Bile acids (BAs) are newly recognized signaling molecules in glucose and energy homeostasis. Differences in BA profiles with type 2 diabetes mellitus (T2D) remain incompletely understood. Objective: The objective of the study was to assess serum BA composition in impaired glucose-tolerant, T2D, and normal glucose-tolerant persons and to monitor the effects of improving glycemia on serum BA composition in T2D patients. Design and Setting: This was a cross-sectional cohort study in a general population (cohort 1) and nonrandomized intervention (cohort 2). Patients and Interventions: Ninety-nine volunteers underwent oral glucose tolerance testing, and 12 persons with T2D and hyperglycemia underwent 8 weeks of intensification of treatment. Main Outcome Measures: Serum free BA and respective taurine and glycine conjugates were measured by HPLC tandem mass spectrometry. Results: Oral glucose tolerance testing identified 62 normal-, 25 impaired glucose-tolerant, and 12 T2D persons. Concentrations of total taurine-conjugated BA were higher in T2D and intermediate in impaired- compared with normal glucose-tolerant persons (P = .009). Univariate regression revealed a positive association between total taurine-BA and fasting glucose (R = 0.37, P fasting insulin (R = 0.21, P = .03), and homeostatic model assessment-estimated insulin resistance (R = 0.26, P = .01) and an inverse association with oral disposition index (R = −0.36, P fasting serum total BA or BA composition. Conclusion: Fasting taurine-conjugated BA concentrations are higher in T2D and intermediate in impaired compared with normal glucose-tolerant persons and are associated with fasting and postload glucose. Serum BAs are not altered in T2D in response to improved glycemia. Further study may elucidate whether this pattern of taurine-BA conjugation can be targeted to provide novel therapeutic approaches to treat T2D. PMID:24432996

Zero field reversal probability in thermally assisted magnetization reversal

Science.gov (United States)

Prasetya, E. B.; Utari; Purnama, B.

2017-11-01

This paper discussed about zero field reversal probability in thermally assisted magnetization reversal (TAMR). Appearance of reversal probability in zero field investigated through micromagnetic simulation by solving stochastic Landau-Lifshitz-Gibert (LLG). The perpendicularly anisotropy magnetic dot of 50×50×20 nm3 is considered as single cell magnetic storage of magnetic random acces memory (MRAM). Thermally assisted magnetization reversal was performed by cooling writing process from near/almost Curie point to room temperature on 20 times runs for different randomly magnetized state. The results show that the probability reversal under zero magnetic field decreased with the increase of the energy barrier. The zero-field probability switching of 55% attained for energy barrier of 60 k B T and the reversal probability become zero noted at energy barrier of 2348 k B T. The higest zero-field switching probability of 55% attained for energy barrier of 60 k B T which corespond to magnetif field of 150 Oe for switching.

Fast spin-echo MR imaging of the eye

International Nuclear Information System (INIS)

Hosten, N.; Lemke, A.J.; Bornfeld, N.; Wassmuth, R.; Schweiger, U.; Terstegge, K.; Felix, R.

1996-01-01

Magnetic resonance imaging of the eye usually includes T2-weighted images both for screening purposes and for characterization of melanoma. Conventional T2-weighted spin-echo (SE) imaging suffers both from long acquisition times and incomplete recovery of the virteous' signal. A fast SE sequence was therefore compared prospectively with conventional sequences in 29 consecutive patients with lesions of the eye. Fast SE images delineated melanoma and other lesions of the eye from vitreous better than conventional T2-weighted images. Image quality and lesion conspicuity were improved on the fast sequence. Whereas melanoma appeared hypointense to vitreous on both types of images, subretinal effusion was hypointense on fast images and hyperintense on conventional T2-weighted images. Ghosting of the globe, which, however, did not decrease diagnostic value, was more pronounced on fast images. Conventional T2-weighted images may be replaced by fast SE images in MR studies of the eye with a gain in lesion conspicuity and significant time saving. (orig.)

Proton T2 Relaxation effect of superparamagnetic iron oxide on fast spin echo sequence. Influence of echo number (even or odd) of effective TE

International Nuclear Information System (INIS)

Tsuchihashi, Toshio; Maki, Toshio; Kitagawa, Matsuo; Suzuki, Takeshi; Fujita, Isao

1999-01-01

The T 2 relaxation effect of the fast spin echo sequence (FSE) was investigated using superparamagnetic iron oxide (SPIO) particles. When even echoes were used as the effective TE of FSE, the signal intensity ratio [signal intensity of FSE/signal intensity of conventional spin echo sequence (CSE)] of FSE and CSE increased, whereas the T 2 relaxation effect of SPIO with FSE was reduced. However, when odd echoes were used, neither signal intensity changed, and weakening of the T 2 relaxation effect, considered a problem with FSE, was reduced. This phenomenon was not observed when the refocusing flip angle was changed to 30 and 60 degrees. However, it was observed when the refocusing flip angle was 120 and 150 degrees. Thus, this phenomenon can be considered to be related to oscillation in longitudinal magnetization when using the Carr-Purcell-Meiboom-Gill (CPMG) technique. (author)

MRI of acute cerebral infarction: a comparison of FLAIR and T2-weighted fast spin-echo imaging

International Nuclear Information System (INIS)

Noguchi, K.; Ogawa, T.; Inugami, A.; Fujita, H.; Hatazawa, J.; Shimosegawa, E.; Okudera, T.; Uemura, K.; Seto, H.

1997-01-01

Fluid-attenuated inversion-recovery (FLAIR) sequences have been reported to provide high sensitivity to a wide range of central nervous system diseases. To our knowledge, however, FLAIR sequences have not been used to study patients with acute cerebral infarcts. We evaluated the usefulness of FLAIR sequences in this context. FLAIR sequences were acquired on a 0.5 T superconducting unit within 8 h of the onset in 19 patients (aged 26-80 years) with a total of 23 ischaemic lesions. The images were reviewed retrospectively by three neuroradiologists, and the FLAIR images were compared with T2-weighted fast spin-echo images. All but one of the ischaemic lesions involving grey matter was clearly demonstrated on FLAIR images as increased signal intensity in cortical or central grey matter. FLAIR images were particularly useful for detecting the hyperacute cortical infarcts within 3 h of onset, which were not readily detected on the spin-echo images. In 9 of 11 patients with complete proximal occlusion, the distal portion of the cerebral artery was visible as an area of high signal intensity on FLAIR images. (orig.). With 4 figs., 1 tab

Agreement between fasting and postprandial LDL cholesterol measured with 3 methods in patients with type 2 diabetes mellitus

DEFF Research Database (Denmark)

Lund, Søren S.; Petersen, Martin; Frandsen, Merete

2011-01-01

LDL cholesterol (LDL-C) is a modifiable cardiovascular disease risk factor. We used 3 LDL-C methods to study the agreement between fasting and postprandial LDL-C in type 2 diabetes (T2DM) patients.......LDL cholesterol (LDL-C) is a modifiable cardiovascular disease risk factor. We used 3 LDL-C methods to study the agreement between fasting and postprandial LDL-C in type 2 diabetes (T2DM) patients....

Derivation of the Time-Reversal Anomaly for (2 +1 )-Dimensional Topological Phases

Science.gov (United States)

Tachikawa, Yuji; Yonekura, Kazuya

2017-09-01

We prove an explicit formula conjectured recently by Wang and Levin for the anomaly of time-reversal symmetry in (2 +1 )-dimensional fermionic topological quantum field theories. The crucial step is to determine the cross-cap state in terms of the modular S matrix and T2 eigenvalues, generalizing the recent analysis by Barkeshli et al. in the bosonic case.

Calculation and Analysis of B/T (Burning and/or Transmutation Rate of Minor Actinides and Plutonium Performed by Fast B/T Reactor

Directory of Open Access Journals (Sweden)

Marsodi

2006-01-01

Full Text Available Calculation and analysis of B/T (Burning and/or Transmutation rate of MA (minor actinides and Pu (Plutonium has been performed in fast B/T reactor. The study was based on the assumption that the spectrum shift of neutron flux to higher side of neutron energy had a potential significance for designing the fast B/T reactor and a remarkable effect for increasing the B/T rate of MA and/or Pu. The spectrum shifts of neutron have been performed by change MOX to metallic fuel. Blending fraction of MA and or Pu in B/T fuel and the volume ratio of fuel to coolant in the reactor core were also considered. Here, the performance of fast B/T reactor was evaluated theoretically based on the calculation results of the neutronics and burn-up analysis. In this study, the B/T rate of MA and/or Pu increased by increasing the blending fraction of MA and or Pu and by changing the F/C ratio. According to the results, the total B/T rate, i.e. [B/T rate]MA + [B/T rate]Pu, could be kept nearly constant under the critical condition, if the sum of the MA and Pu inventory in the core is nearly constant. The effect of loading structure was examined for inner or outer loading of concentric geometry and for homogeneous loading. Homogeneous loading of B/T fuel was the good structure for obtaining the higher B/T rate, rather than inner or outer loading

Studies on the response of resistive-wall modes to applied magnetic perturbations in the EXTRAP T2R reversed field pinch

Science.gov (United States)

Gregoratto, D.; Drake, J. R.; Yadikin, D.; Liu, Y. Q.; Paccagnella, R.; Brunsell, P. R.; Bolzonella, T.; Marchiori, G.; Cecconello, M.

2005-09-01

Arrays of magnetic coils and sensors in the EXTRAP T2R [P. R. Brunsell et al., Plasma Phys. Controlled Fusion 43 1457 (2001)] reversed-field pinch have been used to investigate the plasma response to an applied resonant magnetic perturbation in the range of the resistive-wall modes (RWMs). Measured RWM growth rates agree with predictions of a cylindrical ideal-plasma model. The linear growth of low-n marginally stable RWMs is related to the so-called resonant-field amplification due to a dominant ∣n∣=2 machine error field of about 2 G. The dynamics of the m =1 RWMs interacting with the applied field produced by the coils can be accurately described by a two-pole system. Estimated poles and residues are given with sufficient accuracy by the cylindrical model with a thin continuous wall.

T2-weighted imaging of the heart—A pictorial review

International Nuclear Information System (INIS)

Mirakhur, Anirudh; Anca, Nicoleta; Mikami, Yoko; Merchant, Naeem

2013-01-01

Spin-Echo techniques in cardiovascular magnetic resonance (CMR) have been used for decades, primarily to image cardiac anatomy. More recently, T2-weighted (T2W) imaging has seen an increased role in CMR protocols, especially in tissue characterization in acute myocardial processes. This article will review current methodologies of cardiac T2W acquisition and their limitations, as well as approach to both semi-quantitative and quantitative analyses. The appearance and utility of T2W imaging in a myriad of pathologic myocardial processes such as acute myocardial infarction, acute viral myocarditis, reversible stress-related cardiomyopathy, hypertrophic cardiomyopathy, and cardiac sarcoidosis, will also be discussed

Degenerative disc disease of the lumbar spine: a prospective comparison of fast T1-weighted fluid-attenuated inversion recovery and T1-weighted turbo spin echo MR imaging

International Nuclear Information System (INIS)

Erdem, L. Oktay; Erdem, C. Zuhal; Acikgoz, Bektas; Gundogdu, Sadi

2005-01-01

Objective: To compare fast T1-weighted fluid-attenuated inversion recovery (FLAIR) and T1-weighted turbo spin-echo (TSE) imaging of the degenerative disc disease of the lumbar spine. Materials and methods: Thirty-five consecutive patients (19 females, 16 males; mean age 41 years, range 31-67 years) with suspected degenerative disc disease of the lumbar spine were prospectively evaluated. Sagittal images of the lumbar spine were obtained using T1-weighted TSE and fast T1-weighted FLAIR sequences. Two radiologists compared these sequences both qualitatively and quantitatively. Results: On qualitative evaluation, CSF nulling, contrast at the disc-CSF interface, the disc-spinal cord (cauda equina) interface, and the spinal cord (cauda equina)-CSF interface of fast T1-weighted FLAIR images were significantly higher than those for T1-weighted TSE images (P < 0.001). On quantitative evaluation of the first 15 patients, signal-to-noise ratios of cerebrospinal fluid of fast T1-weighted FLAIR imaging were significantly lower than those for T1-weighted TSE images (P < 0.05). Contrast-to-noise ratios of spinal cord/CSF and normal bone marrow/disc for fast T1-weighted FLAIR images were significantly higher than those for T1-weighted TSE images (P < 0.05). Conclusion: Results in our study have shown that fast T1-weighted FLAIR imaging may be a valuable imaging modality in the armamentarium of lumbar spinal T1-weighted MR imaging, because the former technique has definite superior advantages such as CSF nulling, conspicuousness of the normal anatomic structures and changes in the lumbar spinal discogenic disease and image contrast and also almost equally acquisition times

Degenerative disc disease of the lumbar spine: a prospective comparison of fast T1-weighted fluid-attenuated inversion recovery and T1-weighted turbo spin echo MR imaging

Energy Technology Data Exchange (ETDEWEB)

Erdem, L. Oktay [Department of Radiology, Zonguldak Karaelmas University, School of Medicine, 6700 Kozlu, Zonguldak (Turkey)]. E-mail: sunarerdem@yahoo.com; Erdem, C. Zuhal [Department of Radiology, Zonguldak Karaelmas University, School of Medicine, 6700 Kozlu, Zonguldak (Turkey); Acikgoz, Bektas [Department of Neurosurgery, Zonguldak Karaelmas University, School of Medicine, Zonguldak (Turkey); Gundogdu, Sadi [Department of Radiology, Zonguldak Karaelmas University, School of Medicine, 6700 Kozlu, Zonguldak (Turkey)

2005-08-01

Objective: To compare fast T1-weighted fluid-attenuated inversion recovery (FLAIR) and T1-weighted turbo spin-echo (TSE) imaging of the degenerative disc disease of the lumbar spine. Materials and methods: Thirty-five consecutive patients (19 females, 16 males; mean age 41 years, range 31-67 years) with suspected degenerative disc disease of the lumbar spine were prospectively evaluated. Sagittal images of the lumbar spine were obtained using T1-weighted TSE and fast T1-weighted FLAIR sequences. Two radiologists compared these sequences both qualitatively and quantitatively. Results: On qualitative evaluation, CSF nulling, contrast at the disc-CSF interface, the disc-spinal cord (cauda equina) interface, and the spinal cord (cauda equina)-CSF interface of fast T1-weighted FLAIR images were significantly higher than those for T1-weighted TSE images (P < 0.001). On quantitative evaluation of the first 15 patients, signal-to-noise ratios of cerebrospinal fluid of fast T1-weighted FLAIR imaging were significantly lower than those for T1-weighted TSE images (P < 0.05). Contrast-to-noise ratios of spinal cord/CSF and normal bone marrow/disc for fast T1-weighted FLAIR images were significantly higher than those for T1-weighted TSE images (P < 0.05). Conclusion: Results in our study have shown that fast T1-weighted FLAIR imaging may be a valuable imaging modality in the armamentarium of lumbar spinal T1-weighted MR imaging, because the former technique has definite superior advantages such as CSF nulling, conspicuousness of the normal anatomic structures and changes in the lumbar spinal discogenic disease and image contrast and also almost equally acquisition times.

The Usefulness of Fast-Spin-Echo T2-Weighted MR Imaging in Nutcracker Syndrome: a Case Report

Energy Technology Data Exchange (ETDEWEB)

Wong, Heong Leng; Chen, Matt Chiung Yu; Wu, Cgek Siung; Fu, Kuo An; Lin, Cheng Hao [Yuan' s General Hospital, Kaohsiung (China); Weng, Mei Jui; Liang, Huei Lung; Pan, Huay Ben [National Yang-Ming University, Taipei (Korea, Republic of)

2010-06-15

Nutcracker syndrome occurs when the left renal vein (LRV) is compressed between the superior mesenteric artery and the aorta, and this syndrome is often characterized by venous hypertension and related pathologies. However, invasive studies such as phlebography and measuring the reno-caval pressure gradient should be performed to identify venous hypertension. Here we present a case of Nutcracker syndrome where the LRV and intra-renal varicosities appeared homogeneously hyperintense on magnetic resonance (MR) fast-spin-echo T2- weighted imaging, which suggested markedly stagnant intravenous blood flow and the presence of venous hypertension. The patient was diagnosed and treated without obtaining the reno-caval pressure gradient. The discomfort of the patient lessened after treatment. Furthermore, on follow-up evaluation, the LRV displayed a signal void, and this was suggestive of a restoration of the normal LRV flow and a decrease in LRV pressure.

A spectroscopic system for time- and space-resolved studies of impurities on the EXTRAP-T2 reversed field pinch

Science.gov (United States)

Sallander, J.

1998-06-01

The radial distribution of impurity line emission in the EXTRAP-T2 reversed field pinch (RFP) is studied with a five viewing chord, absolutely calibrated, spectrometer system. The light is analyzed with a single 0.5 m grating spectrometer. Different parts of the entrance slit are used for different channels. This arrangement makes it possible to use the system over a wide wavelength range, from 2500 to 6500 Å, without having to recalibrate the relative sensitivity for the different channels. The rather short plasma pulses of 10-15 ms require a high time resolution. The use of photomultiplier tubes provides a time resolution of 10 μs which is limited by the transient recorders used. The result is a robust, low-cost system that produces reliable measurements of the radial dependence of emission from a wide range of impurity ions.

Pharmacological approaches to the management of type 2 diabetes in fasting adults during Ramadan

Directory of Open Access Journals (Sweden)

AlMaatouq MA

2012-05-01

Full Text Available Mohamed A AlMaatouqEndocrine Unit, Department of Medicine, College of Medicine and King Khalid University Hospital, King Saud University, Riyadh, Saudi ArabiaAbstract: More than 50 million Muslims throughout the world with type 2 diabetes mellitus (T2DM fast for one lunar month (Ramadan each year. Health care providers within and outside the Muslim world need to be aware of the nature of these partial days of fasting and their risks (and potential benefits to people with T2DM, and need to provide Ramadan-adjusted diabetes care. Hypoglycemia during the fasting days represents the greatest health risk for these patients; hence, diabetes-related pharmacotherapy needs to be tailored and adjusted with this risk in mind. With limited trial data available, this review proposes practical modifications to the usual pre-Ramadan antidiabetic regimens that are based on pathophysiological principles, clinical trial evidence (where available, expert opinion, and extended practical experience. Individualization of care is paramount in this regard to take into consideration the patient and societal, cultural, and economic variables.Keywords: type 2 diabetes mellitus, Ramadan, fasting, hypoglycemia, oral antidiabetic agents, insulin

Highly reversible and fast sodium storage boosted by improved interfacial and surface charge transfer derived from the synergistic effect of heterostructures and pseudocapacitance in SnO2-based anodes.

Science.gov (United States)

Li, Xin; Sun, Xiaohong; Gao, Zhiwen; Hu, Xudong; Ling, Rui; Cai, Shu; Zheng, Chunming; Hu, Wenbin

2018-02-01

Sodium-ion batteries have attracted worldwide attention as potential alternatives for large scale stationary energy storage due to the rich reserves and low cost of sodium resources. However, the practical application of sodium-ion batteries is restricted by unsatisfying capacity and poor rate capability. Herein, a novel mechanism of improving both interfacial and surface charge transfer is proposed by fabricating a graphene oxide/SnO 2 /Co 3 O 4 nanocomposite through a simple hydrothermal method. The formation of heterostructures between ultrafine SnO 2 and Co 3 O 4 could enhance the charge transfer of interfaces owing to the internal electric field. The pseudocapacitive effect, which is led by the high specific area and the existence of ultrafine nanoparticles, takes on a feature of fast faradaic surface charge-transfer. Benefiting from the synergistic advantages of the heterostructures and the pseudocapacitive effect, the as-prepared graphene oxide/SnO 2 /Co 3 O 4 anode achieved a high reversible capacity of 461 mA h g -1 after 80 cycles at a current density of 0.1 A g -1 . Additionally, at a high current density of 1 A g -1 , a high reversible capacity of 241 mA h g -1 after 500 cycles is obtained. A full cell coupled by the as-prepared graphene oxide/SnO 2 /Co 3 O 4 anode and the Na 3 V 2 (PO 4 ) 3 cathode was also constructed, which exhibited a reversible capacity of 310.3 mA h g -1 after 100 cycles at a current density of 1 A g -1 . This method of improving both interfacial and surface charge transfer may pave the way for the development of high performance sodium-ion batteries.

Measurements of T1 and T2 over time in formalin-fixed human whole-brain specimens

International Nuclear Information System (INIS)

Tovi, M.; Ericsson, A.

1992-01-01

T1 and T2 were measured in 5 formalin-fixed human whole-brain specimens as a function of time. Gray matter/white matter contrast reversal was observed around the 4th day and was considered to be due to the greater decrease in T1 in gray than in white matter. A possible explanation for this is that the decomposition of the myelin phospholipid structure by formalin somewhat counteracts the general reductive effect of the fixation procedure on relaxation times. (orig.)

A quantitative description of tubular system Ca(2+) handling in fast- and slow-twitch muscle fibres.

Science.gov (United States)

Cully, Tanya R; Edwards, Joshua N; Murphy, Robyn M; Launikonis, Bradley S

2016-06-01

Current methods do not allow a quantitative description of Ca(2+) movements across the tubular (t-) system membrane without isolating the membranes from their native skeletal muscle fibre. Here we present a fluorescence-based method that allows determination of the t-system [Ca(2+) ] transients and derivation of t-system Ca(2+) fluxes in mechanically skinned skeletal muscle fibres. Differences in t-system Ca(2+) -handling properties between fast- and slow-twitch fibres from rat muscle are resolved for the first time using this new technique. The method can be used to study Ca(2+) handling of the t-system and allows direct comparisons of t-system Ca(2+) transients and Ca(2+) fluxes between groups of fibres and fibres from different strains of animals. The tubular (t-) system of skeletal muscle is an internalization of the plasma membrane that maintains a large Ca(2+) gradient and exchanges Ca(2+) between the extracellular and intracellular environments. Little is known of the Ca(2+) -handling properties of the t-system as the small Ca(2+) fluxes conducted are difficult to resolve with conventional methods. To advance knowledge in this area we calibrated t-system-trapped rhod-5N inside skinned fibres from rat and [Ca(2+) ]t-sys , allowing confocal measurements of Ca(2+) -dependent changes in rhod-5N fluorescence during rapid changes in the intracellular ionic environment to be converted to [Ca(2+) ] transients in the t-system ([Ca(2+) ]t-sys (t)). Furthermore, t-system Ca(2+) -buffering power was determined so that t-system Ca(2+) fluxes could be derived from [Ca(2+) ]t-sys (t). With this new approach, we show that rapid depletion of sarcoplasmic reticulum (SR) Ca(2+) induced a robust store-operated Ca(2+) entry (SOCE) in fast- and slow-twitch fibres, reducing [Ca(2+) ]t-sys to fibre types. Abruptly introducing internal solutions with 1 mm Mg(2+) and [Ca(2+) ]cyto (28 nm-1.3 μm) to Ca(2+) -depleted fibres generated t-system Ca(2+) uptake rates dependent on [Ca(2

Translation of field-reversed configurations in the FRX C/T experiment

Energy Technology Data Exchange (ETDEWEB)

Rej, D.J.; Armstrong, W.T.; Chrien, R.E.; Klingner, P.L.; Linford, R.K.; McKenna, K.F.; Milroy, R.D.; Sherwood, E.G.; Siemon, R.E.; Tuszewski, M.

1984-01-01

One of the unique features inherent to compact toroids is the potential ability to translate the plasma along its geometric axis. CT translation has proven useful in reactor design studies, and has been the focus of several experimental investigations. In this paper, we report on the initial results from translation experiments performed with the field-reversed configuration (FRC) plasmas generated in the FRX-C/T device.

Translation of field-reversed configurations in the FRX C/T experiment

International Nuclear Information System (INIS)

Rej, D.J.; Armstrong, W.T.; Chrien, R.E.

1984-01-01

One of the unique features inherent to compact toroids is the potential ability to translate the plasma along its geometric axis. CT translation has proven useful in reactor design studies, and has been the focus of several experimental investigations. In this paper, we report on the initial results from translation experiments performed with the field-reversed configuration (FRC) plasmas generated in the FRX-C/T device

2-D time evolution of T/sub e/ during sawtooth crash based on fast ECE [electron cyclotron emission] measurements on TFTR

International Nuclear Information System (INIS)

Kuo-Petravic, G.

1988-12-01

Electron cyclotron emission measurements taken at 20 locations in the horizontal midplane during a sawtooth crash have been analysed based on the assumption of fast rigid rotation of the plasma. Due to this fast rotation (∼100μsec), which remains fairly constant throughout the sawtooth crash, we have been able to make time-to-space reconstructions of half the poloidal plane using points which are separated in time by not more than 40μsec. The existence of a temperature flattening in the precursor phase, which we interpret as an m = 1 temperature island, is clearly demonstrated, and its location and width agree well with local emissivity measurements from soft x-ray tomography viewing the same poloidal plane. The rotating temperature island in the precursor phase, the outward movement of the region of high T/sub c/ during the crash phase, and the shape of T/sub e/ during the crash phase, and the shape of T/sub e/ distribution after the crash during the successor phase have all been documented in a time sequence of color contours. 4 refs., 10 figs

Meniscal T1rho and T2 measured with 3.0T MRI increases directly after running a marathon

Energy Technology Data Exchange (ETDEWEB)

Stehling, Christoph [University of California, Musculoskeletal and Quantitative Imaging Group (MQIR), Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); University of Muenster, Department of Clinical Radiology, Muenster (Germany); Luke, Anthony [University of California, Department of Orthopedic Surgery, San Francisco, CA (United States); Stahl, Robert [University of California, Musculoskeletal and Quantitative Imaging Group (MQIR), Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Ludwig Maximilians University of Munich, Department of Clinical Radiology, Munich (Germany); Baum, Thomas; Joseph, Gabby; Pan, Judong; Link, Thomas M. [University of California, Musculoskeletal and Quantitative Imaging Group (MQIR), Department of Radiology and Biomedical Imaging, San Francisco, CA (United States)

2011-06-15

To prospectively evaluate changes in T1rho and T2 relaxation time in the meniscus using 3.0 T MRI in asymptomatic knees of marathon runners and to compare these findings with those of age-matched healthy subjects. Thirteen marathon runners underwent 3.0 T MRI including T1rho and T2 mapping sequences before, 48-72 h after, and 3 months after competition. Ten controls were examined at baseline and after 3 months. All images were analyzed by two musculoskeletal radiologists identifying and grading cartilage, meniscal, ligamentous. and other knee abnormalities with WORMS scores. Meniscal segmentation was performed to generate T1rho and T2 maps in six compartments. No differences in morphological knee abnormalities were found before and after the marathon. However, all marathon runners showed a significant increase in T1rho and T2 values after competition in all meniscus compartments (p < 0.0001), which may indicate changes in the biochemical composition of meniscal tissue. While T2 values decreased after 3 months T1rho values remained at a high level, indicating persisting changes in the meniscal matrix composition after a marathon. T2 values in menisci have the potential to be used as biomarkers for identifying reversible meniscus matrix changes indicating potential tissue damage. T1rho values need further study, but may be a valuable marker for diagnosing early, degenerative changes in the menisci following exercise. (orig.)

Experience with DPP-4 inhibitors in the management of patients with type 2 diabetes fasting during Ramadan

Directory of Open Access Journals (Sweden)

Schweizer A

2013-12-01

Full Text Available Anja Schweizer,1 Serge Halimi,2,3 Sylvie Dejager4 1Novartis Pharma AG, Basel, Switzerland; 2Department of Diabetology, Endocrinology and Nutrition, University Hospital of Grenoble, France; 3Joseph Fourier University, Grenoble, France; 4Novartis Pharma SAS, Rueil-Malmaison, France Abstract: A large proportion of Muslim patients with type 2 diabetes mellitus (T2DM elect to fast during the holy month of Ramadan. For these patients hypo- and hyperglycemia constitute two major complications associated with the profound changes in food pattern during the Ramadan fast, and efficacious treatment options with a low risk of hypoglycemia are therefore needed to manage their T2DM as effectively and safely as possible. Dipeptidyl peptidase-4 (DPP-4 inhibitors modulate insulin and glucagon secretion in a glucose-dependent manner, and consequently a low propensity of hypoglycemia has consistently been reported across different patient populations with these agents. Promising data with DPP-4 inhibitors have now also started to emerge in patients with T2DM fasting during Ramadan. The objective of this review is to provide a comprehensive overview of the currently available evidence and potential role of DPP-4 inhibitors in the management of patients with T2DM fasting during Ramadan whose diabetes is treated with oral antidiabetic drugs, and to discuss the mechanistic basis for their beneficial effects in this setting. Keywords: dipeptidyl peptidase-4, incretin, type 2 diabetes mellitus, hypoglycemia

Tubal Ligation Reversal

Science.gov (United States)

... seal off the fallopian tubes, such as the Essure or Adiana systems, generally aren't reversible. Why ... electrocautery). Some types of sterilization, such as the Essure or Adiana systems, aren't considered reversible. Risks ...

Inappropriate use of the quasi-reversible electrode kinetic model in simulation-experiment comparisons of voltammetric processes that approach the reversible limit.

Science.gov (United States)

Simonov, Alexandr N; Morris, Graham P; Mashkina, Elena A; Bethwaite, Blair; Gillow, Kathryn; Baker, Ruth E; Gavaghan, David J; Bond, Alan M

2014-08-19

Many electrode processes that approach the "reversible" (infinitely fast) limit under voltammetric conditions have been inappropriately analyzed by comparison of experimental data and theory derived from the "quasi-reversible" model. Simulations based on "reversible" and "quasi-reversible" models have been fitted to an extensive series of a.c. voltammetric experiments undertaken at macrodisk glassy carbon (GC) electrodes for oxidation of ferrocene (Fc(0/+)) in CH3CN (0.10 M (n-Bu)4NPF6) and reduction of [Ru(NH3)6](3+) and [Fe(CN)6](3-) in 1 M KCl aqueous electrolyte. The confidence with which parameters such as standard formal potential (E(0)), heterogeneous electron transfer rate constant at E(0) (k(0)), charge transfer coefficient (α), uncompensated resistance (Ru), and double layer capacitance (CDL) can be reported using the "quasi-reversible" model has been assessed using bootstrapping and parameter sweep (contour plot) techniques. Underparameterization, such as that which occurs when modeling CDL with a potential independent value, results in a less than optimal level of experiment-theory agreement. Overparameterization may improve the agreement but easily results in generation of physically meaningful but incorrect values of the recovered parameters, as is the case with the very fast Fc(0/+) and [Ru(NH3)6](3+/2+) processes. In summary, for fast electrode kinetics approaching the "reversible" limit, it is recommended that the "reversible" model be used for theory-experiment comparisons with only E(0), Ru, and CDL being quantified and a lower limit of k(0) being reported; e.g., k(0) ≥ 9 cm s(-1) for the Fc(0/+) process.

Inappropriate Use of the Quasi-Reversible Electrode Kinetic Model in Simulation-Experiment Comparisons of Voltammetric Processes That Approach the Reversible Limit

KAUST Repository

Simonov, Alexandr N.

2014-08-19

Many electrode processes that approach the "reversible" (infinitely fast) limit under voltammetric conditions have been inappropriately analyzed by comparison of experimental data and theory derived from the "quasi-reversible" model. Simulations based on "reversible" and "quasi-reversible" models have been fitted to an extensive series of a.c. voltammetric experiments undertaken at macrodisk glassy carbon (GC) electrodes for oxidation of ferrocene (Fc0/+) in CH3CN (0.10 M (n-Bu)4NPF6) and reduction of [Ru(NH 3)6]3+ and [Fe(CN)6]3- in 1 M KCl aqueous electrolyte. The confidence with which parameters such as standard formal potential (E0), heterogeneous electron transfer rate constant at E0 (k0), charge transfer coefficient (α), uncompensated resistance (Ru), and double layer capacitance (CDL) can be reported using the "quasi- reversible" model has been assessed using bootstrapping and parameter sweep (contour plot) techniques. Underparameterization, such as that which occurs when modeling CDL with a potential independent value, results in a less than optimal level of experiment-theory agreement. Overparameterization may improve the agreement but easily results in generation of physically meaningful but incorrect values of the recovered parameters, as is the case with the very fast Fc0/+ and [Ru(NH3)6]3+/2+ processes. In summary, for fast electrode kinetics approaching the "reversible" limit, it is recommended that the "reversible" model be used for theory-experiment comparisons with only E0, R u, and CDL being quantified and a lower limit of k 0 being reported; e.g., k0 ≥ 9 cm s-1 for the Fc0/+ process. © 2014 American Chemical Society.

Inappropriate Use of the Quasi-Reversible Electrode Kinetic Model in Simulation-Experiment Comparisons of Voltammetric Processes That Approach the Reversible Limit

KAUST Repository

Simonov, Alexandr N.; Morris, Graham P.; Mashkina, Elena A.; Bethwaite, Blair; Gillow, Kathryn; Baker, Ruth E.; Gavaghan, David J.; Bond, Alan M.

