Sample records for t1-weighted-space dark blood

  1. Assessment of carotid stenosis using three-dimensional T2-weighted dark blood imaging: Initial experience.

    PubMed

    Mihai, Georgeta; Winner, Marshall W; Raman, Subha V; Rajagopalan, Sanjay; Simonetti, Orlando P; Chung, Yiu-Cho

    2012-02-01

    To evaluate the use of a T2-weighted SPACE sequence (T2w-SPACE) to assess carotid stenosis via several methods and compare its performance with contrast-enhanced magnetic resonance angiography (ceMRA). Fifteen patients with carotid atherosclerosis underwent dark blood (DB)-MRI using a 3D turbo spin echo with variable flip angles sequence (T2w-SPACE) and ceMRA. Images were coregistered and evaluated by two observers. Comparisons were made for luminal diameter, luminal area, degree of luminal stenosis (NASCET: North American Symptomatic Endarterectomy Trial; ECST: European Carotid Surgery Trial, and area stenosis), and vessel wall area. Degree of NASCET stenosis was clinically classified as mild (<50%), moderate (50%-69%), or severe (>69%). Excellent agreement was seen between ceMRA and T2w-SPACE and between observers for assessment of lumen diameter, lumen area, vessel wall area, and degree of NASCET stenosis (r > 0.80, P < 0.001). ECST stenosis was consistently higher than NASCET stenosis (48 ± 14% vs. 24 ± 22%, P < 0.001). Area stenosis (72 ± 2%) was significantly higher (P < 0.001) than both ESCT and NASCET stenosis. DB-MRI of carotid arteries using T2w-SPACE is clinically feasible. It provides accurate measurements of lumen size and degree of stenosis in comparison with ceMRA and offers a more reproducible measure of ECST stenosis than ceMRA. Copyright © 2011 Wiley Periodicals, Inc.

  2. Dark blood late enhancement imaging.

    PubMed

    Kellman, Peter; Xue, Hui; Olivieri, Laura J; Cross, Russell R; Grant, Elena K; Fontana, Marianna; Ugander, Martin; Moon, James C; Hansen, Michael S

    2016-11-07

    Bright blood late gadolinium enhancement (LGE) imaging typically achieves excellent contrast between infarcted and normal myocardium. However, the contrast between the myocardial infarction (MI) and the blood pool is frequently suboptimal. A large fraction of infarctions caused by coronary artery disease are sub-endocardial and thus adjacent to the blood pool. It is not infrequent that sub-endocardial MIs are difficult to detect or clearly delineate. In this present work, an inversion recovery (IR) T2 preparation was combined with single shot steady state free precession imaging and respiratory motion corrected averaging to achieve dark blood LGE images with good signal to noise ratio while maintaining the desired spatial and temporal resolution. In this manner, imaging was conducted free-breathing, which has benefits for image quality, patient comfort, and clinical workflow in both adults and children. Furthermore, by using a phase sensitive inversion recovery reconstruction the blood signal may be made darker than the myocardium (i.e., negative signal values) thereby providing contrast between the blood and both the MI and remote myocardium. In the proposed approach, a single T1-map scout was used to measure the myocardial and blood T1 using a MOdified Look-Locker Inversion recovery (MOLLI) protocol and all protocol parameters were automatically calculated from these values within the sequence thereby simplifying the user interface. The contrast to noise ratio (CNR) between MI and remote myocardium was measured in n = 30 subjects with subendocardial MI using both bright blood and dark blood protocols. The CNR for the dark blood protocol had a 13 % loss compared to the bright blood protocol. The CNR between the MI and blood pool was positive for all dark blood cases, and was negative in 63 % of the bright blood cases. The conspicuity of subendocardial fibrosis and MI was greatly improved by dark blood (DB) PSIR as well as the delineation of the

  3. Diagnostic performance of dark-blood T2-weighted CMR for evaluation of acute myocardial injury.

    PubMed

    Srichai, Monvadi B; Lim, Ruth P; Lath, Narayan; Babb, James; Axel, Leon; Kim, Daniel

    2013-01-01

    We compared the image quality and diagnostic performance of 2 fat-suppression methods for black-blood T2-weighted fast spin-echo (FSE), which are as follows: (a) short T1 inversion recovery (STIR; FSE-STIR) and (b) spectral adiabatic inversion recovery (SPAIR; FSE-SPAIR), for detection of acute myocardial injury. Edema-sensitive T2-weighted FSE cardiac magnetic resonance (CMR) imaging is useful in detecting acute myocardial injury but may experience reduced myocardial signal and signal dropout. The SPAIR pulse aims to eliminate artifacts associated with the STIR pulse. A total of 65 consecutive patients referred for CMR evaluation of myocardial structure and function underwent FSE-STIR and FSE-SPAIR, in addition to cine and late gadolinium enhancement (LGE) CMR. T2-weighted FSE images were independently evaluated by 2 readers for image quality and artifacts (Likert scale of 1-5; best-worst) and presence of increased myocardial signal suggestive of edema. In addition, clinical CMR interpretation, incorporating all CMR sequences available, was recorded for comparison. Diagnostic performance of each T2-weighted sequence was measured using recent (<30 days) troponin elevation greater than 2 times the upper limit of normal as the reference standard for acute myocardial injury. Of the 65 patients, there were 21 (32%) with acute myocardial injury. Image quality and artifact scores were significantly better with FSE-SPAIR compared with FSE-STIR (2.15 vs 2.68, P < 0.01; 2.62 vs 3.05, P < 0.01, respectively). The sensitivity, specificity, positive predictive value, and negative predictive value for acute myocardial injury were as follows: 29%, 93%, 67%, and 73% for FSE-SPAIR; 38%, 91%, 67%, and 75% for FSE-STIR; 71%, 98%, 94%, and 88% for clinical interpretation including LGE, T2, and wall motion. There was a statistically significant difference in sensitivity between the clinical interpretation and each of the T2-weighted sequences but not between each T2-weighted sequence

  4. Non-contrast T1-mapping detects acute myocardial edema with high diagnostic accuracy: a comparison to T2-weighted cardiovascular magnetic resonance

    PubMed Central

    2012-01-01

    Background T2w-CMR is used widely to assess myocardial edema. Quantitative T1-mapping is also sensitive to changes in free water content. We hypothesized that T1-mapping would have a higher diagnostic performance in detecting acute edema than dark-blood and bright-blood T2w-CMR. Methods We investigated 21 controls (55 ± 13 years) and 21 patients (61 ± 10 years) with Takotsubo cardiomyopathy or acute regional myocardial edema without infarction. CMR performed within 7 days included cine, T1-mapping using ShMOLLI, dark-blood T2-STIR, bright-blood ACUT2E and LGE imaging. We analyzed wall motion, myocardial T1 values and T2 signal intensity (SI) ratio relative to both skeletal muscle and remote myocardium. Results All patients had acute cardiac symptoms, increased Troponin I (0.15-36.80 ug/L) and acute wall motion abnormalities but no LGE. T1 was increased in patient segments with abnormal and normal wall motion compared to controls (1113 ± 94 ms, 1029 ± 59 ms and 944 ± 17 ms, respectively; p < 0.001). T2 SI ratio using STIR and ACUT2E was also increased in patient segments with abnormal and normal wall motion compared to controls (all p < 0.02). Receiver operator characteristics analysis showed that T1-mapping had a significantly larger area-under-the-curve (AUC = 0.94) compared to T2-weighted methods, whether the reference ROI was skeletal muscle or remote myocardium (AUC = 0.58-0.89; p < 0.03). A T1 value of greater than 990 ms most optimally differentiated segments affected by edema from normal segments at 1.5 T, with a sensitivity and specificity of 92 %. Conclusions Non-contrast T1-mapping using ShMOLLI is a novel method for objectively detecting myocardial edema with a high diagnostic performance. T1-mapping may serve as a complementary technique to T2-weighted imaging for assessing myocardial edema in ischemic and non-ischemic heart disease, such as quantifying area-at-risk and diagnosing

  5. The Xenon1T Dark Matter Search Experiment

    NASA Astrophysics Data System (ADS)

    Aprile, Elena

    The worldwide race towards direct dark matter detection in the form of Weakly Interacting Massive Particles (WIMPs) has been dramatically accelerated by the remarkable progress and evolution of liquid xenon time projection chambers (LXeTPCs). With a realistic discovery potential, Xenon100 has already reached a sensitivity of 7 × 10-45 cm2, and continues to accrue data at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy towards its ultimate sensitivity reach at the σ SI ˜ 2 × 10-45 cm2 level for the spin-independent WIMP-nucleon cross-section. To fully explore the favoured parameter space for WIMP dark matter in search of a first robust and statistically significant discovery, or to confirm any hint of a signal from Xenon100, the next phase of the Xenon program will be a detector at the ton scale - Xenon1T. The Xenon1T detector, based on 2.2 ton of LXe viewed by low radioactivity photomultiplier tubes and housed in a water Cherenkov muon veto at LNGS, is presented. With an experimental aim of probing WIMP interaction cross-sections above of order σ SI ˜ 2 × 10-47 cm2 within 2 years of operation, Xenon1T will provide the sensitivity to probe a particularly favourable region of electroweak physics on a timescale compatible with complementary ground and satellite based indirect searches and with accelerator dark matter searches at the LHC. Indeed, for a σ SI ˜ 10-45 cm2 and 100 GeV/c2 WIMP mass, Xenon1T could detect of order 100 events in this exposure, providing statistics for placing significant constraints on the WIMP mass.

  6. A comparison study between 3D T2-weighted SPACE and conventional 2D T2-weighted turbo spin echo in assessment of carotid plaque.

    PubMed

    Lv, Peng; Dai, Yuanyuan; Lin, Jiang; Zhang, Weisheng; Liu, Hao; Liu, Hui; Tang, Xiao

    2017-03-01

    The aim of this study was to compare 3D T2-weighted sampling perfection with application optimized contrast using different flip angle evolutions (T2w SPACE) with conventional 2D T2w turbo-spin echo (TSE) in plaque imaging of carotid artery. 45 patients underwent 3.0-T MRI for carotid arteries imaging. MR sequences included T2w SPACE, T2w TSE, Time of flight (TOF) and T1-weighted (T1w) TSE. The signal intensity of intra-plaque hemorrhage (IPH), lipid-rich necrotic core (LRNC), and loose matrix (LM) were measured and their contrast ratios (CRs) against adjacent muscle were calculated. CRs from T2w SPACE and T2w TSE were compared to each other. CRs of LM, LRNC, and IPH measured on T2w SPACE were 1.74-3.04 (2.44), 0.98-1.66 (1.39), and 1.91-2.93 (2.51), respectively. CRs of LM, LRNC, and IPH on T2w TSE were 1.97-3.41 (2.44), 1.18-1.73 (1.43), and 2.26-3.75 (2.26), respectively. There was no significant difference of CR of the carotid plaques between T2w SPACE and T2w TSE (p = 0.455). Markedly significant differences of CRs were found between LM and LRNC (p < 0.001), and between LRNC and IPH (p < 0.001) on T2w SPACE and T2w TSE. T2w SPACE was comparable with conventional T2w TSE in characterization of carotid plaque.

  7. [Carotid plaque assessment using inversion recovery T1 weighted-3 dimensions variable refocus flip angle turbo spin echo sampling perfection with application optimized contrast using different angle evolutions black blood imaging].

    PubMed

    Inoue, Yuji; Yoneyama, Masami; Nakamura, Masanobu; Ozaki, Satoshi; Ito, Kenjiro; Hiura, Mikio

    2012-01-01

    Vulnerable plaque can be attributed to induction of ischemic symptoms and magnetic resonance imaging of carotid artery is valuable to detect the plaque. Magnetization prepared rapid acquisition with gradient echo (MPRAGE) method could detect hemorrhagic vulnerable plaque as high intensity signal; however, blood flow is not sufficiently masked by this method. The contrast for plaque in T1 weighted image (T1WI) could not be obtained sufficiently with black blood image (BBI) by sampling perfection with application optimized contrast using different angle evolutions (SPACE) method as turbo spin echo (TSE). In addition, an appearance of artifact by slow flow is a problem. Considering these controversial situations in plaque imaging, we examined the modified BBI inversion recovery (IR)-SPACE in which IR was added for SPACE method so that the contrast for plaque in T1WI was optimized. We investigated the application of this method in plaque imaging. As a result of phantom imaging, the contrast for plaque in T1WI was definitely obtained by choosing an appropriate inversion time (TI) for the corresponding repetition time. In clinical cases, blood flow was sufficiently masked by IR-SPACE method and the plaque imaging was clearly obtained in clinical cases to the same extent as MPRAGE method. Since BBI with IR-SPACE method was derived from both IR pulse and flow void effect, this method could obtain the blood flow masking effect definitely. The present study suggested that SPACE method might be applicable to estimate properties of carotid artery plaque.

  8. Weighted image de-fogging using luminance dark prior

    NASA Astrophysics Data System (ADS)

    Kansal, Isha; Kasana, Singara Singh

    2017-10-01

    In this work, the weighted image de-fogging process based upon dark channel prior is modified by using luminance dark prior. Dark channel prior estimates the transmission by using three colour channels whereas luminance dark prior does the same by making use of only Y component of YUV colour space. For each pixel in a patch of ? size, the luminance dark prior uses ? pixels, rather than ? pixels used in DCP technique, which speeds up the de-fogging process. To estimate the transmission map, weighted approach based upon difference prior is used which mitigates halo artefacts at the time of transmission estimation. The major drawback of weighted technique is that it does not maintain the constancy of the transmission in a local patch even if there are no significant depth disruptions, due to which the de-fogged image looks over smooth and has low contrast. Apart from this, in some images, weighted transmission still carries less visible halo artefacts. Therefore, Gaussian filter is used to blur the estimated weighted transmission map which enhances the contrast of de-fogged images. In addition to this, a novel approach is proposed to remove the pixels belonging to bright light source(s) during the atmospheric light estimation process based upon histogram of YUV colour space. To show the effectiveness, the proposed technique is compared with existing techniques. This comparison shows that the proposed technique performs better than the existing techniques.

  9. Preoperative detection of malignant liver tumors: Comparison of 3D-T2-weighted sequences with T2-weighted turbo spin-echo and single shot T2 at 1.5 T.

    PubMed

    Barat, Maxime; Soyer, Philippe; Dautry, Raphael; Pocard, Marc; Lo-Dico, Rea; Najah, Haythem; Eveno, Clarisse; Cassinotto, Christophe; Dohan, Anthony

    2018-03-01

    To assess the performances of three-dimensional (3D)-T2-weighted sequences compared to standard T2-weighted turbo spin echo (T2-TSE), T2-half-Fourier acquisition single-shot turbo spin-echo (T2-HASTE), diffusion weighted imaging (DWI) and 3D-T1-weighted VIBE sequences in the preoperative detection of malignant liver tumors. From 2012 to 2015, all patients of our institution undergoing magnetic resonance imaging (MRI) examination for suspected malignant liver tumors were prospectively included. Patients had contrast-enhanced 3D-T1-weighted, DWI, 3D-T2-SPACE, T2-HASTE and T2-TSE sequences. Imaging findings were compared with those obtained at follow-up, surgery and histopathological analysis. Sensitivities for the detection of malignant liver tumors were compared for each sequence using McNemar test. A subgroup analysis was conducted for HCCs. Image artifacts were analyzed and compared using Wilcoxon paired signed rank-test. Thirty-three patients were included: 13 patients had 40 hepatocellular carcinomas (HCC) and 20 had 54 liver metastases. 3D-T2-weighted sequences had a higher sensitivity than T2-weighted TSE sequences for the detection of malignant liver tumors (79.8% versus 68.1%; P < 0.001). The difference did not reach significance for HCC. T1-weighted VIBE and DWI had a higher sensitivity than T2-weighted sequences. 3D-T2-weighted-SPACE sequences showed significantly less artifacts than T2-weitghted TSE. 3D-T2-weighted sequences show very promising performances for the detection of liver malignant tumors compared to T2-weighted TSE sequences. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Consumption of High-Polyphenol Dark Chocolate Improves Endothelial Function in Individuals with Stage 1 Hypertension and Excess Body Weight

    PubMed Central

    Nogueira, Lívia de Paula; Knibel, Marcela Paranhos; Torres, Márcia Regina Simas Gonçalves; Nogueira Neto, José Firmino; Sanjuliani, Antonio Felipe

    2012-01-01

    Background. Hypertension and excess body weight are important risk factors for endothelial dysfunction. Recent evidence suggests that high-polyphenol dark chocolate improves endothelial function and lowers blood pressure. This study aimed to evaluate the association of chocolate 70% cocoa intake with metabolic profile, oxidative stress, inflammation, blood pressure, and endothelial function in stage 1 hypertensives with excess body weight. Methods. Intervention clinical trial includes 22 stage 1 hypertensives without previous antihypertensive treatment, aged 18 to 60 years and presents a body mass index between 25.0 and 34.9 kg/m2. All participants were instructed to consume 50 g of chocolate 70% cocoa/day (2135 mg polyphenols) for 4 weeks. Endothelial function was evaluated by peripheral artery tonometry using Endo-PAT 2000 (Itamar Medical). Results. Twenty participants (10 men) completed the study. Comparison of pre-post intervention revealed that (1) there were no significant changes in anthropometric parameters, percentage body fat, glucose metabolism, lipid profile, biomarkers of inflammation, adhesion molecules, oxidized LDL, and blood pressure; (2) the assessment of endothelial function through the reactive hyperemia index showed a significant increase: 1.94 ± 0.18 to 2.22 ± 0.08, P = 0.01. Conclusion.In individuals with stage 1 hypertension and excess body weight, high-polyphenol dark chocolate improves endothelial function. PMID:23209885

  11. T1-weighted brain imaging with a 32-channel coil at 3T using TurboFLASH BLADE compared with standard cartesian k-space sampling.

    PubMed

    Attenberger, Ulrike I; Runge, Val M; Williams, Kenneth D; Stemmer, Alto; Michaely, Henrik J; Schoenberg, Stefan O; Reiser, Maximilian F; Wintersperger, Bernd J

    2009-03-01

    Motion artifacts often markedly degrade image quality in clinical scans. The BLADE technique offers an alternative k-space sampling scheme reducing the effect of patient related motion on image quality. The purpose of this study is the comparison of imaging artifacts, signal-to-noise (SNR), and contrast-to-noise ratio (CNR) of a new turboFLASH BLADE k-space trajectory with the standard Cartesian k-space sampling for brain imaging, using a 32-channel coil at 3T. The results from 32 patients included after informed consent are reported. This study was performed with a 32-channel head coil on a 3T scanner. Sagittal and axial T1-weighted FLASH sequences (TR/TE 250/2.46 milliseconds, flip angle 70-degree), acquired with Cartesian k-space sampling and T1-weighted turboFLASH sequences (TR/TE/TIsag/TIax 3200/2.77/1144/1056 milliseconds, flip angle 20-degree), using PROPELLER (BLADE) k-space trajectory, were compared. SNR and CNR were evaluated using a paired student t test. The frequency of motion artifacts was assessed in a blinded read. To analyze the differences between both techniques a McNemar test was performed. A P value <0.05 was considered statistically significant. From the blinded read, the overall preference in terms of diagnostic image quality was statistically significant in favor of the BLADE turboFLASH data sets, compared with standard FLASH for both sagittal (P < 0.0001) and axial (P < 0.0001) planes. The frequency of motion artifacts from the scalp was higher for standard FLASH sequences than for BLADE sequences on both axial (47%, P < 0.0003) and sagittal (69%, P < 0.0001) planes. BLADE was preferred in 100% (sagittal plane) and 80% (axial plane) of in-patient data sets and in 68% (sagittal plane) and 73% (axial plane) of out-patient data sets.The BLADE T1 scan did have lower SNRmean (BLADEax 179 +/- 98, Cartesianax 475 +/- 145, BLADEsag 171 +/- 51, and Cartesiansag 697 +/- 129) with P values indicating accordingly a statistically significant difference

  12. Understanding redshift space distortions in density-weighted peculiar velocity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sugiyama, Naonori S.; Okumura, Teppei; Spergel, David N., E-mail: nao.s.sugiyama@gmail.com, E-mail: teppei.oku@gmail.com, E-mail: dns@astro.princeton.edu

    2016-07-01

    Observations of the kinetic Sunyaev-Zel'dovich (kSZ) effect measure the density-weighted velocity field, a potentially powerful cosmological probe. This paper presents an analytical method to predict the power spectrum and two-point correlation function of the density-weighted velocity in redshift space, the direct observables in kSZ surveys. We show a simple relation between the density power spectrum and the density-weighted velocity power spectrum that holds for both dark matter and halos. Using this relation, we can then extend familiar perturbation expansion techniques to the kSZ power spectrum. One of the most important features of density-weighted velocity statistics in redshift space is themore » change in sign of the cross-correlation between the density and density-weighted velocity at mildly small scales due to nonlinear redshift space distortions. Our model can explain this characteristic feature without any free parameters. As a result, our results can precisely predict the non-linear behavior of the density-weighted velocity field in redshift space up to ∼ 30 h {sup -1} Mpc for dark matter particles at the redshifts of z =0.0, 0.5, and 1.0.« less

  13. The XENON1T dark matter experiment

    NASA Astrophysics Data System (ADS)

    Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Antunes, B.; Arneodo, F.; Balata, M.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breskin, A.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Chiarini, A.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Corrieri, R.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; Gangi, P. Di; Giovanni, A. Di; Diglio, S.; Disdier, J.-M.; Doets, M.; Duchovni, E.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Franco, D.; Front, D.; Fulgione, W.; Rosso, A. Gallo; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Giboni, K.-L.; Goetzke, L. W.; Grandi, L.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Huhmann, C.; Itay, R.; James, A.; Kaminsky, B.; Kazama, S.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Lopes, J. A. M.; Maier, R.; Manfredini, A.; Maris, I.; Undagoitia, T. Marrodán; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.; Morå, K.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Orlandi, D.; Othegraven, R.; Pakarha, P.; Parlati, S.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Pizzella, V.; Piro, M.-C.; Plante, G.; Priel, N.; García, D. Ramírez; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Rupp, N.; Santos, J. M. F. dos; Saldanha, R.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Lavina, L. Scotto; Selvi, M.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Sivers, M. v.; Stern, M.; Stein, A.; Tatananni, D.; Tatananni, L.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Upole, N.; Vargas, M.; Wack, O.; Walet, R.; Wang, H.; Wang, Z.; Wei, Y.; Weinheimer, C.; Wittweg, C.; Wulf, J.; Ye, J.; Zhang, Y.

    2017-12-01

    The XENON1T experiment at the Laboratori Nazionali del Gran Sasso (LNGS) is the first WIMP dark matter detector operating with a liquid xenon target mass above the ton-scale. Out of its 3.2 t liquid xenon inventory, 2.0 t constitute the active target of the dual-phase time projection chamber. The scintillation and ionization signals from particle interactions are detected with low-background photomultipliers. This article describes the XENON1T instrument and its subsystems as well as strategies to achieve an unprecedented low background level. First results on the detector response and the performance of the subsystems are also presented.