2014-01-01

Many electrode processes that approach the "reversible" (infinitely fast) limit under voltammetric conditions have been inappropriately analyzed by comparison of experimental data and theory derived from the "quasi-reversible" model. Simulations based on "reversible" and "quasi-reversible" models have been fitted to an extensive series of a.c. voltammetric experiments undertaken at macrodisk glassy carbon (GC) electrodes for oxidation of ferrocene (Fc0/+) in CH3CN (0.10 M (n-Bu)4NPF6) and reduction of [Ru(NH 3)6]3+ and [Fe(CN)6]3- in 1 M KCl aqueous electrolyte. The confidence with which parameters such as standard formal potential (E0), heterogeneous electron transfer rate constant at E0 (k0), charge transfer coefficient (α), uncompensated resistance (Ru), and double layer capacitance (CDL) can be reported using the "quasi- reversible" model has been assessed using bootstrapping and parameter sweep (contour plot) techniques. Underparameterization, such as that which occurs when modeling CDL with a potential independent value, results in a less than optimal level of experiment-theory agreement. Overparameterization may improve the agreement but easily results in generation of physically meaningful but incorrect values of the recovered parameters, as is the case with the very fast Fc0/+ and [Ru(NH3)6]3+/2+ processes. In summary, for fast electrode kinetics approaching the "reversible" limit, it is recommended that the "reversible" model be used for theory-experiment comparisons with only E0, R u, and CDL being quantified and a lower limit of k 0 being reported; e.g., k0 ≥ 9 cm s-1 for the Fc0/+ process. © 2014 American Chemical Society.

Evaluation of iron colloid-enhanced T{sub 2}-weighted fast MR imaging of hepatocellular carcinoma. Comparison of SE, TSE and TGSE sequences

Energy Technology Data Exchange (ETDEWEB)

Sugihara, Shuji; Suto, Yuji; Kamba, Masayuki; Yoshida, Kotarou; Ohta, Yoshio [Tottori Univ., Yonago (Japan). Faculty of Medicine

1996-06-01

We have applied chondroitin sulfate iron colloid (CSIC) as a contrast agent for MRI in detecting hepatocellular carcinoma (HCC) on conventional spin-echo sequences (SE). In this report, we evaluated CSIC-enhanced T{sub 2}-weighted fast MR imaging of HCC. MR imaging were performed before and after i.v. administration of CSIC in 15 patients with 46 HCCs. T{sub 2}-weighted SE (1800/80/2, 210 x 256 matrix), T{sub 2}-weighted turbo spin-echo (TSE1800) (1800/90/5, echo train length=7, 252 x 256 matrix), TSE (3500/90/5, echo train length=7, 252 x 256 matrix) (TSE7), TSE (3500/99/5, echo train length=11, 242 x 256 matrix) (TSE11) and T{sub 2}-weighted turbo-gradient spine-echo (TGSE) (4500/108/4, echo train length=33, 252 x 256 matrix) images were compared quantitatively and qualitatively. In all sequences, liver signal-to-noise ratio (SNR) was significantly decreased and lesion-to-liver contrast-to-noise ratio (CNR) was significantly increased after CSIC administration. Although decreased ratio in liver and tumor SNR caused by CSIC was smaller on TSE sequences compared with SE and TGSE, increased ratio in lesion-to-liver CNR was largest on TSE7. Either before or after i.v. administration of CSIC, the number of detectable lesions was largest on TSE7. TSE with used longer TR, TE and decreased echo factor was useful method for CSIC-enhanced abdominal MR imaging. (author)

T cell suppression by naturally occurring HLA-G-expressing regulatory CD4+ T cells is IL-10-dependent and reversible.

Science.gov (United States)

Huang, Yu-Hwa; Zozulya, Alla L; Weidenfeller, Christian; Schwab, Nicholas; Wiendl, Heinz

2009-08-01

CD4(+) T cells constitutively expressing the immune-tolerogenic HLA-G have been described recently as a new type of nT(reg) (HLA-G(pos) T(reg)) in humans. HLA-G(pos) T(reg) accumulate at sites of inflammation and are potent suppressors of T cell proliferation in vitro, suggesting their role in immune regulation. We here characterize the mechanism of how CD4(+) HLA-G(pos) T(reg) influence autologous HLA-G(neg) T(resp) function. Using a suppression system free of APC, we demonstrate a T-T cell interaction, resulting in suppression of HLA-G(neg) T(resp), which is facilitated by TCR engagement on HLA-G(pos) T(reg). Suppression is independent of cell-cell contact and is reversible, as the removal of HLA-G(pos) T(reg) from the established coculture restored the proliferative capability of responder cells. Further, HLA-G(pos) T(reg)-mediated suppression critically depends on the secretion of IL-10 but not TGF-beta.

Expression of the alpha 1, alpha 2, and beta 1 T3-receptor mRNAs in the fasted rat measured using competitive PCR

NARCIS (Netherlands)

Bakker, O.; Razaki, H.; de Jong, J.; Ris-Stalpers, C.; Wiersinga, W. M.

1998-01-01

Fasting is associated with a decrease in the maximal binding capacity of the T3-receptor in different tissues and the responsiveness of some genes to exogenous T3 is not as pronounced as normal. One possible explanation for these observations is a change in the expression of one or all of the

Reversible infantile mitochondrial diseases.

Science.gov (United States)

Boczonadi, Veronika; Bansagi, Boglarka; Horvath, Rita

2015-05-01

Mitochondrial diseases are usually severe and progressive conditions; however, there are rare forms that show remarkable spontaneous recoveries. Two homoplasmic mitochondrial tRNA mutations (m.14674T>C/G in mt-tRNA(Glu)) have been reported to cause severe infantile mitochondrial myopathy in the first months of life. If these patients survive the first year of life by extensive life-sustaining measures they usually recover and develop normally. Another mitochondrial disease due to deficiency of the 5-methylaminomethyl-2-thiouridylate methyltransferase (TRMU) causes severe liver failure in infancy, but similar to the reversible mitochondrial myopathy, within the first year of life these infants may also recover completely. Partial recovery has been noted in some other rare forms of mitochondrial disease due to deficiency of mitochondrial tRNA synthetases and mitochondrial tRNA modifying enzymes. Here we summarize the clinical presentation of these unique reversible mitochondrial diseases and discuss potential molecular mechanisms behind the reversibility. Understanding these mechanisms may provide the key to treatments of potential broader relevance in mitochondrial disease, where for the majority of the patients no effective treatment is currently available.

Effect of Ramadan fasting on anthropometric parameters and food consumption in 276 type 2 diabetic obese women.

Science.gov (United States)

Khaled, Boumédiène Méghit; Belbraouet, Slimane

2009-04-01

To assess the effect of Ramadan fasting on body weight and food consumption in type 2 diabetic obese women. A total of 276 outpatient women receiving oral antidiabetic drugs (OADs) (BMI = 34.63 +/- 3.29 kg/m(2)), aged 49 (+/-6 years), were selected. The study was carried out over three periods - before (T1: prefasting), during (T2: fasting), and after (T3: postfasting) Ramadan - in three towns located in the northwestern region of Algeria. During the course of 3 days, the daily food intake and anthropometric parameters weight, height, waist and hip circumferences, body mass index (BMI), and waist-hip ratio (WHR) were recorded. A one-way repeated measures ANOVA test was used to compare the groups. The main effect of fasting during Ramadan was a significant weight loss (-3.12 kg i.e. 3.70%; P Fasting during the month of Ramadan causes weight loss and decrease in calorie intake, which is correlated with a decrease in meal frequency. However, more foods rich in fat and dietary cholesterol were consumed during this period. The latter could constitute a high risk for diabetics who are fasting, in particular when medication advice and/or health care control are insufficient or ignored.

Reversal of dexamethasone induced insulin resistance in 3T3L1 adipocytes by 3β-taraxerol of Mangifera indica.

Science.gov (United States)

Sangeetha, K N; Shilpa, K; Jyothi Kumari, P; Lakshmi, B S

2013-02-15

The present study investigates the efficacy of Mangifera indica ethyl acetate extract (MIEE) and its bioactive compound, 3β-taraxerol in the reversal of dexamethasone (DEX) induced insulin resistance in 3T3L1 adipocytes. MIEE and 3β-taraxerol were evaluated for their ability to restore impaired glucose uptake and, expression of molecular markers in the insulin signaling pathway induced by DEX in 3T3L1 adipocytes using 2-deoxy-D-[1-(3)H] glucose uptake assay and ELISA. An insulin resistant model has been developed using a glucocorticoid, DEX on 3T3L1 adipocytes. Insulin resistant condition was observed at 24h of DEX induction wherein a maximum degree of resistance of about 50% was measured based on inhibition of glucose uptake, which was confirmed using cytotoxicity analysis. The developed model of insulin resistance was studied in comparison to positive control rosiglitazone. DEX induced inhibition of glucose uptake and the expression of insulin signaling markers GLUT4 and PI3K were found to be restored by 3β-taraxerol and MIEE, thus delineating its mechanism of action in the reversal of insulin resistance. 3β-Taraxerol effectively restored DEX induced desensitization via restoration of PI3K and GLUT4 expression. To conclude, since 3β-taraxerol exhibits significant effect in reversing insulin resistance it can be further investigated as an insulin resistance reversal agent. Copyright © 2012 Elsevier GmbH. All rights reserved.

The effect of reverse triiodothyronine (rT3) treatment on the plasma levels of iodothyronines in growing Japanese quails

International Nuclear Information System (INIS)

Niezgoda, J.; Wronska-Fortuna, D.; Sechman, A.; Bobek, S.; Sowa, J.

1994-01-01

It has been established that 3.3',5-triiodothyronine (T 3 ) acts hipermetabolically, whereas 3'3.5'-triiodothyronine (reverse T 3 , rT 3 ) acts hypometabolically. The normal ratio of T 3 to rT 3 in domestic flows fluctuates around 10. Since the excess of T 3 may promote catabolic processes and lower weight gain, the aim of this experiment was to find the optimal ratio of T 3 :rT 3 in blood plasma which corresponds with the greatest weight gain in Japanese quail. Reverse T 3 was given in drinking water (1 μg rT 3 /ml) for 3, 10, 20 or 30 days. It has been found that T 3 /rT 3 ratio of about 5, after 20 days of rT 3 administration, stimulated the weight gain of Japanese quail of both sexes from 7 to 44% with more pronounced effect in female birds. (author). 26 refs, 4 figs, 1 tab

[Reversion of overweight and obesity in Vilafranca del Penedès child population: ACTIVA'T Program (2012)].

Science.gov (United States)

Bibiloni, Maria Del Mar; Fernández-Blanco, Jordi; Pujol-Plana, Noemí; Surià Sonet, Sònia; Pujol-Puyané, Maria Cèlia; Mercadé Fuentes, Sílvia; Ojer Fernández de Soto, Laura; Tur, Josep A

2017-11-20

To assess a 6-month nutritional and physical activity intervention program on the nutritional status of overweight or obese and not very active 8-14 years old children by means of a controlled pre-post design (ACTIVA'T program). Pre-post study in 8-14 years old overweight or obese and low active children from Vilafranca del Penedès (Barcelona, Spain) randomized in control group (n = 51, 47.1% girls, nutritional intervention and ≤3h/wk physical activity) and ACTIVA'T group (n = 45, 37.8% girls, nutritional and physical activity ≥5h/wk intervention). Body mass index, waist/height index, and diet quality by means of KIDMED test at the beginning and at the end of the program were assessed. During the intervention, each participant was accompanied by a relative (father or mother) who performed the same activities as the children. Dietary recommendations have positively changed the habits of both ACTIVA'T and control group. The reversion in the prevalence of overweight and obesity was 93.8% and 58.6%, respectively, in the ACTIVA'T group, compared to 25.0% and 35.8% in the control group. Abdominal obesity was decreased from 42.2% to 17.8% in the ACTIVA'T group and from 47.1% to 27.5% in the control group. The program ACTIVA'T (nutritional education and physical activity promotion) improves the quality of diet and reverses the prevalence of overweight and obesity in the underactive child population. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Field-reversed configuration translation studies in FRX-C/T

International Nuclear Information System (INIS)

Chrien, R.E.; Armstrong, W.T.; Klingner, P.L.; Linford, R.K.; McKenna, K.F.; Rej, D.J.; Sherwood, E.G.; Siemon, R.E.; Tuszewski, M.

1984-01-01

Field-Reversed Configuration (FRC) translation is being studied in the FRX-C/T device. The main goals of this experiment are to demonstrate translation into a dc field region with minimal losses and to study modification of the equilibrium profiles of the FRC by varying x/sub s/, the ratio of separatrix radius (r/sub s/) to conducting wall radius (r/sub w/), through translation. FRC's are formed with a range of densities (1→5 x 10/sup 15/ cm/sup -3/) and x/sub s/ (0.35→0.55) in the FRX-C source, configured as a slightly conical theta pinch coil (r/sub w/ increases from 0.22 m to 0.28 m in four steps over 2 m). In 10→40 μs after formation, the FRC enters a 0.20-m radius stainless steel vessel with a dc field up to 8 kG. The translation velocity varies from 5→12 cm/μs and is typically about one-half the FRC Alfven velocity

Lower omental t-regulatory cell count is associated with higher fasting glucose and lower β-cell function in adults with obesity.

Science.gov (United States)

Gyllenhammer, Lauren E; Lam, Jonathan; Alderete, Tanya L; Allayee, Hooman; Akbari, Omid; Katkhouda, Namir; Goran, Michael I

2016-06-01

T-lymphocytes are potential initiators and regulators of adipose tissue (AT) inflammation, but there is limited human data on omental AT. The aim of this study was to assess the relationship between T cells, particularly Foxp3+ regulatory T (Treg) cells, in human subcutaneous (subQ) and omental AT and type 2 diabetes risk. SubQ and deep subQ (DsubQ) abdominal and omental AT biopsies were collected from 44 patients (body mass index, BMI ≥25) undergoing elective abdominal surgery. Flow cytometry was used to quantify CD4+ T cell (T effector and Treg) and macrophages (M1 and M2), and systemic inflammation was measured in fasting blood. Tregs were significantly lower in omental versus subQ and DsubQ AT, and M1 cell counts were significantly higher in the omental and DsubQ depot relative to the subQ. Only omental AT Tregs were negatively associated with fasting glucose and MCP-1 and positively associated with homeostasis model assessment (HOMA)-β. M1 and M2 cell counts across multiple depots had significant relationships with HOMA-insulin resistance, tumor necrosis factor-α, insulin, and HOMA-β. All relationships were consistent across ethnicities. Tregs were significantly lower in omental versus both subQ adipose depots. Fewer omental Tregs may have metabolic implications based on depot-specific relationships with higher fasting glucose and lower β-cell function. © 2016 The Obesity Society.

The ability of T2/B4 primers to detect Leishmania infantum among ...

African Journals Online (AJOL)

SERVER

2008-04-03

Apr 3, 2008 ... Reverse Primer (5`-CCT CTC TTT TTT CNC TGT GC-3`). (Schönian et al., 1996),. B. Forward Primer (RV1) (5`-GTG GGG GAG GGG CGT TCT-3`) and Reverse Primer (RV2) (5`-ATT TTA CAC CAA CCC CCA GTT-. 3`) (Lachaud et al., 2002; Reale et al., 1999),. C. Forward Primer (T2) (5`-CGG CTT CGC ...

Can T1 w/T2 w ratio be used as a myelin-specific measure in subcortical structures? Comparisons between FSE-based T1 w/T2 w ratios, GRASE-based T1 w/T2 w ratios and multi-echo GRASE-based myelin water fractions.

Science.gov (United States)

Uddin, Md Nasir; Figley, Teresa D; Marrie, Ruth Ann; Figley, Chase R

2018-03-01

Given the growing popularity of T 1 -weighted/T 2 -weighted (T 1 w/T 2 w) ratio measurements, the objective of the current study was to evaluate the concordance between T 1 w/T 2 w ratios obtained using conventional fast spin echo (FSE) versus combined gradient and spin echo (GRASE) sequences for T 2 w image acquisition, and to compare the resulting T 1 w/T 2 w ratios with histologically validated myelin water fraction (MWF) measurements in several subcortical brain structures. In order to compare these measurements across a relatively wide range of myelin concentrations, whole-brain T 1 w magnetization prepared rapid acquisition gradient echo (MPRAGE), T 2 w FSE and three-dimensional multi-echo GRASE data were acquired from 10 participants with multiple sclerosis at 3 T. Then, after high-dimensional, non-linear warping, region of interest (ROI) analyses were performed to compare T 1 w/T 2 w ratios and MWF estimates (across participants and brain regions) in 11 bilateral white matter (WM) and four bilateral subcortical grey matter (SGM) structures extracted from the JHU_MNI_SS 'Eve' atlas. Although the GRASE sequence systematically underestimated T 1 w/T 2 w values compared to the FSE sequence (revealed by Bland-Altman and mountain plots), linear regressions across participants and ROIs revealed consistently high correlations between the two methods (r 2 = 0.62 for all ROIs, r 2 = 0.62 for WM structures and r 2 = 0.73 for SGM structures). However, correlations between either FSE-based or GRASE-based T 1 w/T 2 w ratios and MWFs were extremely low in WM structures (FSE-based, r 2 = 0.000020; GRASE-based, r 2 = 0.0014), low across all ROIs (FSE-based, r 2 = 0.053; GRASE-based, r 2 = 0.029) and moderate in SGM structures (FSE-based, r 2 = 0.20; GRASE-based, r 2 = 0.17). Overall, our findings indicated a high degree of correlation (but not equivalence) between FSE-based and GRASE-based T 1 w/T 2 w ratios, and low correlations between T 1 w/T 2 w ratios and MWFs. This

The effect of control of diabetes mellitus on plasma T4, T3, rT3 levels and half muscle relaxation period

International Nuclear Information System (INIS)

Ismail, A.A.; Hafiez, A.A.; Sayed, S.N.; Abbas, E.Z.; Halawa, F.A.; Youssef, M.M.

1984-01-01

25 diabetics of the maturity onset type who showed no clinical evidence of either peripheral neruropathy or diabetic amyotrophy were selected for this study. All patients were subjected to the following investigations: estimation of half muscle relaxation period of the quadriceps muscle knee-jerk, measurement of plasma levels of thyroxine (T 4 ), triiodothyronine (T 3 ) and reverse triiodothronine (rT 3 ), determination of fasting and two hours postprandial blood sugar levels. The quadriceps muscle relaxation period in uncontrolled diabetics was significantly longer than in normals. Control of diabetes by glibenclamide or gliclazide did not cause a significant change in muscle relaxation period. There was also no significant difference between the effects of the two drugs. (author)

Assessment of diagnosing metastatic bone tumor on T2*-weighted images. Comparison between turbo spin echo (TSE) method and gradient echo (GE) method

International Nuclear Information System (INIS)

Hayashi, Takahiko; Sugiyama, Akira; Katayama, Motoyuki

1996-01-01

We examined the usefulness of T2 * weighted gradient field echo images for diagnosis for metastatic bone tumors in comparison with T2 weighted turbo spin echo (fast spin echo) images. In T2 * weighted gradient field echo sequence to obtain maximum contrast-to-noise ratio (CNR), we experimentally manipulated flip angle (FA) (5deg-90deg), repetition time (TR) (400, 700 msec), and echo time (TE) (10-50 msec). The best CNR was 16.4 in fast low angle shot (FLASH) (TE: 24 msec, TR: 700 msec, FA: 40deg). Magnetic resonance imaging was carried out in 28 patients with metastatic bone tumors. In addition to conventional T1 weighted spin echo images, T2 weighted turbo spin echo (fast spin echo images) and T2 * weighted gradient field echo images were obtained. T2 * weighted gradient field echo images were superior to T2 weighted turbo spin echo (fast spin echo) images in delineating the tumors, adjacent fat tissues, and bone marrow. (author)

Linewidths in OCS: Isotope effects, vibrational effects, temperature dependence, and T1/T2

International Nuclear Information System (INIS)

Creswell, R.A.; Brown, S.R.; Schwendeman, R.H.

1976-01-01

A computer-controlled microwave spectrometer has been used to record the frequency dependence of the absorption of the J=2reverse arrow1 transition of OCS under varying conditions of pressure, temperature, and microwave power. From least-squares fits of the data to Lorentzian line shapes, a variety of linewidths and linewidth parameters have been deduced. The linewidth parameter for the J=2reverse arrow1 transition of 16 O 12 C 32 S in the ground vibrational state has been determined to be 6.03+-0.05 MHz/torr. The ratios of linewidth parameters for this transition for several other species to that for the ground state of 16 O 12 C 32 S are: 16 O 12 C 34 S, ground state, 0.987+-0.003; 16 O 13 C 32 S, ground state, 0.991+-0.005; 18 O 12 C 32 S, ground state, 0.966+-0.018; 16 O 12 C 32 S, v 3 =1, 1.024+-0.026; 16 O 12 C 32 S, v 2 /subl/=2degree, 0.978+-0.003. The linewidth parameter for the ground state of the parent species was determined to be inversely proportional to the absolute temperature in the range 297--346 K. From comparison of theoretical and experimental power-broadened lineshapes it is shown that T 1 /T 2 =1.04+-0.10 for the transition

3D hybrid profile order technique in a single breath-hold 3D T2-weighted fast spin-echo sequence: Usefulness in diagnosis of small liver lesions.

Science.gov (United States)

Hirata, Kenichiro; Nakaura, Takeshi; Okuaki, Tomoyuki; Tsuda, Noriko; Taguchi, Narumi; Oda, Seitaro; Utsunomiya, Daisuke; Yamashita, Yasuyuki

2018-01-01

We compared the efficacy of three-dimensional (3D) isotropic T2-weighted fast spin-echo imaging using a 3D hybrid profile order technique with a single-breath-hold (3D-Hybrid BH) with a two-dimensional (2D) T2-weighted fast spin-echo conventional respiratory-gated (2D-Conventional RG) technique for visualising small liver lesions. This study was approved by our institutional review board. The requirement to obtain written informed consent was waived. Fifty patients with small (≤15mm) hepatocellular carcinomas (HCC) (n=26), or benign cysts (n=24), had undergone hepatic MRI including both 2D-Conventional RG and 3D-Hybrid BH. We calculated the signal-to-noise ratio (SNR) and tumour-to-liver contrast (TLC). The diagnostic performance of the two protocols was analysed. The image acquisition time was 89% shorter with the 3D-Hybrid BH than with 2D-Conventional RG. There was no significant difference in the SNR between the two protocols. The area under the curve (AUC) of the TLC was significantly higher on 3D-Hybrid BH than on 2D-Conventional RG. The 3D-Hybrid BH sequence significantly improved diagnostic performance for small liver lesions with a shorter image acquisition time without sacrificing accuracy. Copyright © 2017. Published by Elsevier B.V.

Impaired Fasting Glucose in Omani Adults with no Family History of Type 2 Diabetes

Directory of Open Access Journals (Sweden)

Sawsan Al-Sinani

2014-05-01

Full Text Available Objectives: The aim of this study was to estimate the prevalence of impaired fasting glucose (IFG among Omani adults with no family history (FH of diabetes and to investigate the factors behind the risk of developing type 2 diabetes (T2D, while excluding a FH of diabetes. Methods: A total of 1,182 Omani adults, aged ≥40 years, visited the Family Medicine & Community Health Clinic at Sultan Qaboos University Hospital, Oman, on days other than the Diabetes Clinic days, from July 2010 to July 2011. The subjects were interviewed and asked if they had T2D or a FH of T2D. Results: Only 191 (16% reported no personal history of T2D or FH of the disease. Of these, anthropometric and biochemical data was complete in 159 subjects. Of these a total of 42 (26% had IFG according to the American Diabetes Association criteria. Body mass index, fasting insulin, haemoglobin A1C and blood pressure (BP, were significantly higher among individuals with IFG (P <0.01, P <0.05, P <0.01 and P <0.01, respectively. In addition, fasting insulin, BP and serum lipid profile were correlated with obesity indices (P <0.05. Obesity indices were strongly associated with the risk of IFG among Omanis, with waist circumference being the strongest predictor. Conclusion: Despite claiming no FH of diabetes, a large number of Omani adults in this study had a high risk of developing diabetes. This is possibly due to environmental factors and endogamy. The high prevalence of obesity combined with genetically susceptible individuals is a warning that diabetes could be a future epidemic in Oman.

Energy efficient and fast reversal of a fixed skyrmion two-terminal memory with spin current assisted by voltage controlled magnetic anisotropy

Science.gov (United States)

Bhattacharya, Dhritiman; Mamun Al-Rashid, Md; Atulasimha, Jayasimha

2017-10-01

Recent work (P-H Jang et al 2015 Appl. Phys. Lett. 107 202401, J. Sampaio et al 2016 Appl. Phys. Lett. 108 112403) suggests that ferromagnetic reversal with spin transfer torque (STT) requires more current in a system in the presence of Dzyaloshinskii-Moriya interaction (DMI) than switching a typical ferromagnet of the same dimensions and perpendicular magnetic anisotropy (PMA). However, DMI promotes the stabilization of skyrmions and we report that when perpendicular anisotropy is modulated (reduced) for both the skyrmion and ferromagnet, it takes a much smaller current to reverse the fixed skyrmion than to reverse the ferromagnet in the same amount of time, or the skyrmion reverses much faster than the ferromagnet at similar levels of current. We show with rigorous micromagnetic simulations that skyrmion switching proceeds along a different path at very low PMA, which results in a significant reduction in the spin current or time required for reversal. This can offer potential for memory applications where a relatively simple modification of the standard STT-RAM (to include a heavy metal adjacent to the soft magnetic layer and with appropriate design of the tunnel barrier) can lead to an energy efficient and fast magnetic memory device based on the reversal of fixed skyrmions.

Heat transport modelling in EXTRAP T2R

Science.gov (United States)

Frassinetti, L.; Brunsell, P. R.; Cecconello, M.; Drake, J. R.

2009-02-01

A model to estimate the heat transport in the EXTRAP T2R reversed field pinch (RFP) is described. The model, based on experimental and theoretical results, divides the RFP electron heat diffusivity χe into three regions, one in the plasma core, where χe is assumed to be determined by the tearing modes, one located around the reversal radius, where χe is assumed not dependent on the magnetic fluctuations and one in the extreme edge, where high χe is assumed. The absolute values of the core and of the reversal χe are determined by simulating the electron temperature and the soft x-ray and by comparing the simulated signals with the experimental ones. The model is used to estimate the heat diffusivity and the energy confinement time during the flat top of standard plasmas, of deep F plasmas and of plasmas obtained with the intelligent shell.

Reverse Osmosis

Indian Academy of Sciences (India)

many applications, one of which is desalination of seawater. The inaugural Nobel Prize in Chemistry was awarded in 1901 to van 't Hoff for his seminal work in this area. The present article explains the principle of osmosis and reverse osmosis. Osmosis and Reverse Osmosis. As the name suggests, reverse osmosis is the ...

The connection domain in reverse transcriptase facilitates the in vivo annealing of tRNALys3 to HIV-1 genomic RNA

Directory of Open Access Journals (Sweden)

Niu Meijuan

2004-10-01

Full Text Available Abstract The primer tRNA for reverse transcription in HIV-1, tRNALys3, is selectively packaged into the virus during its assembly, and annealed to the viral genomic RNA. The ribonucleoprotein complex that is involved in the packaging and annealing of tRNALys into HIV-1 consists of Gag, GagPol, tRNALys, lysyl-tRNA synthetase (LysRS, and viral genomic RNA. Gag targets tRNALys for viral packaging through Gag's interaction with LysRS, a tRNALys-binding protein, while reverse transcriptase (RT sequences within GagPol (the thumb domain bind to tRNALys. The further annealing of tRNALys3 to viral RNA requires nucleocapsid (NC sequences in Gag, but not the NC sequences GagPol. In this report, we further show that while the RT connection domain in GagPol is not required for tRNALys3 packaging into the virus, it is required for tRNALys3 annealing to the viral RNA genome.

Fast wave current drive in neutral beam heated plasmas on DIII-D

International Nuclear Information System (INIS)

Petty, C.C.; Forest, C.B.; Pinsker, R.I.

1997-04-01

The physics of non-inductive current drive and current profile control using the fast magnetosonic wave has been demonstrated on the DIII-D tokamak. In non-sawtoothing discharges formed by neutral beam injection (NBI), the radial profile of the fast wave current drive (FWCD) was determined by the response of the loop voltage profile to co, counter, and symmetric antenna phasings, and was found to be in good agreement with theoretical models. The application of counter FWCD increased the magnetic shear reversal of the plasma and delayed the onset of sawteeth, compared to co FWCD. The partial absorption of fast waves by energetic beam ions at high harmonics of the ion cyclotron frequency was also evident from a build up of fast particle pressure near the magnetic axis and a correlated increase in the neutron rate. The anomalous fast particle pressure and neutron rate increased with increasing NBI power and peaked when a harmonic of the deuterium cyclotron frequency passed through the center of the plasma. The experimental FWCD efficiency was highest at 2 T where the interaction between the fast waves and the beam ions was weakest; as the magnetic field strength was lowered, the FWCD efficiency decreased to approximately half of the maximum theoretical value

Time-resolved VUV spectroscopy in the EXTRAP-T2 reversed field pinch

International Nuclear Information System (INIS)

Hedqvist, A.; Rachlew-Kaellne, E.

1998-01-01

Time-resolved VUV spectroscopy has been used to investigate the effects of impurities in a reversed field pinch operating with a resistive shell. Results of electron temperature, impurity ion densities, particle confinement time and Z eff together with a description of the interpretation and the equipment are presented. (author)

Time-resolved VUV spectroscopy in the EXTRAP-T2 reversed field pinch

Science.gov (United States)

Hedqvist, Anders; Rachlew-Källne, Elisabeth

1998-09-01

Time-resolved VUV spectroscopy has been used to investigate the effects of impurities in a reversed field pinch operating with a resistive shell. Results of electron temperature, impurity ion densities, particle confinement time and 0741-3335/40/9/004/img1 together with a description of the interpretation and the equipment are presented.

Fast T2 gradient-spin-echo (T2-GraSE) mapping for myocardial edema quantification: first in vivo validation in a porcine model of ischemia/reperfusion

OpenAIRE

Fern?ndez-Jim?nez, Rodrigo; S?nchez-Gonz?lez, Javier; Aguero, Jaume; del Trigo, Mar?a; Gal?n-Arriola, Carlos; Fuster, Valentin; Ib??ez, Borja

2015-01-01

Background Several T2-mapping sequences have been recently proposed to quantify myocardial edema by providing T2 relaxation time values. However, no T2-mapping sequence has ever been validated against actual myocardial water content for edema detection. In addition, these T2-mapping sequences are either time-consuming or require specialized software for data acquisition and/or post-processing, factors impeding their routine clinical use. Our objective was to obtain in vivo validation of a seq...

Simultaneous acquisition for T2 -T2 Exchange and T1 -T2 correlation NMR experiments

Science.gov (United States)

Montrazi, Elton T.; Lucas-Oliveira, Everton; Araujo-Ferreira, Arthur G.; Barsi-Andreeta, Mariane; Bonagamba, Tito J.

2018-04-01

The NMR measurements of longitudinal and transverse relaxation times and its multidimensional correlations provide useful information about molecular dynamics. However, these experiments are very time-consuming, and many researchers proposed faster experiments to reduce this issue. This paper presents a new way to simultaneously perform T2 -T2 Exchange and T1 -T2 correlation experiments by taking the advantage of the storage time and the two steps phase cycling used for running the relaxation exchange experiment. The data corresponding to each step is either summed or subtracted to produce the T2 -T2 and T1 -T2 data, enhancing the information obtained while maintaining the experiment duration. Comparing the results from this technique with traditional NMR experiments it was possible to validate the method.

Contrast-enhanced fast fluid-attenuated inversion recovery MR imaging in patients with brain tumors

International Nuclear Information System (INIS)

Kim, Chan Kyo; Na, Dong Gyu; Ryoo, Wook Jae; Byun Hong Sik; Yoon, Hye Kyung; Kim, Jong hyun

2000-01-01

To assess the feasibility of contrast-enhanced fast fluid-attenuated inversion recovery (fast FLAIR) MR imaging in patients with brain tumors. This study involved 31 patients with pathologically proven brain tumors and nine with clinically diagnosed metastases. In all patients, T2-weighted, fast FLAIR, images were visual contrast-enhanced T1-weighted MR images were obtained. Contrast-enhanced fast FLAIR images were visually compared with other MR sequences in terms of tumor conspicuity. In order to distinguish tumor and surrounding edema, contrast-enhanced fast FLAIR images were compared with fast FLAIR and T2-weighted images. The tumor-to- white matter contrast-to-noise ratios (CNRs), as demonstrated by T2-weighted, fast FLAIR, contrast-enhanced fast FLAIR and contrast-enhanced T1-weighted imaging, were quantitatively assessed and compared. For the visual assessment of tumor conspicuity, contrast-enhanced fast FLAIR image imaging superior to fast FLAIR in 60% of cases (24/40), and superior to T2-weighted in 70% (28/40). Contrast-enhanced fast FLAIR imaging was inferior to contrast-enhanced T1-weighted in 58% of cases (23/40). For distinguishing between tumor and surrounding edema, contrast-enhanced fast FLAIR imaging was superior to fast FLAIR or T2-weighted in 22 of 27 tumors with peritumoral edema (81%). Quantitatively, CNR was the highest on contrast-enhanced fast FLAIR image and the lowest on fast FLAIR. For the detection of leptomeningeal metastases, contrast-enhanced fast FLAIR was partially superior to contrast-enhanced T1-weighted imaging in two of three high-grade gliomas. Although contrast-enhanced fast FLAIR imaging should not be seen as a replacement for conventional modalities, it provides additional informaton for assessment of the extent of glial cell tumors and leptomeningeal metastases in patients with brain tumors. (author)

Error field assessment from driven rotation of stable external kinks at EXTRAP-T2R reversed field pinch

Science.gov (United States)

Volpe, F. A.; Frassinetti, L.; Brunsell, P. R.; Drake, J. R.; Olofsson, K. E. J.

2013-04-01

A new non-disruptive error field (EF) assessment technique not restricted to low density and thus low beta was demonstrated at the EXTRAP-T2R reversed field pinch. Stable and marginally stable external kink modes of toroidal mode number n = 10 and n = 8, respectively, were generated, and their rotation sustained, by means of rotating magnetic perturbations of the same n. Due to finite EFs, and in spite of the applied perturbations rotating uniformly and having constant amplitude, the kink modes were observed to rotate non-uniformly and be modulated in amplitude. This behaviour was used to precisely infer the amplitude and approximately estimate the toroidal phase of the EF. A subsequent scan permitted to optimize the toroidal phase. The technique was tested against deliberately applied as well as intrinsic EFs of n = 8 and 10. Corrections equal and opposite to the estimated error fields were applied. The efficacy of the error compensation was indicated by the increased discharge duration and more uniform mode rotation in response to a uniformly rotating perturbation. The results are in good agreement with theory, and the extension to lower n, to tearing modes and to tokamaks, including ITER, is discussed.

Ageing, fragility and the reversibility window in bulk alloy glasses

International Nuclear Information System (INIS)

Chakravarty, S; Georgiev, D G; Boolchand, P; Micoulaut, M

2005-01-01

Non-reversing relaxation enthalpies (ΔH nr ) at glass transitions T g (x) in the P x Ge x Se 1-2x ternary display wide, sharp and deep global minima (∼0) in the 0.09 g s become thermally reversing. In this reversibility window, glasses are found not to age, in contrast to ageing observed for fragile glass compositions outside the window. Thermal reversibility and lack of ageing seem to be paradigms of self-organization which molecular glasses share with protein structures which repetitively and reversibly change conformation near T g and the folding temperature respectively. (letter to the editor)

Prolonged food deprivation increases mRNA expression of deiodinase 1 and 2, and thyroid hormone receptor β-1 in a fasting-adapted mammal.

Science.gov (United States)

Martinez, Bridget; Soñanez-Organis, José G; Vázquez-Medina, José Pablo; Viscarra, Jose A; MacKenzie, Duncan S; Crocker, Daniel E; Ortiz, Rudy M

2013-12-15

Food deprivation in mammals is typically associated with reduced thyroid hormone (TH) concentrations and deiodinase content and activity to suppress metabolism. However, in prolonged-fasted, metabolically active elephant seal pups, TH levels are maintained, if not elevated. The functional relevance of this apparent paradox is unknown and demonstrates variability in the regulation of TH levels, metabolism and function in food-deprived mammals. To address our hypothesis that cellular TH-mediated activity is upregulated with fasting duration, we quantified the mRNA expression and protein content of adipose and muscle deiodinase type I (DI1) and type II (DI2), and TH receptor beta-1 (THrβ-1) after 1, 3 and 7 weeks of fasting in northern elephant seal pups (N=5-7 per week). Fasting did not decrease the concentrations of plasma thyroid stimulating hormone, total triiodothyronine (tT3), free T3, total thyroxine (tT4) or free T4, suggesting that the hypothalamic-pituitary-thyroid axis is not suppressed, but rather maintained during fasting. Mean mRNA expression of adipose DI1 and DI2 increased threefold and fourfold, respectively, and 20- and 30-fold, respectively, in muscle. With the exception of adipose DI1, protein expression of adipose DI2 and muscle DI1 and DI2 increased twofold to fourfold. Fasting also increased adipose (fivefold) and muscle (fourfold) THrβ-1 mRNA expression, suggesting that the mechanisms mediating cellular TH activity are upregulated with prolonged fasting. The data demonstrate a unique, atypical mechanism of TH activity and regulation in mammals adapted to prolonged food deprivation in which the potential responsiveness of peripheral tissues and cellular TH activity are increased, which may contribute to their lipid-based metabolism.

L0 Confirmation with fast, Tsa based tracking in the T-stations

CERN Document Server

Albrecht, J; Terrier, H

2007-01-01

A fast tracking algorithm to confirm the high $p_T$ L0 trigger objects with tracks from the T-stations is presented. The L0 trigger candidate is used to define a search window to a potential track. Using this, a seeded track search is performed. The track finding algorithm is based on the \\textit{TsaSeeding} algorithm~\\cite{bib:Tsa}. The efficiency to confirm a true L0 trigger signal is around 96\\%, the momentum can be measured up to $\\Delta p/p$=3\\%.

Human immunodeficiency virus uses tRNA(Lys,3) as primer for reverse transcription in HeLa-CD4+ cells

NARCIS (Netherlands)

Das, A. T.; Koken, S. E.; Essink, B. B.; van Wamel, J. L.; Berkhout, B.

1994-01-01

Significant amounts of different tRNA molecules are present in retroviral particles, but one specific tRNA species functions as primer in reverse transcription. It is generally believed that the HIV-1 virus uses the tRNA(Lys,3) molecule as primer. This is based on sequence complementarity between

Effects of intermittent fasting on health markers in those with type 2 diabetes: A pilot study.

Science.gov (United States)

Arnason, Terra G; Bowen, Matthew W; Mansell, Kerry D

2017-04-15

To determine the short-term biochemical effects and clinical tolerability of intermittent fasting (IF) in adults with type 2 diabetes mellitus (T2DM). We describe a three-phase observational study (baseline 2 wk, intervention 2 wk, follow-up 2 wk) designed to determine the clinical, biochemical, and tolerability of IF in community-dwelling volunteer adults with T2DM. Biochemical, anthropometric, and physical activity measurements (using the Yale Physical Activity Survey) were taken at the end of each phase. Participants reported morning, afternoon and evening self-monitored blood glucose (SMBG) and fasting duration on a daily basis throughout all study stages, in addition to completing a remote food photography diary three times within each study phase. Fasting blood samples were collected on the final days of each study phase. At baseline, the ten participants had a confirmed diagnosis of T2DM and were all taking metformin, and on average were obese [mean body mass index (BMI) 36.90 kg/m 2 ]. We report here that a short-term period of IF in a small group of individuals with T2DM led to significant group decreases in weight (-1.395 kg, P = 0.009), BMI (-0.517, P = 0.013), and at-target morning glucose (SMBG). Although not a study requirement, all participants preferentially chose eating hours starting in the midafternoon. There was a significant increase ( P 0.1). Postprandial SMBGs were also improved during the IF phase, with 60.5% readings below 9.05 mmol/L, compared to 52.6% at baseline, and with less glucose variation. Neither insulin resistance (HOMA-IR), nor inflammatory markers (C-reactive protein) normalized during the IF phase. IF led to an overall spontaneous decrease in caloric intake as measured by food photography (Remote Food Photography Method). The data demonstrated discernable trends during IF for lower energy, carbohydrate, and fat intake when compared to baseline. Physical activity, collected by a standardized measurement tool (Yale Physical

Effects of A One-week Fasting Therapy in Patients with Type-2 Diabetes Mellitus and Metabolic Syndrome - A Randomized Controlled Explorative Study.

Science.gov (United States)

Li, Chenying; Sadraie, Badri; Steckhan, Nico; Kessler, Christian; Stange, Rainer; Jeitler, Michael; Michalsen, Andreas

2017-10-01

There is increasing experimental evidence for beneficial effects of calorie restriction and intermittent fasting in type 2 diabetes mellitus (T2DM). In humans, prolonged fasting is established as a health-promoting complementary treatment in Europe and claimed to improve metabolism by a complex hormetic response. We aimed to investigate effects of a one-week fasting period compared to usual care in T2DM by means of a pilot trial. Patients with manifest T2DM medically treated with oral hypoglycemic agents and/or insulin were randomly assigned to a 7-day fasting program followed by dietary advice or to usual care and dietary advice only. Fasting was performed according to the method of Buchinger with a nutritional energy intake of 300kcal/day by liquids only and stepwise re-introduction of solid food thereafter. Outcomes were assessed baseline and after 4 months. Of 46 enrolled participants, 32 (n=16 each group) completed the trial and were included for final analyses. Fasting was well accepted, there were no serious adverse events. After 4 months mean weight decreased by 3.5 kg and 2.0 kg in the fasting vs. control group (p=0.03) paralleled by greater reduction of abdominal circumference (p=0.001). Fasting led to a significant decrease of systolic/diastolic blood pressure (p=0.01; p=0.003) and increased quality-of-life (p=0.04), while for HbA 1c , insulin and HOMA-index only non-significant improvements were observed. Results of this study suggest that prolonged fasting is feasible and might have beneficial clinical effects. The effectiveness of fasting should be proved in larger confirmatory trials that include intermittent fasting in follow-ups to enable more pronounced and long-term effects. © Georg Thieme Verlag KG Stuttgart · New York.

Study of the fast inversion recovery pulse sequence. With reference to fast fluid attenuated inversion recovery and fast short TI inversion recovery pulse sequence

International Nuclear Information System (INIS)

Tsuchihashi, Toshio; Maki, Toshio; Suzuki, Takeshi

1997-01-01

The fast inversion recovery (fast IR) pulse sequence was evaluated. We compared the fast fluid attenuated inversion recovery (fast FLAIR) pulse sequence in which inversion time (TI) was established as equal to the water null point for the purpose of the water-suppressed T 2 -weighted image, with the fast short TI inversion recovery (fast STIR) pulse sequence in which TI was established as equal to the fat null point for purpose of fat suppression. In the fast FLAIR pulse sequence, the water null point was increased by making TR longer. In the FLAIR pulse sequence, the longitudinal magnetization contrast is determined by TI. If TI is increased, T 2 -weighted contrast improves in the same way as increasing TR for the SE pulse sequence. Therefore, images should be taken with long TR and long TI, which are longer than TR and longer than the water null point. On the other hand, the fat null point is not affected by TR in the fast STIR pulse sequence. However, effective TE was affected by variation of the null point. This increased in proportion to the increase in effective TE. Our evaluation indicated that the fast STIR pulse sequence can control the extensive signals from fat in a short time. (author)

Safety of Sodium-Glucose Co-Transporter 2 Inhibitors during Ramadan Fasting: Evidence, Perceptions and Guidelines

Directory of Open Access Journals (Sweden)

Salem A. Beshyah

2016-06-01

Full Text Available Sodium-glucose co-transporter 2 (SGLT2 inhibitors are a new glucose-lowering therapy for T2DM with documented benefits on blood glucose, hypertension, weight reduction and long term cardiovascular benefit. They have an inherent osmotic diuretic effect and lead to some volume loss and possible dehydration. There is some concern about the safety of using SGLT2 inhibitors in Muslim type 2 diabetes mellitus (T2DM patients during the fast during Ramadan. Currently, there is a dearth of research data to help guide physicians and reassure patients.  One study confirmed good glycemic control with less risk of hypoglycemia and no marked volume depletion. Data in the elderly and in combination with diuretics are reassuring of their safe to use in Ramadan in general. SGLT2 inhibitor-related diabetic ketoacidosis has not been reported during Ramadan and is unlikely to be relevant. Survey of physicians revealed that the majority felt that SGLT2 inhibitors are generally safe in T2DM patients during Ramadan fasting but should be discontinued in certain high risk patients. Some professional groups with interest in diabetes and Ramadan fasting included SGLT2 inhibitors in their guidelines on management of diabetes during Ramadan. They acknowledged the lack of trial data, recommended caution in high risk groups, advised regular monitoring and emphasized pre-Ramadan patients’ education. In conclusion, currently, knowledge, data and experience with SGLT2 inhibitors in Ramadan are limited. Nonetheless, stable patients with normal kidney function and low risk of dehydration may safely use the SGLT2 inhibitors therapy. Higher risk patients should be observed carefully and managed on individual basis.

Volumetric fat-water separated T2-weighted MRI

International Nuclear Information System (INIS)

Vasanawala, Shreyas S.; Sonik, Arvind; Madhuranthakam, Ananth J.; Venkatesan, Ramesh; Lai, Peng; Brau, Anja C.S.

2011-01-01

Pediatric body MRI exams often cover multiple body parts, making the development of broadly applicable protocols and obtaining uniform fat suppression a challenge. Volumetric T2 imaging with Dixon-type fat-water separation might address this challenge, but it is a lengthy process. We develop and evaluate a faster two-echo approach to volumetric T2 imaging with fat-water separation. A volumetric spin-echo sequence was modified to include a second shifted echo so two image sets are acquired. A region-growing reconstruction approach was developed to decompose separate water and fat images. Twenty-six children were recruited with IRB approval and informed consent. Fat-suppression quality was graded by two pediatric radiologists and compared against conventional fat-suppressed fast spin-echo T2-W images. Additionally, the value of in- and opposed-phase images was evaluated. Fat suppression on volumetric images had high quality in 96% of cases (95% confidence interval of 80-100%) and were preferred over or considered equivalent to conventional two-dimensional fat-suppressed FSE T2 imaging in 96% of cases (95% confidence interval of 78-100%). In- and opposed-phase images had definite value in 12% of cases. Volumetric fat-water separated T2-weighted MRI is feasible and is likely to yield improved fat suppression over conventional fat-suppressed T2-weighted imaging. (orig.)

Fat-suppressed fast spin-echo mid-TE (TE[effective]=34) MR images: comparison with fast spin-echo T2-weighted images for the diagnosis of tears and anatomic variants of the glenoid labrum

Energy Technology Data Exchange (ETDEWEB)

Tuite, M J [Dept. of Radiology, Univ. of Wisconsin School of Medicine, Madison (United States); University of Wisconsin Hospital and Clinics, Dept. of Radiology, Madison, WI (United States); Shinners, T J; Hollister, M C [Dept. of Radiology, Univ. of Wisconsin School of Medicine, Madison (United States); Orwin, J F [Dept. of Orthopedic Surgery, University of Wisconsin School of Medicine, Madison (United States)

1999-12-01

Objective. To compare the sensitivity, specificity, and accuracy of fat-suppressed fast spin-echo (FSE) mid-TE (TE[effective]=34) images with fat-suppressed FSE T2-weighted images for the diagnosis of labral abnormalities.Design and patients. The study included 27 consecutive patients who had axial fat-suppressed FSE T2-weighted and fat-suppressed FSE mid-TE MR images, and had labral abnormalities diagnosed at arthroscopy. The acquisition time was about 5 min for each sequence, but the mid-TE sequence allowed a higher spatial resolution than the T2-weighted images (256 x 256 versus 256 x 192). Twenty-eight age-matched patients with arthroscopically normal labra were included as a control group. The labrum was graded on the MR images as normal or abnormal separately by two musculoskeletal radiologists who were masked to the history and arthroscopic results. The surgical findings were used as the gold standard for calculating the sensitivity, specificity, and accuracy for interpreting the correct location of a labral abnormality. The sensitivity, specificity, and accuracy for the two sequences were compared with a McNemar test, and significance defined as P<0.05.Results. For observer 1, the sensitivity for labral abnormalities was 0.59 on the T2-weighted images, and 0.78 on the mid-TE images (P=0.12). The specificity was 0.54 for the T2-weighted, and 0.64 for the mid-TE images (P=0.51). The accuracy was 0.56 for the T2-weighted, and 0.71 for the mid-TE images (P=0.08). For observer 2, the sensitivity/specificity/accuracy was 0.67/0.93/0.80 for the T2-weighted, and 0.70/0.86/0.78 for the mid-TE images (all P>0.5).Conclusion. In this small study there is no statistically significant difference for demonstrating labral abnormalities between FSE T2-weighted images, and higher-resolution fat-suppressed FSE mid-TE (TE[effective]=34) images obtained with a similar acquisition time. Although there was a general trend toward higher sensitivity and accuracy with the mid

Selection of TI for Suppression Fat Tissue of SPAIR and Comparative Study of SPAIR and STIR of Brain Fast SE T2 Weighted Imaging

International Nuclear Information System (INIS)

Lee, Hoo Min; Kim, Ham Gyum; Kong, Seok Kyo

2009-01-01

The purpose of this research is to seek SPAIR's reversal time (TI) which satisfies two conditions ; maintaining the suppression ability of fat tissue and simultaneously minimizing the inhomogeneity of fat tissue in T2 high-speed spin echo 3.0T magnetic resonance image (MRI) of the brain, and to compare SPAIR with STIR which is fat-suppression technique. The reversal times (TI) of SPAIR protocol are set to 1/2, 1/3, 1/6 and 1/12 of SPAIR TR (420 msec), namely 210 msec (8 people), 140 msec (26 people), 70 msec (26 people) and 35 msec (18 people) and STIR TI is set with 250 msec (26 people). With these parameter sets, we acquired the axis direction 104 images of the brain. In ROI (50 mm 2 ) of output image, signal intensities of the fatty tissue, the muscular tissue, and the background were measured and the CNRs of fatty tissue and the muscular tissue were calculated. The inhomogeneity of the fatty tissue is SD/mean, where SD is the standard deviation and 'mean' is a average fatty tissue signal. Consequently, SPAIR TI is determined on either 1/3 or 1/6 of TR (420 ms) ; 140 ms or 70 ms. Because the difference of statistics in fat-suppression ability and inhomogeneity of fatty tissue is very small (p < 0.001), Selecting 140 ms seems to be better choice for the image quality. Meanwhile, Comparing SPAIR (TI : 140 ms) with STIR, the fat-suppression is not able to be considered statistically (p < 0.252), but the image quality is able to be considered statistically (p < 0.01). In conclusion, SPAIR is better than STIR in the image quality.

Comparing an accelerated 3D fast spin-echo sequence (CS-SPACE) for knee 3-T magnetic resonance imaging with traditional 3D fast spin-echo (SPACE) and routine 2D sequences

Energy Technology Data Exchange (ETDEWEB)

Altahawi, Faysal F.; Blount, Kevin J.; Omar, Imran M. [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Morley, Nicholas P. [Marshfield Clinic, Department of Radiology, Marshfield, WI (United States); Raithel, Esther [Siemens Healthcare GmbH, Erlangen (Germany)

2017-01-15

To compare a faster, new, high-resolution accelerated 3D-fast-spin-echo (3D-FSE) acquisition sequence (CS-SPACE) to traditional 2D and high-resolution 3D sequences for knee 3-T magnetic resonance imaging (MRI). Twenty patients received knee MRIs that included routine 2D (T1, PD ± FS, T2-FS; 0.5 x 0.5 x 3 mm{sup 3}; ∝10 min), traditional 3D FSE (SPACE-PD-FS; 0.5 x 0.5 x 0.5 mm{sup 3}; ∝7.5 min), and accelerated 3D-FSE prototype (CS-SPACE-PD-FS; 0.5 x 0.5 x 0.5 mm{sup 3}; ∝5 min) acquisitions on a 3-T MRI system (Siemens MAGNETOM Skyra). Three musculoskeletal radiologists (MSKRs) prospectively and independently reviewed the studies with graded surveys comparing image and diagnostic quality. Tissue-specific signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were also compared. MSKR-perceived diagnostic quality of cartilage was significantly higher for CS-SPACE than for SPACE and 2D sequences (p < 0.001). Assessment of diagnostic quality of menisci and synovial fluid was higher for CS-SPACE than for SPACE (p < 0.001). CS-SPACE was not significantly different from SPACE but had lower assessments than 2D sequences for evaluation of bones, ligaments, muscles, and fat (p ≤ 0.004). 3D sequences had higher spatial resolution, but lower overall assessed contrast (p < 0.001). Overall image quality from CS-SPACE was assessed as higher than SPACE (p = 0.007), but lower than 2D sequences (p < 0.001). Compared to SPACE, CS-SPACE had higher fluid SNR and CNR against all other tissues (all p < 0.001). The CS-SPACE prototype allows for faster isotropic acquisitions of knee MRIs over currently used protocols. High fluid-to-cartilage CNR and higher spatial resolution over routine 2D sequences may present a valuable role for CS-SPACE in the evaluation of cartilage and menisci. (orig.)

Fast CSF MRI for brain segmentation; Cross-validation by comparison with 3D T1-based brain segmentation methods

NARCIS (Netherlands)

van der Kleij, Lisa A; de Bresser, Jeroen; Hendrikse, Jeroen; Siero, Jeroen C W; Petersen, Esben T; De Vis, Jill B

2018-01-01

OBJECTIVE: In previous work we have developed a fast sequence that focusses on cerebrospinal fluid (CSF) based on the long T2 of CSF. By processing the data obtained with this CSF MRI sequence, brain parenchymal volume (BPV) and intracranial volume (ICV) can be automatically obtained. The aim of

Utility of single shot fast spin echo technique in evaluating pancreaticobiliary diseases: T2-weighted image and magnetic resonance cholangiopancreatography

International Nuclear Information System (INIS)

Choi, Byoung Wook; Kim, Myeong Jin; Chung, Jae Bok; Ko, Heung Kyu; Kim, Dong Joon; Kim, Joo Hee; Chung, Jae Joon; Yoo, Hyung Sik; Lee, Jong Tae

1999-01-01

To evaluate the accuracy of T2-weighted imaging an MR cholangiopancreatography using the single shot fast spin-echo technique for evaluating pancreaticobiliary disease. Between March and July 1997, axial and coronal T2-weighted images(TE: 80-200 msec) and MR cholangiopancreatograms (TE: 800-1200 msec) were obtained in two ways [single slab (thickness: 30-50 mm) and multislice acquisition under chemical fat saturation] using SSFSE pulse sequencing in 131 cases of suspected pancreati-cobiliary disease. The accuracy of SSFSE MR imaging was assessed in 89 lesions of 74 patients [male, 48; female, 26; age range, 30-86 (mean, 59) years] confirmed surgicopathologically (50 lesions in 39 patients) and clinically (39 lesions in 35 patients). Two radiologists reviewed the MR images and diagnosis was determined by consensus. Correct diagnosis was confirmed in 84 of 89 lesions (94%). Seven lesions were falsely interpreted, false positive and false negative results accounting for two and five cases, respectively. Two pancreatic cancers were misdiagnosed as pancreatitis and a cancer of the proximal common bile duct(CBD) was interpreted as a distal CBD cancer. The sensitivity of SSFSE MR imaging for malignancy was 93 %. One CBD stone revealed by endoscopic retrograde cholangiopancreatography (ERCP) was not detected on MR images. In contrast, a stone in the CBD seen on MR images was not apparent on subsequent ERCP. Sensitivity and specificity for calculous disease were 96% and 99.7%, respectively. A benign stricture of the ampulla of Vater was falsely interpreted as normal, and correct diagnosis was possible in two falsely diagnosed cases when MR images were reviewed retrospectively. The combination of T2-weighted and cholangiographic images using SSFSE is an accurate method for diagnosing pancreatcobiliary diseases

Overview of C-2W Field-Reversed Configuration Experimental Program

Science.gov (United States)

Gota, H.; Binderbauer, M. W.; Tajima, T.; Putvinski, S.; Tuszewski, M.; Dettrick, S.; Korepanov, S.; Romero, J.; Smirnov, A.; Song, Y.; Thompson, M. C.; van Drie, A.; Yang, X.; Ivanov, A. A.; TAE Team

2017-10-01

Tri Alpha Energy's research has been devoted to producing a high temperature, stable, long-lived field-reversed configuration (FRC) plasma state by neutral-beam injection (NBI) and edge biasing/control. C-2U experiments have demonstrated drastic improvements in particle and energy confinement properties of FRC's, and the plasma performance obtained via 10 MW NBI has achieved plasma sustainment of up to 5 ms and plasma (diamagnetism) lifetimes of 10 + ms. The emerging confinement scaling, whereby electron energy confinement time is proportional to a positive power of the electron temperature, is very attractive for higher energy plasma confinement; accordingly, verification of the observed Te scaling law will be a key future research objective. The new experimental device, C-2W (now also called ``Norman''), has the following key subsystem upgrades from C-2U: (i) higher injected power, optimum energies, and extended pulse duration of the NBI system; (ii) installation of inner divertors with upgraded edge-biasing systems; (iii) fast external equilibrium/mirror-coil current ramp-up capability; and (iv) installation of trim/saddle coils for active feedback control of the FRC plasma. This paper will review highlights of the C-2W program.

Reversion of thyrotoxic atrial fibrillation in hypothyroid state after radioiodine treatment

International Nuclear Information System (INIS)

Yamamoto, Makiko; Saito, Shintaro; Sakurada, Toshiro; Yoshida, Katsumi; Kaise, Kazuro; Kaise, Nobuko; Fukazawa, Hiroshi; Itagaki, Yoichi; Yoshinaga, Kaoru

1992-01-01

Twenty patients with thyrotoxic Basedow's disease complicated by atrial fibrillation lasting more than one month despite treatment with antithyroidal drugs were treated with radioiodine supplemented with an antithyroidal drug or inorganic iodine. We classified the 20 patients on the basis of strial fibrillation reversion into two groups, one with reversion (group I) and the other without reversion (group II). In all 12 patients in group I, T 4 and T 3 decreased to hypothyroid levels in 3.2±1.3 months, and one month later all patients had their sinus rhythm restored while T 4 and T 3 also remained below normal (2.6±1.1 μg/dl and 77.9±34.4 ng/dl, respectively). Although T 4 and T 3 also decreased within 3.5±1.8 months in all 8 patients in group II, one month later, atrial fibrillation persisted while T 4 and T 3 (10.4±5.3 μg/dl and 157.7±67.5 ng/dl, respectively) rose significantly compared to those in group I (p<0.001 and p<0.01, respectively). For reversion of atrial fibrillation it is important that the onset of hypothyroidism is rapidly induced by radioiodine and that hypothyroidism continues for at least one month. (author)

Securing Biometric Images using Reversible Watermarking

OpenAIRE

Thampi, Sabu M.; Jacob, Ann Jisma

2011-01-01

Biometric security is a fast growing area. Protecting biometric data is very important since it can be misused by attackers. In order to increase security of biometric data there are different methods in which watermarking is widely accepted. A more acceptable, new important development in this area is reversible watermarking in which the original image can be completely restored and the watermark can be retrieved. But reversible watermarking in biometrics is an understudied area. Reversible ...

SU-F-I-16: Short Breast MRI with High-Resolution T2-Weighted and Dynamic Contrast Enhanced T1-Weighted Images

International Nuclear Information System (INIS)

Ma, J; Son, J; Arun, B; Hazle, J; Hwang, K; Madewell, J; Yang, W; Dogan, B; Wang, K; Bayram, E

2016-01-01

Purpose: To develop and demonstrate a short breast (sb) MRI protocol that acquires both T2-weighted and dynamic contrast-enhanced T1-weighted images in approximately ten minutes. Methods: The sb-MRI protocol consists of two novel pulse sequences. The first is a flexible fast spin-echo triple-echo Dixon (FTED) sequence for high-resolution fat-suppressed T2-weighted imaging, and the second is a 3D fast dual-echo spoiled gradient sequence (FLEX) for volumetric fat-suppressed T1-weighted imaging before and post contrast agent injection. The flexible FTED sequence replaces each single readout during every echo-spacing period of FSE with three fast-switching bipolar readouts to produce three raw images in a single acquisition. These three raw images are then post-processed using a Dixon algorithm to generate separate water-only and fat-only images. The FLEX sequence acquires two echoes using dual-echo readout after each RF excitation and the corresponding images are post-processed using a similar Dixon algorithm to yield water-only and fat-only images. The sb-MRI protocol was implemented on a 3T MRI scanner and used for patients who had undergone concurrent clinical MRI for breast cancer screening. Results: With the same scan parameters (eg, spatial coverage, field of view, spatial and temporal resolution) as the clinical protocol, the total scan-time of the sb-MRI protocol (including the localizer, bilateral T2-weighted, and dynamic contrast-enhanced T1-weighted images) was 11 minutes. In comparison, the clinical breast MRI protocol took 43 minutes. Uniform fat suppression and high image quality were consistently achieved by sb-MRI. Conclusion: We demonstrated a sb-MRI protocol comprising both T2-weighted and dynamic contrast-enhanced T1-weighted images can be performed in approximately ten minutes. The spatial and temporal resolution of the images easily satisfies the current breast MRI accreditation guidelines by the American College of Radiology. The protocol has the

SU-F-I-16: Short Breast MRI with High-Resolution T2-Weighted and Dynamic Contrast Enhanced T1-Weighted Images

Energy Technology Data Exchange (ETDEWEB)

Ma, J; Son, J; Arun, B; Hazle, J; Hwang, K; Madewell, J; Yang, W; Dogan, B [UT MD Anderson Cancer Center, Houston, TX (United States); Wang, K; Bayram, E [GE Healthcare Technologies, Waukesha, Wisconsin (United States)

2016-06-15

Purpose: To develop and demonstrate a short breast (sb) MRI protocol that acquires both T2-weighted and dynamic contrast-enhanced T1-weighted images in approximately ten minutes. Methods: The sb-MRI protocol consists of two novel pulse sequences. The first is a flexible fast spin-echo triple-echo Dixon (FTED) sequence for high-resolution fat-suppressed T2-weighted imaging, and the second is a 3D fast dual-echo spoiled gradient sequence (FLEX) for volumetric fat-suppressed T1-weighted imaging before and post contrast agent injection. The flexible FTED sequence replaces each single readout during every echo-spacing period of FSE with three fast-switching bipolar readouts to produce three raw images in a single acquisition. These three raw images are then post-processed using a Dixon algorithm to generate separate water-only and fat-only images. The FLEX sequence acquires two echoes using dual-echo readout after each RF excitation and the corresponding images are post-processed using a similar Dixon algorithm to yield water-only and fat-only images. The sb-MRI protocol was implemented on a 3T MRI scanner and used for patients who had undergone concurrent clinical MRI for breast cancer screening. Results: With the same scan parameters (eg, spatial coverage, field of view, spatial and temporal resolution) as the clinical protocol, the total scan-time of the sb-MRI protocol (including the localizer, bilateral T2-weighted, and dynamic contrast-enhanced T1-weighted images) was 11 minutes. In comparison, the clinical breast MRI protocol took 43 minutes. Uniform fat suppression and high image quality were consistently achieved by sb-MRI. Conclusion: We demonstrated a sb-MRI protocol comprising both T2-weighted and dynamic contrast-enhanced T1-weighted images can be performed in approximately ten minutes. The spatial and temporal resolution of the images easily satisfies the current breast MRI accreditation guidelines by the American College of Radiology. The protocol has the

T2 black lesions on routine knee MRI: differential considerations

International Nuclear Information System (INIS)

Wadhwa, Vibhor; Cho, Gina; Moore, Daniel; Pezeshk, Parham; Coyner, Katherine; Chhabra, Avneesh

2016-01-01

The majority of abnormal findings or lesions on T2-weighted fast spin-echo (FSE) magnetic resonance imaging (MRI) are hyperintense due to increased perfusion or fluid content, such as infections, tumours or synovitis. Hypointense lesions on T2-weighted images (both fat-suppressed and non-fat-suppressed) are less common and can sometimes be overlooked. Such lesions have limited differential diagnostic possibilities, and include vacuum phenomenon, loose body, tenosynovial giant cell tumour, rheumatoid arthritis, haemochromatosis, gout, amyloid, chondrocalcinosis, hydroxyapetite deposition disease, lipoma arborescens, arthrofibrosis and iatrogenic lesions. These lesions often show characteristic appearances and predilections in the knee. In this article, the authors describe the MRI features of hypointense T2 lesions on routine knee MRI and outline a systematic diagnostic approach towards their evaluation. (orig.)

Optimal MR pulse sequences for hepatic hemangiomas : comparison of T2-weighted turbo-spin-echo, T2-weighted breath-hold turbo-spin-echo, and T1-weighted FLASH dynamic imaging

International Nuclear Information System (INIS)

Wang, Wen Chao; Choi, Byung Ihn; Han, Joon Koo; Kim, Tae Kyoung; Cho, Soon Gu

1997-01-01

To optimize MR imaging pulse sequences in the imaging of hepatic hemangioma and to evaluate on dynamic MR imaging the enhancing characteristics of the lesions. Twenty patients with 35 hemangiomas were studied by using Turbo-spin-echo (TSE) sequence (T2-weighted, T2- and heavily T2-weighted breath-hold) and T1-weighted FLASH imaging acquired before, immediately on, and 1, 3 and 5 minutes after injection of a bolus of Gd-DTPA (0.1mmol/kg). Phased-array multicoil was employed. Images were quantitatively analyzed for lesion-to-liver signal difference to noise ratios (SD/Ns), and lesion-to-liver signal ratios (H/Ls), and qualitatively analyzed for lesion conspicuity. The enhancing characteristics of the hemangiomas were described by measuring the change of signal intensity as a curve in T1-weighted FLASH dynamic imaging. For T2-weighted images, breath-hold T2-weighted TSE had a slightly higher SD/N than other pulse sequences, but there was no statistical difference in three fast pulse sequences (p=0.211). For lesion conspicuity, heavily T2-weighted breath-hold TSE images was superior to T2-weighted breath-hold or non-breath-hold TSE (H/L, 5.75, 3.81, 2.87, respectively, p<0.05). T2-weighted breath-hold TSE imaging was more effective than T2-weighted TSE imaging in removing lesion blurring or lack of sharpness, and there was a 12-fold decrease in acquisition time (20sec versus 245 sec). T1-weighted FLASH dynamic images of normal liver showed peak enhancement at less than 1 minute, and of hemangioma at more than 3 minutes;the degree of enhancement for hemangioma decreased after a 3 minute delay. T2-weighed breath-hold TSE imaging and Gd-DTPA enhanced FLASH dynamic imaging with 5 minutes delay are sufficient for imaging hepatic hemangiomas

Synthesis and operation of an FFT-decoupled fixed-order reversed-field pinch plasma control system based on identification data

Energy Technology Data Exchange (ETDEWEB)

Olofsson, K Erik J; Brunsell, Per R; Drake, James R [School of Electrical Engineering, Royal Institute of Technology (KTH), Association EURATOM-VR, Stockholm (Sweden); Witrant, Emmanuel, E-mail: erik.olofsson@ee.kth.s [Control Systems Department, UJF/GIPSA-lab, INPG/UJF Grenoble University (France)

2010-10-15

Recent developments and applications of system identification methods for the reversed-field pinch (RFP) machine EXTRAP T2R have yielded plasma response parameters for decoupled dynamics. These data sets are fundamental for a real-time implementable fast Fourier transform (FFT) decoupled discrete-time fixed-order strongly stabilizing synthesis as described in this work. Robustness is assessed over the data set by bootstrap calculation of the sensitivity transfer function worst-case H{sub {infinity}}-gain distribution. Output tracking and magnetohydrodynamic mode m = 1 tracking are considered in the same framework simply as two distinct weighted traces of a performance channel output-covariance matrix as derived from the closed-loop discrete-time Lyapunov equation. The behaviour of the resulting multivariable controller is investigated with dedicated T2R experiments.