  14. Low vs. higher-dose dark chocolate and blood pressure in cardiovascular high-risk patients.

    PubMed

    Desch, Steffen; Kobler, Daniela; Schmidt, Johanna; Sonnabend, Melanie; Adams, Volker; Sareban, Mahdi; Eitel, Ingo; Blüher, Matthias; Schuler, Gerhard; Thiele, Holger

    2010-06-01

    Dark chocolate may have blood pressure-lowering properties. We conducted a prospective randomized open-label blinded end-point design trial to study a potential dose dependency of the presumed antihypertensive effect of dark chocolate by directly comparing low vs. higher doses of dark chocolate over the course of 3 months. We enrolled a total of 102 patients with prehypertension/stage 1 hypertension and established cardiovascular end-organ damage or diabetes mellitus. Patients were randomly assigned to receive either 6 or 25 g/day of flavanol-rich dark chocolate for 3 months. The difference in 24-h mean blood pressure between groups was defined as the primary outcome measure. Significant reductions in mean ambulatory 24-h blood pressure were observed between baseline and follow-up in both groups (6 g/day: -2.3 mm Hg, 95% confidence interval -4.1 to -0.4; 25 g/day: -1.9 mm Hg, 95% confidence interval -3.6 to -0.2). There were no significant differences in blood pressure changes between groups. In the higher-dose group, a slight increase in body weight was noted (0.8 kg, 95% confidence interval 0.06 to 1.6). The findings are consistent with the hypothesis that dark chocolate may be associated with a reduction in blood pressure (BP). However, due to the lack of a control group, confounding may be possible and the results should be interpreted with caution.

  15. Dark chocolate for children's blood pressure: randomised trial.

    PubMed

    Chan, Eunice K; Quach, Jon; Mensah, Fiona K; Sung, Valerie; Cheung, Michael; Wake, Melissa

    2012-07-01

    Higher adult blood pressure, even without hypertension, predicts cardiovascular outcomes, and is predicted by childhood blood pressure. Regular dark chocolate intake lowers blood pressure in adults, but effects in children are unknown. To examine the feasibility of school-based provision of dark chocolate and its short-term efficacy in reducing mean group blood pressure. 194 children (aged 10-12 years) were randomised by class to intervention (7 g dark chocolate daily for 7 weeks, n=124) or control (n=70) groups; 98% and 93% provided baseline and follow-up measurements, respectively. Intervention and control students had similar systolic (mean difference 1.7 mm Hg, 95% CI -0.6 to 4.1) and diastolic (-1.2 mm Hg, 95% CI -3.6 to 1.3) blood pressure, anthropometry and well-being at outcome. Results show that providing dark chocolate is feasible and acceptable in the school setting. For a definitive trial, the authors recommend a larger sample, endovascular function measures, and consideration of higher antioxidant 'dose' by virtue of duration and/or content.

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ma, J; Son, J; Arun, B

    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 singlemore » 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

  17. Cosmological viability conditions for f(T) dark energy models

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Setare, M.R.; Mohammadipour, N., E-mail: rezakord@ipm.ir, E-mail: N.Mohammadipour@uok.ac.ir

    2012-11-01

    Recently f(T) modified teleparallel gravity where T is the torsion scalar has been proposed as the natural gravitational alternative for dark energy. We perform a detailed dynamical analysis of these models and find conditions for the cosmological viability of f(T) dark energy models as geometrical constraints on the derivatives of these models. We show that in the phase space exists two cosmologically viable trajectory which (i) The universe would start from an unstable radiation point, then pass a saddle standard matter point which is followed by accelerated expansion de sitter point. (ii) The universe starts from a saddle radiation epoch,more » then falls onto the stable matter era and the system can not evolve to the dark energy dominated epoch. Finally, for a number of f(T) dark energy models were proposed in the more literature, the viability conditions are investigated.« less

  18. Measurement of T1 of human arterial and venous blood at 7T.

    PubMed

    Rane, Swati D; Gore, John C

    2013-04-01

    Techniques for measuring cerebral perfusion require accurate longitudinal relaxation (T1) of blood, an MRI parameter that is field dependent. T1 of arterial and venous human blood was measured at 7T using three different sources - pathology laboratory, blood bank and in vivo. The T1 of venous blood was measured from sealed samples from a pathology lab and in vivo. Samples from a blood bank were oxygenated and mixed to obtain different physiological concentrations of hematocrit and oxygenation. T1 relaxation times were estimated using a three-point fit to a simple inversion recovery equation. At 37°C, the T1 of blood at arterial pO2 was 2.29±0.1s and 2.07±0.12 at venous pO2. The in vivo T1 of venous blood, in three subjects, was slightly longer at 2.45±0.11s. T1 of arterial and venous blood at 7T was measured and found to be significantly different. The T1 values were longer in vivo than in vitro. While the exact cause for the discrepancy is unknown, the additives in the blood samples, degradation during experiment, oxygenation differences, and the non-stagnant nature of blood in vivo could be potential contributors to the lower values of T1 in the venous samples. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. The XENONnT Dark Matter Experiment

    NASA Astrophysics Data System (ADS)

    Aprile, Elena; Xenon Collaboration

    2017-01-01

    With XENON1T ready to search for dark matter with the highest sensivity of any experiment to-date the XENON collaboration started to secure funding and resources to upgrade the detector by the end of 2018- phase which we refer to as XENONnT. The XENONnT experiment will utilize the already-built-and-tested XENON1T infrastructures, such as the cryogenic system, Kr distillation system and Xe storage and recovery system, with the main upgrade of the time projection chamber (TPC). The upgraded XENONnT detector will be filled with 7.5-ton ultra-pure liquid xenon, tripling the active liquid xenon target mass of XENON1T. About 500 low-radioactive three-inch R11410 PMTs will be used. Background from internal sources such as radon will be reduced. It will enable another order of magnitude improvement in dark matter search sensitivity compared to that of XENON1T, or accumulate statistics if a positive dark matter signal is observed by XENON1T. The detailed TPC upgrade plan, the background control and reduction techniques, the predicted sensitivity reach will be presented.

  20. Improved dark blood late gadolinium enhancement (DB-LGE) imaging using an optimized joint inversion preparation and T2 magnetization preparation.

    PubMed

    Basha, Tamer A; Tang, Maxine C; Tsao, Connie; Tschabrunn, Cory M; Anter, Elad; Manning, Warren J; Nezafat, Reza

    2018-01-01

    To develop a dark blood-late gadolinium enhancement (DB-LGE) sequence that improves scar-blood contrast and delineation of scar region. The DB-LGE sequence uses an inversion pulse followed by T 2 magnetization preparation to suppress blood and normal myocardium. Time delays inserted after preparation pulses and T 2 -magnetization-prep duration are used to adjust tissue contrast. Selection of these parameters was optimized using numerical simulations and phantom experiments. We evaluated DB-LGE in 9 swine and 42 patients (56 ± 14 years, 33 male). Improvement in scar-blood contrast and overall image quality was subjectively evaluated by two independent readers (1 = poor, 4 = excellent). The signal ratios among scar, blood, and myocardium were compared. Simulations and phantom studies demonstrated that simultaneous nulling of myocardium and blood can be achieved by selecting appropriate timing parameters. The scar-blood contrast score was significantly higher for DB-LGE (P < 0.001) with no significant difference in overall image quality (P > 0.05). Scar-blood signal ratios for DB-LGE versus LGE were 5.0 ± 2.8 versus 1.5 ± 0.5 (P < 0.001) for patients, and 2.2 ± 0.7 versus 1.0 ± 0.4 (P = 0.0023) for animals. Scar-myocardium signal ratios were 5.7 ± 2.9 versus 6.3 ± 2.6 (P = 0.35) for patients, and 3.7 ± 1.1 versus 4.1 ± 2.0 (P = 0.60) for swine. The DB-LGE sequence simultaneously reduces normal myocardium and blood signal intensity, thereby enhancing scar-blood contrast while preserving scar-myocardium contrast. Magn Reson Med 79:351-360, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  1. DESTINY, The Dark Energy Space Telescope

    NASA Technical Reports Server (NTRS)

    Pasquale, Bert A.; Woodruff, Robert A.; Benford, Dominic J.; Lauer, Tod

    2007-01-01

    We have proposed the development of a low-cost space telescope, Destiny, as a concept for the NASA/DOE Joint Dark Energy Mission. Destiny is a 1.65m space telescope, featuring a near-infrared (0.85-1.7m) survey camera/spectrometer with a moderate flat-field field of view (FOV). Destiny will probe the properties of dark energy by obtaining a Hubble diagram based on Type Ia supernovae and a large-scale mass power spectrum derived from weak lensing distortions of field galaxies as a function of redshift.

  2. Dark chocolate and blood pressure: a novel study from Jordan.

    PubMed

    Al-Safi, Saafan A; Ayoub, Nehad M; Al-Doghim, Imad; Aboul-Enein, Faisal H

    2011-11-01

    The goal of this study was to assess the effect of dark chocolate intake on cardiovascular parameters like blood pressure and heart rate values in a normotensive population. This is a randomized cross-sectional study involving a total of 14,310 adults that were selected from various regions of Jordan. Well-trained pharmacy students interviewed participants in the outpatient settings. Participants reported their weekly intake of dark chocolate that has been further classified into mild (1-2 bars/week), moderate (3-4 bars/week), and high intake ( > 4 bars/week). For each participant, the systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate were measured three times with (10-15) minute intervals in the sitting position and the resting state. The arterial blood pressure (ABP) was calculated from the measured SBP and DBP values. All measured blood pressure values were significantly decreased for participants who reported higher dark chocolate consumption. Our results showed that heart rate values were not affected by variable intake of dark chocolate. In addition, increasing dark chocolate intake was associated with a significant decrease of blood pressure values in participants irrespective of the family history of hypertension or the age of the individual. However, heart rate values were unaffected. Higher intake of dark chocolate can be associated with lower values of blood pressure, while its effect on heart rate values was not consistent.

  3. Individual T1-weighted/T2-weighted ratio brain networks: Small-worldness, hubs and modular organization

    NASA Astrophysics Data System (ADS)

    Wu, Huijun; Wang, Hao; Lü, Linyuan

    Applying network science to investigate the complex systems has become a hot topic. In neuroscience, understanding the architectures of complex brain networks was a vital issue. An enormous amount of evidence had supported the brain was cost/efficiency trade-off with small-worldness, hubness and modular organization through the functional MRI and structural MRI investigations. However, the T1-weighted/T2-weighted (T1w/T2w) ratio brain networks were mostly unexplored. Here, we utilized a KL divergence-based method to construct large-scale individual T1w/T2w ratio brain networks and investigated the underlying topological attributes of these networks. Our results supported that the T1w/T2w ratio brain networks were comprised of small-worldness, an exponentially truncated power-law degree distribution, frontal-parietal hubs and modular organization. Besides, there were significant positive correlations between the network metrics and fluid intelligence. Thus, the T1w/T2w ratio brain networks open a new avenue to understand the human brain and are a necessary supplement for future MRI studies.

  4. Effectiveness of a Rapid Lumbar Spine MRI Protocol Using 3D T2-Weighted SPACE Imaging Versus a Standard Protocol for Evaluation of Degenerative Changes of the Lumbar Spine.

    PubMed

    Sayah, Anousheh; Jay, Ann K; Toaff, Jacob S; Makariou, Erini V; Berkowitz, Frank

    2016-09-01

    Reducing lumbar spine MRI scanning time while retaining diagnostic accuracy can benefit patients and reduce health care costs. This study compares the effectiveness of a rapid lumbar MRI protocol using 3D T2-weighted sampling perfection with application-optimized contrast with different flip-angle evolutions (SPACE) sequences with a standard MRI protocol for evaluation of lumbar spondylosis. Two hundred fifty consecutive unenhanced lumbar MRI examinations performed at 1.5 T were retrospectively reviewed. Full, rapid, and complete versions of each examination were interpreted for spondylotic changes at each lumbar level, including herniations and neural compromise. The full examination consisted of sagittal T1-weighted, T2-weighted turbo spin-echo (TSE), and STIR sequences; and axial T1- and T2-weighted TSE sequences (time, 18 minutes 40 seconds). The rapid examination consisted of sagittal T1- and T2-weighted SPACE sequences, with axial SPACE reformations (time, 8 minutes 46 seconds). The complete examination consisted of the full examination plus the T2-weighted SPACE sequence. Sensitivities and specificities of the full and rapid examinations were calculated using the complete study as the reference standard. The rapid and full studies had sensitivities of 76.0% and 69.3%, with specificities of 97.2% and 97.9%, respectively, for all degenerative processes. Rapid and full sensitivities were 68.7% and 66.3% for disk herniation, 85.2% and 81.5% for canal compromise, 82.9% and 69.1% for lateral recess compromise, and 76.9% and 69.7% for foraminal compromise, respectively. Isotropic SPACE T2-weighted imaging provides high-quality imaging of lumbar spondylosis, with multiplanar reformatting capability. Our SPACE-based rapid protocol had sensitivities and specificities for herniations and neural compromise comparable to those of the protocol without SPACE. This protocol fits within a 15-minute slot, potentially reducing costs and discomfort for a large subgroup of

  5. Blood collection kit for Space Lab 1

    NASA Image and Video Library

    1981-02-02

    S81-26158 (Feb 1981) --- A close-up view of a training version of a STS-40/SLS-1 blood kit. Blood samples from crewmembers are critical to a number of Space Life Sciences-1 (SLS-1) investigations. One day's collection equipment, color coded for each crewmember, is neatly organized in the kit.

  6. Black-blood native T1 mapping: Blood signal suppression for reduced partial voluming in the myocardium.

    PubMed

    Weingärtner, Sebastian; Meßner, Nadja M; Zöllner, Frank G; Akçakaya, Mehmet; Schad, Lothar R

    2017-08-01

    To study the feasibility of black-blood contrast in native T 1 mapping for reduction of partial voluming at the blood-myocardium interface. A saturation pulse prepared heart-rate-independent inversion recovery (SAPPHIRE) T 1 mapping sequence was combined with motion-sensitized driven-equilibrium (MSDE) blood suppression for black-blood T 1 mapping at 3 Tesla. Phantom scans were performed to assess the T 1 time accuracy. In vivo black-blood and conventional SAPPHIRE T 1 mapping was performed in eight healthy subjects and analyzed for T 1 times, precision, and inter- and intraobserver variability. Furthermore, manually drawn regions of interest (ROIs) in all T 1 maps were dilated and eroded to analyze the dependence of septal T 1 times on the ROI thickness. Phantom results and in vivo myocardial T 1 times show comparable accuracy with black-blood compared to conventional SAPPHIRE (in vivo: black-blood: 1562 ± 56 ms vs. conventional: 1583 ± 58 ms, P = 0.20); Using black-blood SAPPHIRE precision was significantly lower (standard deviation: 133.9 ± 24.6 ms vs. 63.1 ± 6.4 ms, P < .0001), and blood T 1 time measurement was not possible. Significantly increased interobserver interclass correlation coefficient (ICC) (0.996 vs. 0.967, P = 0.011) and similar intraobserver ICC (0.979 vs. 0.939, P = 0.11) was obtained with the black-blood sequence. Conventional SAPPHIRE showed strong dependence on the ROI thickness (R 2 = 0.99). No such trend was observed using the black-blood approach (R 2 = 0.29). Black-blood SAPPHIRE successfully eliminates partial voluming at the blood pool in native myocardial T 1 mapping while providing accurate T 1 times, albeit at a reduced precision. Magn Reson Med 78:484-493, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  7. Hyperpolarized (129)Xe T (1) in oxygenated and deoxygenated blood

    NASA Technical Reports Server (NTRS)

    Albert, M. S.; Balamore, D.; Kacher, D. F.; Venkatesh, A. K.; Jolesz, F. A.

    2000-01-01

    The viability of the new technique of hyperpolarized (129)Xe MRI (HypX-MRI) for imaging organs other than the lungs depends on whether the spin-lattice relaxation time, T(1), of (129)Xe is sufficiently long in the blood. In previous experiments by the authors, the T(1) was found to be strongly dependent upon the oxygenation of the blood, with T(1) increasing from about 3 s in deoxygenated samples to about 10 s in oxygenated samples. Contrarily, Tseng et al. (J. Magn. Reson. 1997; 126: 79-86) reported extremely long T(1) values deduced from an indirect experiment in which hyperpolarized (129)Xe was used to create a 'blood-foam'. They found that oxygenation decreased T(1). Pivotal to their experiment is the continual and rapid exchange of hyperpolarized (129)Xe between the gas phase (within blood-foam bubbles) and the dissolved phase (in the skin of the bubbles); this necessitated a complicated analysis to extract the T(1) of (129)Xe in blood. In the present study, the experimental design minimizes gas exchange after the initial bolus of hyperpolarized (129)Xe has been bubbled through the sample. This study confirms that oxygenation increases the T(1) of (129)Xe in blood, from about 4 s in freshly drawn venous blood, to about 13 s in blood oxygenated to arterial levels, and also shifts the red blood cell resonance to higher frequency. Copyright 2000 John Wiley & Sons, Ltd. Abbreviations used BOLD blood oxygen level dependent NOE nuclear overhouses effect PO(2) oxygen partial pressure RBC red blood cells RF radio frequency SNR signal-to-noise ratio.

  8. Low-Molecular-Weight Iron Chelates May Be an Alternative to Gadolinium-based Contrast Agents for T1-weighted Contrast-enhanced MR Imaging.

    PubMed

    Boehm-Sturm, Philipp; Haeckel, Akvile; Hauptmann, Ralf; Mueller, Susanne; Kuhl, Christiane K; Schellenberger, Eyk A

    2018-02-01

    Purpose To synthesize two low-molecular-weight iron chelates and compare their T1 contrast effects with those of a commercial gadolinium-based contrast agent for their applicability in dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging. Materials and Methods The animal experiments were approved by the local ethics committee. Two previously described iron (Fe) chelates of pentetic acid (Fe-DTPA) and of trans-cyclohexane diamine tetraacetic acid (Fe-tCDTA) were synthesized with stability constants several orders of magnitude higher than those of gadolinium-based contrast agents. The T1 contrast effects of the two chelates were compared with those of gadopentetate dimeglumine in blood serum phantoms at 1.5 T, 3 T, and 7 T. For in vivo studies, a human breast cancer cell line (MDA-231) was implanted in five mice per group. The dynamic contrast effects of the chelates were compared by performing DCE MR imaging with intravenous application of Fe-DTPA or Fe-tCDTA on day 1 and DCE MR imaging in the same tumors with gadopentetate dimeglumine on day 2. Quantitative DCE maps were generated with software and were compared by means of a one-tailed Pearson correlation test. Results Relaxivities in serum (0.94 T at room temperature) of Fe-tCDTA (r1 = 2.2 mmol -1 · sec -1 , r2 = 2.5 mmol -1 · sec -1 ) and Fe-DTPA (r1 = 0.9 mmol -1 · sec -1 , r2 = 0.9 mmol -1 · sec -1 ) were approximately twofold and fivefold lower, respectively, compared with those of gadopentetate dimeglumine (r1 = 4.1 mmol -1 · sec -1 , r2 = 4.8 mmol -1 · sec -1 ). Used at moderately higher concentrations, however, iron chelates generated similar contrast effects at T1-weighted MR imaging in vitro in serum, in vivo in blood, and for DCE MR imaging of breast cancer xenografts. The volume transfer constant values for Fe-DTPA and Fe-tCDTA in the same tumors correlated well with those observed for gadopentetate dimeglumine (Fe-tCDTA Pearson R, 0.99; P = .0003; Fe-DTPA Pearson R, 0.97; P

  9. Comparison of contrast-enhanced T1-weighted FLAIR with BLADE, and spin-echo T1-weighted sequences in intracranial MRI.

    PubMed

    Alkan, Ozlem; Kizilkiliç, Osman; Yildirim, Tülin; Alibek, Sedat

    2009-06-01

    We compared periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER, BLADE) MR technique with spin echo (SE) technique for evaluation of artifacts, and detection and delineation of brain lesions. Contrast-enhanced T1-weighted fluid attenuated inversion recovery (FLAIR) images with BLADE technique (CE T1W-FLAIR BLADE) and contrast-enhanced T1-weighted SE (CE T1W-SE) were performed in 50 patients with intracranial enhancing lesions. These techniques were compared by two neuroradiologists for qualitative analysis of artifacts, lesion detectability, lesion delineation from adjacent structures, and preferred imaging technique; and for quantitative variables, i.e., lesion-to-background and lesion-to-cerebrospinal fluid (CSF) contrast-to-noise (CNR) ratios. Reader agreement was assessed by kappa statistics. All lesions depicted with the CE T1W-SE were also detected with the CE T1W-FLAIR BLADE technique. Delineation of lesions was better on CE T1W-FLAIR BLADE in the majority of patients. Flow-related artifacts were considerably reduced with CE T1W-FLAIR BLADE. A star-like artifact at the level of the 4(th) ventricle was noted on CE T1W-FLAIR BLADE but not on CE T1W-SE. The lesion-to-background CNR and lesion-to-CSF CNR did not show a statistically significant difference between the two techniques. CE T1W-FLAIR BLADE images were preferred by the observers over the CE T1w-SE images, indicating good interobserver agreement (k = 0.70). CE T1W-FLAIR BLADE technique is superior to CE T1WSE for delineation of lesions and reduction of flow-related artifacts, especially within the posterior fossa, and is preferred by readers. CE T1W-FLAIR BLADE may be an alternative approach to imaging, especially for posterior fossa lesions.

  10. Hybrid nanotrimers for dual T 1 and T 2-weighted magnetic resonance imaging

    DOE PAGES

    Cheng, Kai; Yang, Meng; Zhang, Ruiping; ...

    2014-10-04

    Development of multifunctional nanoparticle-based probes for dual T 1- and T 2-weighted magnetic resonance imaging (MRI) could allow us to image and diagnose the tumors or other abnormalities in an exceptionally accurate and reliable manner. In this study, by fusing distinct nanocrystals via solid-state interfaces, we built hybrid heteronanostructures to combine both T 1 and T 2- weighted contrast agents together for MRI with high accuracy and reliability. The resultant hybrid heterotrimers showed high stability in physiological conditions and could induce both simultaneous positive and negative contrast enhancements in MR images. Small animal positron emission tomography imaging study revealed thatmore » the hybrid heterostructures displayed favorable biodistribution and were suitable for in vivo imaging. Furthermore, their potential as dual contrast agents for T 1 and T 2-weighted MRI was further demonstrated by in vitro and in vivo imaging and relaxivity measurements.« less

  11. Contrast-enhanced T1-weighted fluid-attenuated inversion-recovery BLADE magnetic resonance imaging of the brain: an alternative to spin-echo technique for detection of brain lesions in the unsedated pediatric patient?

    PubMed

    Alibek, Sedat; Adamietz, Boris; Cavallaro, Alexander; Stemmer, Alto; Anders, Katharina; Kramer, Manuel; Bautz, Werner; Staatz, Gundula

    2008-08-01

    We compared contrast-enhanced T1-weighted magnetic resonance (MR) imaging of the brain using different types of data acquisition techniques: periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER, BLADE) imaging versus standard k-space sampling (conventional spin-echo pulse sequence) in the unsedated pediatric patient with focus on artifact reduction, overall image quality, and lesion detectability. Forty-eight pediatric patients (aged 3 months to 18 years) were scanned with a clinical 1.5-T whole body MR scanner. Cross-sectional contrast-enhanced T1-weighted spin-echo sequence was compared to a T1-weighted dark-fluid fluid-attenuated inversion-recovery (FLAIR) BLADE sequence for qualitative and quantitative criteria (image artifacts, image quality, lesion detectability) by two experienced radiologists. Imaging protocols were matched for imaging parameters. Reader agreement was assessed using the exact Bowker test. BLADE images showed significantly less pulsation and motion artifacts than the standard T1-weighted spin-echo sequence scan. BLADE images showed statistically significant lower signal-to-noise ratio but higher contrast-to-noise ratios with superior gray-white matter contrast. All lesions were demonstrated on FLAIR BLADE imaging, and one false-positive lesion was visible in spin-echo sequence images. BLADE MR imaging at 1.5 T is applicable for central nervous system imaging of the unsedated pediatric patient, reduces motion and pulsation artifacts, and minimizes the need for sedation or general anesthesia without loss of relevant diagnostic information.