Fast T Wave Detection Calibrated by Clinical Knowledge with Annotation of P and T Waves

Directory of Open Access Journals (Sweden)

Mohamed Elgendi

2015-07-01

Full Text Available Background: There are limited studies on the automatic detection of T waves in arrhythmic electrocardiogram (ECG signals. This is perhaps because there is no available arrhythmia dataset with annotated T waves. There is a growing need to develop numerically-efficient algorithms that can accommodate the new trend of battery-driven ECG devices. Moreover, there is also a need to analyze long-term recorded signals in a reliable and time-efficient manner, therefore improving the diagnostic ability of mobile devices and point-of-care technologies. Methods: Here, the T wave annotation of the well-known MIT-BIH arrhythmia database is discussed and provided. Moreover, a simple fast method for detecting T waves is introduced. A typical T wave detection method has been reduced to a basic approach consisting of two moving averages and dynamic thresholds. The dynamic thresholds were calibrated using four clinically known types of sinus node response to atrial premature depolarization (compensation, reset, interpolation, and reentry. Results: The determination of T wave peaks is performed and the proposed algorithm is evaluated on two well-known databases, the QT and MIT-BIH Arrhythmia databases. The detector obtained a sensitivity of 97.14% and a positive predictivity of 99.29% over the first lead of the validation databases (total of 221,186 beats. Conclusions: We present a simple yet very reliable T wave detection algorithm that can be potentially implemented on mobile battery-driven devices. In contrast to complex methods, it can be easily implemented in a digital filter design.

Synthesis of visible light driven cobalt tailored Ag2O/TiON nanophotocatalyst by reverse micelle processing for degradation of Eriochrome Black T

KAUST Repository

Hussain, Syed Tajammul

2013-02-01

An ultra efficient cobalt tailored silver and nitrogen co-doped titania (TiON/Ag2O/Co) visible nanophotocatalyst is successfully synthesized using modified reverse micelle processing. Composition, phase, distribution of dopants, functional group analysis, optical properties and morphology of synthesized materials are investigated by means of X-ray diffraction (XRD), transmission electron microscopy (TEM) based techniques and others. Charge states of titanium (Ti) and silver are explored through core-loss electron energy loss spectroscopy (EELS) analysis and X ray photoelectron spectroscopy (XPS). Our characterization results showed that the synthesized nanophotocatalyst consisted of anatase phased qausispherical nanoparticles that exhibited homogeneous distribution of dopants, large surface area, high quantum efficiency and enhanced optical properties. At lower content of doped Co ions, the TiON/Ag2O responded with extraordinary photocatalytic properties. The cobalt tailored nanophotocatalyst showed remarkable activity against Eriochrome Black T (EBT). Moreover, comparative degradation behavior of EBT with TiON, Ag2O/TiON and Co/Ag2O/TiON is also investigated. © 2012 Elsevier Ltd.

Synthesis of visible light driven cobalt tailored Ag2O/TiON nanophotocatalyst by reverse micelle processing for degradation of Eriochrome Black T

KAUST Repository

Hussain, Syed Tajammul; Rashid,; Anjum, Dalaver H.; Siddiqa, Asima; Badshah, Amin

2013-01-01

An ultra efficient cobalt tailored silver and nitrogen co-doped titania (TiON/Ag2O/Co) visible nanophotocatalyst is successfully synthesized using modified reverse micelle processing. Composition, phase, distribution of dopants, functional group analysis, optical properties and morphology of synthesized materials are investigated by means of X-ray diffraction (XRD), transmission electron microscopy (TEM) based techniques and others. Charge states of titanium (Ti) and silver are explored through core-loss electron energy loss spectroscopy (EELS) analysis and X ray photoelectron spectroscopy (XPS). Our characterization results showed that the synthesized nanophotocatalyst consisted of anatase phased qausispherical nanoparticles that exhibited homogeneous distribution of dopants, large surface area, high quantum efficiency and enhanced optical properties. At lower content of doped Co ions, the TiON/Ag2O responded with extraordinary photocatalytic properties. The cobalt tailored nanophotocatalyst showed remarkable activity against Eriochrome Black T (EBT). Moreover, comparative degradation behavior of EBT with TiON, Ag2O/TiON and Co/Ag2O/TiON is also investigated. © 2012 Elsevier Ltd.

Transition metal redox switches for reversible "on/off" and "slow/fast" single-molecule magnet behaviour in dysprosium and erbium bis-diamidoferrocene complexes.

Science.gov (United States)

Dickie, Courtney M; Laughlin, Alexander L; Wofford, Joshua D; Bhuvanesh, Nattamai S; Nippe, Michael

2017-12-01

Single-molecule magnets (SMMs) are considered viable candidates for next-generation data storage and quantum computing. Systems featuring switchability of their magnetization dynamics are particularly interesting with respect to accessing more complex logic gates and device architectures. Here we show that transition metal based redox events can be exploited to enable reversible switchability of slow magnetic relaxation of magnetically anisotropic lanthanide ions. Specifically, we report anionic homoleptic bis-diamidoferrocene complexes of Dy 3+ (oblate) and Er 3+ (prolate) which can be reversibly oxidized by one electron to yield their respective charge neutral redox partners (Dy: [1] - , 1 ; Er: [2] - , 2 ). Importantly, compounds 1 and 2 are thermally stable which allowed for detailed studies of their magnetization dynamics. We show that the Dy 3+ [1] - / 1 system can function as an "on"/"off" or a "slow"/"fast" redox switchable SMM system in the absence or presence of applied dc fields, respectively. The Er 3+ based [2] - / 2 system features "on"/"off" switchability of SMM properties in the presence of applied fields. Results from electrochemical investigations, UV-vis-NIR spectroscopy, and 57 Fe Mössbauer spectroscopy indicate the presence of significant electronic communication between the mixed-valent Fe ions in 1 and 2 in both solution and solid state. This comparative evaluation of redox-switchable magnetization dynamics in low coordinate lanthanide complexes may be used as a potential blueprint toward the development of future switchable magnetic materials.

Rapid Determination of Bile Acids in Bile from Various Mammals by Reversed-Phase Ultra-Fast Liquid Chromatography.

Science.gov (United States)

Si, Gu Leng Ri; Yao, Peng; Shi, Luwen

2015-08-01

A valid and efficient reversed-phase ultra-fast liquid chromatography method was developed for the simultaneous determination of 13 bile acids in the bile of three mammal species, including rat, pig and human gallstone patients. Chromatographic separation was performed with a Shim-pack XR-ODS column, and the mobile phase consisted of acetonitrile and potassium phosphate buffer (pH 2.6) at a flow rate of 0.5 mL min(-1). The linear detection range of most bile acids ranged from 2 to 600 ng µL(-1) with a good correlation coefficient (>0.9995). The precision of each bile acid was bile acids were separated in 15 min with satisfactory resolution, and the total analysis time was 18 min, including equilibration. The method was successfully applied in rapid screening of bile samples from the three mammals. Significant metabolic frameworks of bile acids among various species were observed, whereas considerable quantitative variations in both inter- and intraspecies were also observed, especially for gallstone patients. Our results suggest that detecting the change of bile acid profiles could be applied for the diagnosis of gallstone disease. © Crown copyright 2014.

Effect of reverse cyclic loading on the fracture resistance curve in C(T) specimen

International Nuclear Information System (INIS)

Sung Seok, C.; Jin Kim, Y.; Il Weon, J.

1999-01-01

Fracture resistance (J-R) curves, which are used for elastic-plastic fracture mechanics analyses, are known to be dependent on the cyclic loading history. The objective of this paper is to investigate the effect of reverse cyclic loading on the J-R curves in C(T) specimens. The effect of two parameters was observed on the J-R curves during the reverse cyclic loading. One was the minimum-to-maximum load ratio (R) and the other was the incremental plastic displacement (δ cycle /δ i ), which is related to the amount of crack growth that occurs in a cycle. Fracture resistance tests on C(T) specimens with varying the load ratio and the incremental plastic displacement were performed, and the test results showed that the J-R curves were decreased with decreasing the load ratio and decreasing the incremental plastic displacement. Direct current potential drop (DCPD) method was used for the detection of crack initiation and crack growth in typical laboratory J-R tests. The values of crack initiation J-integral (J I ) and crack initiation displacement (δ i ) were also obtained by using the DCPD method. (orig.)

Posterior reversible encephalopathy syndrome: diagnosis with CT and MRI

International Nuclear Information System (INIS)

Wang Guangbin; Zhao Bin; Yang Zhenzhen; Shi Hao; Chiu, L.C.; Shan Ruiqin

2006-01-01

Objective: To evaluate the role of CT and MRI in the diagnosis of posterior reversible encephalopathy syndrome (PRES). Methods: Eight women with PRES (6 pregnant women, 1 case after chemotherapy, and 1 patient with hypertension)were enrolled in our study. All of them had MR imaging (T 1 WI, T 2 WI, FLAIR, DWI), and five cases underwent post-contrast T 1 WI and three dimensional contrast enhanced MR angiography (3D CEMRA). Two cases also had CT scan. Results: MRV in all 8 patients showed no evidence of stenosis, dilation, or thrombosis in cranial veins and sinuses. MRI demonstrated multiple lesions located in bilateral parieto-occipital lobes (8 cases), bilateral basal ganglia (2 cases), and bilateral frontal lobes (4 cases). The lesions were prominent within white matter, some of them involved gray matter (3 cases). Lesions appeared as hyperintense signals on FLAIR and T 2 -weighted images, isointense or mildly hypointense signals on T 1 -weighted images, normal or decreased intensity on DWI, and isointensity or hyperintensity on apparent diffusion coefficient (ADC) maps. Post-contrast T 1 WI showed mild reversible enhancement and 3D CEMRA displayed numerous reversible 'grape-like' enhancements in terminal arterial branches along the middle cerebral artery (MCA), anterior cerebral artery (ACA) and posterior cerebral artery (PCA). Follow-up scan showed decreased abnormal signals. Conclusion: Lesions of PRES are usually located in parieto-occipital lobes, especially in white matter, but they can also be seen in frontal lobes and basal ganglia bilaterally. Post-contrast T 1 WI and 3D enhanced MRA can provide useful information in the manifestation of reversible enhancement. MRI has advantages to display lesion in PRES. (authors)

Generating bit reversed numbers for calculating fast fourier transform

Digital Repository Service at National Institute of Oceanography (India)

Suresh, T.

prerequisite of these methods are that data elements be available for shuffling in an array. Thus in a software environment, if the input data values are to be read from a file, reordering can be done only after al1 the values have been read into the array.... Alternately, data values can be read and placed directly at respective bit reversed positions by generating bit reversed addresses. Such a method can help in real-time data acquisition and FFT calculation. Thus, an efficient method of generating sequence...

SPAMM, cine phase contrast imaging and fast spin-echo T2-weighted imaging in the study of intracranial cerebrospinal fluid (CSF) flow

International Nuclear Information System (INIS)

Connor, S.E.J.; O'Gorman, R.; Summers, P.; Simmons, A.; Moore, E.M.; Chandler, C.; Jarosz, J.M.

2001-01-01

AIM: To compare the qualitative assessment of cerebrospinal fluid (CSF) flow using a SPAMM (spatial modulation of magnetization) technique with cine phase contrast images (cine PC) and fast spin echo (FSE) T2-weighted images. MATERIALS AND METHODS: SPAMM, PC and T2-weighted sequences were performed on 22 occasions in 19 patients. Eleven of the studies were performed following a neuroendoscopic third ventriculostomy (NTV), and in these cases, the success of the NTV was determined by clinical follow-up. Two observers used consensus to grade the presence of CSF flow at nine different sites for each study. RESULTS: At 14 of the 178 matched sites, which could be assessed by both SPAMM and cine PC, SPAMM CSF flow grade was higher than that of cine PC. At a further 14/178 matched sites, the cine PC grade was higher than that of SPAMM. There was definite CSF flow at 113/182 (62%) of all the cine PC sites assessed, and 110/181 (61%) of all SPAMM sites assessed whilst 108/198 (54%) of FSE T2-weighted image sites demonstrated flow voids. Cine PC grades were higher than SPAMM at the cerebral aqueduct (P < 0.05, Wilcoxon sign rank test). Definite CSF flow within the anterior third ventricle was present in 4/5 (SPAMM) and 3/5 (cine PC) successful NTVs, 0/2 (SPAMM and cine PC) unsuccessful NTVs and 1/10 (SPAMM and cine PC) patients without NTV. CONCLUSION: SPAMM provides a comparable assessment of intracranial CSF flow to that of cine phase contrast imaging at all CSF sites except the cerebral aqueduct. Connor, S.E.J. et al. (2001)

A fast fractional difference algorithm

DEFF Research Database (Denmark)

Jensen, Andreas Noack; Nielsen, Morten Ørregaard

2014-01-01

We provide a fast algorithm for calculating the fractional difference of a time series. In standard implementations, the calculation speed (number of arithmetic operations) is of order T 2, where T is the length of the time series. Our algorithm allows calculation speed of order T log...

A Fast Fractional Difference Algorithm

DEFF Research Database (Denmark)

Jensen, Andreas Noack; Nielsen, Morten Ørregaard

We provide a fast algorithm for calculating the fractional difference of a time series. In standard implementations, the calculation speed (number of arithmetic operations) is of order T 2, where T is the length of the time series. Our algorithm allows calculation speed of order T log...

Compatibility evaluation between La 2Mo 2O 9 fast oxide-ion conductor and Ni-based materials

Science.gov (United States)

Corbel, Gwenaël; Lacorre, Philippe

2006-05-01

The chemical reactivity of La 2NiO 4+δ and nickel metal or nickel oxide with fast oxide-ion conductor La 2Mo 2O 9 is investigated in the annealing temperature range between 600 and 1000 °C, using room temperature X-ray powder diffraction. Within the La 2NiO 4+δ/La 2Mo 2O 9 system, subsequent reaction is evidenced at relatively low annealing temperature (600 °C), with formation of La 2MoO 6 and NiO. The reaction is complete at 1000 °C. At reverse, no reaction occurs between Ni or NiO and La 2Mo 2O 9 up to 1000 °C. Together with a previous work [G. Corbel, S. Mestiri, P. Lacorre, Solid State Sci. 7 (2005) 1216], the current study shows that Ni-CGO cermets might be chemically and mechanically compatible anode materials to work with LAMOX electrolytes in solid oxide fuel cells.

Time-reversal invariance in multiple collisions between coupled masses

International Nuclear Information System (INIS)

Crawford, F.S.

1989-01-01

The time evolution of two mechanical oscillators coupled by a spring can (but need not) exhibit an instant t = 2t' when the initial conditions at t = 0 have been exactly restored. When that is the case, then at t = t' energy and momentum have been exchanged exactly as in an elastic collision between two free particles, and the evolution of the system from t = t' to 2t' is related to that from 0 to t' by time-reversal invariance. A similar ''simulation of elastic scattering'' at t = t' can occur for two free particles coupled via collisions with an intermediary mass that bounces back and forth between the two particles provided the intermediary is left at rest at t = t'. Examined here is the time evolution of the exchange of momentum and energy for these two examples, determining the values of the coupling spring constant (or mass value) of the intermediating spring (or mass) needed to simulate single elastic scattering between free particles, and looking at the manifestation of time-reversal invariance

Comparison of 3D vs. 2D fast spin echo imaging for evaluation of articular cartilage in the knee on a 3 T system scientific research

International Nuclear Information System (INIS)

Milewski, Matthew D.; Smitaman, Edward; Moukaddam, Hicham; Katz, Lee D.; Essig, David A.; Medvecky, Michael J.; Haims, Andrew H.

2012-01-01

Highlights: ► Compared 3D to 2D MR sequences for articular cartilage in the knee. ► 3D imaging acquired in a single plane, 2D acquired in 3 separate planes. ► No significant difference in accuracy between 3D and 2D sequences. - Abstract: Purpose: We sought to retrospectively compare the accuracy of a three-dimensional fat-suppressed, fast spin-echo sequences acquired in the sagittal plane, with multiplanar reconstructions to that of two-dimensional fat-suppressed, fast spin echo sequences acquired in three planes on a 3 T MR system for the evaluation of articular cartilage in the knee. Materials and methods: Our study group consisted of all patients (N = 34) that underwent 3 T MR imaging of the knee at our institution with subsequent arthroscopy over an 18-month period. There were 21 males and 13 females with an average age of 36 years. MR images were reviewed by 3 musculoskeletal radiologists, blinded to operative results. 3D and 2D sequences were reviewed at different sittings separated by 4 weeks to prevent bias. Six cartilage surfaces were evaluated both with MR imaging and arthroscopically with a modified Noyes scoring system and arthroscopic results were used as the gold standard. Sensitivity, specificity, and accuracy were calculated for each reader along with Fleiss Kappa assessment agreement between the readers. Accuracies for each articular surface were compared using a difference in proportions test with a 95% confidence interval and statistical significance was calculated using a Fisher's Exact Test. Results: Two hundred and four articular surfaces were evaluated and 49 articular cartilage lesions were present at arthroscopy. For the patellofemoral surfaces, the sensitivity, specificity, and accuracy were 76.5%, 83%, and 78.2% for the 3D sequences and were 82.3%, 76%, and 82% respectively for the 2D sequences. For the medial compartment surfaces, the sensitivity, specificity, and accuracy were 81.1%, 65.1%, and 78.5% for the 3D sequences and were

Reversion of thyrotoxic atrial fibrillation in hypothyroid state after radioiodine treatment

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Makiko; Saito, Shintaro; Sakurada, Toshiro; Yoshida, Katsumi; Kaise, Kazuro; Kaise, Nobuko; Fukazawa, Hiroshi; Itagaki, Yoichi; Yoshinaga, Kaoru [Tohoku Univ., Sendai (Japan). School of Medicine

1992-06-01

Twenty patients with thyrotoxic Basedow's disease complicated by atrial fibrillation lasting more than one month despite treatment with antithyroidal drugs were treated with radioiodine supplemented with an antithyroidal drug or inorganic iodine. We classified the 20 patients on the basis of strial fibrillation reversion into two groups, one with reversion (group I) and the other without reversion (group II). In all 12 patients in group I, T{sub 4} and T{sub 3} decreased to hypothyroid levels in 3.2{+-}1.3 months, and one month later all patients had their sinus rhythm restored while T{sub 4} and T{sub 3} also remained below normal (2.6{+-}1.1 {mu}g/dl and 77.9{+-}34.4 ng/dl, respectively). Although T{sub 4} and T{sub 3} also decreased within 3.5{+-}1.8 months in all 8 patients in group II, one month later, atrial fibrillation persisted while T{sub 4} and T{sub 3} (10.4{+-}5.3 {mu}g/dl and 157.7{+-}67.5 ng/dl, respectively) rose significantly compared to those in group I (p<0.001 and p<0.01, respectively). For reversion of atrial fibrillation it is important that the onset of hypothyroidism is rapidly induced by radioiodine and that hypothyroidism continues for at least one month. (author).

Reversion of thyrotoxic atrial fibrillation in hypothyroid state after radioiodine treatment

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Makiko; Saito, Shintaro; Sakurada, Toshiro; Yoshida, Katsumi; Kaise, Kazuro; Kaise, Nobuko; Fukazawa, Hiroshi; Itagaki, Yoichi; Yoshinaga, Kaoru (Tohoku Univ., Sendai (Japan). School of Medicine)

1992-06-01

Twenty patients with thyrotoxic Basedow's disease complicated by atrial fibrillation lasting more than one month despite treatment with antithyroidal drugs were treated with radioiodine supplemented with an antithyroidal drug or inorganic iodine. We classified the 20 patients on the basis of strial fibrillation reversion into two groups, one with reversion (group I) and the other without reversion (group II). In all 12 patients in group I, T{sub 4} and T{sub 3} decreased to hypothyroid levels in 3.2{+-}1.3 months, and one month later all patients had their sinus rhythm restored while T{sub 4} and T{sub 3} also remained below normal (2.6{+-}1.1 {mu}g/dl and 77.9{+-}34.4 ng/dl, respectively). Although T{sub 4} and T{sub 3} also decreased within 3.5{+-}1.8 months in all 8 patients in group II, one month later, atrial fibrillation persisted while T{sub 4} and T{sub 3} (10.4{+-}5.3 {mu}g/dl and 157.7{+-}67.5 ng/dl, respectively) rose significantly compared to those in group I (p<0.001 and p<0.01, respectively). For reversion of atrial fibrillation it is important that the onset of hypothyroidism is rapidly induced by radioiodine and that hypothyroidism continues for at least one month. (author).

Optimized reversible binary-coded decimal adders

DEFF Research Database (Denmark)

Thomsen, Michael Kirkedal; Glück, Robert

2008-01-01

Abstract Babu and Chowdhury [H.M.H. Babu, A.R. Chowdhury, Design of a compact reversible binary coded decimal adder circuit, Journal of Systems Architecture 52 (5) (2006) 272-282] recently proposed, in this journal, a reversible adder for binary-coded decimals. This paper corrects and optimizes...... their design. The optimized 1-decimal BCD full-adder, a 13 × 13 reversible logic circuit, is faster, and has lower circuit cost and less garbage bits. It can be used to build a fast reversible m-decimal BCD full-adder that has a delay of only m + 17 low-power reversible CMOS gates. For a 32-decimal (128-bit....... Keywords: Reversible logic circuit; Full-adder; Half-adder; Parallel adder; Binary-coded decimal; Application of reversible logic synthesis...

The effect of fast particles' irradiation on electrooptical properties of GaP LEDs

International Nuclear Information System (INIS)

Gontaruk, O.; Kovalenko, A.; Malyj, E.; Petrenko, I.; Pinkovska, M.; Polivtcev, L.; Tartachnyk, V.

2013-01-01

The electrooptical properties of industrial AL 102 GaP light-emitting diodes (LEDs) irradiated with fast particles have been studied. 2 MeV electrons and fast reactor neutrons were used and devices' microplsma emitting, current-voltage and capacitance-voltage characteristics were measured. It was shown that electron irradiation in the range (2-5)10 16 cm -2 leads to the drop of microplasma emitting intensity, decrease of capacity and reverse currents and increase of reverse bias. The annealing study of current-voltage characteristics after neutron irradiation of diodes confirms the assumption about prevailing radiation influence on diode base due to induce of deep levels. (authors)

Results from TRX-2 slow field-reversed-theta-pinch

International Nuclear Information System (INIS)

Slough, J.T.; Harding, D.; Hoffman, A.L.

1984-01-01

FRCs have been successfully generated in the TRX-2 slow risetime theta pinch. Initial studies indicate that the flux trapping through field reversal is about as good (''50%) as on TRX-1, although the quarter cycle time of the main coil was increased from 3 to 10 μsec. Formation studies have been started using the programmed formation techniques developed on TRX-1. The plasma dynamics are very similar to those exhibited in the faster rise TRX-1 experiments. The formation phase shows the same high degree of symmetry and reproducibility that was observed in TRX-1. Equilibrium behaviour of the FRCs formed is very similar to that observed on TRX-1, as long as impurity content is kept low. T/sub e/ + T/sub i/ temperatures of 400 to 500 eV are obtained and confirmed by impurity line broadening and decay rates. Flux and particle lifetimes ≅ 100 μsec have been observed and show the same strong scaling with x/sub s/ that was observed on TRX-1

NMR analysis of t-butyl-catalyzed deuterium exchange at unactivated arene localities.

Science.gov (United States)

Stack, Douglas E; Eastman, Rachel

2016-10-01

Regioselective labelling of arene rings via electrophilic exchange is often dictated by the electronic environment caused by substituents present on the aromatic system. Previously, we observed the presence of a t-butyl group, either covalently bond or added as an external reagent, could impart deuterium exchange to the unactivated, C1-position of estrone. Here, we provide nuclear magnetic resonance analysis of this exchange in a solvent system composed of 50:50 trifluoroacetic acid and D 2 O with either 2-t-butylestrone or estrone in the presence of t-butyl alcohol has shed insights into the mechanism of this t-butyl-catalyzed exchange. Fast exchange of the t-butyl group concurrent with the gradual reduction of the H1 proton signal in both systems suggest a mechanism involving ipso attack of the t-butyl position by deuterium. The reversible addition/elimination of the t-butyl group activates the H1 proton towards exchange by a mechanism of t-butyl incorporation, H1 activation and exchange, followed by eventual t-butyl elimination. Density functional calculations are consistent with the observation of fast t-butyl exchange concurrent with slower H1 exchange. The σ-complex resulting from ipso attack of deuterium at the t-butyl carbon was 6.6 kcal/mol lower in energy than that of the σ-complex resulting from deuterium attack at C1. A better understanding of the t-butyl-catalyzed exchange could help in the design of labelling recipes for other phenolic metabolites. Copyright © 2016 The Authors. Journal of Labelled Compounds and Radiopharmaceuticals published by John Wiley & Sons, Ltd.

Fast imaging measurements and modeling of neutral and impurity density on C-2U

Science.gov (United States)

Granstedt, Erik; Deng, B.; Dettrick, S.; Gupta, D. K.; Osin, D.; Roche, T.; Zhai, K.; TAE Team

2016-10-01

The C-2U device employed neutral beam injection and end-biasing to sustain an advanced beam-driven Field-Reversed Configuration plasma for 5+ ms, beyond characteristic transport time-scales. Three high-speed, filtered cameras observed visible light emission from neutral hydrogen and impurities, as well as deuterium pellet ablation and compact-toroid injection which were used for auxiliary particle fueling. Careful vacuum practices and titanium gettering successfully reduced neutral recycling from the confinement vessel wall. As a result, a large fraction of the remaining neutrals originate from charge-exchange between the neutral beams and plasma ions. Measured H/D- α emission is used with DEGAS2 neutral particle modeling to reconstruct the strongly non-axissymmetric neutral distribution. This is then used in fast-ion modeling to more accurately estimate their charge-exchange loss rate. Oxygen emission due to electron-impact excitation and charge-exchange recombination has also been measured using fast imaging. Reconstructed emissivity of O4+ is localized on the outboard side of the core plasma near the estimated location of the separatrix inferred by external magnetic measurements. Tri Alpha Energy.

Reticuloendothelial negative contrast media for hepatocellular carcinoma. Initial comparison of chondroitin sulfate iron colloid and Ferrixan in fast T2-weighted MR imaging

International Nuclear Information System (INIS)

Sugihara, Shuji; Suto, Yuji; Kamba, Masayuki; Yoshida, Kotaro

1996-01-01

Chondroitin sulfate iron colloid (CSIC), a paramagnetic substance, and Ferrixan (SHU555A), a superparamagnetic substance, were administered to 20 patients with 26 nodules of hepatocellular carcinoma, and the visualization of the lesions by fast T2-weighted magnetic resonance imaging (MRI) was quantitatively evaluated. Conventional spin-echo (CSE), turbo spin-echo (TSE), and turbo gradient spin-echo (TGSE) sequences were performed in all patients before and after the administration of the iron colloid preparations. The signal-to-noise ratio (SNR) in the liver decreased significantly after administration of iron colloid preparations by all sequences and at all doses. A reduction in SNR in the liver similar to that obtained with SHU555A could be obtained by increasing the dose of CSIC, which has a weaker T2-shortening effect. In the TSE sequence with a weaker susceptibility effect, the decrease in SNR in the liver tended to be equalized to those in the CSE or TGSE sequences by high dose administration of the iron colloid preparation. We think perhaps that the imaging ability for hepatocellular carcinoma, similar to that of superparamagnetic contrast media, can be obtained with paramagnetic CSIC by administering it at a higher dose. (author)

Reticuloendothelial negative contrast media for hepatocellular carcinoma. Initial comparison of chondroitin sulfate iron colloid and Ferrixan in fast T2-weighted MR imaging

Energy Technology Data Exchange (ETDEWEB)

Sugihara, Shuji; Suto, Yuji; Kamba, Masayuki; Yoshida, Kotaro [Tottori Univ., Yonago (Japan). Faculty of Medicine

1996-11-01

Chondroitin sulfate iron colloid (CSIC), a paramagnetic substance, and Ferrixan (SHU555A), a superparamagnetic substance, were administered to 20 patients with 26 nodules of hepatocellular carcinoma, and the visualization of the lesions by fast T2-weighted magnetic resonance imaging (MRI) was quantitatively evaluated. Conventional spin-echo (CSE), turbo spin-echo (TSE), and turbo gradient spin-echo (TGSE) sequences were performed in all patients before and after the administration of the iron colloid preparations. The signal-to-noise ratio (SNR) in the liver decreased significantly after administration of iron colloid preparations by all sequences and at all doses. A reduction in SNR in the liver similar to that obtained with SHU555A could be obtained by increasing the dose of CSIC, which has a weaker T2-shortening effect. In the TSE sequence with a weaker susceptibility effect, the decrease in SNR in the liver tended to be equalized to those in the CSE or TGSE sequences by high dose administration of the iron colloid preparation. We think perhaps that the imaging ability for hepatocellular carcinoma, similar to that of superparamagnetic contrast media, can be obtained with paramagnetic CSIC by administering it at a higher dose. (author)

Draft Genome Sequence of a Highly Flagellated, Fast-Swimming Archaeon, Methanocaldococcus villosus Strain KIN24-T80 (DSM 22612)

KAUST Repository

Thennarasu, Sugumar; Poli Reddy, Dinesh Reddy; Antony, Aju; Yada, Madhava; Alqarawi, Sami; Neelamegam, Sivakumar

2013-01-01

We report the draft genome sequence of a hyperthermophilic Methanocaldococcus villosus strain, KIN24-T80. The gene associated with its heavy flagellum formation was annotated in the 1.2-Mb draft genome sequence, and this strain may be a good model system to study the extensive functional role of flagella and their fast motor activity.

Draft Genome Sequence of a Highly Flagellated, Fast-Swimming Archaeon, Methanocaldococcus villosus Strain KIN24-T80 (DSM 22612)

KAUST Repository

Thennarasu, Sugumar

2013-07-11

We report the draft genome sequence of a hyperthermophilic Methanocaldococcus villosus strain, KIN24-T80. The gene associated with its heavy flagellum formation was annotated in the 1.2-Mb draft genome sequence, and this strain may be a good model system to study the extensive functional role of flagella and their fast motor activity.

Forced selection of a human immunodeficiency virus type 1 variant that uses a non-self tRNA primer for reverse transcription: Involvement of viral RNA sequences and the reverse transcriptase enzyme

NARCIS (Netherlands)

Abbink, Truus E. M.; Beerens, Nancy; Berkhout, Ben

2004-01-01

Human immunodeficiency virus type 1 uses the tRNA(3)(Lys) molecule as a selective primer for reverse transcription. This primer specificity is imposed by sequence complementarity between the tRNA primer and two motifs in the viral RNA genome: the primer-binding site (PBS) and the primer activation

The specificity and flexibility of l1 reverse transcription priming at imperfect T-tracts.

Directory of Open Access Journals (Sweden)

Clément Monot

2013-05-01

Full Text Available L1 retrotransposons have a prominent role in reshaping mammalian genomes. To replicate, the L1 ribonucleoprotein particle (RNP first uses its endonuclease (EN to nick the genomic DNA. The newly generated DNA end is subsequently used as a primer to initiate reverse transcription within the L1 RNA poly(A tail, a process known as target-primed reverse transcription (TPRT. Prior studies demonstrated that most L1 insertions occur into sequences related to the L1 EN consensus sequence (degenerate 5'-TTTT/A-3' sites and frequently preceded by imperfect T-tracts. However, it is currently unclear whether--and to which degree--the liberated 3'-hydroxyl extremity on the genomic DNA needs to be accessible and complementary to the poly(A tail of the L1 RNA for efficient priming of reverse transcription. Here, we employed a direct assay for the initiation of L1 reverse transcription to define the molecular rules that guide this process. First, efficient priming is detected with as few as 4 matching nucleotides at the primer 3' end. Second, L1 RNP can tolerate terminal mismatches if they are compensated within the 10 last bases of the primer by an increased number of matching nucleotides. All terminal mismatches are not equally detrimental to DNA extension, a C being extended at higher levels than an A or a G. Third, efficient priming in the context of duplex DNA requires a 3' overhang. This suggests the possible existence of additional DNA processing steps, which generate a single-stranded 3' end to allow L1 reverse transcription. Based on these data we propose that the specificity of L1 reverse transcription initiation contributes, together with the specificity of the initial EN cleavage, to the distribution of new L1 insertions within the human genome.

The specificity and flexibility of l1 reverse transcription priming at imperfect T-tracts.

Science.gov (United States)

Monot, Clément; Kuciak, Monika; Viollet, Sébastien; Mir, Ashfaq Ali; Gabus, Caroline; Darlix, Jean-Luc; Cristofari, Gaël

2013-05-01

L1 retrotransposons have a prominent role in reshaping mammalian genomes. To replicate, the L1 ribonucleoprotein particle (RNP) first uses its endonuclease (EN) to nick the genomic DNA. The newly generated DNA end is subsequently used as a primer to initiate reverse transcription within the L1 RNA poly(A) tail, a process known as target-primed reverse transcription (TPRT). Prior studies demonstrated that most L1 insertions occur into sequences related to the L1 EN consensus sequence (degenerate 5'-TTTT/A-3' sites) and frequently preceded by imperfect T-tracts. However, it is currently unclear whether--and to which degree--the liberated 3'-hydroxyl extremity on the genomic DNA needs to be accessible and complementary to the poly(A) tail of the L1 RNA for efficient priming of reverse transcription. Here, we employed a direct assay for the initiation of L1 reverse transcription to define the molecular rules that guide this process. First, efficient priming is detected with as few as 4 matching nucleotides at the primer 3' end. Second, L1 RNP can tolerate terminal mismatches if they are compensated within the 10 last bases of the primer by an increased number of matching nucleotides. All terminal mismatches are not equally detrimental to DNA extension, a C being extended at higher levels than an A or a G. Third, efficient priming in the context of duplex DNA requires a 3' overhang. This suggests the possible existence of additional DNA processing steps, which generate a single-stranded 3' end to allow L1 reverse transcription. Based on these data we propose that the specificity of L1 reverse transcription initiation contributes, together with the specificity of the initial EN cleavage, to the distribution of new L1 insertions within the human genome.

Error reduction and parameter optimization of the TAPIR method for fast T1 mapping.

Science.gov (United States)

Zaitsev, M; Steinhoff, S; Shah, N J

2003-06-01

A methodology is presented for the reduction of both systematic and random errors in T(1) determination using TAPIR, a Look-Locker-based fast T(1) mapping technique. The relations between various sequence parameters were carefully investigated in order to develop recipes for choosing optimal sequence parameters. Theoretical predictions for the optimal flip angle were verified experimentally. Inversion pulse imperfections were identified as the main source of systematic errors in T(1) determination with TAPIR. An effective remedy is demonstrated which includes extension of the measurement protocol to include a special sequence for mapping the inversion efficiency itself. Copyright 2003 Wiley-Liss, Inc.

Columbia University: Direct Reversal of Glucocorticoid Resistance by AKT inhibition in Acute Lymphoblastic Leukemia (T-ALL) | Office of Cancer Genomics

Science.gov (United States)

The goal of this project is to identify key druggable regulators of glucocorticoid resistance in T-ALL. To this end, a reverse-engineered T-ALL context-specific regulatory interaction network was created from a phenotypically diverse T-ALL gene expression dataset, and then this network was interrogated using master regulator analysis to find drivers of glucocorticoid resistance.

Observation of the reversed current effect

International Nuclear Information System (INIS)

Jones, I.R.; Silawatshananai, C.

1979-05-01

The paper describes an observation of the reversed current effect, and its consequences, in a 'stabilized' Z-pinch. Magnetic probe measurements and holographic interferometry were used to follow the development of a reversed current layer and to pinpoint its location in the outer region of the pinched plasma column. The subsequent ejection of the outer plasma layer was observed using fast photography

Prevalence of impaired fasting glucose and type 1 and 2 diabetes mellitus in a large nationwide working population in Spain.

Science.gov (United States)

Reviriego, Jesús; Vázquez, Luis Alberto; Goday, Albert; Cabrera, Martha; García-Margallo, María Teresa; Calvo, Eva

2016-04-01

To report the prevalence of impaired fasting glucose (IFG), undiagnosed and diagnosed diabetes, and their association to occupational categories in a representative sample of working population in Spain. A cross-sectional study of workers who attended routine medical check-ups from January 2007 to December 2007. A structured questionnaire was completed, and physical examinations and routine serum biochemical tests were performed. IFG was defined as fasting glucose levels ranging from 100 to 125 mg/dl with no diagnosis of T1DM or T2DM; T1DM was defined as previous diagnosis of T1DM; and T2DM as previous diagnosis of T2DM, treatment with oral antidiabetic drugs or insulin or fasting glucose levels ≥126 mg/dl, according to ADA criteria. Of the 371,997 participants (median age 35 [interquartile range 29-44] years), 72.4% were male. Raw prevalence rates (95% CI) of IFG, undiagnosed (UKDM), and previously known type 2 (KDM2) and type 1 (KDM1) diabetes were 10.4% (10.3-10.5%), 1.3% (1.2-1.3%), 1.1% (1.1-1.2%), and 0.3% (0.3-0.3%), respectively. With the exception of KDM1, prevalence of these conditions increased with age and was greater among manual/blue-collar workers (12.1%, 1.5%, 1.3% and 0.3%, respectively) as compared to non-manual/white-collar workers (7.3%, 0.8%, 0.8% and 0.3%, respectively). Age- and sex-adjusted prevalence rates of IFG, UKDM and KDM2 were 13.1%, 2.0% and 2.4%, respectively. In this sample of Spanish working population, impaired glycemic profiles were common. Prevalence rates of IFG and T2DM were high among blue-collar workers (except for T1DM). These data emphasize the need for earlier structured preventive schemes. Copyright © 2016 SEEN. Published by Elsevier España, S.L.U. All rights reserved.

Pharmacological approaches to the management of type 2 diabetes in fasting adults during Ramadan

Directory of Open Access Journals (Sweden)

Al Sifri S

2012-08-01

Full Text Available Saud Al SifriEndocrinology Department, Alhada Armed Forces Hospital, Taif, Saudi ArabiaI read with great interest the recent review article by AlMaatouq regarding the pharmacological approaches to the management of type 2 diabetes in fasting adults during Ramadan.1 This article stated that "A recent prospective study of more than 1000 patients with T2DMwho fasted during Ramadan found that the risk of hypoglycemia associated with a vildagliptin-based regimen (vildagliptin 100 mg once daily was lower than that of a sulfonylurea-based regimen (both with and without metformin."1 This statement needs to be corrected.Ramadan is the lunar month observed each year in which Muslim adults will fast. This fast includes abstinence from eating, drinking, and smoking from sunrise to sunset. Hypoglycemia during this period represents the greatest health risk for these patients. Recently introduced modulators of the incretin system are the dipeptidylpeptidase-4 inhibitors, which include sitagliptin, vildagliptin, alogliptin, saxagliptin, and linagliptin. These agents are not associated with hypoglycemia.View original paper by AlMaatouq

Comparison of FSE T2 W PROPELLER and 3D-FIESTA of 3 T MR for the internal auditory canal.

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Wu, Hai-Bo; Yuan, Hui-Shu; Ma, Furong; Zhao, Qiang

The study compared the use of periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) technique fast spin echo (FSE) T2 W and the sequence of three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) technique in the MRI of the internal auditory canal for overall image quality improvement. One hundred thirty-two patients undergoing FSE T2 W PROPELLER and 3D-FIESTA examinations of the internal auditory canal were included. All examinations were performed at 3.0 T with comparison of a sagittal oblique FSE T2 W sequence with the PROPELLER technique to 3D-FIESTA in the same reconstructed orientation with PROPELLER. Image quality was evaluated by two radiologists using a 4-point scale. The Wilcoxon signed rank test was used to compare the data of the two techniques. The image quality of FSE T2 W PROPELLER was significantly improved compared to the reconstructed images of 3D-FIESTA. Observer 1: median FSE T2 W with PROPELLER, 4 [mean, 3.455] versus median reconstructed 3D-FIESTA, 3 [mean, 3.15], (PW with PROPELLER, 4 [mean, 3.47] versus median reconstructed 3D-FIESTA, 3 [mean, 3.25], (PW PROPELLER technique for MRI of internal auditory canal reduced uncertainty caused by motion artifact and improved the quality of the image compared to the reconstructed 3D-FIESTA. It was affected by different parameters including the blade width, echo train length (ETL). This is explained by data oversampling at the center region of k-space, which requires additional imaging time over conventional MRI techniques. Increasing blade was expected to improve motion correction effects but also the signal-to-noise ratio. ETL increases the image sharpness and the overall image quality. Copyright © 2016. Published by Elsevier Inc.

Principles of a reversible programming language

DEFF Research Database (Denmark)

Yokoyama, Tetsuo; Axelsen, Holger Bock; Glück, Robert

2008-01-01

The principles of reversible programming languages are explicated and illustrated with reference to the design of a high-level imperative language, Janus. The fundamental properties for such languages include backward as well as forward determinism and reversible updates of data. The unique design...... languages, and demonstrate this for Janus. We show the practicality of the language by implementation of a reversible fast Fourier transform. Our results indicate that the reversible programming paradigm has fundamental properties that are relevant to many different areas of computer science....... features of the language include explicit post-condition assertions, direct access to an inverse semantics and the possibility of clean (i.e., garbage-free) computation of injective functions. We suggest the clean simulation of reversible Turing machines as a criterion for computing strength of reversible...

Reverse Message-Framing Effects on Accelerometer-Assessed Physical Activity Among Older Outpatients With Type 2 Diabetes.

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Li, Kin-Kit; Ng, Lorna; Cheng, Sheung-Tak; Fung, Helene H

2017-06-01

It has been suggested that gain-framed messages are more effective than loss-framed messages in promoting low-risk health behaviors such as physical activity. Because of a heightened health concern and possible medical complications, older adults with type 2 diabetes (T2D) may consider physical activity to be risky. This study examined whether a reverse message-framing effect would be found among older adults with T2D. The participants included 211 sedentary and older adults with T2D recruited from an outpatient clinic. The participants were randomly assigned to receive either gain-framed or loss-framed messages and wore an accelerometer to monitor their physical activity for 2 weeks. The participants who received loss-framed messages were more physically active than those who received gain-framed messages (β = 0.13, p = .033). This loss-frame advantage might be attributable to the heightened perceived risks among older outpatients with T2D and the temporarily activated prevention-focused orientation in a clinical setting.

Impaired incretin effect and fasting hyperglucagonaemia characterizing type 2 diabetic subjects are early signs of dysmetabolism in obesity.

Science.gov (United States)

Knop, Filip K; Aaboe, K; Vilsbøll, T; Vølund, A; Holst, J J; Krarup, T; Madsbad, S

2012-06-01

People with type 2 diabetes mellitus (T2DM) are characterized by reduced incretin effect and inappropriate glucagon levels. We evaluated α and β-cell responses to oral glucose tolerance test (OGTT) and isoglycaemic intravenous glucose infusion (IIGI) in lean and obese persons with T2DM or normal glucose tolerance (NGT) to elucidate the impact of obesity on the incretin effect and incretin hormone and glucagon responses. Four hour 50-g OGTT and IIGI were performed in (i) Eight obese patients with T2DM [mean body mass index (BMI): 37 (range: 35-41) kg/m(2)]; (ii) Eight obese subjects with NGT [BMI: 33 (35-38) kg/m(2)]; (iii) Eight lean patients with T2DM [BMI: 24 (22-25) kg/m(2)]; and (iv) Eight lean healthy subjects [BMI: 23 (20-25) kg/m(2)]. The incretin effect was significantly (p obese: 7 ± 7% [mean ± standard error of the mean (SEM)]; lean: 29 ± 8%; p = 0.06)} and was lower in obese subjects (41 ± 4%) than in lean subjects with NGT (53 ± 4%; p Obese subjects with NGT were also characterized by elevated fasting plasma glucagon levels, but the inappropriate glucagon responses to OGTT found in the T2DM patients were not evident in these subjects. Our findings suggest that reduced incretin effect and fasting hyperglucagonaemia constitute very early steps in the pathophysiology of T2DM detectable even in obese people who despite their insulin-resistant state have NGT. © 2011 Blackwell Publishing Ltd.

Assessment of Myocardial Fibrosis in Mice Using a T2*-Weighted 3D Radial Magnetic Resonance Imaging Sequence.

Directory of Open Access Journals (Sweden)

Bastiaan J van Nierop

Full Text Available Myocardial fibrosis is a common hallmark of many diseases of the heart. Late gadolinium enhanced MRI is a powerful tool to image replacement fibrosis after myocardial infarction (MI. Interstitial fibrosis can be assessed indirectly from an extracellular volume fraction measurement using contrast-enhanced T1 mapping. Detection of short T2* species resulting from fibrotic tissue may provide an attractive non-contrast-enhanced alternative to directly visualize the presence of both replacement and interstitial fibrosis.To goal of this paper was to explore the use of a T2*-weighted radial sequence for the visualization of fibrosis in mouse heart.C57BL/6 mice were studied with MI (n = 20, replacement fibrosis, transverse aortic constriction (TAC (n = 18, diffuse fibrosis, and as control (n = 10. 3D center-out radial T2*-weighted images with varying TE were acquired in vivo and ex vivo (TE = 21 μs-4 ms. Ex vivo T2*-weighted signal decay with TE was analyzed using a 3-component model. Subtraction of short- and long-TE images was used to highlight fibrotic tissue with short T2*. The presence of fibrosis was validated using histology and correlated to MRI findings.Detailed ex vivo T2*-weighted signal analysis revealed a fast (T2*fast, slow (T2*slow and lipid (T2*lipid pool. T2*fast remained essentially constant. Infarct T2*slow decreased significantly, while a moderate decrease was observed in remote tissue in post-MI hearts and in TAC hearts. T2*slow correlated with the presence of diffuse fibrosis in TAC hearts (r = 0.82, P = 0.01. Ex vivo and in vivo subtraction images depicted a positive contrast in the infarct co-localizing with the scar. Infarct volumes from histology and subtraction images linearly correlated (r = 0.94, P<0.001. Region-of-interest analysis in the in vivo post-MI and TAC hearts revealed significant T2* shortening due to fibrosis, in agreement with the ex vivo results. However, in vivo contrast on subtraction images was rather poor

Temperature dependent polarization reversal mechanism in 0.94(Bi1/2Na1/2) TiO3-0.06Ba(Zr0.02Ti0.98)O3 relaxor ceramics

DEFF Research Database (Denmark)

Glaum, Julia; Simons, Hugh; Hudspeth, Jessica

2015-01-01

and structural investigation of the polarization reversal process in the prototypical lead-free relaxor 0.94(Bi1/2Na1/2)TiO3-0.06Ba(Zr0.02Ti0.98)O3 reveals that an applied electric field can trigger depolarization and onset of relaxor-like behavior well below TF-R. The polarization reversal process can...... as such be described as a combination of (1) ferroelectric domain switching and (2) a reversible phase transition between two polar ferroelectric states mediated by a non-polar relaxor state. Furthermore, the threshold fields of the second, mediated polarization reversal mechanism depend strongly on temperature....... These results are concomitant with a continuous ferroelectric to relaxortransition occurring over a broad temperature range, during which mixed behavior is observed. The nature of polarization reversal can be illustrated in electric-field-temperature (E-T) diagrams showing the electric field amplitudes...

Error Field Assessment from Driven Mode Rotation: Results from Extrap-T2R Reversed-Field-Pinch and Perspectives for ITER

Science.gov (United States)

Volpe, F. A.; Frassinetti, L.; Brunsell, P. R.; Drake, J. R.; Olofsson, K. E. J.

2012-10-01

A new ITER-relevant non-disruptive error field (EF) assessment technique not restricted to low density and thus low beta was demonstrated at the Extrap-T2R reversed field pinch. Resistive Wall Modes (RWMs) were generated and their rotation sustained by rotating magnetic perturbations. In particular, stable modes of toroidal mode number n=8 and 10 and unstable modes of n=1 were used in this experiment. Due to finite EFs, and in spite of the applied perturbations rotating uniformly and having constant amplitude, the RWMs were observed to rotate non-uniformly and be modulated in amplitude (in the case of unstable modes, the observed oscillation was superimposed to the mode growth). This behavior was used to infer the amplitude and toroidal phase of n=1, 8 and 10 EFs. The method was first tested against known, deliberately applied EFs, and then against actual intrinsic EFs. Applying equal and opposite corrections resulted in longer discharges and more uniform mode rotation, indicating good EF compensation. The results agree with a simple theoretical model. Extensions to tearing modes, to the non-uniform plasma response to rotating perturbations, and to tokamaks, including ITER, will be discussed.

Parallelization of Reversible Ripple-carry Adders

DEFF Research Database (Denmark)

Thomsen, Michael Kirkedal; Axelsen, Holger Bock

2009-01-01

The design of fast arithmetic logic circuits is an important research topic for reversible and quantum computing. A special challenge in this setting is the computation of standard arithmetical functions without the generation of \\emph{garbage}. Here, we present a novel parallelization scheme...... wherein $m$ parallel $k$-bit reversible ripple-carry adders are combined to form a reversible $mk$-bit \\emph{ripple-block carry adder} with logic depth $\\mathcal{O}(m+k)$ for a \\emph{minimal} logic depth $\\mathcal{O}(\\sqrt{mk})$, thus improving on the $mk$-bit ripple-carry adder logic depth $\\mathcal...

The product of fasting plasma glucose and triglycerides improves risk prediction of type 2 diabetes in middle-aged Koreans.

Science.gov (United States)

Lee, Joung-Won; Lim, Nam-Kyoo; Park, Hyun-Young

2018-05-30

Screening for risk of type 2 diabetes mellitus (T2DM) is an important public health issue. Previous studies report that fasting plasma glucose (FPG) and triglyceride (TG)-related indices, such as lipid accumulation product (LAP) and the product of fasting glucose and triglyceride (TyG index), are associated with incident T2DM. We aimed to evaluate whether FPG or TG-related indices can improve the predictive ability of a diabetes risk model for middle-aged Koreans. 7708 Koreans aged 40-69 years without diabetes at baseline were eligible from the Korean Genome and Epidemiology Study. The overall cumulative incidence of T2DM was 21.1% (766 cases) in men and 19.6% (797 cases) in women. Therefore, the overall cumulative incidence of T2DM was 20.3% (1563 cases). Multiple logistic regression analysis was conducted to compare the odds ratios (ORs) for incident T2DM for each index. The area under the receiver operating characteristic curve (AROC), continuous net reclassification improvement (cNRI), and integrated discrimination improvement (IDI) were calculated when each measure was added to the basic risk model for diabetes. All the TG-related indices and FPG were more strongly associated with incident T2DM than WC in our study population. The adjusted ORs for the highest quartiles of WC, TG, FPG, LAP, and TyG index compared to the lowest, were 1.64 (95% CI, 1.13-2.38), 2.03 (1.59-2.61), 3.85 (2.99-4.97), 2.47 (1.82-3.34), and 2.79 (2.16-3.60) in men, and 1.17 (0.83-1.65), 2.42 (1.90-3.08), 2.15 (1.71-2.71), 2.44 (1.82-3.26), and 2.85 (2.22-3.66) in women, respectively. The addition of TG-related parameters or FPG, but not WC, to the basic risk model for T2DM (including age, body mass index, family history of diabetes, hypertension, current smoking, current drinking, and regular exercise) significantly increased cNRI, IDI, and AROC in both sexes. Adding either TyG index or FPG into the basic risk model for T2DM increases its prediction and reclassification ability

Reversal of CD8 T-Cell–Mediated Mucocutaneous Graft-Versus-Host-Like Disease by the JAK Inhibitor Tofacitinib

Science.gov (United States)

Okiyama, Naoko; Furumoto, Yasuko; Villarroel, Vadim A; Linton, Jay T; Tsai, Wanxia L; Gutermuth, Jan; Ghoreschi, Kamran; Gadina, Massimo; O'Shea, John J; Katz, Stephen I

2014-01-01

The utility of allogeneic hematopoietic stem cell transplantation is limited by graft-versus-host disease (GVHD), a significant cause of morbidity and mortality. Patients with GVHD exhibit cutaneous manifestations with histological features of interface dermatitis followed by scleroderma-like changes. JAK inhibitors represent a class of immunomodulatory drugs that inhibit signaling by multiple cytokines. Herein we report the effects of tofacitinib in a murine model of GVHD. Oral administration of tofacitinib prevented GVHD-like disease manifested by weight loss and mucocutaneous lesions. More importantly, tofacitinib was also effective in reversing established disease. Tofacitinib diminished the expansion and activation of murine CD8 T cells in this model, and had similar effects on IL-2-stimulated human CD8 T cells. Tofacitinib also inhibited the expression of IFN-γ-inducible chemoattractants by keratinocytes, and IFN-γ-inducible cell death of keratinocytes. Tofacitinib may be an effective drug for treatment against CD8 T-cell–mediated mucocutaneous diseases in patients with GVHD. PMID:24213371

Electrostatic Fluxes and Plasma Rotation in the Edge Region of EXTRAP-T2R

Science.gov (United States)

Serianni, G.; Antoni, V.; Bergsåker, H.; Brunsell, P.; Drake, J. R.; Spolaore, M.; Sätherblom, H. E.; Vianello, N.

2001-10-01

The EXTRAP-T2 reversed field pinch has undergone a significant reconstruction into the new T2R device. This paper reports the first measurements performed with Langmuir probes in the edge region of EXTRAP-T2R. The radial profiles of plasma parameters like electron density and temperature, plasma potential, electrical fields and electrostatic turbulence-driven particle flux are presented. These profiles are interpreted in a momentum balance model where finite Larmor radius losses occur over a distance of about two Larmor radii from the limiter position. The double shear layer of the E×B drift velocity is discussed in terms of the Biglari-Diamond-Terry theory of turbulence decorrelation.

Fast CSF MRI for brain segmentation; Cross-validation by comparison with 3D T1-based brain segmentation methods.

Science.gov (United States)

van der Kleij, Lisa A; de Bresser, Jeroen; Hendrikse, Jeroen; Siero, Jeroen C W; Petersen, Esben T; De Vis, Jill B

2018-01-01

In previous work we have developed a fast sequence that focusses on cerebrospinal fluid (CSF) based on the long T2 of CSF. By processing the data obtained with this CSF MRI sequence, brain parenchymal volume (BPV) and intracranial volume (ICV) can be automatically obtained. The aim of this study was to assess the precision of the BPV and ICV measurements of the CSF MRI sequence and to validate the CSF MRI sequence by comparison with 3D T1-based brain segmentation methods. Ten healthy volunteers (2 females; median age 28 years) were scanned (3T MRI) twice with repositioning in between. The scan protocol consisted of a low resolution (LR) CSF sequence (0:57min), a high resolution (HR) CSF sequence (3:21min) and a 3D T1-weighted sequence (6:47min). Data of the HR 3D-T1-weighted images were downsampled to obtain LR T1-weighted images (reconstructed imaging time: 1:59 min). Data of the CSF MRI sequences was automatically segmented using in-house software. The 3D T1-weighted images were segmented using FSL (5.0), SPM12 and FreeSurfer (5.3.0). The mean absolute differences for BPV and ICV between the first and second scan for CSF LR (BPV/ICV: 12±9/7±4cc) and CSF HR (5±5/4±2cc) were comparable to FSL HR (9±11/19±23cc), FSL LR (7±4, 6±5cc), FreeSurfer HR (5±3/14±8cc), FreeSurfer LR (9±8, 12±10cc), and SPM HR (5±3/4±7cc), and SPM LR (5±4, 5±3cc). The correlation between the measured volumes of the CSF sequences and that measured by FSL, FreeSurfer and SPM HR and LR was very good (all Pearson's correlation coefficients >0.83, R2 .67-.97). The results from the downsampled data and the high-resolution data were similar. Both CSF MRI sequences have a precision comparable to, and a very good correlation with established 3D T1-based automated segmentations methods for the segmentation of BPV and ICV. However, the short imaging time of the fast CSF MRI sequence is superior to the 3D T1 sequence on which segmentation with established methods is performed.

Evaluation of MR imaging with T1 and T2* mapping for the determination of hepatic iron overload.

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Henninger, B; Kremser, C; Rauch, S; Eder, R; Zoller, H; Finkenstedt, A; Michaely, H J; Schocke, M

2012-11-01

To evaluate MRI using T1 and T2* mapping sequences in patients with suspected hepatic iron overload (HIO). Twenty-five consecutive patients with clinically suspected HIO were retrospectively studied. All underwent MRI and liver biopsy. For the quantification of liver T2* values we used a fat-saturated multi-echo gradient echo sequence with 12 echoes (TR = 200 ms, TE = 0.99 ms +  n × 1.41 ms, flip angle 20°). T1 values were obtained using a fast T1 mapping sequence based on an inversion recovery snapshot FLASH sequence. Parameter maps were analysed using regions of interest. ROC analysis calculated cut-off points at 10.07 ms and 15.47 ms for T2* in the determination of HIO with accuracy 88 %/88 %, sensitivity 84 %/89.5 % and specificity 100 %/83 %. MRI correctly classified 20 patients (80 %). All patients with HIO only had decreased T1 and T2* relaxation times. There was a significant difference in T1 between patients with HIO only and patients with HIO and steatohepatitis (P = 0.018). MRI-based T2* relaxation diagnoses HIO very accurately, even at low iron concentrations. Important additional information may be obtained by the combination of T1 and T2* mapping. It is a rapid, non-invasive, accurate and reproducible technique for validating the evidence of even low hepatic iron concentrations. • Hepatic iron overload causes fibrosis, cirrhosis and increases hepatocellular carcinoma risk. • MRI detects iron because of the field heterogeneity generated by haemosiderin. • T2* relaxation is very accurate in diagnosing hepatic iron overload. • Additional information may be obtained by T1 and T2* mapping.

Progression from impaired fasting glucose to type 2 diabetes mellitus among Chinese subjects with and without hypertension in a primary care setting.

Science.gov (United States)

Fu, Sau Nga; Luk, Wan; Wong, Carlos King Ho; Cheung, Kwok Leung

2014-09-01

The progression from impaired fasting glucose (IFG) to type 2 diabetes mellitus (T2DM) in Chinese subjects, with and without hypertension, in a primary care setting was unknown. The present retrospective multicenter 5-year (2002-2007) cohort study was performed on IFG subjects attending 23 general outpatient clinics who were identified by their elevated fasting blood glucose laboratory results. Development of T2DM was determined by physician diagnosis of T2DM or starting of oral antidiabetic drugs within 5 years. The relationship between the time of T2DM diagnosis and subject characteristics was assessed by adjusted hazard ratios (aHR) from Cox hazards model. Of the 9161 IFG subjects, 4080 (45%) were men and 5081 (55%) were women. There were 1998 subjects who developed T2DM. The 5-year cumulative incidence was 0.218, whereas the overall annual incidence rate was 5.981/100 person-years. Subjects were more likely to develop T2DM if they were hypertensive (aHR = 1.44; 95% confidence interval [CI] 1.28-1.62; P < 0.001), aged <60 years (aHR = 1.36, 95% CI 1.24-1.49; P < 0.001), female (aHR = 1.18, 95% CI 1.08-1.29; P < 0.001), and had higher fasting glucose levels (6.39 ± 0.49 vs 6.24 ± 0.43 mmol/L in the group that developed T2DM vs the group without T2DM, respectively; aHR = 2.01, 95% CI 1.83-2.20; P < 0.001). Overall, more than one-fifth of IFG subjects in the primary care setting developed T2DM within 5 years. Health care professionals can target interventions to patients with risk factors for disease progression. © 2014 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

Geomagnetic reversal rates following Palaeozoic superchrons have a fast restart mechanism.

Science.gov (United States)

Hounslow, Mark W

2016-08-30

Long intervals of single geomagnetic polarity (superchrons) reflect geodynamo processes, driven by core-mantle boundary interactions; however, it is not clear what initiates the start and end of superchrons, other than superchrons probably reflect lower heat flow across the core-mantle boundary compared with adjacent intervals. Here geomagnetic polarity timescales, with confidence intervals, are constructed before and following the reverse polarity Kiaman (Carboniferous-Permian) and Moyero (Ordovician) superchrons, providing a window into the geodynamo processes. Similar to the Cretaceous, asymmetry in reversal rates is seen in the Palaeozoic superchrons, but the higher reversal rates imply higher heatflow thresholds for entering the superchron state. Similar to the Cretaceous superchron, unusually long-duration chrons characterize the ∼10 Myr interval adjacent to the superchrons, indicating a transitional reversing state to the superchrons. This may relate to a weak pattern in the clustering of chron durations superimposed on the dominant random arrangement of chron durations.

Magnetic resonance fingerprinting using echo-planar imaging: Joint quantification of T1 and T2∗ relaxation times.

Science.gov (United States)

Rieger, Benedikt; Zimmer, Fabian; Zapp, Jascha; Weingärtner, Sebastian; Schad, Lothar R

2017-11-01

To develop an implementation of the magnetic resonance fingerprinting (MRF) paradigm for quantitative imaging using echo-planar imaging (EPI) for simultaneous assessment of T 1 and T2∗. The proposed MRF method (MRF-EPI) is based on the acquisition of 160 gradient-spoiled EPI images with rapid, parallel-imaging accelerated, Cartesian readout and a measurement time of 10 s per slice. Contrast variation is induced using an initial inversion pulse, and varying the flip angles, echo times, and repetition times throughout the sequence. Joint quantification of T 1 and T2∗ is performed using dictionary matching with integrated B1+ correction. The quantification accuracy of the method was validated in phantom scans and in vivo in 6 healthy subjects. Joint T 1 and T2∗ parameter maps acquired with MRF-EPI in phantoms are in good agreement with reference measurements, showing deviations under 5% and 4% for T 1 and T2∗, respectively. In vivo baseline images were visually free of artifacts. In vivo relaxation times are in good agreement with gold-standard techniques (deviation T 1 : 4 ± 2%, T2∗: 4 ± 5%). The visual quality was comparable to the in vivo gold standard, despite substantially shortened scan times. The proposed MRF-EPI method provides fast and accurate T 1 and T2∗ quantification. This approach offers a rapid supplement to the non-Cartesian MRF portfolio, with potentially increased usability and robustness. Magn Reson Med 78:1724-1733, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Reverse engineering of TLX oncogenic transcriptional networks identifies RUNX1 as tumor suppressor in T-ALL.

Science.gov (United States)

Della Gatta, Giusy; Palomero, Teresa; Perez-Garcia, Arianne; Ambesi-Impiombato, Alberto; Bansal, Mukesh; Carpenter, Zachary W; De Keersmaecker, Kim; Sole, Xavier; Xu, Luyao; Paietta, Elisabeth; Racevskis, Janis; Wiernik, Peter H; Rowe, Jacob M; Meijerink, Jules P; Califano, Andrea; Ferrando, Adolfo A

2012-02-26

The TLX1 and TLX3 transcription factor oncogenes have a key role in the pathogenesis of T cell acute lymphoblastic leukemia (T-ALL). Here we used reverse engineering of global transcriptional networks to decipher the oncogenic regulatory circuit controlled by TLX1 and TLX3. This systems biology analysis defined T cell leukemia homeobox 1 (TLX1) and TLX3 as master regulators of an oncogenic transcriptional circuit governing T-ALL. Notably, a network structure analysis of this hierarchical network identified RUNX1 as a key mediator of the T-ALL induced by TLX1 and TLX3 and predicted a tumor-suppressor role for RUNX1 in T cell transformation. Consistent with these results, we identified recurrent somatic loss-of-function mutations in RUNX1 in human T-ALL. Overall, these results place TLX1 and TLX3 at the top of an oncogenic transcriptional network controlling leukemia development, show the power of network analyses to identify key elements in the regulatory circuits governing human cancer and identify RUNX1 as a tumor-suppressor gene in T-ALL.

Optimization image of magnetic resonance imaging (MRI) T2 fast spin echo (FSE) with variation echo train length (ETL) on the rupture tendon achilles case

International Nuclear Information System (INIS)

Muzamil, Akhmad; Firmansyah, Achmad Haries

2017-01-01

The research was done the optimization image of Magnetic Resonance Imaging (MRI) T2 Fast Spin Echo (FSE) with variation Echo Train Length (ETL) on the Rupture Tendon Achilles case. This study aims to find the variations Echo Train Length (ETL) from the results of ankle’s MRI image and find out how the value of Echo Train Length (ETL) works on the MRI ankle to produce optimal image. In this research, the used ETL variations were 12 and 20 with the interval 2 on weighting T2 FSE sagittal. The study obtained the influence of Echo Train Length (ETL) on the quality of ankle MRI image sagittal using T2 FSE weighting and analyzed in 25 images of five patients. The data analysis has done quantitatively with the Region of Interest (ROI) directly on computer MRI image planes which conducted statistical tests Signal to Noise Ratio (SNR) and Contras to Noise Ratio (CNR). The Signal to Noise Ratio (SNR) was the highest finding on fat tissue, while the Contras to Noise Ratio (CNR) on the Tendon-Fat tissue with ETL 12 found in two patients. The statistics test showed the significant SNR value of the 0.007 (p<0.05) of Tendon tissue, 0.364 (p>0.05) of the Fat, 0.912 (p>0.05) of the Fibula, and 0.436 (p>0.05) of the Heel Bone. For the contrast to noise ratio (CNR) of the Tendon-FAT tissue was about 0.041 (p>0.05). The results of the study showed that ETL variation with T2 FSE sagittal weighting had difference at Tendon tissue and Tendon-Fat tissue for MRI imaging quality. SNR and CNR were an important aspect on imaging optimization process to give the diagnose information. (paper)

Low-frequency and rare exome chip variants associate with fasting glucose and type 2 diabetes susceptibility

DEFF Research Database (Denmark)

Wessel, Jennifer; Chu, Audrey Y; Willems, Sara M

2015-01-01

Fasting glucose and insulin are intermediate traits for type 2 diabetes. Here we explore the role of coding variation on these traits by analysis of variants on the HumanExome BeadChip in 60,564 non-diabetic individuals and in 16,491 T2D cases and 81,877 controls. We identify a novel association...