  12. First Dark Matter Search Results from the XENON1T Experiment

    NASA Astrophysics Data System (ADS)

    Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; di Gangi, P.; di Giovanni, A.; Diglio, S.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Gardner, R.; Geis, C.; Goetzke, L. W.; Grandi, L.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Howlett, J.; Itay, R.; Kaminsky, B.; Kazama, S.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Lopes, J. A. M.; Manfredini, A.; Mariş, I.; Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.; Morâ, K.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Pizzella, V.; Piro, M.-C.; Plante, G.; Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Riedel, B.; Rizzo, A.; Rosendahl, S.; Rupp, N.; Saldanha, R.; Dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Sivers, M. V.; Stein, A.; Thapa, S.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Vargas, M.; Upole, N.; Wang, H.; Wang, Z.; Wei, Y.; Weinheimer, C.; Wulf, J.; Ye, J.; Zhang, Y.; Zhu, T.; Xenon Collaboration

    2017-11-01

    We report the first dark matter search results from XENON1T, a ˜2000 -kg -target-mass dual-phase (liquid-gas) xenon time projection chamber in operation at the Laboratori Nazionali del Gran Sasso in Italy and the first ton-scale detector of this kind. The blinded search used 34.2 live days of data acquired between November 2016 and January 2017. Inside the (1042 ±12 )-kg fiducial mass and in the [5 ,40 ] keVnr energy range of interest for weakly interacting massive particle (WIMP) dark matter searches, the electronic recoil background was (1.93 ±0.25 )×10-4 events /(kg ×day ×keVee) , the lowest ever achieved in such a dark matter detector. A profile likelihood analysis shows that the data are consistent with the background-only hypothesis. We derive the most stringent exclusion limits on the spin-independent WIMP-nucleon interaction cross section for WIMP masses above 10 GeV /c2 , with a minimum of 7.7 ×10-47 cm2 for 35 -GeV /c2 WIMPs at 90% C.L.

  13. Breath-hold black-blood T1rho mapping improves liver T1rho quantification in healthy volunteers.

    PubMed

    Wáng, Yì Xiáng J; Deng, Min; Lo, Gladys G; Liang, Dong; Yuan, Jing; Chen, Weitian

    2018-03-01

    Background Recent researches suggest that T1rho may be a non-invasive and quantitative technique for detecting and grading liver fibrosis. Purpose To compare a multi-breath-hold bright-blood fast gradient echo (GRE) imaging and a single breath-hold single-shot fast spin echo (FSE) imaging with black-blood effect for liver parenchyma T1rho measurement and to study liver physiological T1rho value in healthy volunteers. Material and Methods The institutional Ethics Committee approved this study. 28 healthy participants (18 men, 10 women; age = 29.6 ± 5.1 years) underwent GRE liver T1rho imaging, and 20 healthy participants (10 men, 10 women; age = 36.9 ± 10.3 years) underwent novel black-blood FSE liver T1rho imaging, both at 3T with spin-lock frequency of 500 Hz. The FSE technique allows simultaneous acquisition of four spin lock times (TSLs; 1 ms, 10 ms, 30 ms, 50msec) in 10 s. Results For FSE technique the intra-scan repeatability intraclass correlation coefficient (ICC) was 0.98; while the inter-scan reproducibility ICC was 0.82 which is better than GRE technique's 0.76. Liver T1rho value in women tended to have a higher value than T1rho values in men (FSE: 42.28 ± 4.06 ms for women and 39.13 ± 2.12 ms for men; GRE: 44.44 ± 1.62 ms for women and 42.36 ± 2.00 ms for men) and FSE technique showed liver T1rho value decreased slightly as age increased. Conclusion Single breath-hold black-blood FSE sequence has better scan-rescan reproducibility than multi-breath-hold bright-blood GRE sequence. Gender and age dependence of liver T1rho in healthy participants is observed, with young women tending to have a higher T1rho measurement.

  14. Three-dimensional T1rho-weighted MRI at 1.5 Tesla.

    PubMed

    Borthakur, Arijitt; Wheaton, Andrew; Charagundla, Sridhar R; Shapiro, Erik M; Regatte, Ravinder R; Akella, Sarma V S; Kneeland, J Bruce; Reddy, Ravinder

    2003-06-01

    To design and implement a magnetic resonance imaging (MRI) pulse sequence capable of performing three-dimensional T(1rho)-weighted MRI on a 1.5-T clinical scanner, and determine the optimal sequence parameters, both theoretically and experimentally, so that the energy deposition by the radiofrequency pulses in the sequence, measured as the specific absorption rate (SAR), does not exceed safety guidelines for imaging human subjects. A three-pulse cluster was pre-encoded to a three-dimensional gradient-echo imaging sequence to create a three-dimensional, T(1rho)-weighted MRI pulse sequence. Imaging experiments were performed on a GE clinical scanner with a custom-built knee-coil. We validated the performance of this sequence by imaging articular cartilage of a bovine patella and comparing T(1rho) values measured by this sequence to those obtained with a previously tested two-dimensional imaging sequence. Using a previously developed model for SAR calculation, the imaging parameters were adjusted such that the energy deposition by the radiofrequency pulses in the sequence did not exceed safety guidelines for imaging human subjects. The actual temperature increase due to the sequence was measured in a phantom by a MRI-based temperature mapping technique. Following these experiments, the performance of this sequence was demonstrated in vivo by obtaining T(1rho)-weighted images of the knee joint of a healthy individual. Calculated T(1rho) of articular cartilage in the specimen was similar for both and three-dimensional and two-dimensional methods (84 +/- 2 msec and 80 +/- 3 msec, respectively). The temperature increase in the phantom resulting from the sequence was 0.015 degrees C, which is well below the established safety guidelines. Images of the human knee joint in vivo demonstrate a clear delineation of cartilage from surrounding tissues. We developed and implemented a three-dimensional T(1rho)-weighted pulse sequence on a 1.5-T clinical scanner. Copyright 2003

  15. Biocompatible and high-performance amino acids-capped MnWO4 nanocasting as a novel non-lanthanide contrast agent for X-ray computed tomography and T1-weighted magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Dong, Kai; Liu, Zhen; Liu, Jianhua; Huang, Sa; Li, Zhenhua; Yuan, Qinghai; Ren, Jinsong; Qu, Xiaogang

    2014-01-01

    In the present work, a novel non-lanthanide dual-modality contrast agent, manganese tungstate (MnWO4), has been successfully constructed by a facile and versatile hydrothermal route. With the merits of a high atomic number and a well-positioned K-edge energy of tungsten, our well-prepared non-lanthanide nanoprobes provide a higher contrast efficacy than routine iodine-based agents in clinics. Additionally, the presence of Mn in these nanoparticles endow them with excellent T1-weighted MR imaging capabilities. As an alternative to T2-weighted MRI and CT dual-modality contrast agents, the nanoprobes can provide a positive contrast signal, which prevents confusion with the dark signals from hemorrhage and blood clots. To the best of our knowledge, this is the first report that a non-lanthanide imaging nanoprobe is applied for CT and T1-weighted MRI simultaneously. Moreover, comparing with gadolinium-based T1-weighted MRI and CT dual-modality contrast agents that were associated with nephrogenic systemic fibrosis (NSF), our contrast agents have superior biocompatibility, which is proved by a detailed study of the pharmacokinetics, biodistribution, and in vivo toxicology. Together with excellent dispersibility, high biocompatibility and superior contrast efficacy, these nanoprobes provide detailed and complementary information from dual-modality imaging over traditional single-mode imaging and bring more opportunities to the new generation of non-lanthanide nanoparticulate-based contrast agents.In the present work, a novel non-lanthanide dual-modality contrast agent, manganese tungstate (MnWO4), has been successfully constructed by a facile and versatile hydrothermal route. With the merits of a high atomic number and a well-positioned K-edge energy of tungsten, our well-prepared non-lanthanide nanoprobes provide a higher contrast efficacy than routine iodine-based agents in clinics. Additionally, the presence of Mn in these nanoparticles endow them with excellent T1

  16. Rapid dark-blood carotid vessel-wall imaging with random bipolar gradients in a radial SSFP acquisition.

    PubMed

    Lin, Hung-Yu; Flask, Chris A; Dale, Brian M; Duerk, Jeffrey L

    2007-06-01

    To investigate and evaluate a new rapid dark-blood vessel-wall imaging method using random bipolar gradients with a radial steady-state free precession (SSFP) acquisition in carotid applications. The carotid artery bifurcations of four asymptomatic volunteers (28-37 years old, mean age = 31 years) were included in this study. Dark-blood contrast was achieved through the use of random bipolar gradients applied prior to the signal acquisition of each radial projection in a balanced SSFP acquisition. The resulting phase variation for moving spins established significant destructive interference in the low-frequency region of k-space. This phase variation resulted in a net nulling of the signal from flowing spins, while the bipolar gradients had a minimal effect on the static spins. The net effect was that the regular SSFP signal amplitude (SA) in stationary tissues was preserved while dark-blood contrast was achieved for moving spins. In this implementation, application of the random bipolar gradient pulses along all three spatial directions nulled the signal from both in-plane and through-plane flow in phantom and in vivo studies. In vivo imaging trials confirmed that dark-blood contrast can be achieved with the radial random bipolar SSFP method, thereby substantially reversing the vessel-to-lumen contrast-to-noise ratio (CNR) of a conventional rectilinear SSFP "bright-blood" acquisition from bright blood to dark blood with only a modest increase in TR (approximately 4 msec) to accommodate the additional bipolar gradients. Overall, this sequence offers a simple and effective dark-blood contrast mechanism for high-SNR SSFP acquisitions in vessel wall imaging within a short acquisition time.

  17. Plane Symmetric Dark Energy Models in the Form of Wet Dark Fluid in f ( R, T) Gravity

    NASA Astrophysics Data System (ADS)

    Chirde, V. R.; Shekh, S. H.

    2016-06-01

    In this paper, we have investigated the plane symmetric space-time with wet dark fluid (WDF), which is a candidate for dark energy, in the framework of f ( R, T) gravity Harko et al. 2011, Phys. Rev. D, 84, 024020), where R and T denote the Ricci scalar and the trace of the energy-momentum tensor respectively. We have used the equation of state in the form of WDF for the dark energy component of the Universe. It is modeled on the equation of state p = ω( ρ - ρ ∗). The exact solutions to the corresponding field equations are obtained for power-law and exponential volumetric expansion. The geometrical and physical parameters for both the models are studied. Also, we have discussed the well-known astrophysical phenomena, namely the look-back time, proper distance, the luminosity distance and angular diameter distance with red shift.

  18. First Dark Matter Search Results from the XENON1T Experiment.

    PubMed

    Aprile, E; Aalbers, J; Agostini, F; Alfonsi, M; Amaro, F D; Anthony, M; Arneodo, F; Barrow, P; Baudis, L; Bauermeister, B; Benabderrahmane, M L; Berger, T; Breur, P A; Brown, A; Brown, A; Brown, E; Bruenner, S; Bruno, G; Budnik, R; Bütikofer, L; Calvén, J; Cardoso, J M R; Cervantes, M; Cichon, D; Coderre, D; Colijn, A P; Conrad, J; Cussonneau, J P; Decowski, M P; de Perio, P; Di Gangi, P; Di Giovanni, A; Diglio, S; Eurin, G; Fei, J; Ferella, A D; Fieguth, A; Fulgione, W; Gallo Rosso, A; Galloway, M; Gao, F; Garbini, M; Gardner, R; Geis, C; Goetzke, L W; Grandi, L; Greene, Z; Grignon, C; Hasterok, C; Hogenbirk, E; Howlett, J; Itay, R; Kaminsky, B; Kazama, S; Kessler, G; Kish, A; Landsman, H; Lang, R F; Lellouch, D; Levinson, L; Lin, Q; Lindemann, S; Lindner, M; Lombardi, F; Lopes, J A M; Manfredini, A; Mariş, I; Marrodán Undagoitia, T; Masbou, J; Massoli, F V; Masson, D; Mayani, D; Messina, M; Micheneau, K; Molinario, A; Morå, K; Murra, M; Naganoma, J; Ni, K; Oberlack, U; Pakarha, P; Pelssers, B; Persiani, R; Piastra, F; Pienaar, J; Pizzella, V; Piro, M-C; Plante, G; Priel, N; Rauch, L; Reichard, S; Reuter, C; Riedel, B; Rizzo, A; Rosendahl, S; Rupp, N; Saldanha, R; Dos Santos, J M F; Sartorelli, G; Scheibelhut, M; Schindler, S; Schreiner, J; Schumann, M; Scotto Lavina, L; Selvi, M; Shagin, P; Shockley, E; Silva, M; Simgen, H; Sivers, M V; Stein, A; Thapa, S; Thers, D; Tiseni, A; Trinchero, G; Tunnell, C; Vargas, M; Upole, N; Wang, H; Wang, Z; Wei, Y; Weinheimer, C; Wulf, J; Ye, J; Zhang, Y; Zhu, T

    2017-11-03

    We report the first dark matter search results from XENON1T, a ∼2000-kg-target-mass dual-phase (liquid-gas) xenon time projection chamber in operation at the Laboratori Nazionali del Gran Sasso in Italy and the first ton-scale detector of this kind. The blinded search used 34.2 live days of data acquired between November 2016 and January 2017. Inside the (1042±12)-kg fiducial mass and in the [5,40]  keV_{nr} energy range of interest for weakly interacting massive particle (WIMP) dark matter searches, the electronic recoil background was (1.93±0.25)×10^{-4}  events/(kg×day×keV_{ee}), the lowest ever achieved in such a dark matter detector. A profile likelihood analysis shows that the data are consistent with the background-only hypothesis. We derive the most stringent exclusion limits on the spin-independent WIMP-nucleon interaction cross section for WIMP masses above 10  GeV/c^{2}, with a minimum of 7.7×10^{-47}  cm^{2} for 35-GeV/c^{2} WIMPs at 90% C.L.

  19. Quantitative DLA-based compressed sensing for T1-weighted acquisitions

    NASA Astrophysics Data System (ADS)

    Svehla, Pavel; Nguyen, Khieu-Van; Li, Jing-Rebecca; Ciobanu, Luisa

    2017-08-01

    High resolution Manganese Enhanced Magnetic Resonance Imaging (MEMRI), which uses manganese as a T1 contrast agent, has great potential for functional imaging of live neuronal tissue at single neuron scale. However, reaching high resolutions often requires long acquisition times which can lead to reduced image quality due to sample deterioration and hardware instability. Compressed Sensing (CS) techniques offer the opportunity to significantly reduce the imaging time. The purpose of this work is to test the feasibility of CS acquisitions based on Diffusion Limited Aggregation (DLA) sampling patterns for high resolution quantitative T1-weighted imaging. Fully encoded and DLA-CS T1-weighted images of Aplysia californica neural tissue were acquired on a 17.2T MRI system. The MR signal corresponding to single, identified neurons was quantified for both versions of the T1 weighted images. For a 50% undersampling, DLA-CS can accurately quantify signal intensities in T1-weighted acquisitions leading to only 1.37% differences when compared to the fully encoded data, with minimal impact on image spatial resolution. In addition, we compared the conventional polynomial undersampling scheme with the DLA and showed that, for the data at hand, the latter performs better. Depending on the image signal to noise ratio, higher undersampling ratios can be used to further reduce the acquisition time in MEMRI based functional studies of living tissues.

  20. Material radioassay and selection for the XENON1T dark matter experiment

    NASA Astrophysics Data System (ADS)

    Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; Di Gangi, P.; Di Giovanni, A.; Diglio, S.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Franco, D.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Grandi, L.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Itay, R.; Kaminsky, B.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Le Calloch, M.; Lin, Q.; Lindemann, S.; Lindner, M.; Lopes, J. A. M.; Manfredini, A.; Maris, I.; Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Miguez, B.; Molinario, A.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Piro, M.-C.; Pizzella, V.; Plante, G.; Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Rupp, N.; Saldanha, R.; dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Sivers, M. v.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Upole, N.; Wang, H.; Wei, Y.; Weinheimer, C.; Wulf, J.; Ye, J.; Zhang, Y.; Laubenstein, M.; Nisi, S.

    2017-12-01

    The XENON1T dark matter experiment aims to detect weakly interacting massive particles (WIMPs) through low-energy interactions with xenon atoms. To detect such a rare event necessitates the use of radiopure materials to minimize the number of background events within the expected WIMP signal region. In this paper we report the results of an extensive material radioassay campaign for the XENON1T experiment. Using gamma-ray spectroscopy and mass spectrometry techniques, systematic measurements of trace radioactive impurities in over one hundred samples within a wide range of materials were performed. The measured activities allowed for stringent selection and placement of materials during the detector construction phase and provided the input for XENON1T detection sensitivity estimates through Monte Carlo simulations.

  1. Europium-doped gadolinium sulfide nanoparticles as a dual-mode imaging agent for T1-weighted MR and photoluminescence imaging.

    PubMed

    Jung, Jongjin; Kim, Mi Ae; Cho, Jee-Hyun; Lee, Seung Jae; Yang, Ilseung; Cho, Janggeun; Kim, Seong Keun; Lee, Chulhyun; Park, Joung Kyu

    2012-08-01

    We present a facile synthesis of europium-doped gadolinium sulfide (GdS:Eu(3+)) opto-magnetic nanoparticles (NPs) via sonochemistry. Their photoluminescence and strong paramagnetic properties enable these NPs to be utilized as an in vitro cell imaging and in vivo T(1)-weighted MR imaging probe. The GdS:Eu(3+) NPs have a prominent longitudinal (r(1)) relaxivity value, which is a critical parameter for T(1)-weighted MR imaging. Here, we showed not only their strong positive contrast effect to blood vessels and organs of mice, but also blood half-life and biodistribution including clearance from organs, in order to assess the GdS:Eu(3+) NPs as a competent nanocrystal-based T(1) contrast agent. We further showed confocal images of breast cancer cells containing GdS:Eu(3+) NPs to evaluate as a photoluminescence probe. Dual-mode imaging capability obtained from the GdS:Eu(3+) NPs will allow target-oriented cellular imaging as well as the resulting disease-specific MR imaging. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Optimization of PROPELLER reconstruction for free-breathing T1-weighted cardiac imaging.

    PubMed

    Huang, Teng-Yi; Tseng, Yu-Shen; Tang, Yu-Wei; Lin, Yi-Ru

    2012-08-01

    Clinical cardiac MR imaging techniques generally require patients to hold their breath during the scanning process to minimize respiratory motion-related artifacts. However, some patients cannot hold their breath because of illness or limited breath-hold capacity. This study aims to optimize the PROPELLER reconstruction for free-breathing myocardial T1-weighted imaging. Eight healthy volunteers (8 men; mean age 26.4 years) participated in this study after providing institutionally approved consent. The PROPELLER encoding method can reconstruct a low-resolution image from every blade because of k-space center oversampling. This study investigated the feasibility of extracting a respiratory trace from the PROPELLER blades by implementing a fully automatic region of interest selection and introducing a best template index to account for the property of the human respiration cycle. Results demonstrated that the proposed algorithm significantly improves the contrast-to-noise ratio and the image sharpness (p < 0.05). The PROPELLER method is expected to provide a robust tool for clinical application in free-breathing myocardial T1-weighted imaging. It could greatly facilitate the acquisition procedures during such a routine examination.

  3. Effect of dark chocolate on nitric oxide serum levels and blood pressure in prehypertension subjects.

    PubMed

    Sudarma, Verawati; Sukmaniah, Sri; Siregar, Parlindungan

    2011-10-01

    to investigate the effect of consumption of dark chocolate 30 g/day for fifteen days on Nitric oxide (NO) serum levels and blood pressure in male and female employees with prehypertension. the study was a parallel randomized clinical trial. A total of thirty-two subjects was divided into two groups using block randomization. Sixteen subjects received 30 g/day dark chocolate and dietary counseling (treatment group) and the other 16 subjects received white chocolate 25 g/day and dietary counseling (control group) for fifteen days. Data collected in this study consisted of age, physical activity, body massa index, intake of energy, intake of sodium, and intake of polyphenol, NO serum levels and blood pressure. The measurement of NO serum levels was done in pre- and after- treatment, while blood pressure was assessed in pre- , during- and after- treatment. Statistical analysis was performed using independent t-test for normal distribution data and Mann-Whitney test for not normal distribution data, with the level of significancy of 5%. after 15 days treatment, NO serum level between treatment and control groups were significantly different 7.70 ± 3.84 vs 1.92(-0.79 ± 17.78) (p=0.001). Both groups had decreased systolic and diastolic blood pressure. Systolic blood pressure was different significantly between groups after treatment 120.64 ± 8.47 vs 131.19 ± 7.45 (p=0.001), while diastolic blood pressure was not significant 74.14 ± 6.30 vs 77.44 ± 10.29 (p=0.308). in prehypertension subjects, dark chocolate 30 g/day increased NOx serum levels and decreased systolic blood pressure after 15 days of treatment.

  4. Breast cancer detection using double reading of unenhanced MRI including T1-weighted, T2-weighted STIR, and diffusion-weighted imaging: a proof of concept study.

    PubMed

    Trimboli, Rubina M; Verardi, Nicola; Cartia, Francesco; Carbonaro, Luca A; Sardanelli, Francesco

    2014-09-01

    The purpose of this study was to investigate the diagnostic performance of unenhanced MRI in detecting breast cancer and to assess the impact of double reading. A total of 116 breasts of 67 women who were 36-89 years old were studied at 1.5 T using an unenhanced protocol including axial T1-weighted gradient-echo, T2-weighted STIR, and echo-planar diffusion-weighted imaging (DWI). Two blinded readers (R1 and R2) independently evaluated unenhanced images using the BIRADS scale. A combination of pathology and negative follow-up served as the reference standard. McNemar and kappa statistics were used. Per-breast cancer prevalence was 37 of 116 (32%): 30 of 37 (81%) invasive ductal carcinoma, five of 37 (13%) ductal carcinoma in situ, and two of 37 (6%) invasive lobular carcinoma. Per-breast sensitivity of unenhanced MRI was 29 of 37 (78%) for R1, 28 of 37 (76%) for R2, and 29 of 37 (78%) for double reading. Specificity was 71 of 79 (90%) for both R1 and R2 and 69 of 79 (87%) for double reading. Double reading did not provide a significant increase in sensitivity. Interobserver agreement was almost perfect (Cohen κ = 0.873). An unenhanced breast MRI protocol composed of T1-weighted gradient echo, T2-weighted STIR, and echo-planar DWI enabled breast cancer detection with sensitivity of 76-78% and specificity of 90% without a gain in sensitivity from double reading.

  5. Accelerated whole brain intracranial vessel wall imaging using black blood fast spin echo with compressed sensing (CS-SPACE).