Fast CSF MRI for brain segmentation; Cross-validation by comparison with 3D T1-based brain segmentation methods

DEFF Research Database (Denmark)

van der Kleij, Lisa A.; de Bresser, Jeroen; Hendrikse, Jeroen

2018-01-01

ObjectiveIn previous work we have developed a fast sequence that focusses on cerebrospinal fluid (CSF) based on the long T-2 of CSF. By processing the data obtained with this CSF MRI sequence, brain parenchymal volume (BPV) and intracranial volume (ICV) can be automatically obtained. The aim...... of this study was to assess the precision of the BPV and ICV measurements of the CSF MRI sequence and to validate the CSF MRI sequence by comparison with 3D T-1-based brain segmentation methods.Materials and methodsTen healthy volunteers (2 females; median age 28 years) were scanned (3T MRI) twice......cc) and CSF HR (5 +/- 5/4 +/- 2cc) were comparable to FSL HR (9 +/- 11/19 +/- 23cc), FSL LR (7 +/- 4,6 +/- 5cc),FreeSurfer HR (5 +/- 3/14 +/- 8cc), FreeSurfer LR (9 +/- 8,12 +/- 10cc), and SPM HR (5 +/- 3/4 +/- 7cc), and SPM LR (5 +/- 4,5 +/- 3cc). The correlation between the measured volumes...

Effect of Ramadan Fasting on Anthropometric Measures and Metabolic Profiles among Type 2 Diabetic Subjects

Directory of Open Access Journals (Sweden)

Ajit Kumar Paul

2015-05-01

Full Text Available Background: Fasting from dawn to dusk during the month of Holy Ramadan is obligatory for all healthy adult Muslims. Individuals are exempted from fasting if they are suffering from an illness that could be adversely affected by fasting. Although The Quran exempts sick people from fasting, many Muslim diabetic patients may not perceive themselves as sick and are keenly interested to fast. But they fast without proper medical guidance exposing themselves to certain risks as a direct consequence of fasting. So we designed this study to assess the impact of fasting during Ramadan and to evaluate the effects of fasting on their biochemical profiles in patients with diabetes. Objective: The objective of this study was to investigate whether Ramadan fasting has any effect on body weight, blood pressure, fasting glucose, HbA1C, serum lipids, serum creatinine among type 2 diabetic patients. Materials and Methods: Fifty two stable outpatients with type 2 diabetes with intention to fast were studied in the month of Ramadan 1434 Hijri calendar year (11th July to 9th August, 2013 at two points of time: one week before Ramadan (visit 1 and within last 3 days before the end of Ramadan (visit 2. During each visit the height, body weight and blood pressure were recorded. Blood samples were collected for fasting glucose, HbA1C, total cholesterol, triglyceride, high density and low density lipoprotein cholesterol and creatinine. Data were analyzed by Student’s paired t-test using SPSS system and results were expressed as mean ± SD. Probability values were considered to be significant if it was less than 0.05. Results: There were 30 (62.8% males and 22 (37.2% females with a mean age of 54.7 ± 11.55 (range 35–80 years and mean duration of diabetes was 5.5 ± 5.2 years (range 9 months–18 years. In this study mean weight of the patients decreased significantly from 60.5 ± 12.6 kg to 58.5 ± 11.3 kg (p<0.001. Blood pressure reduced but not significantly

3D Fast Spin Echo T2-weighted Contrast for Imaging the Female Cervix

Science.gov (United States)

Vargas Sanchez, Andrea Fernanda

Magnetic Resonance Imaging (MRI) with T2-weighted contrast is the preferred modality for treatment planning and monitoring of cervical cancer. Current clinical protocols image the volume of interest multiple times with two dimensional (2D) T2-weighted MRI techniques. It is of interest to replace these multiple 2D acquisitions with a single three dimensional (3D) MRI acquisition to save time. However, at present the image contrast of standard 3D MRI does not distinguish cervical healthy tissue from cancerous tissue. The purpose of this thesis is to better understand the underlying factors that govern the contrast of 3D MRI and exploit this understanding via sequence modifications to improve the contrast. Numerical simulations are developed to predict observed contrast alterations and to propose an improvement. Improvements of image contrast are shown in simulation and with healthy volunteers. Reported results are only preliminary but a promising start to establish definitively 3D MRI for cervical cancer applications.

New genetic loci implicated in fasting glucose homeostasis and their impact on type 2 diabetes risk

Science.gov (United States)

Dupuis, Josée; Langenberg, Claudia; Prokopenko, Inga; Saxena, Richa; Soranzo, Nicole; Jackson, Anne U; Wheeler, Eleanor; Glazer, Nicole L; Bouatia-Naji, Nabila; Gloyn, Anna L; Lindgren, Cecilia M; Mägi, Reedik; Morris, Andrew P; Randall, Joshua; Johnson, Toby; Elliott, Paul; Rybin, Denis; Thorleifsson, Gudmar; Steinthorsdottir, Valgerdur; Henneman, Peter; Grallert, Harald; Dehghan, Abbas; Hottenga, Jouke Jan; Franklin, Christopher S; Navarro, Pau; Song, Kijoung; Goel, Anuj; Perry, John R B; Egan, Josephine M; Lajunen, Taina; Grarup, Niels; Sparsø, Thomas; Doney, Alex; Voight, Benjamin F; Stringham, Heather M; Li, Man; Kanoni, Stavroula; Shrader, Peter; Cavalcanti-Proença, Christine; Kumari, Meena; Qi, Lu; Timpson, Nicholas J; Gieger, Christian; Zabena, Carina; Rocheleau, Ghislain; Ingelsson, Erik; An, Ping; O’Connell, Jeffrey; Luan, Jian'an; Elliott, Amanda; McCarroll, Steven A; Payne, Felicity; Roccasecca, Rosa Maria; Pattou, François; Sethupathy, Praveen; Ardlie, Kristin; Ariyurek, Yavuz; Balkau, Beverley; Barter, Philip; Beilby, John P; Ben-Shlomo, Yoav; Benediktsson, Rafn; Bennett, Amanda J; Bergmann, Sven; Bochud, Murielle; Boerwinkle, Eric; Bonnefond, Amélie; Bonnycastle, Lori L; Borch-Johnsen, Knut; Böttcher, Yvonne; Brunner, Eric; Bumpstead, Suzannah J; Charpentier, Guillaume; Chen, Yii-Der Ida; Chines, Peter; Clarke, Robert; Coin, Lachlan J M; Cooper, Matthew N; Cornelis, Marilyn; Crawford, Gabe; Crisponi, Laura; Day, Ian N M; de Geus, Eco; Delplanque, Jerome; Dina, Christian; Erdos, Michael R; Fedson, Annette C; Fischer-Rosinsky, Antje; Forouhi, Nita G; Fox, Caroline S; Frants, Rune; Franzosi, Maria Grazia; Galan, Pilar; Goodarzi, Mark O; Graessler, Jürgen; Groves, Christopher J; Grundy, Scott; Gwilliam, Rhian; Gyllensten, Ulf; Hadjadj, Samy; Hallmans, Göran; Hammond, Naomi; Han, Xijing; Hartikainen, Anna-Liisa; Hassanali, Neelam; Hayward, Caroline; Heath, Simon C; Hercberg, Serge; Herder, Christian; Hicks, Andrew A; Hillman, David R; Hingorani, Aroon D; Hofman, Albert; Hui, Jennie; Hung, Joe; Isomaa, Bo; Johnson, Paul R V; Jørgensen, Torben; Jula, Antti; Kaakinen, Marika; Kaprio, Jaakko; Kesaniemi, Y Antero; Kivimaki, Mika; Knight, Beatrice; Koskinen, Seppo; Kovacs, Peter; Kyvik, Kirsten Ohm; Lathrop, G Mark; Lawlor, Debbie A; Le Bacquer, Olivier; Lecoeur, Cécile; Li, Yun; Lyssenko, Valeriya; Mahley, Robert; Mangino, Massimo; Manning, Alisa K; Martínez-Larrad, María Teresa; McAteer, Jarred B; McCulloch, Laura J; McPherson, Ruth; Meisinger, Christa; Melzer, David; Meyre, David; Mitchell, Braxton D; Morken, Mario A; Mukherjee, Sutapa; Naitza, Silvia; Narisu, Narisu; Neville, Matthew J; Oostra, Ben A; Orrù, Marco; Pakyz, Ruth; Palmer, Colin N A; Paolisso, Giuseppe; Pattaro, Cristian; Pearson, Daniel; Peden, John F; Pedersen, Nancy L.; Perola, Markus; Pfeiffer, Andreas F H; Pichler, Irene; Polasek, Ozren; Posthuma, Danielle; Potter, Simon C; Pouta, Anneli; Province, Michael A; Psaty, Bruce M; Rathmann, Wolfgang; Rayner, Nigel W; Rice, Kenneth; Ripatti, Samuli; Rivadeneira, Fernando; Roden, Michael; Rolandsson, Olov; Sandbaek, Annelli; Sandhu, Manjinder; Sanna, Serena; Sayer, Avan Aihie; Scheet, Paul; Scott, Laura J; Seedorf, Udo; Sharp, Stephen J; Shields, Beverley; Sigurðsson, Gunnar; Sijbrands, Erik J G; Silveira, Angela; Simpson, Laila; Singleton, Andrew; Smith, Nicholas L; Sovio, Ulla; Swift, Amy; Syddall, Holly; Syvänen, Ann-Christine; Tanaka, Toshiko; Thorand, Barbara; Tichet, Jean; Tönjes, Anke; Tuomi, Tiinamaija; Uitterlinden, André G; van Dijk, Ko Willems; van Hoek, Mandy; Varma, Dhiraj; Visvikis-Siest, Sophie; Vitart, Veronique; Vogelzangs, Nicole; Waeber, Gérard; Wagner, Peter J; Walley, Andrew; Walters, G Bragi; Ward, Kim L; Watkins, Hugh; Weedon, Michael N; Wild, Sarah H; Willemsen, Gonneke; Witteman, Jaqueline C M; Yarnell, John W G; Zeggini, Eleftheria; Zelenika, Diana; Zethelius, Björn; Zhai, Guangju; Zhao, Jing Hua; Zillikens, M Carola; Borecki, Ingrid B; Loos, Ruth J F; Meneton, Pierre; Magnusson, Patrik K E; Nathan, David M; Williams, Gordon H; Hattersley, Andrew T; Silander, Kaisa; Salomaa, Veikko; Smith, George Davey; Bornstein, Stefan R; Schwarz, Peter; Spranger, Joachim; Karpe, Fredrik; Shuldiner, Alan R; Cooper, Cyrus; Dedoussis, George V; Serrano-Ríos, Manuel; Morris, Andrew D; Lind, Lars; Palmer, Lyle J; Hu, Frank B.; Franks, Paul W; Ebrahim, Shah; Marmot, Michael; Kao, W H Linda; Pankow, James S; Sampson, Michael J; Kuusisto, Johanna; Laakso, Markku; Hansen, Torben; Pedersen, Oluf; Pramstaller, Peter Paul; Wichmann, H Erich; Illig, Thomas; Rudan, Igor; Wright, Alan F; Stumvoll, Michael; Campbell, Harry; Wilson, James F; Hamsten, Anders; Bergman, Richard N; Buchanan, Thomas A; Collins, Francis S; Mohlke, Karen L; Tuomilehto, Jaakko; Valle, Timo T; Altshuler, David; Rotter, Jerome I; Siscovick, David S; Penninx, Brenda W J H; Boomsma, Dorret; Deloukas, Panos; Spector, Timothy D; Frayling, Timothy M; Ferrucci, Luigi; Kong, Augustine; Thorsteinsdottir, Unnur; Stefansson, Kari; van Duijn, Cornelia M; Aulchenko, Yurii S; Cao, Antonio; Scuteri, Angelo; Schlessinger, David; Uda, Manuela; Ruokonen, Aimo; Jarvelin, Marjo-Riitta; Waterworth, Dawn M; Vollenweider, Peter; Peltonen, Leena; Mooser, Vincent; Abecasis, Goncalo R; Wareham, Nicholas J; Sladek, Robert; Froguel, Philippe; Watanabe, Richard M; Meigs, James B; Groop, Leif; Boehnke, Michael; McCarthy, Mark I; Florez, Jose C; Barroso, Inês

2010-01-01

Circulating glucose levels are tightly regulated. To identify novel glycemic loci, we performed meta-analyses of 21 genome-wide associations studies informative for fasting glucose (FG), fasting insulin (FI) and indices of β-cell function (HOMA-B) and insulin resistance (HOMA-IR) in up to 46,186 non-diabetic participants. Follow-up of 25 loci in up to 76,558 additional subjects identified 16 loci associated with FG/HOMA-B and two associated with FI/HOMA-IR. These include nine new FG loci (in or near ADCY5, MADD, ADRA2A, CRY2, FADS1, GLIS3, SLC2A2, PROX1 and FAM148B) and one influencing FI/HOMA-IR (near IGF1). We also demonstrated association of ADCY5, PROX1, GCK, GCKR and DGKB/TMEM195 with type 2 diabetes (T2D). Within these loci, likely biological candidate genes influence signal transduction, cell proliferation, development, glucose-sensing and circadian regulation. Our results demonstrate that genetic studies of glycemic traits can identify T2D risk loci, as well as loci that elevate FG modestly, but do not cause overt diabetes. PMID:20081858

Metabolism and thermoregulation during fasting in king penguins, Aptenodytes patagonicus, in air and water.

Science.gov (United States)

Fahlman, A; Schmidt, A; Handrich, Y; Woakes, A J; Butler, P J

2005-09-01

We measured oxygen consumption rate (Vo(2)) and body temperatures in 10 king penguins in air and water. Vo(2) was measured during rest and at submaximal and maximal exercise before (fed) and after (fasted) an average fasting duration of 14.4 +/- 2.3 days (mean +/- 1 SD, range 10-19 days) in air and water. Concurrently, we measured subcutaneous temperature and temperature of the upper (heart and liver), middle (stomach) and lower (intestine) abdomen. The mean body mass (M(b)) was 13.8 +/- 1.2 kg in fed and 11.0 +/- 0.6 kg in fasted birds. After fasting, resting Vo(2) was 93% higher in water than in air (air: 86.9 +/- 8.8 ml/min; water: 167.3 +/- 36.7 ml/min, P water in fed animals (air: 117.1 +/- 20.0 ml O(2)/min; water: 114.8 +/- 32.7 ml O(2)/min, P > 0.6). In air, Vo(2) decreased with M(b), while it increased with M(b) in water. Body temperature did not change with fasting in air, whereas in water, there were complex changes in the peripheral body temperatures. These latter changes may, therefore, be indicative of a loss in body insulation and of variations in peripheral perfusion. Four animals were given a single meal after fasting and the temperature changes were partly reversed 24 h after refeeding in all body regions except the subcutaneous, indicating a rapid reversal to a prefasting state where body heat loss is minimal. The data emphasize the importance in considering nutritional status when studying king penguins and that the fasting-related physiological changes diverge in air and water.

A biomarker-responsive T2ex MRI contrast agent.

Science.gov (United States)

Daryaei, Iman; Randtke, Edward A; Pagel, Mark D

2017-04-01

This study investigated a fundamentally new type of responsive MRI contrast agent for molecular imaging that alters T 2 exchange (T 2ex ) properties after interacting with a molecular biomarker. The contrast agent Tm-DO3A-oAA was treated with nitric oxide (NO) and O 2 . The R 1 and R 2 relaxation rates of the reactant and product were measured with respect to concentration, temperature, and pH. Chemical exchange saturation transfer (CEST) spectra of the reactant and product were acquired using a 7 Tesla (T) MRI scanner and analyzed to estimate the chemical exchange rates and r 2ex relaxivities. The reaction of Tm-DO3A-oAA with NO and O 2 caused a 6.4-fold increase in the r 2 relaxivity of the agent, whereas r 1 relaxivity remained unchanged, which demonstrated that Tm-DO3A-oAA is a responsive T 2ex agent. The effects of pH and temperature on the r 2 relaxivities of the reactant and product supported the conclusion that the product's benzimidazole ligand caused the agent to have a fast chemical exchange rate relative to the slow exchange rate of the reactant's ortho-aminoanilide ligand. T 2ex MRI contrast agents are a new type of responsive agent that have good detection sensitivity and specificity for detecting a biomarker, which can serve as a new tool for molecular imaging. Magn Reson Med 77:1665-1670, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Measurements of hot electrons in the Extrap T1 reversed-field pinch

Science.gov (United States)

Welander, A.; Bergsåker, H.

1998-02-01

The presence of an anisotropic energetic electron population in the edge region is a characteristic feature of reversed-field pinch (RFP) plasmas. In the Extrap T1 RFP, the anisotropic, parallel heat flux in the edge region measured by calorimetry was typically several hundred 0741-3335/40/2/011/img1. To gain more insight into the origin of the hot electron component and to achieve time resolution of the hot electron flow during the discharge, a target probe with a soft x-ray monitor was designed, calibrated and implemented. The x-ray emission from the target was measured with a surface barrier detector covered with a set of different x-ray filters to achieve energy resolution. A calibration in the range 0.5-2 keV electron energy was performed on the same target and detector assembly using a 0741-3335/40/2/011/img2 cathode electron gun. The calibration data are interpolated and extrapolated numerically. A directional asymmetry of more than a factor of 100 for the higher energy electrons is observed. The hot electrons are estimated to constitute 10% of the total electron density at the edge and their energy distribution is approximated by a half-Maxwellian with a temperature slightly higher than the central electron temperature. Scalings with plasma current, as well as correlations with local 0741-3335/40/2/011/img3 measurements and radial dependences, are presented.

Design of a novel quantum reversible ternary up-counter

Science.gov (United States)

Houshmand, Pouran; Haghparast, Majid

2015-08-01

Reversible logic has been recently considered as an interesting and important issue in designing combinational and sequential circuits. The combination of reversible logic and multi-valued logic can improve power dissipation, time and space utilization rate of designed circuits. Only few works have been reported about sequential reversible circuits and almost there are no paper exhibited about quantum ternary reversible counter. In this paper, first we designed 2-qutrit and 3-qutrit quantum reversible ternary up-counters using quantum ternary reversible T-flip-flop and quantum reversible ternary gates. Then we proposed generalized quantum reversible ternary n-qutrit up-counter. We also introduced a new approach for designing any type of n-qutrit ternary and reversible counter. According to the results, we can conclude that applying second approach quantum reversible ternary up-counter is better than the others.

Reversed shear Alfven eigenmode stabilization by localized electron cyclotron heating

Energy Technology Data Exchange (ETDEWEB)

Van Zeeland, M A; Hyatt, A W; Lohr, J; Petty, C C [General Atomics, PO Box 85608 San Diego, CA 92186-5608 (United States); Heidbrink, W W [University of California-Irvine, Irvine, CA 92697 (United States); Nazikian, R; Solomon, W M; Gorelenkov, N N; Kramer, G J [Princeton Plasma Physics Laboratory, Princeton, NJ 08543-0451 (United States); Austin, M E [University of Texas-Austin, Austin, TX 78712 (United States); Berk, H L [Institute for Fusion Studies, University of Texas at Austin, Austin, TX 78712 (United States); Holcomb, C T; Makowski, M A [Lawrence Livermore National Laboratory, Livermore, CA (United States); McKee, G R [University of Wisconsin-Madison, Madison, WI 53726 (United States); Sharapov, S E [Euratom/UKAEA Fusion Association, Culham, Abingdon, Oxfordshire, OX14 3DB (United Kingdom); Rhodes, T L [University of California-Los Angeles, Los Angeles, California, 90095 (United States)], E-mail: vanzeeland@fusion.gat.com

2008-03-15

Reversed shear Alfven eigenmode (RSAE) activity in DIII-D is stabilized by electron cyclotron heating (ECH) applied near the minimum of the magnetic safety factor (q{sub min}) in neutral beam heated discharges with reversed-magnetic shear. The degree of RSAE stabilization, fast ion density and the volume averaged neutron production (S{sub n}) are highly dependent on ECH deposition location relative to q{sub min}. While discharges with ECH stabilization of RSAEs have higher S{sub n} and more peaked fast ion profiles than discharges with significant RSAE activity, neutron production remains strongly reduced (up to 60% relative to TRANSP predictions assuming classical fast ion transport) even when RSAEs are stabilized.

Low-frequency and rare exome chip variants associate with fasting glucose and type 2 diabetes susceptibility

NARCIS (Netherlands)

Wessel, Jennifer; Chu, Audrey Y.; Willems, Sara M.; Wang, Shuai; Yaghootkar, Hanieh; Brody, Jennifer A.; Dauriz, Marco; Hivert, Marie-France; Raghavan, Sridharan; Lipovich, Leonard; Hidalgo, Bertha; Fox, Keolu; Huffman, Jennifer E.; An, Ping; Lu, Yingchang; Rasmussen-Torvik, Laura J.; Grarup, Niels; Ehm, Margaret G.; Li, Li; Baldridge, Abigail S.; Stancakova, Alena; Abrol, Ravinder; Besse, Celine; Boland, Anne; Bork-Jensen, Jette; Fornage, Myriam; Freitag, Daniel F.; Garcia, Melissa E.; Guo, Xiuqing; Hara, Kazuo; Isaacs, Aaron; Jakobsdottir, Johanna; Lange, Leslie A.; Layton, Jill C.; Li, Man; Zhao, Jing Hua; Meidtner, Karina; Morrison, Alanna C.; Nalls, Mike A.; Peters, Marjolein J.; Sabater-Lleal, Maria; Schurmann, Claudia; Silveira, Angela; Smith, Albert V.; Southam, Lorraine; Stoiber, Marcus H.; Strawbridge, Rona J.; Taylor, Kent D.; Varga, Tibor V.; Allin, Kristine H.; Amin, Najaf; Aponte, Jennifer L.; Aung, Tin; Barbieri, Caterina; Bihlmeyer, Nathan A.; Boehnke, Michael; Bombieri, Cristina; Bowden, Donald W.; Burns, Sean M.; Chen, Yuning; Chen, Yii-Deri; Cheng, Ching-Yu; Correa, Adolfo; Czajkowski, Jacek; Dehghan, Abbas; Ehret, Georg B.; Eiriksdottir, Gudny; Escher, Stefan A.; Farmaki, Aliki-Eleni; Franberg, Mattias; Gambaro, Giovanni; Giulianini, Franco; Goddard, William A.; Goel, Anuj; Gottesman, Omri; Grove, Megan L.; Gustafsson, Stefan; Hai, Yang; Hallmans, Goeran; Heo, Jiyoung; Hoffmann, Per; Ikram, Mohammad K.; Jensen, Richard A.; Jorgensen, Marit E.; Jorgensen, Torben; Karaleftheri, Maria; Khor, Chiea C.; Kirkpatrick, Andrea; Kraja, Aldi T.; Kuusisto, Johanna; Lange, Ethan M.; Lee, I. T.; Lee, Wen-Jane; Leong, Aaron; Liao, Jiemin; Liu, Chunyu; Liu, Yongmei; Lindgren, Cecilia M.; Linneberg, Allan; Malerba, Giovanni; Mamakou, Vasiliki; Marouli, Eirini; Maruthur, Nisa M.; Matchan, Angela; McKean-Cowdin, Roberta; McLeod, Olga; Metcalf, Ginger A.; Mohlke, Karen L.; Muzny, Donna M.; Ntalla, Ioanna; Palmer, Nicholette D.; Pasko, Dorota; Peter, Andreas; Rayner, Nigel W.; Renstroem, Frida; Rice, Ken; Sala, Cinzia F.; Sennblad, Bengt; Serafetinidis, Ioannis; Smith, Jennifer A.; Soranzo, Nicole; Speliotes, Elizabeth K.; Stahl, Eli A.; Stirrups, Kathleen; Tentolouris, Nikos; Thanopoulou, Anastasia; Torres, Mina; Traglia, Michela; Tsafantakis, Emmanouil; Javad, Sundas; Yanek, Lisa R.; Zengini, Eleni; Becker, Diane M.; Bis, Joshua C.; Brown, James B.; Cupples, L. Adrienne; Hansen, Torben; Ingelsson, Erik; Karter, Andrew J.; Lorenzo, Carlos; Mathias, Rasika A.; Norris, Jill M.; Peloso, Gina M.; Sheu, Wayne H. -H.; Toniolo, Daniela; Vaidya, Dhananjay; Varma, Rohit; Wagenknecht, Lynne E.; Boeing, Heiner; Bottinger, Erwin P.; Dedoussis, George; Deloukas, Panos; Ferrannini, Ele; Franco, Oscar H.; Franks, Paul W.; Gibbs, Richard A.; Gudnason, Vilmundur; Hamsten, Anders; Harris, Tamara B.; Hattersley, Andrew T.; Hayward, Caroline; Hofman, Albert; Jansson, Jan-Hakan; Langenberg, Claudia; Launer, Lenore J.; Levy, Daniel; Oostra, Ben A.; O'Donnell, Christopher J.; O'Rahilly, Stephen; Padmanabhan, Sandosh; Pankow, James S.; Polasek, Ozren; Province, Michael A.; Rich, Stephen S.; Ridker, Paul M.; Rudan, Igor; Schulze, Matthias B.; Smith, Blair H.; Uitterlinden, Andre G.; Walker, Mark; Watkins, Hugh; Wong, Tien Y.; Zeggini, Eleftheria; Laakso, Markku; Borecki, Ingrid B.; Chasman, Daniel I.; Pedersen, Oluf; Psaty, Bruce M.; Tai, E. Shyong; van Duijn, Cornelia M.; Wareham, Nicholas J.; Waterworth, Dawn M.; Boerwinkle, Eric; Kao, W. H. Linda; Florez, Jose C.; Loos, Ruth J. F.; Wilson, James G.; Frayling, Timothy M.; Siscovick, David S.; Dupuis, Josee; Rotter, Jerome I.; Meigs, James B.; Scott, Robert A.; Goodarzi, Mark O.; Sharp, Stephen J.; Forouhi, Nita G.; Kerrison, Nicola D.; Lucarelli, Debora M. E.; Sims, Matt; Barroso, Ines; McCarthy, Mark I.; Arriola, Larraitz; Balkau, Beverley; Barricarte, Aurelio; Gonzalez, Carlos; Grioni, Sara; Kaaks, Rudolf; Key, Timothy J.; Navarro, Carmen; Nilsson, Peter M.; Overvad, Kim; Palli, Domenico; Panico, Salvatore; Quiros, J. Ramon; Rolandsson, Olov; Sacerdote, Carlotta; Sanchez, Maria-Jose; Slimani, Nadia; Tjonneland, Anne; Tumino, Rosario; van der A, Daphne L.; van der Schouw, Yvonne T.; Riboli, Elio

Fasting glucose and insulin are intermediate traits for type 2 diabetes. Here we explore the role of coding variation on these traits by analysis of variants on the HumanExome BeadChip in 60,564 non-diabetic individuals and in 16,491 T2D cases and 81,877 controls. We identify a novel association of

Electrostatic fluxes and plasma rotation in the edge region of EXTRAP-T2R

International Nuclear Information System (INIS)

Serianni, G.; Antoni, V.; Bergsaaker, H.; Brunsell, P.; Drake, J.R.; Spolaore, M.; Saetherblom, H.E.; Vianello, N.

2001-01-01

The EXTRAP-T2 reversed field pinch has undergone a significant reconstruction into the new T2R device. This paper reports the first measurements performed with Langmuir probes in the edge region of EXTRAP-T2R. The radial profiles of plasma parameters like electron density and temperature, plasma potential, electrical fields and electrostatic turbulence-driven particle flux are presented. These profiles are interpreted in a momentum balance model where finite Larmor radius losses occur over a distance of about two Larmor radii from the limiter position. The double shear layer of the ExB drift velocity is discussed in terms of the Biglari-Diamond-Terry theory of turbulence decorrelation. (author)

The effect of vildagliptin relative to sulphonylureas in Muslim patients with type 2 diabetes fasting during Ramadan: the VIRTUE study

Science.gov (United States)

Al-Arouj, M; Hassoun, A A K; Medlej, R; Pathan, M F; Shaltout, I; Chawla, M S; Hristoskova, S; DiTommaso, S; Kadwa, M Y

2013-01-01

SUMMARY Aims To assess, in a real-world setting, the effect of vildagliptin compared with sulphonylurea (SU) treatment on hypoglycaemia in Muslim patients with type 2 diabetes mellitus (T2DM) fasting during Ramadan. Methods This multinational, non-interventional study, conducted in Asia and the Middle East, included Muslim adult patients with T2DM who received treatment with vildagliptin or SU as add-on to metformin or monotherapy. During a ∼16-week observation period, data were collected up to 6 weeks before and 6 weeks after Ramadan fasting. The primary study objective was to compare the proportion of patients with ≥ 1 hypoglycaemic event (HE) during fasting. Results Of > 1300 patients enrolled in the study, 684 were treated with vildagliptin and 631 with SUs. Significantly fewer patients experienced ≥ 1 HE with vildagliptin compared with those receiving SUs (5.4% vs. 19.8%, respectively; p vildagliptin-treated patients reported a grade 2 HE, vs. 4 SU-treated patients (p = 0.053). Mean HbA1c changes from baseline were vildagliptin: –0.24%, SUs: +0.02% (p vildagliptin: –0.76 kg, SUs: –0.13 kg (p vildagliptin (22.8% vs. 10.2%). This difference was driven by hypoglycaemia as the most common AE. Conclusions In this real-world study of fasting Muslim patients with T2DM, vildagliptin was associated with significantly fewer hypoglycaemic episodes compared with SU therapy. This outcome is particularly meaningful when viewed in the context of good glycaemic and weight control observed in vildagliptin-treated patients. Vildagliptin was well tolerated in this patient population. Linked Comment: Ahmed. Int J Clin Pract 2013; 67: 933–4. PMID:24001317

Rational design of reversible fluorescent probes for live-cell imaging and quantification of fast glutathione dynamics

Science.gov (United States)

Umezawa, Keitaro; Yoshida, Masafumi; Kamiya, Mako; Yamasoba, Tatsuya; Urano, Yasuteru

2017-03-01

Alterations in glutathione (GSH) homeostasis are associated with a variety of diseases and cellular functions, and therefore, real-time live-cell imaging and quantification of GSH dynamics are important for understanding pathophysiological processes. However, existing fluorescent probes are unsuitable for these purposes due to their irreversible fluorogenic mechanisms or slow reaction rates. In this work, we have successfully overcome these problems by establishing a design strategy inspired by Mayr's work on nucleophilic reaction kinetics. The synthesized probes exhibit concentration-dependent, reversible and rapid absorption/fluorescence changes (t1/2 = 620 ms at [GSH] = 1 mM), as well as appropriate Kd values (1-10 mM: within the range of intracellular GSH concentrations). We also developed FRET-based ratiometric probes, and demonstrated that they are useful for quantifying GSH concentration in various cell types and also for real-time live-cell imaging of GSH dynamics with temporal resolution of seconds.

Effect of Vildagliptin Versus Sulfonylurea in Muslim Patients with Type 2 Diabetes Fasting During Ramadan in Egypt: Results from VIRTUE Study.

Science.gov (United States)

Khattab, Mohamed; Mahmoud, Khalifa; Shaltout, Inass

2016-09-01

Fasting in patients with type 2 diabetes mellitus (T2DM) is associated with high risk of hypoglycemia. The aim of this study was to compare the effectiveness and safety of vildagliptin in T2DM patients fasting during Ramadan in a real-life setting in Egypt. In this 16-week prospective and noninterventional study, data were collected up to 6 weeks before and after Ramadan fasting. Patients who had received vildagliptin or sulfonylurea (SU) either as dual therapy with metformin or as monotherapy were enrolled into the study. Two hundred fifty four patients were enrolled in the study, out of which 246 [121 (97.6%) treated with vildagliptin and 125 (99.2%) with SU] were included in the safety analysis set. A significantly lower proportion of patients experienced ≥1 hypoglycemic event (HE) with vildagliptin as compared to those receiving SUs (1.7% vs. 19.2%, respectively; p vildagliptin and SU were -0.1% and +0.3%, respectively, with a between-treatment difference of -0.4% (p vildagliptin and SU were -0.8 and -0.1 kg, with a between-treatment difference of -0.7 kg (p = 0.011). A higher proportion of SU-treated patients experienced adverse events compared to those treated with vildagliptin (23.2% vs. 5.8%, respectively), the primary reason being the high incidence of hypoglycemia in the SU group (n = 24, 19.2%). Treatment with vildagliptin was associated with lower incidence of hypoglycemia compared with SU and showed good glycemic and weight control in patients with T2DM fasting during Ramadan in a real-life setting in Egypt. Novartis Pharma AG.

Parametric T2 and T2* mapping techniques to visualize intervertebral disc degeneration in patients with low back pain: initial results on the clinical use of 3.0 Tesla MRI

International Nuclear Information System (INIS)

Welsch, Goetz Hannes; Trattnig, Siegfried; Goed, Sabine; Stelzeneder, David; Paternostro-Sluga, Tatjana; Bohndorf, Klaus; Mamisch, Tallal Charles

2011-01-01

To assess, compare and correlate quantitative T2 and T2* relaxation time measurements of intervertebral discs (IVDs) in patients suffering from low back pain, with respect to the IVD degeneration as assessed by the morphological Pfirrmann Score. Special focus was on the spatial variation of T2 and T2* between the annulus fibrosus (AF) and the nucleus pulposus (NP). Thirty patients (mean age: 38.1 ± 9.1 years; 20 female, 10 male) suffering from low back pain were included. Morphological (sagittal T1-FSE, sagittal and axial T2-FSE) and biochemical (sagittal T2- and T2* mapping) MRI was performed at 3 Tesla covering IVDs L1-L2 to L5-S1. All IVDs were morphologically classified using the Pfirrmann score. Region-of-interest (ROI) analysis was performed on midsagittal T2 and T2* maps at five ROIs from anterior to posterior to obtain information on spatial variation between the AF and the NP. Statistical analysis-of-variance and Pearson correlation was performed. The spatial variation as an increase in T2 and T2* values from the AF to the NP was highest at Pfirmann grade I and declined at higher Pfirmann grades II-IV (p < 0.05). With increased IVD degeneration, T2 and T2* revealed a clear differences in the NP, whereas T2* was additionally able to depict changes in the posterior AF. Correlation between T2 and T2* showed a medium Pearson's correlation (0.210 to 0.356 [p < 0.001]). The clear differentiation of IVD degeneration and the possible quantification by means of T2 and fast T2* mapping may provide a new tool for follow-up therapy protocols in patients with low back pain. (orig.)