    PubMed

    Zhu, Chengcheng; Tian, Bing; Chen, Luguang; Eisenmenger, Laura; Raithel, Esther; Forman, Christoph; Ahn, Sinyeob; Laub, Gerhard; Liu, Qi; Lu, Jianping; Liu, Jing; Hess, Christopher; Saloner, David

    2018-06-01

    Develop and optimize an accelerated, high-resolution (0.5 mm isotropic) 3D black blood MRI technique to reduce scan time for whole-brain intracranial vessel wall imaging. A 3D accelerated T 1 -weighted fast-spin-echo prototype sequence using compressed sensing (CS-SPACE) was developed at 3T. Both the acquisition [echo train length (ETL), under-sampling factor] and reconstruction parameters (regularization parameter, number of iterations) were first optimized in 5 healthy volunteers. Ten patients with a variety of intracranial vascular disease presentations (aneurysm, atherosclerosis, dissection, vasculitis) were imaged with SPACE and optimized CS-SPACE, pre and post Gd contrast. Lumen/wall area, wall-to-lumen contrast ratio (CR), enhancement ratio (ER), sharpness, and qualitative scores (1-4) by two radiologists were recorded. The optimized CS-SPACE protocol has ETL 60, 20% k-space under-sampling, 0.002 regularization factor with 20 iterations. In patient studies, CS-SPACE and conventional SPACE had comparable image scores both pre- (3.35 ± 0.85 vs. 3.54 ± 0.65, p = 0.13) and post-contrast (3.72 ± 0.58 vs. 3.53 ± 0.57, p = 0.15), but the CS-SPACE acquisition was 37% faster (6:48 vs. 10:50). CS-SPACE agreed with SPACE for lumen/wall area, ER measurements and sharpness, but marginally reduced the CR. In the evaluation of intracranial vascular disease, CS-SPACE provides a substantial reduction in scan time compared to conventional T 1 -weighted SPACE while maintaining good image quality.

  6. 5D.07: THE IMPACT OF FLAVONOL-RICH DARK CHOCOLATE ON BLOOD PRESSURE AND VASCULAR FUNCTION IN HEALTHY SUBJECTS.

    PubMed

    Heuten, H; Van Ackeren, K; Hoymans, V; Wouters, K; Goovaerts, I; Conraads, V; Vrints, C

    2015-06-01

    Flavanoids may have a beneficial effect on blood pressure (BP) and endothelial function. There is however, limited data on this effect during a longer period (8 weeks) and no data on the effect on EPC (endothelial progenitor cells) in healthy subjects. Healthy, non-smoking, male and female volunteers aged 35-65 year with no history of diabetes or cardiovascular disease and with normal or mild hypertensive blood pressure (<160/100 mmHg) were included. Subjects could not take any medication affecting blood pressure or endothelial function. The subjects were randomised (double-blind) in two groups: Group 1(n = 25): daily consuming 20 gram of high-flavanol dark chocolate (High-DC). Group 2 (n = 26): daily consuming 20 gram of low-flavanol dark chocolate (Low-DC). At week 0,4,6,7 and 8 blood pressure was assessed in all subjects, and endothelial function (FMD, flow mediated dilation) in a subgroup. A blood sample was taken in each subject at week 0 and 8 for measuring glucose, lipids and EPC. Baseline characteristics were comparable between both groups. There was a decrease in systolic and diastolic blood pressure over time in both groups, however at 8 weeks there was no statistically significant difference between groups (delta SBP -2.17  + /-8.53 mmHg in gr 1 versus -4.06 + /-8.05 mmHg in gr 2, p = 0.4; delta DBP -3.97  + /-7.1 mmHg in gr 1 versus -4.67  + /-5.99 mmHg in gr 2, p = 0.7).FMD was performed in 9 subjects from each group, no significant difference was noted between both groups over time (delta FMD gr 1: -3.50  + /- 6.00 % versus gr 2: + 0.12  + /- 2.51 %, p = 0.06). EPC values did not differ between groups at baseline (T0) and at the end of the study (T8) (ISHAGE count (T8-T0): gr1: 3.23 (-68.01 - 41.71) versus gr 2: -9.23 (-57.59 - 17.28), p = 0.4). Glucose and lipids were comparable between both groups at baseline and at the end of the study (p = ns). In this study, no beneficial effect

  7. Hierarchical phase space structure of dark matter haloes: Tidal debris, caustics, and dark matter annihilation

    NASA Astrophysics Data System (ADS)

    Afshordi, Niayesh; Mohayaee, Roya; Bertschinger, Edmund

    2009-04-01

    Most of the mass content of dark matter haloes is expected to be in the form of tidal debris. The density of debris is not constant, but rather can grow due to formation of caustics at the apocenters and pericenters of the orbit, or decay as a result of phase mixing. In the phase space, the debris assemble in a hierarchy that is truncated by the primordial temperature of dark matter. Understanding this phase structure can be of significant importance for the interpretation of many astrophysical observations and, in particular, dark matter detection experiments. With this purpose in mind, we develop a general theoretical framework to describe the hierarchical structure of the phase space of cold dark matter haloes. We do not make any assumption of spherical symmetry and/or smooth and continuous accretion. Instead, working with correlation functions in the action-angle space, we can fully account for the hierarchical structure (predicting a two-point correlation function ∝ΔJ-1.6 in the action space), as well as the primordial discreteness of the phase space. As an application, we estimate the boost to the dark matter annihilation signal due to the structure of the phase space within virial radius: the boost due to the hierarchical tidal debris is of order unity, whereas the primordial discreteness of the phase structure can boost the total annihilation signal by up to an order of magnitude. The latter is dominated by the regions beyond 20% of the virial radius, and is largest for the recently formed haloes with the least degree of phase mixing. Nevertheless, as we argue in a companion paper, the boost due to small gravitationally-bound substructure can dominate this effect at low redshifts.

  8. Role of T1 mapping as a complementary tool to T2* for non-invasive cardiac iron overload assessment.

    PubMed

    Torlasco, Camilla; Cassinerio, Elena; Roghi, Alberto; Faini, Andrea; Capecchi, Marco; Abdel-Gadir, Amna; Giannattasio, Cristina; Parati, Gianfranco; Moon, James C; Cappellini, Maria D; Pedrotti, Patrizia

    2018-01-01

    Iron overload-related heart failure is the principal cause of death in transfusion dependent patients, including those with Thalassemia Major. Linking cardiac siderosis measured by T2* to therapy improves outcomes. T1 mapping can also measure iron; preliminary data suggests it may have higher sensitivity for iron, particularly for early overload (the conventional cut-point for no iron by T2* is 20ms, but this is believed insensitive). We compared T1 mapping to T2* in cardiac iron overload. In a prospectively large single centre study of 138 Thalassemia Major patients and 32 healthy controls, we compared T1 mapping to dark blood and bright blood T2* acquired at 1.5T. Linear regression analysis was used to assess the association of T2* and T1. A "moving window" approach was taken to understand the strength of the association at different levels of iron overload. The relationship between T2* (here dark blood) and T1 is described by a log-log linear regression, which can be split in three different slopes: 1) T2* low, <20ms, r2 = 0.92; 2) T2* = 20-30ms, r2 = 0.48; 3) T2*>30ms, weak relationship. All subjects with T2*<20ms had low T1; among those with T2*>20ms, 38% had low T1 with most of the subjects in the T2* range 20-30ms having a low T1. In established cardiac iron overload, T1 and T2* are concordant. However, in the 20-30ms T2* range, T1 mapping appears to detect iron. These data support previous suggestions that T1 detects missed iron in 1 out of 3 subjects with normal T2*, and that T1 mapping is complementary to T2*. The clinical significance of a low T1 with normal T2* should be further investigated.

  9. Non-invasive evaluation of blood oxygen saturation and hematocrit from T1 and T2 relaxation times: In-vitro validation in fetal blood.

    PubMed

    Portnoy, Sharon; Seed, Mike; Sled, John G; Macgowan, Christopher K

    2017-12-01

    We propose an analytical method for calculating blood hematocrit (Hct) and oxygen saturation (sO 2 ) from measurements of its T 1 and T 2 relaxation times. Through algebraic substitution, established two-compartment relationships describing R1=T1-1 and R2=T2-1 as a function of hematocrit and oxygen saturation were rearranged to solve for Hct and sO 2 in terms of R 1 and R 2 . Resulting solutions for Hct and sO 2 are the roots of cubic polynomials. Feasibility of the method was established by comparison of Hct and sO 2 estimates obtained from relaxometry measurements (at 1.5 Tesla) in cord blood specimens to ground-truth values obtained by blood gas analysis. Monte Carlo simulations were also conducted to assess the effect of T 1 , T 2 measurement uncertainty on precision of Hct and sO 2 estimates. Good agreement was observed between estimated and ground-truth blood properties (bias = 0.01; 95% limits of agreement = ±0.13 for Hct and sO 2 ). Considering the combined effects of biological variability and random measurement noise, we estimate a typical uncertainty of ±0.1 for Hct, sO 2 estimates. Results demonstrate accurate quantification of Hct and sO 2 from T 1 and T 2 . This method is applicable to noninvasive fetal vessel oximetry-an application where existing oximetry devices are unusable or require risky blood-sampling procedures. Magn Reson Med 78:2352-2359, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  10. Universal clustering of dark matter in phase space

    NASA Astrophysics Data System (ADS)

    Zavala, Jesús; Afshordi, Niayesh

    2016-03-01

    We have recently introduced a novel statistical measure of dark matter clustering in phase space, the particle phase-space average density (P2SAD). In a two-paper series, we studied the structure of P2SAD in the Milky Way-size Aquarius haloes, constructed a physically motivated model to describe it, and illustrated its potential as a powerful tool to predict signals sensitive to the nanostructure of dark matter haloes. In this work, we report a remarkable universality of the clustering of dark matter in phase space as measured by P2SAD within the subhaloes of host haloes across different environments covering a range from dwarf-size to cluster-size haloes (1010-1015 M⊙). Simulations show that the universality of P2SAD holds for more than seven orders of magnitude, over a 2D phase space, covering over three orders of magnitude in distance/velocity, with a simple functional form that can be described by our model. Invoking the universality of P2SAD, we can accurately predict the non-linear power spectrum of dark matter at small scales all the way down to the decoupling mass limit of cold dark matter particles. As an application, we compute the subhalo boost to the annihilation of dark matter in a wide range of host halo masses.

  11. Dark Energy and Dark Matter Hidden in the Geometry of Space?

    NASA Astrophysics Data System (ADS)

    Buchert, Thomas

    A spatially flat and infinite Universe in the form of a "concordant" standard model of cosmology rules present-day thinking of cosmologists. The price to pay is an unknown physical origin of Dark Energy and Dark Matter that are supposed to exist and even appear to rule the dynamics of our Universe. A growing number of cosmologists question the existence of dark constituents: the standard model of cosmology may be just too simple, since it neglects the influence of structure in the Universe on its global expansion history. The key-issue appears to be the curvature of space: the formation of structure interacts with the geometry of space, changing our global picture of the Universe. This chapter explains the underlying mechanism that works in the right direction to uncover the dark faces of the standard model of cosmology. If successful, this novel approach furnishes a new paradigm of modern cosmology. Hundreds of researchers have recently embarked into studies of this new subject. We understand much at present, but there are many open questions.

  12. Dark Chocolate Intake Acutely Enhances Neutrophil Count in Peripheral Venous Blood.

    PubMed

    Montagnana, Martina; Danese, Elisa; Lima-Oliveira, Gabriel; Salvagno, Gian Luca; Lippi, Giuseppe

    2017-01-01

    Beside the well-established impact on decreasing the risk of cardiovascular diseases (1), recent attention has been paid to the relationship between cocoa-containing foods and the immune system (2), showing that dark chocolate consumption enhances the systemic defense against bacterial (3) and viral (4) infections. Hence, the current study aimed at investigating the acute effect of dark chocolate intake on peripheral blood leukocytes.

  13. Dark Chocolate Intake Acutely Enhances Neutrophil Count in Peripheral Venous Blood

    PubMed Central

    Montagnana, Martina; Danese, Elisa; Lima-Oliveira, Gabriel; Salvagno, Gian Luca; Lippi, Giuseppe

    2017-01-01

    Beside the well-established impact on decreasing the risk of cardiovascular diseases (1), recent attention has been paid to the relationship between cocoa-containing foods and the immune system (2), showing that dark chocolate consumption enhances the systemic defense against bacterial (3) and viral (4) infections. Hence, the current study aimed at investigating the acute effect of dark chocolate intake on peripheral blood leukocytes. PMID:29531561

  14. Lowering the radioactivity of the photomultiplier tubes for the XENON1T dark matter experiment

    DOE PAGES

    Aprile, E.; Agostini, F.; Alfonsi, M.; ...

    2015-11-23

    The low-background, VUV-sensitive 3-inch diameter photomultiplier tube R11410 has been developed by Hamamatsu for dark matter direct detection experiments using liquid xenon as the target material. We present the results from the joint effort between the XENON collaboration and the Hamamatsu company to produce a highly radio-pure photosensor (version R11410-21) for the XENON1T dark matter experiment. After introducing the photosensor and its components, we show the methods and results of the radioactive contamination measurements of the individual materials employed in the photomultiplier production. We then discuss the adopted strategies to reduce the radioactivity of the various PMT versions. Finally, wemore » detail the results from screening 286 tubes with ultra-low background germanium detectors, as well as their implications for the expected electronic and nuclear recoil background of the XENON1T experiment.« less

  15. Conquering the Dark Side: Colloidal Iron Oxide Nanoparticles

    PubMed Central

    Senpan, Angana; Caruthers, Shelton D.; Rhee, Ilsu; Mauro, Nicholas A.; Pan, Dipanjan; Hu, Grace; Scott, Michael J.; Fuhrhop, Ralph W.; Gaffney, Patrick J.; Wickline, Samuel A.; Lanza, Gregory M.

    2009-01-01

    Nanomedicine approaches to atherosclerotic disease will have significant impact on the practice and outcomes of cardiovascular medicine. Iron oxide nanoparticles have been extensively used for nontargeted and targeted imaging applications based upon highly sensitive T2* imaging properties, which typically result in negative contrast effects that can only be imaged 24 or more hours after systemic administration due to persistent blood pool interference. Although recent advances involving MR pulse sequences have converted these dark contrast voxels into bright ones, the marked delays in imaging from persistent magnetic background interference and prominent dipole blooming effects of the magnetic susceptibility remain barriers to overcome. We report a T1-weighted (T1w) theranostic colloidal iron oxide nanoparticle platform, CION, which is achieved by entrapping oleate-coated magnetite particles within a cross-linked phospholipid nanoemulsion. Contrary to expectations, this formulation decreased T2 effects thus allowing positive T1w contrast detection down to low nanomolar concentrations. CION, a vascular constrained nanoplatform administered in vivo permitted T1w molecular imaging 1 hour after treatment without blood pool interference, although some T2 shortening effects on blood, induced by the superparamagnetic particles persisted. Moreover, CION was shown to encapsulate antiangiogenic drugs, like fumagillin, and retained them under prolonged dissolution, suggesting significant theranostic functionality. Overall, CION is a platform technology, developed with generally recognized as safe components, that overcomes the temporal and spatial imaging challenges associated with current iron oxide nanoparticle T2 imaging agents, and which has theranostic potential in vascular diseases for detecting unstable ruptured plaque or treating atherosclerotic angiogenesis. PMID:19908850

  16. Hidden sector monopole, vector dark matter and dark radiation with Higgs portal

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Baek, Seungwon; Ko, P.; Park, Wan-Il, E-mail: sbaek1560@gmail.com, E-mail: pko@kias.re.kr, E-mail: wipark@kias.re.kr

    2014-10-01

    We show that the 't Hooft-Polyakov monopole model in the hidden sector with Higgs portal interaction makes a viable dark matter model, where monopole and massive vector dark matter (VDM) are stable due to topological conservation and the unbroken subgroup U(1 {sub X}. We show that, even though observed CMB data requires the dark gauge coupling to be quite small, a right amount of VDM thermal relic can be obtained via s-channel resonant annihilation for the mass of VDM close to or smaller than the half of SM higgs mass, thanks to Higgs portal interaction. Monopole relic density turns outmore » to be several orders of magnitude smaller than the observed dark matter relic density. Direct detection experiments, particularly, the projected XENON1T experiment, may probe the parameter space where the dark Higgs is lighter than ∼< 50 GeV. In addition, the dark photon associated with the unbroken U(1 {sub X} contributes to the radiation energy density at present, giving Δ N{sub eff}{sup ν} ∼ 0.1 as the extra relativistic neutrino species.« less

  17. Hyperecho PROPELLER-MRI: Application to rapid high-resolution motion-insensitive T2 -weighted black-blood imaging of the carotid arterial vessel wall and plaque.

    PubMed

    Yoneyama, Masami; Nakamura, Masanobu; Obara, Makoto; Okuaki, Tomoyuki; Sashi, Ryuji; Sawano, Seishi; Tatsuno, Satoshi; Van Cauteren, Marc

    2017-02-01

    To demonstrate the usefulness of hyperecho and PROPELLER (HEP) for carotid arterial vessel wall imaging by using a quantitative comparison with conventional methods. PROPELLER is a motion-insensitive turbo spin-echo (TSE) sequence and has recently been utilized in magnetic resonance (MR) plaque imaging instead of double inversion recovery TSE (DIR-TSE). Wider blade-width, higher k-space density, and an improved blood suppression effect result in better image quality. In this study we introduce a new combination of HEP. A total of 17 subjects were examined on a 3.0T system. We conducted quantitative comparisons for signal-to-noise ratio (SNR), contrast-to-noise-ratio, and image sharpness among HEP, DIR-TSE, and conventional PROPELLER (c-PROPELLER). Subsequently, images obtained with DIR-TSE, c-PROPELLER, and HEP were visually evaluated using a three-point scale by two board-certified radiologists. HEP showed high SNR similar to c-PROPELLER, good T 2 contrast approximating DIR-TSE, and better blood suppression compared with the other two methods (P < 0.05). The image sharpness of HEP (2.55 ± 0.53) was higher than that of DIR-TSE (1.89 ± 0.33) and the absence of ghost or streak artifacts in HEP (2.89 ± 0.33) was better than that in both other methods (2.22 ± 0.83 for DIR-TSE and 2.00 ± 0.50 for c-PROPELLER) (P < 0.05). Furthermore, the degree of blood suppression, particularly in cases of slow or turbulent flow close to the atherosclerotic plaque, was identical for HEP (2.80 ± 0.45) and DIR-TSE (2.80 ± 0.45) but was significantly better than for c-PROPELLER (1.60 ± 0.55) (P < 0.05). This study demonstrates the usefulness of HEP in the carotid arteries. HEP can provide higher-resolution T 2 -weighted black-blood imaging without flow- and/or motion-related artifacts, compared to conventional techniques. 3 J. Magn. Reson. Imaging 2017;45:515-524. © 2016 International Society for Magnetic Resonance in Medicine.

  18. James Webb Space Telescope Studies of Dark Energy

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.; Stiavelli, Massimo; Mather, John C.

    2010-01-01

    The Hubble Space Telescope (HST) has contributed significantly to studies of dark energy. It was used to find the first evidence of deceleration at z=1.8 (Riess et al. 2001) through the serendipitous discovery of a type 1a supernova (SN1a) in the Hubble Deep Field. The discovery of deceleration at z greater than 1 was confirmation that the apparent acceleration at low redshift (Riess et al. 1998; Perlmutter et al. 1999) was due to dark energy rather than observational or astrophysical effects such as systematic errors, evolution in the SN1a population or intergalactic dust. The GOODS project and associated follow-up discovered 21 SN1a, expanding on this result (Riess et al. 2007). HST has also been used to constrain cosmological parameters and dark energy through weak lensing measurements in the COSMOS survey (Massey et al 2007; Schrabback et al 2009) and strong gravitational lensing with measured time delays (Suyu et al 2010). Constraints on dark energy are often parameterized as the equation of state, w = P/p. For the cosmological constant model, w = -1 at all times; other models predict a change with time, sometimes parameterized generally as w(a) or approximated as w(sub 0)+(1-a)w(sub a), where a = (1+z)(sup -1) is the scale factor of the universe relative to its current scale. Dark energy can be constrained through several measurements. Standard candles, such as SN1a, provide a direct measurement of the luminosity distance as a function of redshift, which can be converted to H(z), the change in the Hubble constant with redshift. An analysis of weak lensing in a galaxy field can be used to derive the angular-diameter distance from the weak-lensing equation and to measure the power spectrum of dark-matter halos, which constrains the growth of structure in the Universe. Baryonic acoustic oscillations (BAO), imprinted on the distribution of matter at recombination, provide a standard rod for measuring the cosmological geometry. Strong gravitational lensing of a

  19. Bright-dark and dark-dark solitons in coupled nonlinear Schrödinger equation with P T -symmetric potentials

    NASA Astrophysics Data System (ADS)

    Nath, Debraj; Gao, Yali; Babu Mareeswaran, R.; Kanna, T.; Roy, Barnana

    2017-12-01

    We explore different nonlinear coherent structures, namely, bright-dark (BD) and dark-dark (DD) solitons in a coupled nonlinear Schrödinger/Gross-Pitaevskii equation with defocusing/repulsive nonlinearity coefficients featuring parity-time ( P T )-symmetric potentials. Especially, for two choices of P T -symmetric potentials, we obtain the exact solutions for BD and DD solitons. We perform the linear stability analysis of the obtained coherent structures. The results of this linear stability analysis are well corroborated by direct numerical simulation incorporating small random noise. It has been found that there exists a parameter regime which can support stable BD and DD solitons.

  20. Comparison of post-contrast 3D-T1-MPRAGE, 3D-T1-SPACE and 3D-T2-FLAIR MR images in evaluation of meningeal abnormalities at 3-T MRI.

    PubMed

    Jeevanandham, Balaji; Kalyanpur, Tejas; Gupta, Prashant; Cherian, Mathew

    2017-06-01

    This study was to assess the usefulness of newer three-dimensional (3D)-T 1 sampling perfection with application optimized contrast using different flip-angle evolutions (SPACE) and 3D-T 2 fluid-attenuated inversion recovery (FLAIR) sequences in evaluation of meningeal abnormalities. 78 patients who presented with high suspicion of meningeal abnormalities were evaluated using post-contrast 3D-T 2 -FLAIR, 3D-T 1 magnetization-prepared rapid gradient-echo (MPRAGE) and 3D-T 1 -SPACE sequences. The images were evaluated independently by two radiologists for cortical gyral, sulcal space, basal cisterns and dural enhancement. The diagnoses were confirmed by further investigations including histopathology. Post-contrast 3D-T 1 -SPACE and 3D-T 2 -FLAIR images yielded significantly more information than MPRAGE images (p < 0.05 for both SPACE and FLAIR images) in detection of meningeal abnormalities. SPACE images best demonstrated abnormalities in dural and sulcal spaces, whereas FLAIR was useful for basal cisterns enhancement. Both SPACE and FLAIR performed equally well in detection of gyral enhancement. In all 10 patients, where both SPACE and T 2 -FLAIR images failed to demonstrate any abnormality, further analysis was also negative. The 3D-T 1 -SPACE sequence best demonstrated abnormalities in dural and sulcal spaces, whereas FLAIR was useful for abnormalities in basal cisterns. Both SPACE and FLAIR performed holds good for detection of gyral enhancement. Post-contrast SPACE and FLAIR sequences are superior to the MPRAGE sequence for evaluation of meningeal abnormalities and when used in combination have the maximum sensitivity for leptomeningeal abnormalities. The negative-predictive value is nearly 100%, where no leptomeningeal abnormality was detected on these sequences. Advances in knowledge: Post-contrast 3D-T 1 -SPACE and 3D-T 2 -FLAIR images are more useful than 3D-T 1 -MPRAGE images in evaluation of meningeal abnormalities.