T2 relaxometry of the infrapatellar fat pad after arthroscopic surgery

Energy Technology Data Exchange (ETDEWEB)

Torriani, Martin; Bredella, Miriam A. [Massachusetts General Hospital and Harvard Medical School, Musculoskeletal Imaging and Intervention, Department of Radiology, Boston, MA (United States); Taneja, Atul K. [Hospital do Coracao (HCor), Teleimagem, and Hospital Israelita Albert Einstein, Division of Musculoskeletal Imaging, Department of Radiology, Sao Paulo (Brazil); Hosseini, Ali; Li, Guoan [Massachusetts General Hospital and Harvard Medical School, Bioengineering Laboratory, Department of Orthopedics, Boston, MA (United States); Gill, Thomas J. [Massachusetts General Hospital and Harvard Medical School, Sports Medicine Center, Department of Orthopedics, Boston, MA (United States)

2014-03-15

To investigate the T2 relaxation values of the infrapatellar fat pad (IFP) after arthroscopic surgery. This study was approved by the institutional review board; all individuals signed informed consent. We performed MRI in 16 knees from 8 subjects. Prior to imaging, each subject had unilateral arthroscopic knee surgery and an asymptomatic non-operated contralateral knee. We used a 10-echo multiple-TE fast-spin echo pulse sequence for creation of T2 relaxation time maps. Two musculoskeletal radiologists independently placed regions of interest in the IFP, suprapatellar subcutaneous and deep intermuscular adipose tissue. Qualitative assessments were performed to assess fibrotic changes affecting patellar retinaculum and IFP. Statistical analyses of T2 values determined differences between groups, correlation with time after surgery, and cut-off values to differentiate groups. The average time between arthroscopy and imaging was 3.5 ± 0.4 years. IFP of knees with prior surgery had significantly shorter mean T2 values (133 ± 14 ms) compared with control knees (147 ± 8 ms, P = 0.03). There was no significant difference between operated and control knees regarding T2 values of suprapatellar subcutaneous (P = 0.3) or deep intermuscular adipose tissue (P = 0.2). There was no correlation between IFP T2 values and time after surgery (P > 0.2). IFP T2 values ≤ 139 ms had 75 % sensitivity and 88 % specificity in identifying prior arthroscopy. Shortening of T2 relaxation values is present in IFP chronically after arthroscopic surgery and may be an indicator of adipose tissue fibrosis. (orig.)

Colorectal carcinoma: Ex vivo evaluation using 3-T high-spatial-resolution quantitative T2 mapping and its correlation with histopathologic findings.

Science.gov (United States)

Yamada, Ichiro; Yoshino, Norio; Hikishima, Keigo; Miyasaka, Naoyuki; Yamauchi, Shinichi; Uetake, Hiroyuki; Yasuno, Masamichi; Saida, Yukihisa; Tateishi, Ukihide; Kobayashi, Daisuke; Eishi, Yoshinobu

2017-05-01

In this study, we aimed to evaluate the feasibility of determining the mural invasion depths of colorectal carcinomas using high-spatial-resolution (HSR) quantitative T2 mapping on a 3-T magnetic resonance (MR) scanner. Twenty colorectal specimens containing adenocarcinomas were imaged on a 3-T MR system equipped with a 4-channel phased-array surface coil. HSR quantitative T2 maps were acquired using a spin-echo sequence with a repetition time/echo time of 7650/22.6-361.6ms (16 echoes), 87×43.5-mm field of view, 2-mm section thickness, 448×224 matrix, and average of 1. HSR fast-spin-echo T2-weighted images were also acquired. Differences between the T2 values (ms) of the tumor tissue, colorectal wall layers, and fibrosis were measured, and the MR images and histopathologic findings were compared. In all specimens (20/20, 100%), the HSR quantitative T2 maps clearly depicted an 8-layer normal colorectal wall in which the T2 values of each layer differed from those of the adjacent layer(s) (PT2 maps and histopathologic data yielded the same findings regarding the tumor invasion depth. Our results indicate that 3-T HSR quantitative T2 mapping is useful for distinguishing colorectal wall layers and differentiating tumor and fibrotic tissues. Accordingly, this technique could be used to determine mural invasion by colorectal carcinomas with a high level of accuracy. Copyright © 2017 Elsevier Inc. All rights reserved.

Diagnostic value of the fast-FLAIR sequence in MR imaging of intracranial tumors

International Nuclear Information System (INIS)

Husstedt, H.W.; Sickert, M.; Koestler, H.; Haubitz, B.; Becker, H.

2000-01-01

The aim of this study was to quantify imaging characteristics of fast fluid-attenuated inversion recovery (FLAIR) sequence in brain tumors compared with T1-postcontrast- and T2-sequences. Fast-FLAIR-, T2 fast spin echo (FSE)-, and T1 SE postcontrast images of 74 patients with intracranial neoplasms were analyzed. Four neuroradiologists rated signal intensity and inhomogeneity of the tumor, rendering of cystic parts, demarcation of the tumor vs brain, of the tumor vs edema and of brain vs edema, as well as the presence of motion and of other artifacts. Data analysis was performed for histologically proven astrocytomas, glioblastomas, and meningiomas, for tumors with poor contrast enhancement, and for all patients pooled. Only for tumors with poor contrast enhancement (n = 12) did fast FLAIR provide additional information about the lesion. In these cases, signal intensity, demarcation of the tumor vs brain, and differentiation of the tumor vs edema were best using fast FLAIR. In all cases, rendering of the tumor's inner structure was poor. For all other tumor types, fast FLAIR did not give clinically relevant information, the only exception being a better demarcation of the edema from brain tissue. Artifacts rarely interfered with evaluation of fast-FLAIR images. Thus, fast FLAIR cannot replace T2-weighted series. It provides additional information only in tumors with poor contrast enhancement. It is helpful for defining the exact extent of the edema of any tumor but gives little information about their inner structure. (orig.)

Diagnostic value of the fast-FLAIR sequence in MR imaging of intracranial tumors.

Science.gov (United States)

Husstedt, H W; Sickert, M; Köstler, H; Haubitz, B; Becker, H

2000-01-01

The aim of this study was to quantify imaging characteristics of fast fluid-attenuated inversion recovery (FLAIR) sequence in brain tumors compared with T1-postcontrast- and T2-sequences. Fast-FLAIR-, T2 fast spin echo (FSE)-, and T1 SE postcontrast images of 74 patients with intracranial neoplasms were analyzed. Four neuroradiologists rated signal intensity and inhomogeneity of the tumor, rendering of cystic parts, demarcation of the tumor vs brain, of the tumor vs edema and of brain vs edema, as well as the presence of motion and of other artifacts. Data analysis was performed for histologically proven astrocytomas, glioblastomas, and meningiomas, for tumors with poor contrast enhancement, and for all patients pooled. Only for tumors with poor contrast enhancement (n = 12) did fast FLAIR provide additional information about the lesion. In these cases, signal intensity, demarcation of the tumor vs brain, and differentiation of the tumor vs edema were best using fast FLAIR. In all cases, rendering of the tumor's inner structure was poor. For all other tumor types, fast FLAIR did not give clinically relevant information, the only exception being a better demarcation of the edema from brain tissue. Artifacts rarely interfered with evaluation of fast-FLAIR images. Thus, fast FLAIR cannot replace T2-weighted series. It provides additional information only in tumors with poor contrast enhancement. It is helpful for defining the exact extent of the edema of any tumor but gives little information about their inner structure.

The sensitivity calibration of the ultra-fast quench plastic scintillation detector for D-T neutrons

International Nuclear Information System (INIS)

Tang Changhuan; Yan Meiqiong; Xie Chaomei

1998-01-01

The authors introduce some characteristics of ultra-fast quench plastic scintillation detectors. When the detectors are composed of different scintillators, light guides and microchannel plate photomultiplier tube (MCP-PMT), their sensitivities to D-T neutrons are calibrated by a pulse neutron tube with a neutron pulse width about 10 ns

ATF edge plasma turbulence studies using a fast reciprocating Langmuir probe

International Nuclear Information System (INIS)

Uckan, T.; Hidalgo, C.; Bell, J.D.; Harris, J.H.; Dunlap, J.L.; Dyer, G.R.; Mioduszewski, P.K.; Wilgen, J.B.; Ritz, C.P.; Wootton, A.J.; Rhodes, T.L.; Carter, K.

1991-01-01

Electrostatic turbulence on the edge of the Advanced Toroidal Facility (ATF) torsatron is investigated experimentally with a fast reciprocating Langmuir probe (FRLP) array. Initial measurements of plasma electron density n e and temperature T e and fluctuations in density (n e ) and plasma floating potential (φ f ) are made in electron cyclotron heated plasmas at 1 T. At the last closed flux surface (LCFS, r√a ∼ 1), T e ∼ 20--40 eV and n e ∼ 10 12 cm -3 for a line-averaged electron density bar n e = (3--6) x 10 12 cm -3 . Relative fluctuation levels, as the FRLP is moved into core plasma where T e > 20 eV, are n e /n e ∼ 5% and eφ f /T e ∼ 2n e /n e about 2 cm inside the LCFS. The observed fluctuation spectra are broadband (40--300 kHz) with bar kρ s ≤ 0.1, where bar k is the wavenumber of the fluctuations and ρ s is the ion Larmor radius at the sound speed. The propagation direction of the fluctuations reverses to the electron diamagnetic direction around r√a ph ∼ v de ). The fluctuation-induced particle flux is comparable to fluxes estimated from the particle balance using the H α spectroscopic measurements. Many of the features seen in these experiments resemble the features of ohmically heated plasmas in the Texas Experimental Tokamak (TEXT). 18 refs., 10 figs

Stainless austenitic steels strengthened due to reversible phase transformations and by ageing

International Nuclear Information System (INIS)

Sagaradze, V.V.; Kositsyna, I.I.; Ozhiganov, A.V.

1981-01-01

The effect of the reversible phase transformations, consisting in the conduction of the direct and reverse martensite transformations and aging, during which the intermetallide γ'-phase of the composition Ni 3 Ti is formed, on the streng-thening of alloys in the Fe-Cr-Ni-Ti system is considered. Stainless austenitic steels Kh12N12T3 and Kh12N14T3, which acquire high mechanical properties: σsub(0.2)=685-785 MPa, σsub(B)=1275 MPa, delta >= 20%, as a result of reversible phase transformations and aging, are suggested. After the reversible phase transformations and ageing the steels possess a high resistance to γ-α-transformation during cold treatment [ru

A Reverse Shock in GRB 160509A

Science.gov (United States)

Laskar, Tanmoy; Alexander, Kate D.; Berger, Edo; Fong, Wen-fai; Margutti, Raffaella; Shivvers, Isaac; Williams, Peter K. G.; Kopač, Drejc; Kobayashi, Shiho; Mundell, Carole; Gomboc, Andreja; Zheng, WeiKang; Menten, Karl M.; Graham, Melissa L.; Filippenko, Alexei V.

2016-12-01

We present the second multi-frequency radio detection of a reverse shock in a γ-ray burst. By combining our extensive radio observations of the Fermi-Large Area Telescope γ-ray burst 160509A at z = 1.17 up to 20 days after the burst with Swift X-ray observations and ground-based optical and near-infrared data, we show that the afterglow emission comprises distinct reverse shock and forward shock contributions: the reverse shock emission dominates in the radio band at ≲10 days, while the forward shock emission dominates in the X-ray, optical, and near-infrared bands. Through multi-wavelength modeling, we determine a circumburst density of {n}0≈ {10}-3 {{cm}}-3, supporting our previous suggestion that a low-density circumburst environment is conducive to the production of long-lasting reverse shock radiation in the radio band. We infer the presence of a large excess X-ray absorption column, N H ≈ 1.5 × 1022 {{cm}}-2, and a high rest-frame optical extinction, A V ≈ 3.4 mag. We identify a jet break in the X-ray light curve at {t}{jet}≈ 6 {days}, and thus derive a jet opening angle of {θ }{jet}≈ 4^\\circ , yielding a beaming-corrected kinetic energy and radiated γ-ray energy of {E}{{K}}≈ 4× {10}50 erg and {E}γ ≈ 1.3× {10}51 erg (1-104 keV, rest frame), respectively. Consistency arguments connecting the forward shocks and reverse shocks suggest a deceleration time of {t}{dec} ≈ 460 s ≈ T 90, a Lorentz factor of {{Γ }}({t}{dec})≈ 330, and a reverse-shock-to-forward-shock fractional magnetic energy density ratio of {R}{{B}}\\equiv {ɛ }{{B},{RS}}/{ɛ }{{B},{FS}}≈ 8. Our study highlights the power of rapid-response radio observations in the study of the properties and dynamics of γ-ray burst ejecta.

High transmittance contrast in amorphous to hexagonal phase of Ge2Sb2Te5: Reversible NIR-window

Science.gov (United States)

Singh, Palwinder; Singh, A. P.; Kanda, Neetu; Mishra, Monu; Gupta, Govind; Thakur, Anup

2017-12-01

Ge2Sb2Te5 (GST) is one of the best phase change materials because of its splendid set of properties, viz., high thermal stability, fast crystallization speed, good endurance, scalability, and reliability. Phase transition [amorphous → face centered cubic (fcc) → hexagonal close packed (hcp)] of GST thin films with annealing was studied using X-ray diffraction. Thin films in amorphous, fcc, and hcp phases are highly, medium, and negligible transparent in the near infra-red region, respectively. The optical transmission in amorphous, fcc, and hcp phases is ˜92%, ˜46%, and ˜2%, respectively, at the wavelength of 2740 nm. At 2740 nm, a high transmission contrast (˜90%) is observed with phase transition from the amorphous to hcp phase. By utilizing large transmission contrast, it is demonstrated that GST can be availed as a potential candidate for reversible near infra-red-window. The sharp change in optical transmission with phase transition can be understood from the change in density of states in the valence band.

Surface structure of YBa2Cu3O7-x probed by reversed-bias scanning tunneling microscopy

International Nuclear Information System (INIS)

Edwards, H.L.; Markert, J.T.; Lozanne, A.L.d.

1994-01-01

We report the results of scanning tunneling microscopy studies on high-quality single crystals of YBa 2 Cu 3 O 7-x (YBCO) which were cleaved along a basal plane in situ at 20 K prior to measurement. The initial results of a systematic study of the YBCO surface are presented. Reversed-bias images of the CuO chain layer reveal modulations 3.3±0.3|b|=1.3±0.1 nm in wavelength which change phase by 180 degree under bias polarity reversal along solid chains, and are invariant under bias polarity reversal at a point defect. Regions of sharp unit-cell-sized square corrugations with disordered islands are also observed. We interpret these new results in terms of our previous model [H. L. Edwards, J. T. Markert, and A. L. de Lozanne, Phys. Rev. Lett. 69, 2967 (1992)] of the cleaved YBCO surface

Type 2 iodothyronine deiodinase levels are higher in slow-twitch than fast-twitch mouse skeletal muscle and are increased in hypothyroidism.

Science.gov (United States)

Marsili, Alessandro; Ramadan, Waile; Harney, John W; Mulcahey, Michelle; Castroneves, Luciana Audi; Goemann, Iuri Martin; Wajner, Simone Magagnin; Huang, Stephen A; Zavacki, Ann Marie; Maia, Ana Luiza; Dentice, Monica; Salvatore, Domenico; Silva, J Enrique; Larsen, P Reed

2010-12-01

Because of its large mass, relatively high metabolic activity and responsiveness to thyroid hormone, skeletal muscle contributes significantly to energy expenditure. Despite the presence of mRNA encoding the type 2 iodothyronine-deiodinase (D2), an enzyme that activates T(4) to T3, very low or undetectable activity has been reported in muscle homogenates of adult humans and mice. With a modified D2 assay, using microsomal protein, overnight incubation and protein from D2 knockout mouse muscle as a tissue-specific blank, we examined slow- and fast-twitch mouse skeletal muscles for D2 activity and its response to physiological stimuli. D2 activity was detectable in all hind limb muscles of 8- to 12-wk old C57/BL6 mice. Interestingly, it was higher in the slow-twitch soleus than in fast-twitch muscles (0.40 ± 0.06 vs. 0.076 ± 0.01 fmol/min · mg microsomal protein, respectively, P Hypothyroidism caused a 40% (P hypothyroidism argue for a more important role for D2-generated T(3) in skeletal muscle physiology than previously assumed.

Fat-Suppressed T2* Sequences for Routine 3.0-Tesla Lumbar Spine Magnetic Resonance Imaging: A Preliminary Report

International Nuclear Information System (INIS)

McKinney, A. M.; Gadani, S.; Palmer, C. S.; Vidarsson, L.

2008-01-01

Background: Clear depiction of the ligamentum flavum on routine lumbar magnetic resonance imaging (MRI) is essential in accurately describing the extent of degenerative disease. In routine, noncontrast evaluations, focal fatty deposition or hemangiomas can be difficult to distinguish from malignant foci on fast spin-echo (FSE) T2-weighted images. Purpose: To describe the use of T2* fast field echo (T2FFE) in combination with spectral presaturation inversion recovery (SPIR) fat suppression for noncontrast, routine lumbar spine outpatient MR imaging at 3.0 Tesla (3T). Material and Methods: An axial gradient echo (GE) T2FFE sequence was combined with SPIR fat suppression (T2FFE-SPIR), via a 3T Philips Intera (Philips Medical Systems, Best, The Netherlands) scanner, and added to the routine, noncontrast lumbar MRI examinations, which included sagittal FSE T1-weighted (T1WI), T2-weighted (T2WI), short-tau inversion recovery (STIR), and axial FSE T2WI. The sequence was performed in over 500 patients over a 1-year period, without intravenous contrast, and with slice thickness and planes of section identical to the axial FSE T1WI and T2WI images. The sequence typically lasted about 4.5-6 min. Results: The use of T2FFE-SPIR enabled visualization of the ligamentum flavum in degenerative disease, and the exclusion of focal fatty lesions on FSE T2WI. Other benefits included: the identification of malignant foci, the uncommon detection of hemorrhage, and the elimination of spurious flow voids. Several brief examples are provided to demonstrate the utility of this technique. Conclusion: The addition of T2FFE-SPIR to routine, noncontrast protocols in outpatients could provide further confidence in the visualization of the ligamentum flavum in degenerative disease, and can exclude malignancy in T2-bright areas of focal fatty marrow. Larger studies would be helpful to evaluate the accuracy of this technique versus FSE techniques in depicting degenerative, malignant, or inflammatory

Fat-Suppressed T2 Sequences for Routine 3.0-Tesla Lumbar Spine Magnetic Resonance Imaging: A Preliminary Report

Energy Technology Data Exchange (ETDEWEB)

McKinney, A. M.; Gadani, S.; Palmer, C. S.; Vidarsson, L. (Dept. of Radiology, Hennepin County and Univ. of Minnesota Medical Centers, Minneapolis, MN (United States))

2008-09-15

Background: Clear depiction of the ligamentum flavum on routine lumbar magnetic resonance imaging (MRI) is essential in accurately describing the extent of degenerative disease. In routine, noncontrast evaluations, focal fatty deposition or hemangiomas can be difficult to distinguish from malignant foci on fast spin-echo (FSE) T2-weighted images. Purpose: To describe the use of T2 fast field echo (T2FFE) in combination with spectral presaturation inversion recovery (SPIR) fat suppression for noncontrast, routine lumbar spine outpatient MR imaging at 3.0 Tesla (3T). Material and Methods: An axial gradient echo (GE) T2FFE sequence was combined with SPIR fat suppression (T2FFE-SPIR), via a 3T Philips Intera (Philips Medical Systems, Best, The Netherlands) scanner, and added to the routine, noncontrast lumbar MRI examinations, which included sagittal FSE T1-weighted (T1WI), T2-weighted (T2WI), short-tau inversion recovery (STIR), and axial FSE T2WI. The sequence was performed in over 500 patients over a 1-year period, without intravenous contrast, and with slice thickness and planes of section identical to the axial FSE T1WI and T2WI images. The sequence typically lasted about 4.5-6 min. Results: The use of T2FFE-SPIR enabled visualization of the ligamentum flavum in degenerative disease, and the exclusion of focal fatty lesions on FSE T2WI. Other benefits included: the identification of malignant foci, the uncommon detection of hemorrhage, and the elimination of spurious flow voids. Several brief examples are provided to demonstrate the utility of this technique. Conclusion: The addition of T2FFE-SPIR to routine, noncontrast protocols in outpatients could provide further confidence in the visualization of the ligamentum flavum in degenerative disease, and can exclude malignancy in T2-bright areas of focal fatty marrow. Larger studies would be helpful to evaluate the accuracy of this technique versus FSE techniques in depicting degenerative, malignant, or inflammatory

Reversible Carnot cycle outside a black hole

International Nuclear Information System (INIS)

Xi-Hao, Deng; Si-Jie, Gao

2009-01-01

A Carnot cycle outside a Schwarzschild black hole is investigated in detail. We propose a reversible Carnot cycle with a black hole being the cold reservoir. In our model, a Carnot engine operates between a hot reservoir with temperature T 1 and a black hole with Hawking temperature T H . By naturally extending the ordinary Carnot cycle to the black hole system, we show that the thermal efficiency for a reversible process can reach the maximal efficiency 1 – T H /T 1 . Consequently, black holes can be used to determine the thermodynamic temperature by means of the Carnot cycle. The role of the atmosphere around the black hole is discussed. We show that the thermal atmosphere provides a necessary mechanism to make the process reversible. (general)

Comparison of spin echo T1-weighted sequences versus fast spin-echo proton density-weighted sequences for evaluation of meniscal tears at 1.5 T

International Nuclear Information System (INIS)

Wolff, Andrew B.; Pesce, Lorenzo L.; Wu, Jim S.; Smart, L.R.; Medvecky, Michael J.; Haims, Andrew H.

2009-01-01

At our institution, fast spin-echo (FSE) proton density (PD) imaging is used to evaluate articular cartilage, while conventional spin-echo (CSE) T1-weighted sequences have been traditionally used to characterize meniscal pathology. We sought to determine if FSE PD-weighted sequences are equivalent to CSE T1-weighted sequences in the detection of meniscal tears, obviating the need to perform both sequences. We retrospectively reviewed the records of knee arthroscopies performed by two arthroscopy-focused surgeons from an academic medical center over a 2-year period. The preoperative MRI images were interpreted independently by two fellowship-trained musculoskeletal radiologists who graded the sagittal CSE T1 and FSE PD sequences at different sittings with grades 1-5, where 1 = normal meniscus, 2 = probable normal meniscus, 3 indeterminate, 4 = probable torn meniscus, and 5 = torn meniscus. Each meniscus was divided into an anterior and posterior half, and these halves were graded separately. Operative findings provided the gold standard. Receiver operating characteristic (ROC) analysis was performed to compare the two sequences. There were 131 tears in 504 meniscal halves. Using ROC analysis, the reader 1 area under curve for FSE PD was significantly better than CSE T1 (0.939 vs. 0.902, >95% confidence). For reader 2, the difference met good criteria for statistical non-inferiority but not superiority (0.913 for FSE PD and 0.908 for CSE T1; >95% non-inferiority for difference at most of -0.027). FSE PD-weighted sequences, using our institutional protocol, are not inferior to CSE T1-weighted sequences for the detection of meniscal tears and may be superior. (orig.)

Impact of metformin versus the prandial insulin secretagogue, repaglinide, on fasting and postprandial glucose and lipid responses in non-obese patients with type 2 diabetes

DEFF Research Database (Denmark)

Lund, Søren S; Tarnow, Lise; Frandsen, Merete

2008-01-01

metformin than repaglinide (mean (95% confidence intervals), LDL cholesterol difference metformin versus repaglinide: AUC: -0.17 mmol/l (-0.26; -0.08)). AUC differences remained significant after adjusting for fasting levels. CONCLUSIONS: In non-obese T2DM patients, metformin reduced postprandial levels...... of glycaemia, triglycerides and FFA similarly compared to the prandial insulin secretagogue, repaglinide. Furthermore, metformin reduced fasting and postprandial cholesterolaemia and insulinaemia compared with repaglinide. These data support prescription of metformin as the preferred drug in non-obese patients......OBJECTIVE: Non-obese patients with type 2 diabetes (T2DM) are characterized by predominant defective insulin secretion. However, in non-obese T2DM patients, metformin, targeting insulin resistance, is non-inferior to the prandial insulin secretagogue, repaglinide, controlling overall glycaemia (Hb...

Vitamin K2 for the reversal of warfarin-related coagulopathy.

Science.gov (United States)

Hifumi, Toru; Takada, Hiroaki; Ogawa, Daisuke; Suzuki, Kenta; Hamaya, Hideyuki; Shinohara, Natsuyo; Abe, Yuko; Takano, Koshiro; Kawakita, Kenya; Hagiike, Masanobu; Koido, Yuichi; Kuroda, Yasuhiro

2015-08-01

The American Heart Association/American College of Cardiology Foundation recommends vitamin K1 for warfarin-related coagulopathy. In Japan, vitamin K2 is used more commonly for such purpose. The difference between vitamins K1 and K2 in reversing warfarin-related coagulopathy has not been discussed. Herein, we report a case that was reversed with vitamin K2; alterations in vitamins K1 and K2 levels and coagulation markers are also presented.

Glucocorticoids inhibit the proliferation of IL-2-dependent T cell clones

International Nuclear Information System (INIS)

Fresno, M.; Redondo, J.M.; Lopez-Rivas, A.

1986-01-01

It has been shown that glucocorticoids inhibit mitogen or antigen-induced lymphocyte proliferation by decreasing the production of interleukin-2 (IL-2). They have studied the effect of dexamethasone (Dx) on the proliferation of IL-2-dependent T cell clones. They have found that preincubation of these clones with Dx inhibits ( 3 H) thymidine incorporation and cell proliferation in a dose-dependent manner (ID 50 % 5 x 10 -10 M). The inhibition of DNA synthesis by Dx was dependent on the concentration of IL-2. High concentration of IL-2 reversed completely this inhibition. The action of Dx seems to be mediated through the induction of a protein since the simultaneous presence of cycloheximide and Dx prevented the inhibitory effect of the latter. Moreover, dialyzed conditioned medium of Dx treated cells inhibited DNA synthesis by T cell clones. The biochemical characterization of this protein is in progress

Reversible and irreversible heat engine and refrigerator cycles

Science.gov (United States)

Leff, Harvey S.

2018-05-01

Although no reversible thermodynamic cycles exist in nature, nearly all cycles covered in textbooks are reversible. This is a review, clarification, and extension of results and concepts for quasistatic, reversible and irreversible processes and cycles, intended primarily for teachers and students. Distinctions between the latter process types are explained, with emphasis on clockwise (CW) and counterclockwise (CCW) cycles. Specific examples of each are examined, including Carnot, Kelvin and Stirling cycles. For the Stirling cycle, potentially useful task-specific efficiency measures are proposed and illustrated. Whether a cycle behaves as a traditional refrigerator or heat engine can depend on whether it is reversible or irreversible. Reversible and irreversible-quasistatic CW cycles both satisfy Carnot's inequality for thermal efficiency, η ≤ η C a r n o t . Irreversible CCW cycles with two reservoirs satisfy the coefficient of performance inequality K ≤ K C a r n o t . However, an arbitrary reversible cycle satisfies K ≥ K C a r n o t when compared with a reversible Carnot cycle operating between its maximum and minimum temperatures, a potentially counterintuitive result.

Initial reversed-field pinch experiments on ZT-40 and recent advances in RFP theory

International Nuclear Information System (INIS)

Baker, D.A.; Buchenauer, C.J.; Burkhardt, L.C.

1980-01-01

The ZT-40 reversed-field pinch (RFP) has been operated in several modes: (1) without reversed toroidal field, (2) with self reversal, and (3) with aided reversal. An analytic ohmic heating and ignition model both confirm and provide guidance for transport codes. Nondissipative formation schemes have been analyzed and ideal MHD stable evolution and burn scenarios have been found. Particle and fluid simulations have produced qualitative agreement with respect to the nonlinear behavior of m = 0 resistive g-modes. Helical ohmic reversed field states are produced by a 2-D dynamical simulation, and nonlinear analytic work describes the final state. A fast resistive MHD code for linear stability has clarified the relations between several kinds of resistive instabilities. Ballooning modes and g-modes in systems with arbitrary magnetic shear including resistivity and viscosity, have been studied in a unified treatment with growth rate vs wavenumber showing the existence of important cutoffs

Implementation of model predictive control for resistive wall mode stabilization on EXTRAP T2R

Science.gov (United States)

Setiadi, A. C.; Brunsell, P. R.; Frassinetti, L.

2015-10-01

A model predictive control (MPC) method for stabilization of the resistive wall mode (RWM) in the EXTRAP T2R reversed-field pinch is presented. The system identification technique is used to obtain a linearized empirical model of EXTRAP T2R. MPC employs the model for prediction and computes optimal control inputs that satisfy performance criterion. The use of a linearized form of the model allows for compact formulation of MPC, implemented on a millisecond timescale, that can be used for real-time control. The design allows the user to arbitrarily suppress any selected Fourier mode. The experimental results from EXTRAP T2R show that the designed and implemented MPC successfully stabilizes the RWM.

Implementation of model predictive control for resistive wall mode stabilization on EXTRAP T2R

International Nuclear Information System (INIS)

Setiadi, A C; Brunsell, P R; Frassinetti, L

2015-01-01

A model predictive control (MPC) method for stabilization of the resistive wall mode (RWM) in the EXTRAP T2R reversed-field pinch is presented. The system identification technique is used to obtain a linearized empirical model of EXTRAP T2R. MPC employs the model for prediction and computes optimal control inputs that satisfy performance criterion. The use of a linearized form of the model allows for compact formulation of MPC, implemented on a millisecond timescale, that can be used for real-time control. The design allows the user to arbitrarily suppress any selected Fourier mode. The experimental results from EXTRAP T2R show that the designed and implemented MPC successfully stabilizes the RWM. (paper)

Analysis techniques for diagnosing runaway ion distributions in the reversed field pinch

Energy Technology Data Exchange (ETDEWEB)

Kim, J., E-mail: jkim536@wisc.edu; Anderson, J. K.; Capecchi, W.; Bonofiglo, P. J.; Sears, S. H. [University of Wisconsin—Madison, Madison, Wisconsin 53706 (United States)

2016-11-15

An advanced neutral particle analyzer (ANPA) on the Madison Symmetric Torus measures deuterium ions of energy ranges 8-45 keV with an energy resolution of 2-4 keV and time resolution of 10 μs. Three different experimental configurations measure distinct portions of the naturally occurring fast ion distributions: fast ions moving parallel, anti-parallel, or perpendicular to the plasma current. On a radial-facing port, fast ions moving perpendicular to the current have the necessary pitch to be measured by the ANPA. With the diagnostic positioned on a tangent line through the plasma core, a chord integration over fast ion density, background neutral density, and local appropriate pitch defines the measured sample. The plasma current can be reversed to measure anti-parallel fast ions in the same configuration. Comparisons of energy distributions for the three configurations show an anisotropic fast ion distribution favoring high pitch ions.

Theory of field-reversed mirrors and field-reversed plasma-gun experiments. Paper IAEA-CN-38/R-2

International Nuclear Information System (INIS)

Anderson, D.V.; Auerbach, S.P.; Berk, H.L.

1980-01-01

Experimental and theoretical studies of field reversal in a mirror machine are reported. Plasma-gun experiments demonstrate that reversed-field plasma layers are formed. Low energy plasma flowing behind the initially produced plasma front prevents tearing of the layer from the gun muzzle. MHD simulation shows that tearing can be obtained by impeding the slow plasma flow with a plasma divider. It is demonstrated theoretically that a field-reversed mirror imbedded in a multipole field can be sustained in steady state with neutral-beam injection even in the absence of impurities. MHD stability analysis shows that growth rates of elongated reversed-field theta-pinch configurations decrease with axial extension, which indicates the importance of including finite Larmor radius in the analysis. Tilting-mode criteria are improved by proper shaping, and a problimak shape is proposed. Tearing mode stability of reversed-field theta-pinches is greatly enhanced by flux exclusion. Self-consistent, 1-1/2-dimensional transport codes have been developed, and initial results are presented

Theory of field-reversed mirrors and field-reversed plasma-gun experiments. Paper IAEA-CN-38/R-2

International Nuclear Information System (INIS)

Anderson, D.V.; Auerbach, S.P.; Berk, H.L.

1980-01-01

Experimental and theoretical studies of field reversal in a mirror machine are reported. Plasma-gun experiments demonstrate that reversed-field plasma layers are formed. Low energy plasma flowing behind the initially produced plasma front prevents tearing of the layer from the gun muzzle. MHD simulation shows that tearing can be obtained by impeding the slow plasma flow with a plasma divider. It is demonstrated theoretically that a field-reversed mirror imbedded in a multipole field can be sustained in steady state with neutral-beam injection even in the absence of impurities. MHD stability analysis shows that growth rates of elongated reversed-field theta-pinch configurations decrease with axial extension, which indicates the importance of including finite Larmor radius in the analysis. Tilting-mode criteria are dramatically improved by proper shaping, and a problimak shape is proposed. Tearing mode stability of reversed-field theta-pinches is greatly enhanced by flux exclusion. Self-consistent, 1-1/2-dimensional transport codes have been developed, and initial results are presented

Annealing temperature and O2 partial pressure dependence of T(sub c) in HgBa2CuO(4+delta)

Science.gov (United States)

Xiong, Q.; Cao, Y.; Chen, F.; Xue, Y. Y.; Chu, C. W.