  1. Little Higgs dark matter after PandaX-II/LUX-2016 and LHC Run-1

    NASA Astrophysics Data System (ADS)

    Wu, Lei; Yang, Bingfang; Zhang, Mengchao

    2016-12-01

    In the Littlest Higgs model with T-parity (LHT), the T-odd heavy photon ( A H ) is weakly interacting and can play the role of dark matter. We investigate the lower limit on the mass of A H dark matter under the constraints from Higgs data, EWPOs, R b , Planck 2015 dark matter relic abundance, PandaX-II/LUX 2016 direct detections and LHC-8 TeV monojet results. We find that (1) Higgs data, EWPOs and R b can exclude the mass of A H up to 99 GeV. To produce the correct dark matter relic abundance, A H has to co-annihilate with T-odd quarks ( q H ) or leptons ( ℓ H ); (2) the LUX (PandaX-II) 2016 data can further exclude {m}_{A_H} < 380(270) GeV for ℓ H - A H co-annihilation and {m}_{A_H} < 350(240) GeV for q H - A H co-annihilation; (3) LHC-8 TeV monojet result can give a strong lower limit, {m}_{A_H} > 540 GeV, for q H - A H co-annihilation; (4) future XENON1T(2017) experiment can fully cover the parameter space of ℓ H - A H co-annihilation and will push the lower limit of {m}_{A_H} up to about 640 GeV for q H - A H co-annihilation.

  2. Cortical pathology in multiple sclerosis detected by the T1/T2‐weighted ratio from routine magnetic resonance imaging

    PubMed Central

    Righart, Ruthger; Biberacher, Viola; Jonkman, Laura E.; Klaver, Roel; Schmidt, Paul; Buck, Dorothea; Berthele, Achim; Kirschke, Jan S.; Zimmer, Claus; Hemmer, Bernhard; Geurts, Jeroen J. G.

    2017-01-01

    Objective In multiple sclerosis, neuropathological studies have shown widespread changes in the cerebral cortex. In vivo imaging is critical, because the histopathological substrate of most measurements is unknown. Methods Using a novel magnetic resonance imaging analysis technique, based on the ratio of T1‐ and T2‐weighted signal intensities, we studied the cerebral cortex of a large cohort of patients in early stages of multiple sclerosis. A total of 168 patients with clinically isolated syndrome or relapsing–remitting multiple sclerosis (Expanded Disability Status Scale: median = 1, range = 0–3.5) and 80 age‐ and sex‐matched healthy controls were investigated. We also searched for the histopathological substrate of the T1/T2‐weighted ratio by combining postmortem imaging and histopathology in 9 multiple sclerosis brain donors. Results Patients showed lower T1/T2‐weighted ratio values in parietal and occipital areas. The 4 most significant clusters appeared in the medial occipital and posterior cingulate cortex (each left and right). The decrease of the T1/T2‐weighted ratio in the posterior cingulate was related to performance in attention. Analysis of the T1/T2‐weighted ratio values of postmortem imaging yielded a strong correlation with dendrite density but none of the other parameters including myelin. Interpretation The T1/T2‐weighted ratio decreases in early stages of multiple sclerosis in a widespread manner, with a preponderance of posterior areas and with a contribution to attentional performance; it seems to reflect dendrite pathology. As the method is broadly available and applicable to available clinical scans, we believe that it is a promising candidate for studying and monitoring cortical pathology or therapeutic effects in multiple sclerosis. Ann Neurol 2017;82:519–529 PMID:28833433

  3. Comparison of Different Magnetic Resonance Cholangiography Techniques in Living Liver Donors Including Gd-EOB-DTPA Enhanced T1-Weighted Sequences

    PubMed Central

    Kinner, Sonja; Steinweg, Verena; Maderwald, Stefan; Radtke, Arnold; Sotiropoulos, Georgios; Forsting, Michael; Schroeder, Tobias

    2014-01-01

    Objectives Preoperative evaluation of potential living liver donors (PLLDs) includes the assessment of the biliary anatomy to avoid postoperative complications. Aim of this study was to compare T2-weighted (T2w) and Gd-EOB-DTPA enhanced T1-weighted (T1w) magnetic resonance cholangiography (MRC) techniques in the evaluation of PLLDs. Materials and Methods 30 PLLDs underwent MRC on a 1.5 T Magnetom Avanto (Siemens, Erlangen, Germany) using (A) 2D T2w HASTE (Half Fourier Acquisition Single Shot Turbo Spin Echo) fat saturated (fs) in axial plane, (B) 2D T2w HASTE fs thick slices in coronal plane, (C) free breathing 3D T2w TSE (turbo spin echo) RESTORE (high-resolution navigator corrected) plus (D) maximum intensity projections (MIPs), (E) T2w SPACE (sampling perfection with application optimized contrasts using different flip angle evolutions) plus (F) MIPs and (G) T2w TSE BLADE as well as Gd-EOB-DTPA T1w images without (G) and with (H) inversion recovery. Contrast enhanced CT cholangiography served as reference imaging modality. Two independent reviewers evaluated the biliary tract anatomy on a 5-point scale subjectively and objectively. Data sets were compared using a Mann-Whitney-U-test. Kappa values were also calculated. Results Source images and maximum intensity projections of 3D T2w TSE sequences (RESTORE and SPACE) proved to be best for subjective and objective evaluation directly followed by 2D HASTE sequences. Interobserver variabilities were good to excellent (k = 0.622–0.804). Conclusions 3D T2w sequences are essential for preoperative biliary tract evaluation in potential living liver donors. Furthermore, our results underline the value of different MRCP sequence types for the evaluation of the biliary anatomy in PLLDs including Gd-EOB-DTPA enhanced T1w MRC. PMID:25426932

  4. Fat suppression at three-dimensional T1-weighted MR imaging of the hands: Dixon method versus CHESS technique.

    PubMed

    Kirchgesner, T; Perlepe, V; Michoux, N; Larbi, A; Vande Berg, B

    2018-01-01

    To compare the effectiveness of fat suppression and the image quality of the Dixon method with those of the chemical shift-selective (CHESS) technique in hands of normal subjects at non-enhanced three-dimensional (3D) T1-weighted MR imaging. Both hands of 14 healthy volunteers were imaged with 3D fast spoiled gradient echo (FSPGR) T1-weighted Dixon, 3D FSPGR T1-weighted CHESS and 3D T1-weighted fast spin echo (FSE) CHESS sequences in a 1.5T MR scanner. Three radiologists scored the effectiveness of fat suppression in bone marrow (EFS BM ) and soft tissues (EFS ST ) in 20 joints per subject. One radiologist measured the signal-to-noise ratio (SNR) in 10 bones per subject. Statistical analysis used two-way ANOVA with random effects (P<0.0083), paired t-test (P<0.05) and observed agreement to assess differences in effectiveness of fat suppression, differences in SNR and interobserver agreement. EFS BM was statistically significantly higher for the 3D FSPGR T1-weighted Dixon than for the 3D FSPGR T1-weighted CHESS sequence and the 3D FSE T1-weighted CHESS sequence (P<0.0001). EFS ST was statistically significantly higher for the 3D FSPGR T1-weighted Dixon than for the 3D FSPGR T1-weighted CHESS sequence (P<0.0011) and for the 3D FSE T1-weighted CHESS sequence in the axial plane (P=0.0028). Mean SNR was statistically significantly higher for 3D FSPGR T1-weighted Dixon sequence than for 3D FSPGR T1-weighted CHESS and 3D FSE T1-weighted CHESS sequences (P<0.0001). The Dixon method yields more effective fat suppression and higher SNR than the CHESS technique at 3D T1-weighted MR imaging of the hands. Copyright © 2017 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  5. Singlet particles as cold dark matter in a noncommutative space-time

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ettefaghi, M. M.

    2009-03-15

    We extend the noncommutative (NC) standard model to incorporate singlet particles as cold dark matter. In the NC space-time, the singlet particles can be coupled to the U(1) gauge field in the adjoint representation. We study the relic density of the singlet particles due to the NC induced interaction. Demanding either the singlet fermion or the singlet scalar to serve as cold dark matter and the NC induced interactions to be relevant to the dark matter production, we obtain the corresponding relations between the NC scale and the dark matter masses, which are consistent with some existing bounds.

  6. Does the diffusion dark matter-dark energy interaction model solve cosmological puzzles?

    NASA Astrophysics Data System (ADS)

    Szydłowski, Marek; Stachowski, Aleksander

    2016-08-01

    We study dynamics of cosmological models with diffusion effects modeling dark matter and dark energy interactions. We show the simple model with diffusion between the cosmological constant sector and dark matter, where the canonical scaling law of dark matter (ρd m ,0a-3(t )) is modified by an additive ɛ (t )=γ t a-3(t ) to the form ρd m=ρd m ,0a-3(t )+ɛ (t ). We reduced this model to the autonomous dynamical system and investigate it using dynamical system methods. This system possesses a two-dimensional invariant submanifold on which the dark matter-dark energy (DM-DE) interaction can be analyzed on the phase plane. The state variables are density parameter for matter (dark and visible) and parameter δ characterizing the rate of growth of energy transfer between the dark sectors. A corresponding dynamical system belongs to a general class of jungle type of cosmologies represented by coupled cosmological models in a Lotka-Volterra framework. We demonstrate that the de Sitter solution is a global attractor for all trajectories in the phase space and there are two repellers: the Einstein-de Sitter universe and the de Sitter universe state dominating by the diffusion effects. We distinguish in the phase space trajectories, which become in good agreement with the data. They should intersect a rectangle with sides of Ωm ,0∈[0.2724 ,0.3624 ] , δ ∈[0.0000 ,0.0364 ] at the 95% CL. Our model could solve some of the puzzles of the Λ CDM model, such as the coincidence and fine-tuning problems. In the context of the coincidence problem, our model can explain the present ratio of ρm to ρd e, which is equal 0.457 6-0.0831+0.1109 at a 2 σ confidence level.

  7. T1ρ-weighted Dynamic Glucose-enhanced MR Imaging in the Human Brain.

    PubMed

    Paech, Daniel; Schuenke, Patrick; Koehler, Christina; Windschuh, Johannes; Mundiyanapurath, Sibu; Bickelhaupt, Sebastian; Bonekamp, David; Bäumer, Philipp; Bachert, Peter; Ladd, Mark E; Bendszus, Martin; Wick, Wolfgang; Unterberg, Andreas; Schlemmer, Heinz-Peter; Zaiss, Moritz; Radbruch, Alexander

    2017-12-01

    Purpose To evaluate the ability to detect intracerebral regions of increased glucose concentration at T1ρ-weighted dynamic glucose-enhanced (DGE) magnetic resonance (MR) imaging at 7.0 T. Materials and Methods This prospective study was approved by the institutional review board. Nine patients with newly diagnosed glioblastoma and four healthy volunteers were included in this study from October 2015 to July 2016. Adiabatically prepared chemical exchange-sensitive spin-lock imaging was performed with a 7.0-T whole-body unit with a temporal resolution of approximately 7 seconds, yielding the time-resolved DGE contrast. T1ρ-weighted DGE MR imaging was performed with injection of 100 mL of 20% d-glucose via the cubital vein. Glucose enhancement, given by the relative signal intensity change at T1ρ-weighted MR imaging (DGEρ), was quantitatively investigated in brain gray matter versus white matter of healthy volunteers and in tumor tissue versus normal-appearing white matter of patients with glioblastoma. The median signal intensities of the assessed brain regions were compared by using the Wilcoxon rank-sum test. Results In healthy volunteers, the median signal intensity in basal ganglia gray matter (DGEρ = 4.59%) was significantly increased compared with that in white matter tissue (DGEρ = 0.65%) (P = .028). In patients, the median signal intensity in the glucose-enhanced tumor region as displayed on T1ρ-weighted DGE images (DGEρ = 2.02%) was significantly higher than that in contralateral normal-appearing white matter (DGEρ = 0.08%) (P < .0001). Conclusion T1ρ-weighted DGE MR imaging in healthy volunteers and patients with newly diagnosed, untreated glioblastoma enabled visualization of brain glucose physiology and pathophysiologically increased glucose uptake and may have the potential to provide information about glucose metabolism in tumor tissue. © RSNA, 2017 Online supplemental material is available for this article.

  8. ``Smart'' theranostic lanthanide nanoprobes with simultaneous up-conversion fluorescence and tunable T1-T2 magnetic resonance imaging contrast and near-infrared activated photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Zhang, Yan; Das, Gautom Kumar; Vijayaragavan, Vimalan; Xu, Qing Chi; Padmanabhan, Parasuraman; Bhakoo, Kishore K.; Tamil Selvan, Subramanian; Tan, Timothy Thatt Yang

    2014-10-01

    The current work reports a type of ``smart'' lanthanide-based theranostic nanoprobe, NaDyF4:Yb3+/NaGdF4:Yb3+,Er3+, which is able to circumvent the up-converting poisoning effect of Dy3+ ions to give efficient near infrared (980 nm) triggered up-conversion fluorescence, and offers not only excellent dark T2-weighted MR contrast but also tunable bright and T1-weighted MR contrast properties. Due to the efficient up-converted energy transfer from the nanocrystals to chlorin e6 (Ce6) photosensitizers loaded onto the nanocrystals, cytotoxic singlet oxygen was generated and photodynamic therapy was demonstrated. Therefore, the current multifunctional nanocrystals could be potentially useful in various image-guided diagnoses where bright or dark MRI contrast could be selectively tuned to optimize image quality, but also as an efficient and more penetrative near-infrared activated photodynamic therapy agent.The current work reports a type of ``smart'' lanthanide-based theranostic nanoprobe, NaDyF4:Yb3+/NaGdF4:Yb3+,Er3+, which is able to circumvent the up-converting poisoning effect of Dy3+ ions to give efficient near infrared (980 nm) triggered up-conversion fluorescence, and offers not only excellent dark T2-weighted MR contrast but also tunable bright and T1-weighted MR contrast properties. Due to the efficient up-converted energy transfer from the nanocrystals to chlorin e6 (Ce6) photosensitizers loaded onto the nanocrystals, cytotoxic singlet oxygen was generated and photodynamic therapy was demonstrated. Therefore, the current multifunctional nanocrystals could be potentially useful in various image-guided diagnoses where bright or dark MRI contrast could be selectively tuned to optimize image quality, but also as an efficient and more penetrative near-infrared activated photodynamic therapy agent. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr01717j

  9. On the fallacy of quantitative segmentation for T1-weighted MRI

    NASA Astrophysics Data System (ADS)

    Plassard, Andrew J.; Harrigan, Robert L.; Newton, Allen T.; Rane, Swati; Pallavaram, Srivatsan; D'Haese, Pierre F.; Dawant, Benoit M.; Claassen, Daniel O.; Landman, Bennett A.

    2016-03-01

    T1-weighted magnetic resonance imaging (MRI) generates contrasts with primary sensitivity to local T1 properties (with lesser T2 and PD contributions). The observed signal intensity is determined by these local properties and the sequence parameters of the acquisition. In common practice, a range of acceptable parameters is used to ensure "similar" contrast across scanners used for any particular study (e.g., the ADNI standard MPRAGE). However, different studies may use different ranges of parameters and report the derived data as simply "T1-weighted". Physics and imaging authors pay strong heed to the specifics of the imaging sequences, but image processing authors have historically been more lax. Herein, we consider three T1-weighted sequences acquired the same underlying protocol (MPRAGE) and vendor (Philips), but "normal study-to-study variation" in parameters. We show that the gray matter/white matter/cerebrospinal fluid contrast is subtly but systemically different between these images and yields systemically different measurements of brain volume. The problem derives from the visually apparent boundary shifts, which would also be seen by a human rater. We present and evaluate two solutions to produce consistent segmentation results across imaging protocols. First, we propose to acquire multiple sequences on a subset of the data and use the multi-modal imaging as atlases to segment target images any of the available sequences. Second (if additional imaging is not available), we propose to synthesize atlases of the target imaging sequence and use the synthesized atlases in place of atlas imaging data. Both approaches significantly improve consistency of target labeling.

  10. Fast T2*-weighted MRI of the prostate at 3 Tesla.

    PubMed

    Hardman, Rulon L; El-Merhi, Fadi; Jung, Adam J; Ware, Steve; Thompson, Ian M; Friel, Harry T; Peng, Qi

    2011-04-01

    To describe a rapid T2*-weighted (T2*W), three-dimensional (3D) echo planar imaging (EPI) sequence and its application in mapping local magnetic susceptibility variations in 3 Tesla (T) prostate MRI. To compare the sensitivity of T2*W EPI with routinely used T1-weighted turbo-spin echo sequence (T1W TSE) in detecting hemorrhage and the implications on sequences sensitive to field inhomogeneities such as MR spectroscopy (MRS). B(0) susceptibility weighted mapping was performed using a 3D EPI sequence featuring a 2D spatial excitation pulse with gradients of spiral k-space trajectory. A series of 11 subjects were imaged using 3T MRI and combination endorectal (ER) and six-channel phased array cardiac coils. T1W TSE and T2*W EPI sequences were analyzed quantitatively for hemorrhage contrast. Point resolved spectroscopy (PRESS MRS) was performed and data quality was analyzed. Two types of susceptibility variation were identified: hemorrhagic and nonhemorrhagic T2*W-positive areas. Post-biopsy hemorrhage lesions showed on average five times greater contrast on the T2*W images than T1W TSE images. Six nonhemorrhage regions of severe susceptibility artifact were apparent on the T2*W images that were not seen on standard T1W or T2W images. All nonhemorrhagic susceptibility artifact regions demonstrated compromised spectral quality on 3D MRS. The fast T2*W EPI sequence identifies hemorrhagic and nonhemorrhagic areas of susceptibility variation that may be helpful in prostate MRI planning at 3.0T. Copyright © 2011 Wiley-Liss, Inc.

  11. Little composite dark matter

    NASA Astrophysics Data System (ADS)

    Balkin, Reuven; Perez, Gilad; Weiler, Andreas

    2018-02-01

    We examine the dark matter phenomenology of a composite electroweak singlet state. This singlet belongs to the Goldstone sector of a well-motivated extension of the Littlest Higgs with T-parity. A viable parameter space, consistent with the observed dark matter relic abundance as well as with the various collider, electroweak precision and dark matter direct detection experimental constraints is found for this scenario. T-parity implies a rich LHC phenomenology, which forms an interesting interplay between conventional natural SUSY type of signals involving third generation quarks and missing energy, from stop-like particle production and decay, and composite Higgs type of signals involving third generation quarks associated with Higgs and electroweak gauge boson, from vector-like top-partners production and decay. The composite features of the dark matter phenomenology allows the composite singlet to produce the correct relic abundance while interacting weakly with the Higgs via the usual Higgs portal coupling λ _{ {DM}}˜ O(1%), thus evading direct detection.

  12. Blood and clonogenic hemopoietic cells of newts after the space flight

    NASA Astrophysics Data System (ADS)

    Michurina, T. V.; Domaratskaya, E. I.; Nikonova, T. M.; Khrushchov, N. G.

    Ribbed newts were used for studying the effect of space flight on board of the biosatellite (Cosmos-2229) on blood and clonogenic hemopoietic cells. In blood of newts of the flight group, the relative proportion of neutrophils increased, whereas that of lymphocytes and eosinophils decreased. Space flight did not result in loss of the ability of newt blood cells to incorporate H^3-thymidine. Analysis of clonogenic hemopoietic cells was performed using the method of hemopoietic colony formation on cellulose acetate membranes implanted into the peritoneal cavity of irradiated newts. To analyze reconstitution of hemopoiesis after irradiation donor hemopoietic cells from flight or control newts were transplanted into irradiated newts whose hemopoietic organs were investigated. The newt can be considered an adequate model for studying hemopoiesis under the conditions of the space flight. Previous studies on rats subjected to 5- to 19-day space flights revealed a decrease in the number of clonogenic cells in their hemopoietic organs accompanied by specific changes in the precursor cell compartment and in blood /1,2/. Hence, it was interesting to analyze blood and hemopoietic tissue of lower vertebrates after a space flight and to compare the response to it of animals belonging to different taxonomic groups. We analyzed blood and clonogenic hemopoietic cells of ribbed newts, Pleurodeles waltl (age one year, weight 20-28 g) subjected to a 12-day space flight on board of a Cosmos-2229 biosatellite. The same animals were used in studies on limb and lens regeneration. The results were compared with those obtained with control groups of newts: (1) basic control, operated newts sacrificed on the day of biosatellite launching (BC); (2) synchronous control, operated newts kept in the laboratory under simulated space flight conditions (SC); and (3) intact newts (IC).

  13. Outcome analysis of hemoglobin A1c, weight, and blood pressure in a VA diabetes education program.

    PubMed

    North, Susan L; Palmer, Glen A

    2015-01-01

    To determine the effect of a specific diabetes education class (Basics) on hemoglobin A1c values, weight, and systolic blood pressure. In this retrospective study, the researchers compared 2 groups of male veterans with a recent diagnosis of type 2 diabetes. One group received diabetes group education (n = 175) over a 4-month period, and the other received standard diabetes management follow-up (n = 184). Outpatient clinic setting in the Midwest. Basics class compared with standard level of care. Pre- and post-laboratory values for hemoglobin A1c, weight, and systolic blood pressure. Multivariate analysis of covariance and follow-up univariate statistics for significant differences. Findings revealed significant differences in hemoglobin A1c (P < .001) and weight (P < .001) in the treatment group compared with the control group. No significant difference was found in systolic blood pressure readings between the 2 groups. There was a significant difference in weight change between groups, with the treatment group demonstrating greater weight loss. There was an association between participation in the Basics diabetes education curriculum and reduction of hemoglobin A1c values. Some participants also had added benefit of significant weight loss. Published by Elsevier Inc.

  14. The Space Motion of Leo I: The Mass of the Milky Way's Dark Matter Halo

    NASA Astrophysics Data System (ADS)

    Boylan-Kolchin, Michael; Bullock, James S.; Sohn, Sangmo Tony; Besla, Gurtina; van der Marel, Roeland P.

    2013-05-01

    We combine our Hubble Space Telescope measurement of the proper motion of the Leo I dwarf spheroidal galaxy (presented in a companion paper) with the highest resolution numerical simulations of Galaxy-size dark matter halos in existence to constrain the mass of the Milky Way's dark matter halo (M vir, MW). Despite Leo I's large Galactocentric space velocity (200 km s-1) and distance (261 kpc), we show that it is extremely unlikely to be unbound if Galactic satellites are associated with dark matter substructure, as 99.9% of subhalos in the simulations are bound to their host. The observed position and velocity of Leo I strongly disfavor a low-mass Milky Way: if we assume that Leo I is the least bound of the Milky Way's classical satellites, then we find that M vir, MW > 1012 M ⊙ at 95% confidence for a variety of Bayesian priors on M vir, MW. In lower mass halos, it is vanishingly rare to find subhalos at 261 kpc moving as fast as Leo I. Should an additional classical satellite be found to be less bound than Leo I, this lower limit on M vir, MW would increase by 30%. Imposing a mass-weighted ΛCDM prior, we find a median Milky Way virial mass of M vir, MW = 1.6 × 1012 M ⊙, with a 90% confidence interval of [1.0-2.4] × 1012 M ⊙. We also confirm a strong correlation between subhalo infall time and orbital energy in the simulations and show that proper motions can aid significantly in interpreting the infall times and orbital histories of satellites.

  15. Detailed T1-Weighted Profiles from the Human Cortex Measured in Vivo at 3 Tesla MRI.

    PubMed

    Ferguson, Bart; Petridou, Natalia; Fracasso, Alessio; van den Heuvel, Martijn P; Brouwer, Rachel M; Hulshoff Pol, Hilleke E; Kahn, René S; Mandl, René C W

    2018-04-01

    Studies into cortical thickness in psychiatric diseases based on T1-weighted MRI frequently report on aberrations in the cerebral cortex. Due to limitations in image resolution for studies conducted at conventional MRI field strengths (e.g. 3 Tesla (T)) this information cannot be used to establish which of the cortical layers may be implicated. Here we propose a new analysis method that computes one high-resolution average cortical profile per brain region extracting myeloarchitectural information from T1-weighted MRI scans that are routinely acquired at a conventional field strength. To assess this new method, we acquired standard T1-weighted scans at 3 T and compared them with state-of-the-art ultra-high resolution T1-weighted scans optimised for intracortical myelin contrast acquired at 7 T. Average cortical profiles were computed for seven different brain regions. Besides a qualitative comparison between the 3 T scans, 7 T scans, and results from literature, we tested if the results from dynamic time warping-based clustering are similar for the cortical profiles computed from 7 T and 3 T data. In addition, we quantitatively compared cortical profiles computed for V1, V2 and V7 for both 7 T and 3 T data using a priori information on their relative myelin concentration. Although qualitative comparisons show that at an individual level average profiles computed for 7 T have more pronounced features than 3 T profiles the results from the quantitative analyses suggest that average cortical profiles computed from T1-weighted scans acquired at 3 T indeed contain myeloarchitectural information similar to profiles computed from the scans acquired at 7 T. The proposed method therefore provides a step forward to study cortical myeloarchitecture in vivo at conventional magnetic field strength both in health and disease.

  16. Dark Matter

    ERIC Educational Resources Information Center

    Lincoln, Don

    2013-01-01

    It's a dark, dark universe out there, and I don't mean because the night sky is black. After all, once you leave the shadow of the Earth and get out into space, you're surrounded by countless lights glittering everywhere you look. But for all of Sagan's billions and billions of stars and galaxies, it's a jaw-dropping fact that the ordinary kind of…

  17. Supersymmetric Dark Matter after LHC Run 1

    DOE PAGES

    Bagnaschi, E. A.; Buchmueller, O.; Cavanaugh, R.; ...

    2015-10-23

    Different mechanisms operate in various regions of the MSSM parameter space to bring the relic density of the lightest neutralino, χ ~0 1, assumed here to be the lightest SUSY particle (LSP) and thus the dark matter (DM) particle, into the range allowed by astrophysics and cosmology. These mechanisms include coannihilation with some nearly degenerate next-to-lightest supersymmetric particle such as the lighter stau τ ~ 1, stop t ~ 1 or chargino χ ~± 1, resonant annihilation via direct-channel heavy Higgs bosons H / A, the light Higgs boson h or the Z boson, and enhanced annihilation via a largermore » Higgsino component of the LSP in the focus-point region. These mechanisms typically select lower-dimensional subspaces in MSSM scenarios such as the CMSSM, NUHM1, NUHM2, and pMSSM10. We analyze how future LHC and direct DM searches can complement each other in the exploration of the different DM mechanisms within these scenarios. We find that the τ~1 coannihilation regions of the CMSSM, NUHM1, NUHM2 can largely be explored at the LHC via searches for /E T events and long-lived charged particles, whereas theirH / A funnel, focus-point and χ ~± 1 coannihilation regions can largely be explored by the LZ and Darwin DM direct detection experiments. Furthermore, we find that the dominant DM mechanism in our pMSSM10 analysis is χ ~ ±1 coannihilation: parts of its parameter space can be explored by the LHC, and a larger portion by future direct DM searches.« less

  18. SU-F-R-35: Repeatability of Texture Features in T1- and T2-Weighted MR Images

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mahon, R; Weiss, E; Karki, K

    Purpose: To evaluate repeatability of lung tumor texture features from inspiration/expiration MR image pairs for potential use in patient specific care models and applications. Repeatability is a desirable and necessary characteristic of features included in such models. Methods: T1-weighted Volumetric Interpolation Breath-Hold Examination (VIBE) and/or T2-weighted MRI scans were acquired for 15 patients with non-small cell lung cancer before and during radiotherapy for a total of 32 and 34 same session inspiration-expiration breath-hold image pairs respectively. Bias correction was applied to the VIBE (VIBE-BC) and T2-weighted (T2-BC) images. Fifty-nine texture features at five wavelet decomposition ratios were extracted from themore » delineated primary tumor including: histogram(HIST), gray level co-occurrence matrix(GLCM), gray level run length matrix(GLRLM), gray level size zone matrix(GLSZM), and neighborhood gray tone different matrix (NGTDM) based features. Repeatability of the texture features for VIBE, VIBE-BC, T2-weighted, and T2-BC image pairs was evaluated by the concordance correlation coefficient (CCC) between corresponding image pairs, with a value greater than 0.90 indicating repeatability. Results: For the VIBE image pairs, the percentage of repeatable texture features by wavelet ratio was between 20% and 24% of the 59 extracted features; the T2-weighted image pairs exhibited repeatability in the range of 44–49%. The percentage dropped to 10–20% for the VIBE-BC images, and 12–14% for the T2-BC images. In addition, five texture features were found to be repeatable in all four image sets including two GLRLM, two GLZSM, and one NGTDN features. No single texture feature category was repeatable among all three image types; however, certain categories performed more consistently on a per image type basis. Conclusion: We identified repeatable texture features on T1- and T2-weighted MRI scans. These texture features should be further investigated

  19. Evaluation of the Subscapularis Tendon Tears on 3T Magnetic Resonance Arthrography: Comparison of Diagnostic Performance of T1-Weighted Spectral Presaturation with Inversion-Recovery and T2-Weighted Turbo Spin-Echo Sequences.

    PubMed

    Lee, Hoseok; Ahn, Joong Mo; Kang, Yusuhn; Oh, Joo Han; Lee, Eugene; Lee, Joon Woo; Kang, Heung Sik

    2018-01-01

    To compare the T1-weighted spectral presaturation with inversion-recovery sequences (T1 SPIR) with T2-weighted turbo spin-echo sequences (T2 TSE) on 3T magnetic resonance arthrography (MRA) in the evaluation of the subscapularis (SSC) tendon tear with arthroscopic findings as the reference standard. This retrospective study included 120 consecutive patients who had undergone MRA within 3 months between April and December 2015. Two musculoskeletal radiologists blinded to the arthroscopic results evaluated T1 SPIR and T2 TSE images in separate sessions for the integrity of the SSC tendon, examining normal/articular-surface partial-thickness tear (PTTa)/full-thickness tear (FTT). Diagnostic performance of T1 SPIR and T2 TSE was calculated with arthroscopic results as the reference standard, and sensitivity, specificity, and accuracy were compared using the McNemar test. Interobserver agreement was measured with kappa (κ) statistics. There were 74 SSC tendon tears (36 PTTa and 38 FTT) confirmed by arthroscopy. Significant differences were found in the sensitivity and accuracy between T1 SPIR and T2 TSE using the McNemar test, with respective rates of 95.9-94.6% vs. 71.6-75.7% and 90.8-91.7% vs. 79.2-83.3% for detecting tear; 55.3% vs. 31.6-34.2% and 85.8% vs. 78.3-79.2%, respectively, for FTT; and 91.7-97.2% vs. 58.3-61.1% and 89% vs. 78-79.3%, respectively, for PTTa. Interobserver agreement for T1 SPIR was almost perfect for T1 SPIR (κ = 0.839) and substantial for T2 TSE (κ = 0.769). T1-weighted spectral presaturation with inversion-recovery sequences is more sensitive and accurate compared to T2 TSE in detecting SSC tendon tear on 3T MRA.

  20. Dark chocolate or tomato extract for prehypertension: a randomised controlled trial.

    PubMed

    Ried, Karin; Frank, Oliver R; Stocks, Nigel P

    2009-07-08

    Flavanol-rich chocolate and lycopene-rich tomato extract have attracted interest as potential alternative treatment options for hypertension, a known risk factor for cardiovascular morbidity and mortality. Treatment of prehypertension (SBP 120-139/DBP 80-89 mmHg) may forestall progression to hypertension. However, there has been only limited research into non-pharmacological treatment options for prehypertension. We investigated the effect of dark chocolate or tomato extract on blood pressure, and their acceptability as an ongoing treatment option in a prehypertensive population. Our trial consisted of two phases: a randomised controlled three-group-parallel trial over 12 weeks (phase 1) followed by a crossover of the two active treatment arms over an additional 12-week period (phase 2). Group 1 received a 50 g daily dose of dark chocolate with 70% cocoa containing 750 mg polyphenols, group 2 were allocated one tomato extract capsule containing 15 mg lycopene per day, and group 3 received one placebo capsule daily over 8 weeks followed by a 4-week washout period. In phase 2 the active treatment groups were crossed over to receive the alternative treatment. Median blood pressure, weight, and abdominal circumference were measured 4-weekly, and other characteristics including physical activity, general health, energy, mood, and acceptability of treatment were assessed by questionnaire at 0, 8 and 20 weeks. We analysed changes over time using a linear mixed model, and one time point differences using Kruskal-Wallis, Fisher's-Exact, or t-tests. Thirty-six prehypertensive healthy adult volunteers completed the 6-month trial. Blood pressure changes over time within groups and between groups were not significant and independent of treatment. Weight and other characteristics did not change significantly during the trial. However, a marked difference in acceptability between the two treatment forms (chocolate or capsule) was revealed (p < 0.0001). Half of the participants

  1. Dark chocolate or tomato extract for prehypertension: a randomised controlled trial

    PubMed Central

    Ried, Karin; Frank, Oliver R; Stocks, Nigel P

    2009-01-01

    Background Flavanol-rich chocolate and lycopene-rich tomato extract have attracted interest as potential alternative treatment options for hypertension, a known risk factor for cardiovascular morbidity and mortality. Treatment of prehypertension (SBP 120–139/DBP 80–89 mmHg) may forestall progression to hypertension. However, there has been only limited research into non-pharmacological treatment options for prehypertension. We investigated the effect of dark chocolate or tomato extract on blood pressure, and their acceptability as an ongoing treatment option in a prehypertensive population. Methods Our trial consisted of two phases: a randomised controlled three-group-parallel trial over 12 weeks (phase 1) followed by a crossover of the two active treatment arms over an additional 12-week period (phase 2). Group 1 received a 50 g daily dose of dark chocolate with 70% cocoa containing 750 mg polyphenols, group 2 were allocated one tomato extract capsule containing 15 mg lycopene per day, and group 3 received one placebo capsule daily over 8 weeks followed by a 4-week washout period. In phase 2 the active treatment groups were crossed over to receive the alternative treatment. Median blood pressure, weight, and abdominal circumference were measured 4-weekly, and other characteristics including physical activity, general health, energy, mood, and acceptability of treatment were assessed by questionnaire at 0, 8 and 20 weeks. We analysed changes over time using a linear mixed model, and one time point differences using Kruskal-Wallis, Fisher's-Exact, or t-tests. Results Thirty-six prehypertensive healthy adult volunteers completed the 6-month trial. Blood pressure changes over time within groups and between groups were not significant and independent of treatment. Weight and other characteristics did not change significantly during the trial. However, a marked difference in acceptability between the two treatment forms (chocolate or capsule) was revealed (p < 0

  2. Supersymmetric dark matter after LHC run 1

    NASA Astrophysics Data System (ADS)

    Bagnaschi, E. A.; Buchmueller, O.; Cavanaugh, R.; Citron, M.; De Roeck, A.; Dolan, M. J.; Ellis, J. R.; Flächer, H.; Heinemeyer, S.; Isidori, G.; Malik, S.; Martínez Santos, D.; Olive, K. A.; Sakurai, K.; de Vries, K. J.; Weiglein, G.

    2015-10-01

    Different mechanisms operate in various regions of the MSSM parameter space to bring the relic density of the lightest neutralino, tilde{χ }^01, assumed here to be the lightest SUSY particle (LSP) and thus the dark matter (DM) particle, into the range allowed by astrophysics and cosmology. These mechanisms include coannihilation with some nearly degenerate next-to-lightest supersymmetric particle such as the lighter stau tilde{τ }1, stop tilde{t}1 or chargino tilde{χ }^± 1, resonant annihilation via direct-channel heavy Higgs bosons H / A, the light Higgs boson h or the Z boson, and enhanced annihilation via a larger Higgsino component of the LSP in the focus-point region. These mechanisms typically select lower-dimensional subspaces in MSSM scenarios such as the CMSSM, NUHM1, NUHM2, and pMSSM10. We analyze how future LHC and direct DM searches can complement each other in the exploration of the different DM mechanisms within these scenarios. We find that the {tilde{τ }_1} coannihilation regions of the CMSSM, NUHM1, NUHM2 can largely be explored at the LHC via searches for / E_T events and long-lived charged particles, whereas their H / A funnel, focus-point and tilde{χ }^± 1 coannihilation regions can largely be explored by the LZ and Darwin DM direct detection experiments. We find that the dominant DM mechanism in our pMSSM10 analysis is tilde{χ }^± 1 coannihilation: parts of its parameter space can be explored by the LHC, and a larger portion by future direct DM searches.

  3. Foetal blood flow measured using phase contrast cardiovascular magnetic resonance--preliminary data comparing 1.5 T with 3.0 T.

    PubMed

    Tsai-Goodman, Beverly; Zhu, Meng Yuan; Al-Rujaib, Mashael; Seed, Mike; Macgowan, Christopher K

    2015-04-18

    Phase contrast cardiovascular magnetic resonance (PC CMR) has emerged as a clinical tool for blood flow quantification but its use in the foetus has been hampered by the need for gating with the foetal heart beat. The previously described metric optimized gating (MOG) technique has been successfully used to measure foetal blood flow in late gestation foetuses on a 1.5 T CMR magnet. However, there is increasing interest in performing foetal cardiac imaging using 3.0 T CMR. We describe our pilot investigation of foetal blood flow measured using 3.0 T CMR. Foetal blood flows were quantified in 5 subjects at late gestational age (35-38 weeks). Three were normal pregnancies and two were pregnancies with ventricular size discrepancy. Data were obtained at 1.5 T and 3.0 T using a previously described PC CMR protocol. After reconstruction using MOG, blood flow was quantified independently by two observers. Intra- and inter-observer reproducibility of flow measurements at the two field strengths was assessed by Pearson correlation coefficient (R(2)), linear regression and Bland Altman analysis. PC CMR flow measurements were obtained in 36 of 40 target vessels. Strong intra-observer agreement was obtained between measurements at each field strength (R(2) = 0.78, slope = 0.83 ± 0.11), with a mean bias of -1 ml/min/kg and 95% confidence limits of ±71 ml/min/kg. Inter-observer agreement was similarly high for measurements at both 1.5 T (R(2) = 0.86, slope = 0.95 ± 0.13, bias = 6 ± 52 ml/min/kg) and 3.0 T (R(2) = 0.88, slope = 0.94 ± 0.13, bias = 4 ± 47 ml/min/kg). Across all PC CMR measurements, SNR per pixel was expectedly higher at 3.0 T relative to 1.5 T (165 ± 50%). The relative differences in flow measurements between observers were low (range: 4-16%) except for pulmonary blood flow which showed much higher variability at 1.5 T (34%) versus that at 3.0 T (11%). This was attributed to the poorly

  4. Human T-Cell Lymphotropic Virus Types 1 and 2 Seropositivity among Blood Donors at Mbarara Regional Blood Bank, South Western Uganda.

    PubMed

    Uchenna Tweteise, Patience; Natukunda, Bernard; Bazira, Joel

    2016-01-01

    Background. The human T-cell lymphotropic virus types 1 and 2 (HTLV 1/2) are retroviruses associated with different pathologies. HTLV-1 causes adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP); HTLV-2 is not clearly associated with a known clinical disease. Both viruses may be transmitted by whole blood transfusion, from mother to child predominantly through breastfeeding, and by sexual contact. Presently, none of the regional blood banks in Uganda perform routine pretransfusion screening for HTLV. The aim of this study was to determine the prevalence of anti-human T-cell lymphotropic virus types 1/2 (HTLV-1/2) antibodies among blood donors at Mbarara Regional Blood Bank in South Western Uganda. A cross-sectional study was conducted between June 2014 and September 2014. Methodology. Consecutive blood samples of 368 blood donors were screened for anti-HTLV-1/2 antibodies using an enzyme linked immunosorbent assay (ELISA). Samples reactive on a first HTLV-1/2 ELISA were further retested in duplicate using the same ELISA. Of the three hundred and sixty-eight blood donors (229 (62.2%) males and 139 (37.8%) females), only two male donors aged 20 and 21 years were HTLV-1/2 seropositive, representing a prevalence of 0.54%. Conclusion. HTLV-1/2 prevalence is low among blood donors at Mbarara Regional Blood Bank. Studies among other categories of people at risk for HTLV 1/2 infection should be carried out.

  5. The interplay of T1- and T2-relaxation on T1-weighted MRI of hMSCs induced by Gd-DOTA-peptides.

    PubMed

    Cao, Limin; Li, Binbin; Yi, Peiwei; Zhang, Hailu; Dai, Jianwu; Tan, Bo; Deng, Zongwu

    2014-04-01

    Three Gd-DOTA-peptide complexes with different peptide sequence are synthesized and used as T1 contrast agent to label human mesenchymal stem cells (hMSCs) for magnetic resonance imaging study. The peptides include a universal cell penetrating peptide TAT, a linear MSC-specific peptide EM7, and a cyclic MSC-specific peptide CC9. A significant difference in labeling efficacy is observed between the Gd-DOTA-peptides as well as a control Dotarem. All Gd-DOTA-peptides as well as Dotarem induce significant increase in T1 relaxation rate which is in favor of T1-weighted MR imaging. Gd-DOTA-CC9 yields the maximum labeling efficacy but poor T1 contrast enhancement. Gd-DOTA-EM7 yields the minimum labeling efficacy but better T1 contrast enhancement. Gd-DOTA-TAT yields a similar labeling efficacy as Gd-DOTA-CC9 and similar T1 contrast enhancement as Gd-DOTA-EM7. The underlying mechanism that governs T1 contrast enhancement effect is discussed. Our results suggest that T1 contrast enhancement induced by Gd-DOTA-peptides depends not only on the introduced cellular Gd content, but more importantly on the effect that Gd-DOTA-peptides exert on the T1-relaxation and T2-relaxation processes/rates. Both T1 and particularly T2 relaxation rate have to be taken into account to interpret T1 contrast enhancement. In addition, the interpretation has to be based on cellular instead of aqueous longitudinal and transverse relaxivities of Gd-DOTA-peptides. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. [Parametrial infiltration of cervix carcinoma: diagnostic value of contrast-enhanced fat-suppressed T1-weighted SE sequences at 1.5 tesla].

    PubMed

    Scheidler, J; Heuck, A; Wencke, K; Kimmig, R; Müller-Lisse, U; Reiser, M

    1997-04-01

    To determine whether contrast-enhanced and fat-suppressed sequences contribute to the MR imaging diagnosis of parametrial invasion. 21 patients with carcinoma of the cervix were prospectively examined with a phased-array coil and a 1.5T MR-scanner using the following sequences: transverse T2-weighted turbo spin echo (T2-TSE), T1-weighted spin echo (T1-SE) and fat suppressed T1-weighted SE sequences before and after Gd-DTPA. The sequences were evaluated separately for the presence of parametrial invasion. Image quality and diagnostic confidence were classified on a scale of 0-10 (nondiagnostic-excellent). Findings were compared to the results of the pathohistological examination. Sensitivity, specificity and diagnostic accuracy were highest for T2-TSE sequences (100%, 79% and 86%, respectively). Contrast-enhanced T1-SE sequences with fat-suppression (71%, 79%, and 76%) showed no improvement compared to T2-TSE. Unenhanced fat-suppressed T1-SE (100%, 30%, and 56%) and unenhanced T1-SE (100%, 7%, and 38%) as well as contrast-enhanced T1-SE (86%, 20%, and 47%) were significantly worse than T2-TSE. With similar image quality (p < 0.05) diagnostic confidence was higher on T2-TSE than on any of the other sequences (p < 0.001). Considering the cost-effectiveness of the examination, for the MR diagnosis of parametrial invasion the use of fat-suppressed contrast-enhanced sequences can be abandoned in favour of T2-weighted TSE sequences.

  7. T1 weighted brain images at 7 Tesla unbiased for Proton Density, T2* contrast and RF coil receive B1 sensitivity with simultaneous vessel visualization.

    PubMed

    Van de Moortele, Pierre-François; Auerbach, Edwards J; Olman, Cheryl; Yacoub, Essa; Uğurbil, Kâmil; Moeller, Steen

    2009-06-01

    At high magnetic field, MR images exhibit large, undesirable signal intensity variations commonly referred to as "intensity field bias". Such inhomogeneities mostly originate from heterogeneous RF coil B(1) profiles and, with no appropriate correction, are further pronounced when utilizing rooted sum of square reconstruction with receive coil arrays. These artifacts can significantly alter whole brain high resolution T(1)-weighted (T(1)w) images that are extensively utilized for clinical diagnosis, for gray/white matter segmentation as well as for coregistration with functional time series. In T(1) weighted 3D-MPRAGE sequences, it is possible to preserve a bulk amount of T(1) contrast through space by using adiabatic inversion RF pulses that are insensitive to transmit B(1) variations above a minimum threshold. However, large intensity variations persist in the images, which are significantly more difficult to address at very high field where RF coil B(1) profiles become more heterogeneous. Another characteristic of T(1)w MPRAGE sequences is their intrinsic sensitivity to Proton Density and T(2)(*) contrast, which cannot be removed with post-processing algorithms utilized to correct for receive coil sensitivity. In this paper, we demonstrate a simple technique capable of producing normalized, high resolution T(1)w 3D-MPRAGE images that are devoid of receive coil sensitivity, Proton Density and T(2)(*) contrast. These images, which are suitable for routinely obtaining whole brain tissue segmentation at 7 T, provide higher T(1) contrast specificity than standard MPRAGE acquisitions. Our results show that removing the Proton Density component can help in identifying small brain structures and that T(2)(*) induced artifacts can be removed from the images. The resulting unbiased T(1)w images can also be used to generate Maximum Intensity Projection angiograms, without additional data acquisition, that are inherently registered with T(1)w structural images. In addition

  8. Light dark Higgs boson in minimal sub-GeV dark matter scenarios

    NASA Astrophysics Data System (ADS)

    Darmé, Luc; Rao, Soumya; Roszkowski, Leszek

    2018-03-01

    Minimal scenarios with light (sub-GeV) dark matter whose relic density is obtained from thermal freeze-out must include new light mediators. In particular, a very well-motivated case is that of a new "dark" massive vector gauge boson mediator. The mass term for such mediator is most naturally obtained by a "dark Higgs mechanism" which leads to the presence of an often long-lived dark Higgs boson whose mass scale is the same as that of the mediator. We study the phenomenology and experimental constraints on two minimal, self-consistent dark sectors that include such a light dark Higgs boson. In one the dark matter is a pseudo-Dirac fermion, in the other a complex scalar. We find that the constraints from BBN and CMB are considerably relaxed in the framework of such minimal dark sectors. We present detection prospects for the dark Higgs boson in existing and projected proton beam-dump experiments. We show that future searches at experiments like Xenon1T or LDMX can probe all the relevant parameter space, complementing the various upcoming indirect constraints from astrophysical observations.