1994-01-01

Samples of HgBa2CuO(4+delta) (Hg-1201) were annealed under various conditions. After carefully controlling annealing time, annealing temperature (T(sub a)) and O2 partial pressure (P(sub 0)), we were able to find the reversible annealing conditions for Hg-1201. Under 1 atm O2 at 260 C less than or equal to T(sub a) less than or equal to 400 C, the obtained T(sub c) is nearly the same (approximately 97 K). However, it decreases quickly with T(sub a) greater than 300 C in high vacuum (P(sub 0) approximately 10(exp -8) atm), and reaches zero at T(sub a) = 400 C. On the other hand, T(sub c) decreases with the decrease of T(sub a) in high-pressure O2 (approximately 500 atm) and reaches approximately 20 K at about 240 C. In the entire annealing region, the oxygen surplus varies significantly from 0.03 to 0.4, and a wide range of T(sub c) variation (0 goes to 97 K goes to 20 K) was obtained with anion doping alone.

Minutes of the 2. Meeting of the WPRS / EGRPANS / Sodium Fast Reactor Task Force (SFR)

International Nuclear Information System (INIS)

Ivanov, Evgeny; Kereszturi, Andras; Pataki, I.; Tota, A.; Vertes, P.; Kim, Taek K.; Taiwo, T.A.; Kugo, Teruhiko; Lee, Yi Kang; Messaoudi, Nadia; Michel-Sendis, Franco; ); Pascal, Vincent; Buiron, Laurent; Varaine, Frederic; Ponomarev, Alexander

2012-01-01

Five organizations (SCK/CEN, KIT, KFKI, CEA, ANL) participated in the Sodium-cooled fast reactor (SFR) Benchmark calculations and all results were collected and compiled by CEA and ANL. The compiled results of the large size cores and medium size cores were presented by V. Pascal (CEA) and T. K. Kim (ANL), respectively. Separately, A. Kereszturi presented his recently updated results. It was observed that there is wide variation in core multiplication factor, kinetics parameters, and reactivity feedback coefficients. In particular, compared to the CEA results, ANL calculated smaller k-eff, Doppler constant, but higher sodium void worth and control rod worth. The core modeling issue (heterogeneous vs. homogeneous) and solution method (diffusion vs. transport) were identified as the potential reasons of these discrepancies, including the minor impacts from the depletion chains and lumped fission product modeling. All participants agreed that additional investigation was needed to identify the reasons of these discrepancies. In addition, V. Pascal presented the informative notes of the reactivity feedback calculations methodology proposed by CEA. This document brings together the 5 presentations (slides) given at this meeting: 1 - SFR Task Force : Core behavior during transient as a function of power size and fuel nature (L. Buiron, V. Pascal, F. Varaine); 2 - Sodium Fast Reactor core Feedback and Transient response (SFRFT) Expert Group: preliminary benchmark results for large cores (L. Buiron, V. Pascal, F. Varaine); 3 - Numerical Benchmark Results for 1000 MWth Sodium-cooled Fast Reactor (T.K. Kim and T.A. Taiwo); 4 - Preliminary results of the WPRS Sodium-Cooled Fast Reactor Benchmark problems (A. Kereszturi, I. Pataki, A. Tota, P. Vertes); 5 - SFR Task Force : proposal for Feedback coefficients estimation methodology (L. Buiron, V.Pascal, F. Varaine)

Effects of Roux-en-Y Gastric Bypass on Fasting and Postprandial Levels of the Inflammatory Markers YKL-40 and MCP-1 in Patients with Type 2 Diabetes and Glucose Tolerant Subjects

Directory of Open Access Journals (Sweden)

Stine Brinkløv Thomsen

2013-01-01

Full Text Available Background. The inflammatory markers YKL-40 and monocyte chemoattractant protein-1 (MCP-1 are elevated in morbidly obese patients and decline after weight loss. The objective of our study was to investigate the possible changes of YKL-40 and MCP-1, in both the fasting and the postprandial states, following Roux-en-Y gastric bypass (RYGB in subjects with type 2 diabetes (T2D and normal glucose tolerance (NGT. Methods. Ten obese patients with T2D and 10 subjects with NGT were examined in the fasting state and after a standard meal prior to and after (1 week, 3 months, and 1 year RYGB. Results. Fasting state MCP-1 levels decreased after RYGB in both groups (P values < 0.0001 whereas fasting YKL-40 levels were unchanged (P values ≥ 0.120. Postprandial MCP-1 levels showed a tendency towards a decrease on most study days; however, the changes were only significant at 1 week (P=0.001 and 1 yr (P<0.0001 in the T2D group and at 3 mo after RYGB in the NGT group (P=0.009. YKL-40 levels showed a slight, postprandial suppression on all study days in the T2D group (all P values ≤ 0.021. Conclusions. Fasting MCP-1 levels, but not YKL-40 levels, decrease after RYGB in subjects with T2D and NGT. Postprandial changes of inflammatory markers are discrete and inconsistent.

Artifact free T2*-weighted imaging at high spatial resolution using segmented EPI sequences

International Nuclear Information System (INIS)

Heiler, Patrick Michael; Schad, Lothar Rudi; Schmitter, Sebastian

2010-01-01

The aim of this work was the development of novel measurement techniques that acquire high resolution T2 * -weighted datasets in measurement times as short as possible without suffering from noticeable blurring and ghosting artifacts. Therefore, two new measurement techniques were developed that acquire a smoother k-space than generic multi shot echo planar imaging sequences. One is based on the principle of echo train shifting, the other on the reversed gradient method. Simulations and phantom measurements demonstrate that echo train shifting works properly and reduces artifacts in multi shot echo planar imaging. For maximum SNR-efficiency this technique was further improved by adding a second contrast. Both contrasts can be acquired within a prolongation in measurement time by a factor of 1.5, leading to an SNR increase by approximately √2. Furthermore it is demonstrated that the reversed gradient method remarkably reduces artifacts caused by a discontinuous k-space weighting. Assuming sequence parameters as feasible for fMRI experiments, artifact free T2 * -weighted images with a matrix size of 256 x 256 leading to an in-plane resolution in the submillimeter range can be obtained in about 2 s per slice. (orig.)

Properties of the reverse transcription reaction in mRNA quantification

DEFF Research Database (Denmark)

Ståhlberg, Anders; Håkansson, Joakim; Xian, Xiaojie

2004-01-01

BACKGROUND: In most measurements of gene expression, mRNA is first reverse-transcribed into cDNA. We studied the reverse transcription reaction and its consequences for quantitative measurements of gene expression. METHODS: We used SYBR green I-based quantitative real-time PCR (QPCR) to measure...... the properties of reverse transcription reaction for the beta-tubulin, glyceraldehyde-3-phosphate dehydrogenase, Glut2, CaV1D, and insulin II genes, using random hexamers, oligo(dT), and gene-specific reverse transcription primers. RESULTS: Experimental variation in reverse transcription-QPCR (RT......-QPCR) was mainly attributable to the reverse transcription step. Reverse transcription efficiency depended on priming strategy, and the dependence was different for the five genes studied. Reverse transcription yields also depended on total RNA concentration. CONCLUSIONS: RT-QPCR gene expression measurements...

Field-reversed configuration confinement in TRX-1

International Nuclear Information System (INIS)

Steinhauer, L.; Slough, J.

1984-01-01

Particle and poloidal flux lifetime data from the TRX-1, field-reversed theta pinch experiment, have been used to infer information on the basic transport behavior. The field-reversed configurations were created over a broad range of plasma parameters: separatrix radii, 4-8 cm; lengths, 35-80 cm; and temperature T/sub e/ + T/sub i/, 150-1000 eV. The confinement times covered a wide range as well: Particles, tau/sub N/ = 30-170 μs; poloidal flux, tau/sub phi/ = 30-140 μs; and energy tau/sub E/ = 20-75 μs. The experimental data was divided, a priori, into three classes: 1) the triggered-reconnection mode; 2) the programmed-formation mode with a good preionization (PI); and 3) programmed formation with poor PI

The misconception of mean-reversion

International Nuclear Information System (INIS)

Eliazar, Iddo I; Cohen, Morrel H

2012-01-01

The notion of random motion in a potential well is elemental in the physical sciences and beyond. Quantitatively, this notion is described by reverting diffusions—asymptotically stationary diffusion processes which are simultaneously (i) driven toward a reversion level by a deterministic force, and (ii) perturbed off the reversion level by a random white noise. The archetypal example of reverting diffusions is the Ornstein–Uhlenbeck process, which is mean-reverting. In this paper we analyze reverting diffusions and establish that: (i) if the magnitude of the perturbing noise is constant then the diffusion's stationary density is unimodal and the diffusion is mode-reverting; (ii) if the magnitude of the perturbing noise is non-constant then, in general, neither is the diffusion's stationary density unimodal, nor is the diffusion mode-reverting. In the latter case we further establish a result asserting when unimodality and mode-reversion do hold. In particular, we demonstrate that the notion of mean-reversion, which is fundamental in economics and finance, is a misconception—as mean-reversion is an exception rather than the norm. (fast track communication)

Measurements of hot electrons in the Extrap T1 reversed-field pinch

International Nuclear Information System (INIS)

Welander, A.; Bergsaaker, H.

1998-01-01

The presence of an anisotropic energetic electron population in the edge region is a characteristic feature of reversed-field pinch (RFP) plasmas. In the Extrap T1 RFP, the anisotropic, parallel heat flux in the edge region measured by calorimetry was typically several hundred MWm -2 . To gain more insight into the origin of the hot electron component and to achieve time resolution of the hot electron flow during the discharge, a target probe with a soft x-ray monitor was designed, calibrated and implemented. The x-ray emission from the target was measured with a surface barrier detector covered with a set of different x-ray filters to achieve energy resolution. A calibration in the range 0.5-2 keV electron energy was performed on the same target and detector assembly using a LaB 6 cathode electron gun. The calibration data are interpolated and extrapolated numerically. A directional asymmetry of more than a factor of 100 for the higher energy electrons is observed. The hot electrons are estimated to constitute 10% of the total electron density at the edge and their energy distribution is approximated by a half-Maxwellian with a temperature slightly higher than the central electron temperature. Scalings with plasma current, as well as correlations with local Hα measurements and radial dependences, are presented. (author)

Histological correlation of 7 T multi-parametric MRI performed in ex-vivo Achilles tendon

Energy Technology Data Exchange (ETDEWEB)

Juras, Vladimir [Center of Excellence for High Field MR, Department of Radiology, Medical University of Vienna Waehringer Guertel 18-20, A-1090, Vienna (Austria); Institute of Measurement Science, Department of Imaging Methods, Dubravska cesta 9, 84104, Bratislava (Slovakia); Apprich, Sebastian; Pressl, Christina; Zbyn, Stefan [Center of Excellence for High Field MR, Department of Radiology, Medical University of Vienna Waehringer Guertel 18-20, A-1090, Vienna (Austria); Szomolanyi, Pavol [Center of Excellence for High Field MR, Department of Radiology, Medical University of Vienna Waehringer Guertel 18-20, A-1090, Vienna (Austria); Institute of Measurement Science, Department of Imaging Methods, Dubravska cesta 9, 84104, Bratislava (Slovakia); Domayer, Stephan; Hofstaetter, Jochen G. [Department of Orthopedic Surgery, Vienna General Hospital, Medical University of Vienna, A-1090 Vienna (Austria); Trattnig, Siegfried, E-mail: siegfried.trattnig@meduniwien.ac.at [Center of Excellence for High Field MR, Department of Radiology, Medical University of Vienna Waehringer Guertel 18-20, A-1090, Vienna (Austria)

2013-05-15

Introduction: The goal of this in vitro validation study was to investigate the feasibility of biochemical MRI techniques, such as sodium imaging, T{sub 2} mapping, fast imaging with steady state precession (FISP), and reversed FISP (PSIF), as potential markers for collagen, glycosaminoglycan and water content in the Achilles tendon. Materials and methods: Five fresh cadaver ankles acquired from a local anatomy department were used in the study. To acquire a sodium signal from the Achilles tendon, a 3D-gradient-echo sequence, optimized for sodium imaging, was used with TE = 7.71 ms and TR = 17 ms. The T{sub 2} relaxation times were obtained using a multi-echo, spin-echo technique with a repetition time (TR) of 1200 ms and six echo times. A 3D, partially balanced, steady-state gradient echo pulse sequence was used to acquire FISP and PSIF images, with TR/TE = 6.96/2.46 ms. MRI parameters were correlated with each other, as well as with histologically assessed glycosaminoglycan and water content in cadaver Achilles tendons. Results: The highest relevant Pearson correlation coefficient was found between sodium SNR and glycosaminoglycan content (r = 0.71, p = 0.007). Relatively high correlation was found between the PSIF signal and T{sub 2} values (r = 0.51, p = 0.036), and between the FISP signal and T{sub 2} values (r = 0.56, p = 0.047). Other correlations were found to be below the moderate level. Conclusion: This study demonstrated the feasibility of progressive biochemical MRI methods for the imaging of the AT. A GAG-specific, contrast-free method (sodium imaging), as well as collagen- and water-sensitive methods (T{sub 2} mapping, FISP, PSIF), may be used in fast-relaxing tissues, such as tendons, in reasonable scan times.

Histological correlation of 7 T multi-parametric MRI performed in ex-vivo Achilles tendon

International Nuclear Information System (INIS)

Juras, Vladimir; Apprich, Sebastian; Pressl, Christina; Zbyn, Stefan; Szomolanyi, Pavol; Domayer, Stephan; Hofstaetter, Jochen G.; Trattnig, Siegfried

2013-01-01

Introduction: The goal of this in vitro validation study was to investigate the feasibility of biochemical MRI techniques, such as sodium imaging, T 2 mapping, fast imaging with steady state precession (FISP), and reversed FISP (PSIF), as potential markers for collagen, glycosaminoglycan and water content in the Achilles tendon. Materials and methods: Five fresh cadaver ankles acquired from a local anatomy department were used in the study. To acquire a sodium signal from the Achilles tendon, a 3D-gradient-echo sequence, optimized for sodium imaging, was used with TE = 7.71 ms and TR = 17 ms. The T 2 relaxation times were obtained using a multi-echo, spin-echo technique with a repetition time (TR) of 1200 ms and six echo times. A 3D, partially balanced, steady-state gradient echo pulse sequence was used to acquire FISP and PSIF images, with TR/TE = 6.96/2.46 ms. MRI parameters were correlated with each other, as well as with histologically assessed glycosaminoglycan and water content in cadaver Achilles tendons. Results: The highest relevant Pearson correlation coefficient was found between sodium SNR and glycosaminoglycan content (r = 0.71, p = 0.007). Relatively high correlation was found between the PSIF signal and T 2 values (r = 0.51, p = 0.036), and between the FISP signal and T 2 values (r = 0.56, p = 0.047). Other correlations were found to be below the moderate level. Conclusion: This study demonstrated the feasibility of progressive biochemical MRI methods for the imaging of the AT. A GAG-specific, contrast-free method (sodium imaging), as well as collagen- and water-sensitive methods (T 2 mapping, FISP, PSIF), may be used in fast-relaxing tissues, such as tendons, in reasonable scan times

Fast cooling phenomena with ice pellet injection in the JIPP T-IIU Tokamak

International Nuclear Information System (INIS)

Sakamoto, M.; Sato, K.N.; Ogawa, Y.

1991-01-01

Ice pellet injection experiments were carried out in the JIPP T-IIU Tokamak in order to study thermal (cooling) transport just after injection. The cut-off problem of ECE signals due to the rise in density has been resolved by careful measurements of the temperature profile at a high time resolution (Δt = 2μs) during its decay phase. The phenomenon of ultra-fast cooling (so-called pre-cooling) has been identified using the two different methods of ECE and soft X-ray (SXR) measurements. In the outer region (r > r q=1 ) of the plasma the cooling propagation velocity is comparable to or slightly greater than the pellet velocity, while in the central region (r q=1 ) the propagation velocity is significantly greater than the pellet velocity. Ice pellets were injected into various kinds of JIPP T-IIU plasmas, the current and sawtooth phase of which had different values, including a no-sawtooth plasma. The existence of the q = 1 surface and arrival of a pellet near the q = 1 surface have turned out to be necessary conditions for pre-cooling, and even just after the sawtooth crash the pre-cooling starts around the q = 1 surface, not at the plasma center. Simultaneous measurements of electron temperature and density profiles indicate that the central temperature always decreases before the central density increases. Some anomalous transport might be induced by pellet injection at the central region. (Author)

Dihydrotestosterone stimulates amino acid uptake and the expression of LAT2 in mouse skeletal muscle fibres through an ERK1/2-dependent mechanism

Science.gov (United States)

Hamdi, M M; Mutungi, G

2011-01-01

Abstract Dihydrotestosterone (DHT) has acute/non-genomic actions in adult mammalian skeletal muscles whose physiological functions are still poorly understood. Therefore, the primary aim of this study was to investigate the acute/non-genomic effects of DHT on amino acid uptake as well as the cellular signal transduction events underlying these actions in mouse fast- and slow-twitch skeletal muscle fibre bundles. 14C-Labelled amino acids were used to investigate the effects of DHT and testosterone (T) on amino acid uptake and pharmacological interventions were used to determine the cellular signal transduction events mediating these actions. While T had no effect on the uptake of isoleucine (Ile) and α-methylaminoisobutyric acid (MeAIB) in both fibre types, DHT increased their uptake in the fast-twitch fibre bundles. This effect was reversed by inhibitors of protein translation, the epidermal growth factor receptor (EGFR), system A, system L, mTOR and MEK. However, it was relatively insensitive to inhibitors of transcription, androgen receptors and PI3K/Akt. Additionally, DHT treatment increased the expression of LAT2 and the phosphorylation of the EGFR in the fast-twitch fibre bundles and that of ERK1/2, RSK1/2 and ATF2 in both fibre types. Also, it decreased the phosphorylation of eEF2 and increased the incorporation of Ile into proteins in both fibre types. Most of these effects were reversed by EGFR and MEK inhibitors. From these findings we suggest that another physiological function of the acute/non-genomic actions of DHT in isolated mammalian skeletal muscle fibres is to stimulate amino acid uptake. This effect is mediated through the EGFR and involves the activation of the MAPK pathway and an increase in LAT2 expression. PMID:21606113

Yeast tRNAPhe expressed in human cells can be selected by HIV-1 for use as a reverse transcription primer

International Nuclear Information System (INIS)

Kelly, Nathan J.; Morrow, Casey D.

2003-01-01

All naturally occurring human immune deficiency viruses (HIV-1) select and use tRNA Lys,3 as the primer for reverse transcription. Studies to elucidate the mechanism of tRNA selection from the intracellular milieu have been hampered due to the difficulties in manipulating the endogenous levels of tRNA Lys,3 . We have previously described a mutant HIV-1 with a primer binding site (PBS) complementary to yeast tRNA Phe (psHIV-Phe) that relies on transfection of yeast tRNA Phe for infectivity. To more accurately recapitulate the selection process, a cDNA was designed for the intracellular expression of the yeast tRNA Phe . Increasing amounts of the plasmid encoding tRNA Phe resulted in a corresponding increase in levels of yeast tRNA Phe in the cell. The yeast tRNA Phe isolated from cells transfected with the cDNA for yeast tRNA Phe , or in the cell lines expressing yeast tRNA Phe , were aminoacylated, indicating that the expressed yeast tRNA Phe was incorporated into tRNA biogenesis pathways and translation. Increasing the cytoplasmic levels of tRNA Phe resulted in increased encapsidation of tRNA Phe in viruses with a PBS complementary to tRNA Phe (psHIV-Phe) or tRNA Lys,3 (wild-type HIV-1). Production of infectious psHIV-Phe was dependent on the amount of cotransfected tRNA Phe cDNA. Increasing amounts of plasmids encoding yeast tRNA Phe produced an increase of infectious psHIV-Phe that plateaued at a level lower than that from the transfection of the wild-type genome, which uses tRNA Lys,3 as the primer for reverse transcription. Cell lines were generated that expressed yeast tRNA Phe at levels approximately 0.1% of that for tRNA Lys,3 . Even with this reduced level of yeast tRNA Phe , the cell lines complemented psHIV-Phe over background levels. The results of these studies demonstrate that intracellular levels of primer tRNA can have a direct effect on HIV-1 infectivity and further support the role for PBS-tRNA complementarity in the primer selection process

Implementing reverse genetics in Rosaceae: analysis of T-DNA flanking sequences of insertional mutant lines in the diploid strawberry, Fragaria vesca.

Science.gov (United States)

Oosumi, Teruko; Ruiz-Rojas, Juan Jairo; Veilleux, Richard E; Dickerman, Allan; Shulaev, Vladimir

2010-09-01

Reverse genetics is used for functional genomics research in model plants. To establish a model system for the systematic reverse genetics research in the Rosaceae family, we analyzed genomic DNA flanking the T-DNA insertions in 191 transgenic plants of the diploid strawberry, Fragaria vesca. One hundred and seventy-six T-DNA flanking sequences were amplified from the right border (RB) and 37 from the left border (LB) by thermal asymmetric interlaced PCR. Analysis of the T-DNA nick positions revealed that T-DNA was most frequently nicked at the cleavage sites. Analysis of 11 T-DNA integration sites indicated that T-DNA was integrated into the F. vesca genome by illegitimate recombination, as reported in other model plants: Arabidopsis, rice and tobacco. First, deletion of DNA was found at T-DNA integration target sites in all transgenic plants tested. Second, microsimilarities of a few base pairs between the left and/or right ends of the T-DNA and genomic sites were found in all transgenic plants tested. Finally, filler DNA was identified in four break-points. Out of 191 transgenic plants, T-DNA flanking sequences of 79 plants (41%) showed significant similarity to genes, elements or proteins of other plant species and 67 (35%) of the sequences are still unknown strawberry gene fragments. T-DNA flanking sequences of 126 plants (66%) showed homology to plant ESTs. This is the first report of T-DNA integration in a sizeable population of a rosaceous species. We have shown in this paper that T-DNA integration in strawberry is not random but directed by sequence microsimilarities in the host genome.

Temperature dependent polarization reversal mechanism in 0.94(Bi1/2Na1/2)TiO3-0.06Ba(Zr0.02Ti0.98)O3 relaxor ceramics

Science.gov (United States)

Glaum, Julia; Simons, Hugh; Hudspeth, Jessica; Acosta, Matias; Daniels, John E.

2015-12-01

The temperature at which the electric field induced long-range ordered ferroelectric state undergoes transition into the short-range ordered relaxor state, TF-R, is commonly defined by the onset of strong dispersion of the dielectric permittivity. However, this combined macroscopic property and structural investigation of the polarization reversal process in the prototypical lead-free relaxor 0.94(Bi1/2Na1/2)TiO3-0.06Ba(Zr0.02Ti0.98)O3 reveals that an applied electric field can trigger depolarization and onset of relaxor-like behavior well below TF-R. The polarization reversal process can as such be described as a combination of (1) ferroelectric domain switching and (2) a reversible phase transition between two polar ferroelectric states mediated by a non-polar relaxor state. Furthermore, the threshold fields of the second, mediated polarization reversal mechanism depend strongly on temperature. These results are concomitant with a continuous ferroelectric to relaxor transition occurring over a broad temperature range, during which mixed behavior is observed. The nature of polarization reversal can be illustrated in electric-field-temperature (E-T) diagrams showing the electric field amplitudes associated with different polarization reversal processes. Such diagrams are useful tools for identifying the best operational temperature regimes for a given composition in actuator applications.

Metal impurity fluxes and plasma-surface interactions in EXTRAP T2R

Science.gov (United States)

Bergsåker, H.; Menmuir, S.; Rachlew, E.; Brunsell, P. R.; Frassinetti, L.; Drake, J. R.

2008-03-01

The EXTRAP T2R is a large aspect ratio Reversed Field Pinch device. The main focus of interest for the experiments is the active feedback control of resistive wall modes [1]. With feedback it has been possible to prolong plasma discharges in T2R from about 20 ms to nearly 100 ms. In a series of experiments in T2R, in H- and D- plasmas with and without feedback, quantitative spectroscopy and passive collector probes have been used to study the flux of metal impurities. Time resolved spectroscopic measurements of Cr and Mo lines showed large metal release towards discharge termination without feedback. Discharge integrated fluxes of Cr, Fe, Ni and Mo were also measured with collector probes at wall position. Reasonable quantitative agreement was found between the spectroscopic and collector probe measurements. The roles of sputtering, thermal evaporation and arcing in impurity production are evaluated based on the composition of the measured impurity flux.

Metal impurity fluxes and plasma-surface interactions in EXTRAP T2R

International Nuclear Information System (INIS)

Bergsaaker, H; Brunsell, P R; Frassinetti, L; Drake, J R; Menmuir, S; Rachlew, E

2008-01-01

The EXTRAP T2R is a large aspect ratio Reversed Field Pinch device. The main focus of interest for the experiments is the active feedback control of resistive wall modes. With feedback it has been possible to prolong plasma discharges in T2R from about 20 ms to nearly 100 ms. In a series of experiments in T2R, in H- and D- plasmas with and without feedback, quantitative spectroscopy and passive collector probes have been used to study the flux of metal impurities. Time resolved spectroscopic measurements of Cr and Mo lines showed large metal release towards discharge termination without feedback. Discharge integrated fluxes of Cr, Fe, Ni and Mo were also measured with collector probes at wall position. Reasonable quantitative agreement was found between the spectroscopic and collector probe measurements. The roles of sputtering, thermal evaporation and arcing in impurity production are evaluated based on the composition of the measured impurity flux

Vpx overcomes a SAMHD1-independent block to HIV reverse transcription that is specific to resting CD4 T cells.

Science.gov (United States)

Baldauf, Hanna-Mari; Stegmann, Lena; Schwarz, Sarah-Marie; Ambiel, Ina; Trotard, Maud; Martin, Margarethe; Burggraf, Manja; Lenzi, Gina M; Lejk, Helena; Pan, Xiaoyu; Fregoso, Oliver I; Lim, Efrem S; Abraham, Libin; Nguyen, Laura A; Rutsch, Frank; König, Renate; Kim, Baek; Emerman, Michael; Fackler, Oliver T; Keppler, Oliver T

2017-03-07

Early after entry into monocytes, macrophages, dendritic cells, and resting CD4 T cells, HIV encounters a block, limiting reverse transcription (RT) of the incoming viral RNA genome. In this context, dNTP triphosphohydrolase SAM domain and HD domain-containing protein 1 (SAMHD1) has been identified as a restriction factor, lowering the concentration of dNTP substrates to limit RT. The accessory lentiviral protein X (Vpx) proteins from the major simian immunodeficiency virus of rhesus macaque, sooty mangabey, and HIV-2 (SIVsmm/SIVmac/HIV-2) lineage packaged into virions target SAMHD1 for proteasomal degradation, increase intracellular dNTP pools, and facilitate HIV cDNA synthesis. We find that virion-packaged Vpx proteins from a second SIV lineage, SIV of red-capped mangabeys or mandrills (SIVrcm/mnd-2), increased HIV infection in resting CD4 T cells, but not in macrophages, and, unexpectedly, acted in the absence of SAMHD1 degradation, dNTP pool elevation, or changes in SAMHD1 phosphorylation. Vpx rcm/mnd-2 virion incorporation resulted in a dramatic increase of HIV-1 RT intermediates and viral cDNA in infected resting CD4 T cells. These analyses also revealed a barrier limiting HIV-1 infection of resting CD4 T cells at the level of nuclear import. Single amino acid changes in the SAMHD1-degrading Vpx mac239 allowed it to enhance early postentry steps in a Vpx rcm/mnd-2-like fashion. Moreover, Vpx enhanced HIV-1 infection of SAMHD1-deficient resting CD4 T cells of a patient with Aicardi-Goutières syndrome. These results indicate that Vpx, in addition to SAMHD1, overcomes a previously unappreciated restriction for lentiviruses at the level of RT that acts independently of dNTP concentrations and is specific to resting CD4 T cells.

Fast fluid-attenuated inversion-recovery MR image in the intracranial tumors: comparison with fast spin-echo image

International Nuclear Information System (INIS)

Choi, Hye Young; Kwang, Hyoen Joo; Baek, Seoung Yeon; Lee, Sun Wha

1997-01-01

To evaluate the significance of fluid-attenuated inversion recovery(FLAIR) magnetic resonance(MR) images for the diagnosis of intracranial tumors. MR imaging was used to study 15 patients with various intracranial tumors and were compared the findings according to fast spin echo and fast FLAIR images. In 12 of 15 patients, tumor signal intensities on FLAIR images were consistent with those shown on T2-weighted(T2W) images. In seven of eight patients who had cystic or necrotic components within the mass, FLAIR images showed isosignal intensity and in the other patient, high signal intensity was seen. There was variation in the signal intensity from cerebrospinal fluid(CSF). In 12 of 13 patients in whom edema was associated with tumor, FLAIR images were clearer than T2W images as their signal intensity was brighter. In eight patients, however, FLAIR and T2W images provided a similar definition of the margin between edema and tumor. In six patients with intratumoral hemorrhage except the chronic cystic stage. We concluded that in the diagnosis of intracranial tumors, FLAIR images can supplement conventional spin-echo images

Magnetic resonance enteroclysis in patients with Crohn's disease: fat saturated T2-weighted sequences for evaluation of inflammatory activity.

Science.gov (United States)

Grieser, Christian; Denecke, Timm; Steffen, Ingo G; Werner, Scarlett; Kröncke, Thomas; Guckelberger, Olaf; Pape, Ulrich-Frank; Meier, Johannes; Thiel, Regina; Kivelitz, Dietmar; Sturm, Andreas; Hamm, Bernd; Röttgen, Rainer

2012-04-01

To evaluate fat saturated (fs) T2-weighted (w) fast relaxation fast spin echo (FRFSE)-sequences compared to the standard protocol with contrast agent for the evaluation of inflammatory activity in patients with Crohn's Disease (CD). Fourty-eight patients (male, 17; female, 33; mean age, 37 years) with suspicion of inflammatory activity in proven CD who underwent MR enteroclysis (MRE) at 1.5T (GE Healthcare) were retrospectively included. Two blinded radiologists analyzed MRE images for presence and extent of CD lesions and degree of local inflammation for fsT2-w FRFSE and contrast enhanced T1-w images (T2-activity; T1-activity; score, 1-4) in consensus. Furthermore, mural signal intensity (SI) ratios (T2-ratio; T1-ratio) were recorded. Patient based MRE findings were correlated with endoscopic (45 patients), surgical (6 patients), histopathological, and clinical data (CDAI) as a surrogate reference standard. In total, 24 of 48 eligible patients presented with acute inflammatory activity with 123 affected bowel segments. ROC analysis of the total inflammatory score presented an AUC of 0.93 (pT2-activity (T1-activity, AUC 0.63; p=0.019). ROC analysis revealed an AUC of 0.76 (pT2-ratio (T1-ratio, AUC 0.51; p=0.93). General linear regression model revealed T2-activity (p=0.001) and age (p=0.024) as predictive factors of acute bowel inflammation. T2-w FRFSE-sequences can depict CD lesions and help to assess the inflammation activity, even with improved accuracy as compared to contrast-enhanced T1-w sequences. Copyright © 2011 European Crohn's and Colitis Organisation. Published by Elsevier B.V. All rights reserved.

Magnetization reversal in weak ferrimagnets and canted antiferromagnets

International Nuclear Information System (INIS)

Kageyama, H.; Khomskii, D.I.; Levitin, R.Z.; Markina, M.M.; Okuyama, T.; Uchimoto, T.; Vasil'ev, A.N.

2003-01-01

In some ferrimagnets the total magnetization vanishes at a certain compensation temperature T*. In weak magnetic fields, the magnetization can change sign at T* (the magnetization reversal). Much rarer is observation of ferrimagnetic-like response in canted antiferromagnets, where the weak ferromagnetic moment is due to the tilting of the sublattice magnetizations. The latter phenomenon was observed in nickel (II) formate dihydrate Ni(HCOO) 2 ·2H 2 O. The observed weak magnetic moment increases initially below T N =15.5 K, equals zero at T*=8.5 K and increases again at lowering temperature. The sign of the low-field magnetization at any given temperature is determined by the sample's magnetic prehistory and the signs are opposite to each other at T N

Parameter dependence of resonant spin torque magnetization reversal

International Nuclear Information System (INIS)

Fricke, L.; Serrano-Guisan, S.; Schumacher, H.W.

2012-01-01

We numerically study ultra fast resonant spin torque (ST) magnetization reversal in magnetic tunneling junctions (MTJ) driven by current pulses having a direct current (DC) and a resonant alternating current (AC) component. The precessional ST dynamics of the single domain MTJ free layer cell are modeled in the macro spin approximation. The energy efficiency, reversal time, and reversal reliability are investigated under variation of pulse parameters like direct and AC current amplitude, AC frequency and AC phase. We find a range of AC and direct current amplitudes where robust resonant ST reversal is obtained with faster switching time and reduced energy consumption per pulse compared to purely direct current ST reversal. However, for a certain range of AC and direct current amplitudes a strong dependence of the reversal properties on AC frequency and phase is found. Such regions of unreliable reversal must be avoided for ST memory applications.

Parameter dependence of resonant spin torque magnetization reversal