  9. T1 weighted Brain Images at 7 Tesla Unbiased for Proton Density, T2* contrast and RF Coil Receive B1 Sensitivity with Simultaneous Vessel Visualization

    PubMed Central

    Van de Moortele, Pierre-François; Auerbach, Edwards J.; Olman, Cheryl; Yacoub, Essa; Uğurbil, Kâmil; Moeller, Steen

    2009-01-01

    At high magnetic field, MR images exhibit large, undesirable signal intensity variations commonly referred to as “intensity field bias”. Such inhomogeneities mostly originate from heterogeneous RF coil B1 profiles and, with no appropriate correction, are further pronounced when utilizing rooted sum of square reconstruction with receive coil arrays. These artifacts can significantly alter whole brain high resolution T1-weighted (T1w) images that are extensively utilized for clinical diagnosis, for gray/white matter segmentation as well as for coregistration with functional time series. In T1 weighted 3D-MPRAGE sequences, it is possible to preserve a bulk amount of T1 contrast through space by using adiabatic inversion RF pulses that are insensitive to transmit B1 variations above a minimum threshold. However, large intensity variations persist in the images, which are significantly more difficult to address at very high field where RF coil B1 profiles become more heterogeneous. Another characteristic of T1w MPRAGE sequences is their intrinsic sensitivity to Proton Density and T2* contrast, which cannot be removed with post-processing algorithms utilized to correct for receive coil sensitivity. In this paper, we demonstrate a simple technique capable of producing normalized, high resolution T1w 3D-MPRAGE images that are devoid of receive coil sensitivity, Proton Density and T2* contrast. These images, which are suitable for routinely obtaining whole brain tissue segmentation at 7 Tesla, provide higher T1 contrast specificity than standard MPRAGE acquisitions. Our results show that removing the Proton Density component can help identifying small brain structures and that T2* induced artifacts can be removed from the images. The resulting unbiased T1w images can also be used to generate Maximum Intensity Projection angiograms, without additional data acquisition, that are inherently registered with T1w structural images. In addition, we introduce a simple technique

  10. On a product-type operator from weighted Bergman-Orlicz space to some weighted type spaces.

    PubMed

    Jiang, Zhi-Jie

    2015-04-01

    Let [Formula: see text] be the open unit disk, [Formula: see text] an analytic self-map of [Formula: see text] and [Formula: see text] an analytic function on [Formula: see text]. Let D be the differentiation operator and [Formula: see text] the weighted composition operator. The boundedness and compactness of the product-type operator [Formula: see text] from the weighted Bergman-Orlicz space to the Bers type space, weighted Bloch space and weighted Zygmund space on [Formula: see text] are characterized.

  11. 3D T2-weighted and Gd-EOB-DTPA-enhanced 3D T1-weighted MR cholangiography for evaluation of biliary anatomy in living liver donors.

    PubMed

    Cai, Larry; Yeh, Benjamin M; Westphalen, Antonio C; Roberts, John; Wang, Zhen J

    2017-03-01

    To investigate whether the addition of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced 3D T1-weighted MR cholangiography (T1w-MRC) to 3D T2-weighted MRC (T2w-MRC) improves the confidence and diagnostic accuracy of biliary anatomy in living liver donors. Two abdominal radiologists retrospectively and independently reviewed pre-operative MR studies in 58 consecutive living liver donors. The second-order bile duct visualization on T1w- and T2w-MRC images was rated on a 4-point scale. The readers also independently recorded the biliary anatomy and their diagnostic confidence using (1) combined T1w- and T2w-MRC, and (2) T2w-MRC. In the 23 right lobe donors, the biliary anatomy at imaging and the imaging-predicted number of duct orifices at surgery were compared to intra-operative findings. T1w-MRC had a higher proportion of excellent visualization than T2w-MRC, 66% vs. 45% for reader 1 and 60% vs. 31% for reader 2. The median confidence score for biliary anatomy diagnosis was significantly higher with combined T1w- and T2w-MRC than T2w-MRC alone for both readers (Reader 1: 3 vs. 2, p < 0.001; Reader 2: 3 vs. 1, p < 0.001). Compared to intra-operative findings, the accuracy of imaging-predicted number of duct orifices using combined T1w-and T2w-MRC was significantly higher than that using T2w-MRC alone (p = 0.034 for reader 1, p = 0.0082 for reader 2). The addition of Gd-EOB-DTPA-enhanced 3D T1w-MRC to 3D T2w-MRC improves second-order bile duct visualization and increases the confidence in biliary anatomy diagnosis and the accuracy in the imaging-predicted number of duct orifices acquired during right lobe harvesting.

  12. Dark chocolate and reduced snack consumption in mildly hypertensive adults: an intervention study.

    PubMed

    Koli, Raika; Köhler, Klaus; Tonteri, Elina; Peltonen, Juha; Tikkanen, Heikki; Fogelholm, Mikael

    2015-08-22

    Several studies have shown that cocoa and cocoa-containing foods have the potential to lower blood pressure and improve endothelial function. Most of the studies reporting the beneficial effects of dark chocolate on blood pressure have been short (≤ 4 weeks). The aim of the present 8-wks (weeks) study was to assess the effects of regular consumption of dark chocolate during a reduced snack consumption intervention on blood pressure and other cardiovascular risk factors in mildly hypertensive individuals. This was a randomized, controlled, cross-over trial involving 22 adults (8 women, 14 men), aged 33-64 y, BMI 27.7 ± 3.7 kg/m(2) with mild hypertension. During the intervention period (8-wks) the participants reduced the intake of habitual snacks and replaced them with dark chocolate (49 g/day). In the control period, they only reduced the snacks without any added chocolate. Data (blood lipid profile, glucose, insulin, 24 h blood pressure) was collected in the beginning and end of both periods (intervention and control), and some variables also in the run-in and run-out periods (weight, body fat percentage, blood pressure, arterial stiffness index, diet and physical activity). Daily consumption of dark chocolate had no effects on 24 h blood pressure, resting blood pressure (mean ± SD, pre 142 ± 11.5/89 ± 8.4 mmHg vs. post 142 ± 14.2/88 ± 9.4 mmHg in systolic and diastolic blood pressure, respectively) or arterial stiffness (mean ± SD, pre 7.68 ± 0.88 vs. post 7.76 ± 0.89). Weight was reduced by 1.0 ± 2.2 kg during the control (reduced snack only) period, but was unchanged while eating chocolate (p < 0.027 between the treatments). The data collected in this study indicates that inclusion of dark chocolate daily in the diet had no significant effects on blood pressure or other cardiovascular risk factors during a reduced snack period. ClinicalTrials.gov identifier NCT02130141.

  13. Contrast-enhanced Magnetic Resonance Imaging of Pelvic Bone Metastases at 3.0 T: Comparison Between 3-dimensional T1-weighted CAIPIRINHA-VIBE Sequence and 2-dimensional T1-weighted Turbo Spin-Echo Sequence.

    PubMed

    Yoon, Min A; Hong, Suk-Joo; Lee, Kyu-Chong; Lee, Chang Hee

    2018-06-12

    This study aimed to compare 3-dimensional T1-weighted gradient-echo sequence (CAIPIRINHA-volumetric interpolated breath-hold examination [VIBE]) with 2-dimensional T1-weighted turbo spin-echo sequence for contrast-enhanced magnetic resonance imaging (MRI) of pelvic bone metastases at 3.0 T. Thirty-one contrast-enhanced MRIs of pelvic bone metastases were included. Two contrast-enhanced sequences were evaluated for the following parameters: overall image quality, sharpness of pelvic bone, iliac vessel clarity, artifact severity, and conspicuity and edge sharpness of the smallest metastases. Quantitative analysis was performed by calculating signal-to-noise ratio and contrast-to-noise ratio of the smallest metastases. Significant differences between the 2 sequences were assessed. CAIPIRINHA-VIBE had higher scores for overall image quality, pelvic bone sharpness, iliac vessel clarity, and edge sharpness of the metastatic lesions, and had less artifacts (all P < 0.05). There was no significant difference in conspicuity, signal-to-noise ratio, or contrast-to-noise ratio of the smallest metastases (P > 0.05). Our results suggest that CAIPIRINHA-VIBE may be superior to turbo spin-echo for contrast-enhanced MRI of pelvic bone metastases at 3.0 T.

  14. Evaluation of neonatal brain myelination using the T1- and T2-weighted MRI ratio.

    PubMed

    Soun, Jennifer E; Liu, Michael Z; Cauley, Keith A; Grinband, Jack

    2017-09-01

    To validate the T1- and T2-weighted (T1w/T2w) MRI ratio technique in evaluating myelin in the neonatal brain. T1w and T2w MR images of 10 term neonates with normal-appearing brain parenchyma were obtained from a single 1.5 Tesla MRI and retrospectively analyzed. T1w/T2w ratio images were created with a postprocessing pipeline and qualitatively compared with standard clinical sequences (T1w, T2w, and apparent diffusion coefficient [ADC]). Quantitative assessment was also performed to assess the ratio technique in detecting areas of known myelination (e.g., posterior limb of the internal capsule) and very low myelination (e.g., optic radiations) using linear regression analysis and the Michelson Contrast equation, a measure of luminance contrast intensity. The ratio image provided qualitative improvements in the ability to visualize regional variation in myelin content of neonates. Linear regression analysis demonstrated a significant inverse relationship between the ratio intensity values and ADC values in the posterior limb of the internal capsule and the optic radiations (R 2  = 0.96 and P < 0.001). The Michelson Contrast equation showed that contrast differences between these two regions for the ratio images were 1.6 times higher than T1w, 2.6 times higher than T2w, and 1.8 times higher than ADC (all P < 0.001). Finally, the ratio improved visualization of the corticospinal tract, one of the earliest myelinated pathways. The T1w/T2w ratio accentuates contrast between myelinated and less myelinated structures and may enhance our diagnostic ability to detect myelination patterns in the neonatal brain. 2 Technical Efficacy: Stage2 J. MAGN. RESON. IMAGING 2017;46:690-696. © 2016 International Society for Magnetic Resonance in Medicine.

  15. Space shuttle: Aerodynamic characteristics of various MDAC space shuttle ascent configurations with parallel burn pressure-fed and SRM boosters. Volume 1: Tanks T1 and T2 ascent configurations

    NASA Technical Reports Server (NTRS)

    Jarrett, T. W.

    1972-01-01

    Various space shuttle ascent configurations were tested in a trisonic wind tunnel to determine the aerodynamic characteristics. The ascent configuration consisted of a NASA/MSC 040 orbiter in combination with various HO centerline tank and booster geometries. The aerodynamic interference between components of the space shuttle and the effect on the orbiter aerodynamics was determined. The various aerodynamic configurations tested were: (1) centerline HO tanks T1 and T2, (2) centerline HO tank T3, and (3) centerline HO tank H4.

  16. High-resolution in vivo Wistar rodent brain atlas based on T1 weighted image

    NASA Astrophysics Data System (ADS)

    Huang, Su; Lu, Zhongkang; Huang, Weimin; Seramani, Sankar; Ramasamy, Boominathan; Sekar, Sakthivel; Guan, Cuntai; Bhakoo, Kishore

    2016-03-01

    Image based atlases for rats brain have a significant impact on pre-clinical research. In this project we acquired T1-weighted images from Wistar rodent brains with fine 59μm isotropical resolution for generation of the atlas template image. By applying post-process procedures using a semi-automatic brain extraction method, we delineated the brain tissues from source data. Furthermore, we applied a symmetric group-wise normalization method to generate an optimized template of T1 image of rodent brain, then aligned our template to the Waxholm Space. In addition, we defined several simple and explicit landmarks to corresponding our template with the well known Paxinos stereotaxic reference system. Anchoring at the origin of the Waxholm Space, we applied piece-wise linear transformation method to map the voxels of the template into the coordinates system in Paxinos' stereotoxic coordinates to facilitate the labelling task. We also cross-referenced our data with both published rodent brain atlas and image atlases available online, methodologically labelling the template to produce a Wistar brain atlas identifying more than 130 structures. Particular attention was paid to the cortex and cerebellum, as these areas encompass the most researched aspects of brain functions. Moreover, we adopted the structure hierarchy and naming nomenclature common to various atlases, so that the names and hierarchy structure presented in the atlas are readily recognised for easy use. It is believed the atlas will present a useful tool in rodent brain functional and pharmaceutical studies.

  17. Advantages of T2 Weighted Three Dimensional and T1 Weighted Three Dimensional Contrast Medium Enhanced Magnetic Resonance Urography in Examination of the Child Population.

    PubMed

    Sehic, Adnan; Julardzija, Fuad; Vegar-Zubovic, Sandra; Sefic-Pasic, Irmina

    2017-03-01

    The aim of this study is to prove the advantages of combined use of T2 weighted three dimensional (T2 W 3D) and T1 weighted three dimensional contrast medium enhanced (T1 W 3D CE) magnetic resonance (MR) urography in displaying urinary tract in child population. Total of 120 patients were included in the study, 71 (59%) male patients and 49 (41%) female patients. The study was conducted on the Radiology clinic, University of Sarajevo Clinical Center, during the period from February to November 2016. Patients were examined on the 1.5T and 3T MRI, with standard protocol which includes T2 W 3D and T1 W 3D contrast medium enhanced MR urography. In the post procesing quantitative measurement of signal intensity and evaluation of the display quality in the area of renal pelvis, middle of ureter and the mouth of the ureter were done. Measurement was concluded on Syngo software B13. Analyzing the acquired data and statistically processing them we got results which have shown higher signal intensity of measured structures on T1 W 3D contrast medium enhanced MR urography on the level p<0.01 and p<0.05 compared to T2 W 3D MR urography in patients that had normal dynamics of contrast medium secretion. However, in kidneys with decreased function, T2 W 3D MR urography provided higher signal intensity and better display compared to T1 W 3D contrast medium enhanced MR urography on the level p<0.05 and p<0.01. T2 W3D MR urography is useful in imaging nonfunctional kidney as well as in patients prone to allergic reactions, where as T1 W3D CE MR urography is at an advantage over T2 W 3D MR urography in imaging the kidney functionality, kidney dynamics measurement, it provides higher MRI signal intensity required for clear 3D reconstructions.

  18. Contrasting weight changes with LY2605541, a novel long-acting insulin, and insulin glargine despite similar improved glycaemic control in T1DM and T2DM.

    PubMed

    Jacober, S J; Rosenstock, J; Bergenstal, R M; Prince, M J; Qu, Y; Beals, J M

    2014-04-01

    The basal insulin analogue LY2605541, a PEGylated insulin lispro with prolonged duration of action, was previously shown to be associated with modest weight loss in Phase 2, randomized, open-label trials in type 2 (N=288) and type 1 (N=137) diabetes mellitus (T2DM and T1DM), compared with modest weight gain with insulin glargine. Exploratory analyses were conducted to further characterize these findings. Pearson correlations between change in body weight and other variables were calculated. Continuous variables were analysed using a mixed linear model with repeated measurements. Proportions of subjects with weight loss were analysed using Fisher's exact test for T2DM and Nagelkerke's method for T1DM. Weight loss was more common in LY2605541-treated patients than in patients treated with insulin glargine (T2DM: 56.9 vs. 40.2%, p=0.011; T1DM: 66.1 vs. 40.3%, p<0.001). More LY2605541-treated patients experienced ≥5% weight loss compared to patients treated with glargine (T2DM: 4.8 vs. 0%, p=0.033; T1DM: 11.9 vs. 0.8%, p<0.001). In both the T1DM and T2DM studies, weight change did not correlate with baseline body mass index (BMI), or change in HDL-cholesterol in either treatment group. No consistent correlations were found across both studies between weight change and any of the variables assessed; however, weight change was significantly correlated with hypoglycaemia rate in glargine-treated T2DM patients. In two Phase 2 trials, improved glycaemic control with long-acting basal insulin analogue LY2605541 is associated with weight loss in previously insulin-treated patients. This weight change is independent of baseline BMI or hypoglycaemia.

  19. Highly automatic quantification of myocardial oedema in patients with acute myocardial infarction using bright blood T2-weighted CMR

    PubMed Central

    2013-01-01

    Background T2-weighted cardiovascular magnetic resonance (CMR) is clinically-useful for imaging the ischemic area-at-risk and amount of salvageable myocardium in patients with acute myocardial infarction (MI). However, to date, quantification of oedema is user-defined and potentially subjective. Methods We describe a highly automatic framework for quantifying myocardial oedema from bright blood T2-weighted CMR in patients with acute MI. Our approach retains user input (i.e. clinical judgment) to confirm the presence of oedema on an image which is then subjected to an automatic analysis. The new method was tested on 25 consecutive acute MI patients who had a CMR within 48 hours of hospital admission. Left ventricular wall boundaries were delineated automatically by variational level set methods followed by automatic detection of myocardial oedema by fitting a Rayleigh-Gaussian mixture statistical model. These data were compared with results from manual segmentation of the left ventricular wall and oedema, the current standard approach. Results The mean perpendicular distances between automatically detected left ventricular boundaries and corresponding manual delineated boundaries were in the range of 1-2 mm. Dice similarity coefficients for agreement (0=no agreement, 1=perfect agreement) between manual delineation and automatic segmentation of the left ventricular wall boundaries and oedema regions were 0.86 and 0.74, respectively. Conclusion Compared to standard manual approaches, the new highly automatic method for estimating myocardial oedema is accurate and straightforward. It has potential as a generic software tool for physicians to use in clinical practice. PMID:23548176

  20. High signal intensity of intervertebral calcified disks on T1-weighted MR images resulting from fat content.

    PubMed

    Malghem, Jacques; Lecouvet, Frédéric E; François, Robert; Vande Berg, Bruno C; Duprez, Thierry; Cosnard, Guy; Maldague, Baudouin E

    2005-02-01

    To explain a cause of high signal intensity on T1-weighted MR images in calcified intervertebral disks associated with spinal fusion. Magnetic resonance and radiological examinations of 13 patients were reviewed, presenting one or several intervertebral disks showing a high signal intensity on T1-weighted MR images, associated both with the presence of calcifications in the disks and with peripheral fusion of the corresponding spinal segments. Fusion was due to ligament ossifications (n=8), ankylosing spondylitis (n=4), or posterior arthrodesis (n=1). Imaging files included X-rays and T1-weighted MR images in all cases, T2-weighted MR images in 12 cases, MR images with fat signal suppression in 7 cases, and a CT scan in 1 case. Histological study of a calcified disk from an anatomical specimen of an ankylosed lumbar spine resulting from ankylosing spondylitis was examined. The signal intensity of the disks was similar to that of the bone marrow or of perivertebral fat both on T1-weighted MR images and on all sequences, including those with fat signal suppression. In one of these disks, a strongly negative absorption coefficient was focally measured by CT scan, suggesting a fatty content. The histological examination of the ankylosed calcified disk revealed the presence of well-differentiated bone tissue and fatty marrow within the disk. The high signal intensity of some calcified intervertebral disks on T1-weighted MR images can result from the presence of fatty marrow, probably related to a disk ossification process in ankylosed spines.

  1. Ultrasmall water-soluble metal-iron oxide nanoparticles as T1-weighted contrast agents for magnetic resonance imaging.

    PubMed

    Zeng, Leyong; Ren, Wenzhi; Zheng, Jianjun; Cui, Ping; Wu, Aiguo

    2012-02-28

    Using an improved hydrolysis method of inorganic salts assisted with water-bath incubation, ultrasmall water-soluble metal-iron oxide nanoparticles (including Fe(3)O(4), ZnFe(2)O(4) and NiFe(2)O(4) nanoparticles) were synthesized in aqueous solutions, which were used as T(1)-weighted contrast agents for magnetic resonance imaging (MRI). The morphology, structure, MRI relaxation properties and cytotoxicity of the as-prepared metal-iron oxide nanoparticles were characterized, respectively. The results showed that the average sizes of nanoparticles were about 4 nm, 4 nm and 5 nm for Fe(3)O(4), ZnFe(2)O(4) and NiFe(2)O(4) nanoparticles, respectively. Moreover, the nanoparticles have good water dispersibility and low cytotoxicity. The MRI test showed the strong T(1)-weighted, but the weak T(2)-weighted MRI performance of metal-iron oxide nanoparticles. The high T(1)-weighted MRI performance can be attributed to the ultrasmall size of metal-iron oxide nanoparticles. Therefore, the as-prepared metal-iron oxide nanoparticles with good water dispersibility and ultrasmall size can have potential applications as T(1)-weighted contrast agent materials for MRI.

  2. T1- or T2-weighted magnetic resonance imaging: what is the best choice to evaluate atrophy of the hippocampus?

    PubMed

    Fischbach-Boulanger, C; Fitsiori, A; Noblet, V; Baloglu, S; Oesterle, H; Draghici, S; Philippi, N; Duron, E; Hanon, O; Dietemann, J-L; Blanc, F; Kremer, S

    2018-05-01

    Magnetic resonance imaging is part of the diagnostic criteria for Alzheimer's disease (AD) through the evaluation of hippocampal atrophy. The objective of this study was to evaluate which sequence of T1-weighted (T1WI) and T2-weighted (T2WI) imaging allowed the best visual evaluation of hippocampal atrophy. Visual qualitative ratings of the hippocampus of 100 patients with mild cognitive impairment (MCI) and 50 patients with AD were made independently by four operators according to the medial temporal lobe atrophy score based either on T1WI or T2WI. These two evaluations were compared in terms of interobserver reproducibility, concordance with a quantitative volumetric measure, discrimination power between AD and MCI groups, and correlation with several neuropsychological tests. The medial temporal lobe atrophy score evaluated on either T1WI or T2WI exhibited similar interobserver variability and accordance with quantitative volumetric evaluation. However, the visual evaluation on T2WI seemed to provide better discrimination power between AD and MCI groups for both left (T1WI, P = 0.0001; T2WI, P = 7.072 × 10 -5 ) and right (T1WI, P = 0.008; T2WI, P = 0.001) hippocampus, and a higher overall correlation with neuropsychological tests. The present study suggests that T2WI provides a more adequate visual rating of hippocampal atrophy. © 2018 EAN.

  3. Hyperintense Dentate Nuclei on T1-Weighted MRI: Relation to Repeat Gadolinium Administration

    PubMed Central

    Adin, M.E.; Kleinberg, L.; Vaidya, D.; Zan, E.; Mirbagheri, S.; Yousem, D.M.

    2016-01-01

    BACKGROUND AND PURPOSE A hyperintense appearance of the dentate nucleus on T1-weighted MR images has been related to various clinical conditions, but the etiology remains indeterminate. We aimed to investigate the possible associations between a hyperintense appearance of the dentate nucleus on T1-weighted MR images in patients exposed to radiation and factors including, but not limited to, the cumulative number of contrast-enhanced MR images, amount of gadolinium administration, dosage of ionizing radiation, and patient demographics. MATERIALS AND METHODS The medical records of 706 consecutive patients who were treated with brain irradiation at The Johns Hopkins Medical Institutions between 1995 and 2010 were blindly reviewed by 2 readers. RESULTS One hundred eighty-four subjects were included for dentate nuclei analysis. Among the 184 subjects who cumulatively underwent 2677 MR imaging studies following intravenous gadolinium administration, 103 patients had hyperintense dentate nuclei on precontrast T1-weighted MR images. The average number of gadolinium-enhanced MR imaging studies performed in the group with normal dentate nuclei was significantly lower than that of the group with hyperintense dentate nuclei. The average follow-up time was 62.5 months. No significant difference was observed between hyperintense and normal dentate nuclei groups in terms of exposed radiation dose, serum creatinine and calcium/phosphate levels, patient demographics, history of chemotherapy, and strength of the scanner. No dentate nuclei abnormalities were found on the corresponding CT scans of patients with hyperintense dentate nuclei (n = 44). No dentate nuclei abnormalities were found in 53 healthy volunteers. CONCLUSIONS Repeat performance of gadolinium-enhanced studies likely contributes to a long-standing hyperintense appearance of dentate nuclei on precontrast T1-weighted-MR images. PMID:26294649

  4. "Smart" theranostic lanthanide nanoprobes with simultaneous up-conversion fluorescence and tunable T1-T2 magnetic resonance imaging contrast and near-infrared activated photodynamic therapy.

    PubMed

    Zhang, Yan; Das, Gautom Kumar; Vijayaragavan, Vimalan; Xu, Qing Chi; Padmanabhan, Parasuraman; Bhakoo, Kishore K; Selvan, Subramanian Tamil; Tan, Timothy Thatt Yang

    2014-11-07

    The current work reports a type of "smart" lanthanide-based theranostic nanoprobe, NaDyF4:Yb(3+)/NaGdF4:Yb(3+),Er(3+), which is able to circumvent the up-converting poisoning effect of Dy(3+) ions to give efficient near infrared (980 nm) triggered up-conversion fluorescence, and offers not only excellent dark T2-weighted MR contrast but also tunable bright and T1-weighted MR contrast properties. Due to the efficient up-converted energy transfer from the nanocrystals to chlorin e6 (Ce6) photosensitizers loaded onto the nanocrystals, cytotoxic singlet oxygen was generated and photodynamic therapy was demonstrated. Therefore, the current multifunctional nanocrystals could be potentially useful in various image-guided diagnoses where bright or dark MRI contrast could be selectively tuned to optimize image quality, but also as an efficient and more penetrative near-infrared activated photodynamic therapy agent.

  5. No effect of weight loss on LINE-1 methylation levels in peripheral blood leukocytes from postmenopausal overweight women.

    PubMed

    Duggan, Catherine; Xiao, Liren; Terry, Mary Beth; McTiernan, Anne

    2014-09-01

    Obesity and weight-loss are associated with methylation patterns in specific genes, but their effect on Long Interspersed Nuclear Elements (LINE-1) methylation, a measure of global methylation is largely unknown. Three hundred overweight/obese post-menopausal women (50-75 years) were part of a completed, 1-year randomized controlled trial, comparing independent and combined effects of a reduced-calorie weight-loss diet, and exercise program, versus control. DNA was extracted from peripheral blood leukocytes collected at baseline and 12-months, and LINE-1 methylation analyzed by pyrosequencing. Mean changes between groups using generalized estimating equations and examined effects of weight-loss on LINE-1 methylation using stratified analyses (gained weight/no weight-loss [N = 84]; <5% [N = 45]; 5%-10% [N = 45]; >10% of baseline weight-loss [N = 126]) within each arm, adjusted by blood cell counts were compared. Associations between LINE-1 methylation and previously measured biomarkers, and anthropometrics were also examined. No significant difference in LINE-1 methylation levels was detected in any intervention group versus controls. The magnitude of weight-loss was not associated with LINE-1 methylation at 12-months. There were no associations between baseline characteristics of participants, or previously measured biomarkers, and LINE-1 methylation. Our results suggest that lifestyle changes sufficient to significantly reduce weight over 12-months may not change LINE-1 DNA methylation levels. © 2014 The Obesity Society.

  6. Magnetic Resonance Imaging in Patients With Mechanical Low Back Pain Using a Novel Rapid-Acquisition Three-Dimensional SPACE Sequence at 1.5-T: A Pilot Study Comparing Lumbar Stenosis Assessment With Routine Two-Dimensional Magnetic Resonance Sequences.

    PubMed

    Swami, Vimarsha G; Katlariwala, Mihir; Dhillon, Sukhvinder; Jibri, Zaid; Jaremko, Jacob L

    2016-11-01

    To minimize the burden of overutilisation of lumbar spine magnetic resonance imaging (MRI) on a resource-constrained public healthcare system, it may be helpful to image some patients with mechanical low-back pain (LBP) using a simplified rapid MRI screening protocol at 1.5-T. A rapid-acquisition 3-dimensional (3D) SPACE (Sampling Perfection with Application-optimized Contrasts using different flip angle Evolution) sequence can demonstrate common etiologies of LBP. We compared lumbar spinal canal stenosis (LSCS) and neural foraminal stenosis (LNFS) assessment on 3D SPACE against conventional 2-dimensional (2D) MRI. We prospectively performed 3D SPACE and 2D spin-echo MRI sequences (axial or sagittal T1-weighted or T2-weighted) at 1.5-T in 20 patients. Two blinded readers assessed levels L3-4, L4-5 and L5-S1 using: 1) morphologic grading systems, 2) global impression on the presence or absence of clinically significant stenosis (n = 60 disc levels for LSCS, n = 120 foramina for LNFS). Reliability statistics were calculated. Acquisition time was ∼5 minutes for SPACE and ∼20 minutes for 2D MRI sequences. Interobserver agreement of LSCS was substantial to near perfect on both sequences (morphologic grading: kappa [k] = 0.71 SPACE, k = 0.69 T2-weighted; global impression: k = 0.85 SPACE, k = 0.78 T2-weighted). LNFS assessment had superior interobserver reliability using SPACE than T1-weighted (k = 0.54 vs 0.37). Intersequence agreement of findings between SPACE and 2D MRI was substantial to near perfect by global impression (LSCS: k = 0.78 Reader 1, k = 0.85 Reader 2; LNFS: k = 0.63 Reader 1, k = 0.66 Reader 2). 3D SPACE was acquired in one-quarter the time as the conventional 2D MRI protocol, had excellent agreement with 2D MRI for stenosis assessment, and had interobserver reliability superior to 2D MRI. These results justify future work to explore the role of 3D SPACE in a rapid MRI screening protocol at 1.5-T for mechanical LBP. Copyright

  7. Tuning the non-covalent confinement of Gd(III) complexes in silica nanoparticles for high T1-weighted MR imaging capability.

    PubMed

    Fedorenko, Svetlana V; Grechkina, Svetlana L; Mustafina, Asiya R; Kholin, Kirill V; Stepanov, Alexey S; Nizameev, Irek R; Ismaev, Ildus E; Kadirov, Marsil K; Zairov, Rustem R; Fattakhova, Alfia N; Amirov, Rustem R; Soloveva, Svetlana E

    2017-01-01

    The present work introduces deliberate synthesis of Gd(III)-doped silica nanoparticles with high relaxivity at magnetic field strengths below 1.5T. Modified microemulsion water-in-oil procedure was used in order to achieve superficial localization of Gd(III) complexes within 40-55nm sized silica spheres. The relaxivities of the prepared nanoparticles were measured at 0.47, 1.41 and 1.5T with the use of both NMR analyzer and whole body NMR scanner. Longitudinal relaxivities of the obtained silica nanoparticles reveal significant dependence on the confinement mode, changing from 4.1 to 49.6mM -1 s -1 at 0.47T when the localization of Gd(III) complexes changes from core to superficial zones of the silica spheres. The results highlight predominant contribution of the complexes located close to silica/water interface to the relaxivity of the nanoparticles. Low effect of blood proteins on the relaxivity in the aqueous colloids of the nanoparticles was exemplified by serum bovine albumin. T 1 - weighted MRI data indicate that the nanoparticles provide strong positive contrast at 1.5T, which along with low cytotoxicity effect make a good basis for their application as contrast agents. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Top-philic dark matter within and beyond the WIMP paradigm

    NASA Astrophysics Data System (ADS)

    Garny, Mathias; Heisig, Jan; Hufnagel, Marco; Lülf, Benedikt

    2018-04-01

    We present a comprehensive analysis of top-philic Majorana dark matter that interacts via a colored t -channel mediator. Despite the simplicity of the model—introducing three parameters only—it provides an extremely rich phenomenology allowing us to accommodate the relic density for a large range of coupling strengths spanning over 6 orders of magnitude. This model features all "exceptional" mechanisms for dark matter freeze-out, including the recently discovered conversion-driven freeze-out mode, with interesting signatures of long-lived colored particles at colliders. We constrain the cosmologically allowed parameter space with current experimental limits from direct, indirect and collider searches, with special emphasis on light dark matter below the top mass. In particular, we explore the interplay between limits from Xenon1T, Fermi-LAT and AMS-02 as well as limits from stop, monojet and Higgs invisible decay searches at the LHC. We find that several blind spots for light dark matter evade current constraints. The region in parameter space where the relic density is set by the mechanism of conversion-driven freeze-out can be conclusively tested by R -hadron searches at the LHC with 300 fb-1 .

  9. Diagnostic value of brain chronic black holes on T1-weighted MR images in clinically isolated syndromes.

    PubMed

    Mitjana, Raquel; Tintoré, Mar; Rocca, Maria A; Auger, Cristina; Barkhof, Frederik; Filippi, Massimo; Polman, Chris; Fazekas, Franz; Huerga, Elena; Montalban, Xavier; Rovira, Alex

    2014-10-01

    Non-enhancing black holes (neBHs) are more common in multiple sclerosis (MS) patients with longer disease durations and progressive disease subtypes. Our aim was to analyse the added value of neBHs in patients with clinically isolated syndromes (CISs) for predicting conversion to clinically definite MS (CDMS). Patients were classified based on the presence or absence of neBHs and on the number of Barkhof-Tintoré (B-T) criteria fulfilled. Dissemination in space (DIS) was defined as the presence of at least three of the four B-T criteria. Dissemination in time (DIT)1 was defined by simultaneous presence of enhancing and non-enhancing lesions. DIT2 was defined by simultaneous presence of neBHs and T2 lesions not apparent on T1-weighted images. Focal T2-hyperintense brain lesions were identified in 87.7% of the 520 CIS patients, and 41.4% of them presented at least one neBH. Patients meeting DIS, DIT1, and DIT2 had a significantly higher rate of conversion to CDMS. After adjusting for DIS, only patients who fulfilled DIT1 preserved a significant increase in CDMS conversion. Non-enhancing black holes in CIS patients are associated with a higher risk of conversion to CDMS. However, the predictive value of this finding is lost when added to the DIS criteria. © The Author(s) 2014.

  10. Energy weighted x-ray dark-field imaging.

    PubMed

    Pelzer, Georg; Zang, Andrea; Anton, Gisela; Bayer, Florian; Horn, Florian; Kraus, Manuel; Rieger, Jens; Ritter, Andre; Wandner, Johannes; Weber, Thomas; Fauler, Alex; Fiederle, Michael; Wong, Winnie S; Campbell, Michael; Meiser, Jan; Meyer, Pascal; Mohr, Jürgen; Michel, Thilo

    2014-10-06

    The dark-field image obtained in grating-based x-ray phase-contrast imaging can provide information about the objects' microstructures on a scale smaller than the pixel size even with low geometric magnification. In this publication we demonstrate that the dark-field image quality can be enhanced with an energy-resolving pixel detector. Energy-resolved x-ray dark-field images were acquired with a 16-energy-channel photon-counting pixel detector with a 1 mm thick CdTe sensor in a Talbot-Lau x-ray interferometer. A method for contrast-noise-ratio (CNR) enhancement is proposed and validated experimentally. In measurements, a CNR improvement by a factor of 1.14 was obtained. This is equivalent to a possible radiation dose reduction of 23%.

  11. Flavonoid-rich dark chocolate improves endothelial function and increases plasma epicatechin concentrations in healthy adults.

    PubMed

    Engler, Mary B; Engler, Marguerite M; Chen, Chung Y; Malloy, Mary J; Browne, Amanda; Chiu, Elisa Y; Kwak, Ho-Kyung; Milbury, Paul; Paul, Steven M; Blumberg, Jeffrey; Mietus-Snyder, Michele L

    2004-06-01

    Dark chocolate derived from the plant (Theobroma cacao) is a rich source of flavonoids. Cardioprotective effects including antioxidant properties, inhibition of platelet activity, and activation of endothelial nitric oxide synthase have been ascribed to the cocoa flavonoids. To investigate the effects of flavonoid-rich dark chocolate on endothelial function, measures of oxidative stress, blood lipids, and blood pressure in healthy adult subjects. The study was a randomized, double-blind, placebo-controlled design conducted over a 2 week period in 21 healthy adult subjects. Subjects were randomly assigned to daily intake of high-flavonoid (213 mg procyanidins, 46 mg epicatechin) or low-flavonoid dark chocolate bars (46 g, 1.6 oz). High-flavonoid chocolate consumption improved endothelium-dependent flow-mediated dilation (FMD) of the brachial artery (mean change = 1.3 +/- 0.7%) as compared to low-flavonoid chocolate consumption (mean change = -0.96 +/- 0.5%) (p = 0.024). No significant differences were noted in the resistance to LDL oxidation, total antioxidant capacity, 8-isoprostanes, blood pressure, lipid parameters, body weight or body mass index (BMI) between the two groups. Plasma epicatechin concentrations were markedly increased at 2 weeks in the high-flavonoid group (204.4 +/- 18.5 nmol/L, p < or = 0.001) but not in the low-flavonoid group (17.5 +/- 9 nmol/L, p = 0.99). Flavonoid-rich dark chocolate improves endothelial function and is associated with an increase in plasma epicatechin concentrations in healthy adults. No changes in oxidative stress measures, lipid profiles, blood pressure, body weight or BMI were seen.

  12. Dark Energy and Dark Matter as w = -1 Virtual Particles and the World Hologram Model

    NASA Astrophysics Data System (ADS)

    Sarfatti, Jack

    2011-04-01

    The elementary physics battle-tested principles of Lorentz invariance, Einstein equivalence principle and the boson commutation and fermion anti-commutation rules of quantum field theory explain gravitationally repulsive dark energy as virtual bosons and gravitationally attractive dark matter as virtual fermion-antifermion pairs. The small dark energy density in our past light cone is the reciprocal entropy-area of our future light cone's 2D future event horizon in a Novikov consistent loop in time in our accelerating universe. Yakir Aharonov's "back-from-the-future" post-selected final boundary condition is set at our observer-dependent future horizon that also explains why the irreversible thermodynamic arrow of time of is aligned with the accelerating dark energy expansion of the bulk 3D space interior to our future 2D horizon surrounding it as the hologram screen. Seth Lloyd has argued that all 2D horizon surrounding surfaces are pixelated quantum computers projecting interior bulk 3D quanta of volume (Planck area)Sqrt(area of future horizon) as their hologram images in 1-1 correspondence.

  13. T1 vs. T2 weighted magnetic resonance imaging to assess total kidney volume in patients with autosomal dominant polycystic kidney disease.

    PubMed

    van Gastel, Maatje D A; Messchendorp, A Lianne; Kappert, Peter; Kaatee, Merel A; de Jong, Marissa; Renken, Remco J; Ter Horst, Gert J; Mahesh, Shekar V K; Gansevoort, Ron T

    2018-05-01

    In ADPKD patients total kidney volume (TKV) measurement using MRI is performed to predict rate of disease progression. Historically T1 weighted images (T1) were used, but the methodology of T2 weighted imaging (T2) has evolved. We compared the performance of both sequences. 40 ADPKD patients underwent an abdominal MRI at baseline and follow-up. TKV was measured by manual tracing with Analyze Direct 11.0 software. Three readers established intra- and interreader coefficients of variation (CV). T1 and T2 measured kidney volumes and growth rates were compared with ICC and Bland-Altman analyses. Participants were 49.7 ± 7.0 years of age, 55.0% female, with estimated GFR of 50.1 ± 11.5 mL/min/1.73 m 2 . CVs were low and comparable for T2 and T1 (intrareader: 0.83% [0.48-1.79] vs. 1.15% [0.34-1.77], P = 0.9, interreader: 2.18% [1.59-2.61] vs. 1.69% [1.07-3.87], P = 0.9). TKV was clinically similar, but statistically significantly different between T2 and T1: 1867 [1172-2721] vs. 1932 [1180-2551] mL, respectively (P = 0.006), with a bias of only 0.8% and high agreement (ICC 0.997). Percentage kidney growth during 2.2 ± 0.3 years was similar for T2 and T1 (9.3 ± 10.6% vs. 7.8 ± 9.9%, P = 0.1, respectively), with a bias of 1.5% and high agreement (ICC 0.843). T2 was more often of sufficient quality for volume measurement (86.7% vs. 71.1%, P < 0.001). In patients with ADPKD, measurement of kidney volume and growth rate performs similarly when using T2 compared to T1 weighted images, although T2 performs better on secondary outcome parameters; they are more often of sufficient quality for volume measurement and result in slightly lower intra- and interreader variability.

  14. The Darkness of Space: A Teaching Strategy

    ERIC Educational Resources Information Center

    Yurumezoglu, Kemal; Oguz, Ayse

    2010-01-01

    This study examines the process by which a teacher may be able to answer a question asked in the classroom by using a scientific approach and a simple activity. This article examines a discussion of the question "Is space light or dark?" Priority in the discussion has been given to determining students' preconceptions about the interaction of…

  15. Spot Sign in Acute Intracerebral Hemorrhage in Dynamic T1-Weighted Magnetic Resonance Imaging.

    PubMed

    Schindlbeck, Katharina A; Santaella, Anna; Galinovic, Ivana; Krause, Thomas; Rocco, Andrea; Nolte, Christian H; Villringer, Kersten; Fiebach, Jochen B

    2016-02-01

    In computed tomographic imaging of acute intracerebral hemorrhage spot sign on computed tomographic angiography has been established as a marker for hematoma expansion and poor clinical outcome. Although, magnetic resonance imaging (MRI) can accurately visualize acute intracerebral hemorrhage, a corresponding MRI marker is lacking to date. We prospectively examined 50 consecutive patients with acute intracerebral hemorrhage within 24 hours of symptom onset. The MRI protocol consisted of a standard stroke protocol and dynamic contrast-enhanced T1-weighted imaging with a time resolution of 7.07 s/batch. Stroke scores were assessed at admission and at time of discharge. Volume measurements of hematoma size and spot sign were performed with MRIcron. Contrast extravasation within sites of the hemorrhage (MRI spot sign) was seen in 46% of the patients. Patients with an MRI spot sign had a significantly shorter time to imaging than those without (P<0.001). The clinical outcome measured by the modified Rankin Scale was significantly worse in patients with spot sign compared with those without (P≤0.001). Hematoma expansion was observed in the spot sign group compared with the nonspot sign group, although the differences were not significant. Spot sign can be detected using MRI on postcontrast T1-weighted and dynamic T1-weighted images. It is associated with worse clinical outcome. The time course of contrast extravasation in dynamic T1 images indicates that these spots represent ongoing bleeding. © 2015 American Heart Association, Inc.

  16. [Imaging characteristics of PROPELLER T2-weighted imaging].

    PubMed

    Goto, Masami; Aoki, Shigeki; Hayashi, Naoto; Mori, Harushi; Watanabe, Yasushi; Ino, Kenji; Satake, Yoshirou; Nishida, Katuji; Sato, Haruo; Iida, Kyouhito; Mima, Kazuo; Ohtomo, Kuni

    2004-11-01

    As the PROPELLER sequence is a combination of the radial scan and fast-spin-echo (FSE) sequence, it can be considered an FSE sequence with a motion correlation. However, there are some differences between PROPELLER and FSE owing to differences in k-space trajectory. We clarified the imaging characteristics of PROPELLER T2-weighted imaging (T2WI) for different parameters in comparison with usual FSE T2WI. When the same parameters were used, PROPELLER T2WI showed a higher signal-to-noise ratio (SNR) and lower spatial resolution than usual FSE. Effective echo time (TE) changed with different echo train lengths (ETL) or different bandwidths on PROPELLER, and imaging contrast changed accordingly to be more effective.

  17. Dark-Blood Delayed Enhancement Cardiac Magnetic Resonance of Myocardial Infarction.

    PubMed

    Kim, Han W; Rehwald, Wolfgang G; Jenista, Elizabeth R; Wendell, David C; Filev, Peter; van Assche, Lowie; Jensen, Christoph J; Parker, Michele A; Chen, Enn-Ling; Crowley, Anna Lisa C; Klem, Igor; Judd, Robert M; Kim, Raymond J

    2017-12-08

    This study introduced and validated a novel flow-independent delayed enhancement technique that shows hyperenhanced myocardium while simultaneously suppressing blood-pool signal. The diagnosis and assessment of myocardial infarction (MI) is crucial in determining clinical management and prognosis. Although delayed enhancement cardiac magnetic resonance (DE-CMR) is an in vivo reference standard for imaging MI, an important limitation is poor delineation between hyperenhanced myocardium and bright LV cavity blood-pool, which may cause many infarcts to become invisible. A canine model with pathology as the reference standard was used for validation (n = 22). Patients with MI and normal controls were studied to ascertain clinical performance (n = 31). In canines, the flow-independent dark-blood delayed enhancement (FIDDLE) technique was superior to conventional DE-CMR for the detection of MI, with higher sensitivity (96% vs. 85%, respectively; p = 0.002) and accuracy (95% vs. 87%, respectively; p = 0.01) and with similar specificity (92% vs, 92%, respectively; p = 1.0). In infarcts that were identified by both techniques, the entire length of the endocardial border between infarcted myocardium and adjacent blood-pool was visualized in 33% for DE-CMR compared with 100% for FIDDLE. There was better agreement for FIDDLE-measured infarct size than for DE-CMR infarct size (95% limits-of-agreement, 2.1% vs. 5.5%, respectively; p < 0.0001). In patients, findings were similar. FIDDLE demonstrated higher accuracy for diagnosis of MI than DE-CMR (100% [95% confidence interval [CI]: 89% to 100%] vs. 84% [95% CI: 66% to 95%], respectively; p = 0.03). The study introduced and validated a novel CMR technique that improves the discrimination of the border between infarcted myocardium and adjacent blood-pool. This dark-blood technique provides diagnostic performance that is superior to that of the current in vivo reference standard for the imaging diagnosis of MI

  18. Association between blood cholesterol and sodium intake in hypertensive women with excess weight.

    PubMed

    Padilha, Bruna Merten; Ferreira, Raphaela Costa; Bueno, Nassib Bezerra; Tassitano, Rafael Miranda; Holanda, Lidiana de Souza; Vasconcelos, Sandra Mary Lima; Cabral, Poliana Coelho

    2018-04-01

    Restricted sodium intake has been recommended for more than 1 century for the treatment of hypertension. However, restriction seems to increase blood cholesterol. In women with excess weight, blood cholesterol may increase even more because of insulin resistance and the high lipolytic activity of adipose tissue.The aim of this study was to assess the association between blood cholesterol and sodium intake in hypertensive women with and without excess weight.This was a cross-sectional study with hypertensive and nondiabetic women aged 20 to 59 years, recruited at the primary healthcare units of Maceio, Alagoas, Brazilian Northeast. Excess weight was defined as body mass index (BMI) ≥25.0 kg/m. Sodium intake was estimated by the 24-hour urinary excretion of sodium. Blood cholesterol was the primary outcome investigated by this study, and its relationship with sodium intake and other variables was assessed by Pearson correlation and multivariate linear regression using a significance level of 5%.This study included 165 hypertensive women. Of these, 135 (81.8%) were with excess weight. The mean sodium intake was 3.7 g (±1.9) and 3.4 g (±2.4) in hypertensive women with and without excess weight, respectively. The multiple normal linear regression models fitted to the "blood cholesterol" in the 2 groups reveal that for the group of hypertensive women without excess weight only 1 independent variable "age" is statistically significant to explain the variability of the blood cholesterol levels. However, for the group of hypertensive women with excess weight, 2 independent variables, age and sodium intake, can statistically explain variations of the blood cholesterol levels.Blood cholesterol is statistically inversely related to sodium intake for hypertensive women with excess weight, but it is not statistically related to sodium intake for hypertensive women without excess weight.

  19. Body weight lower limits of fetal postmortem MRI at 1.5 T.

    PubMed

    Jawad, N; Sebire, N J; Wade, A; Taylor, A M; Chitty, L S; Arthurs, O J

    2016-07-01

    To evaluate the diagnostic yield of postmortem magnetic resonance imaging (PM-MRI) compared with conventional autopsy in fetuses of early gestational age and low body weight. Fetuses of < 31 weeks' gestation that underwent 1.5-T PM-MRI and conventional autopsy were included. The findings of PM-MRI and conventional autopsy were reported blinded to each other. The reports of conventional autopsy and PM-MRI for each organ system (cardiovascular, neurological, abdominal, non-cardiac thoracic and musculoskeletal) were classified as either diagnostic or non-diagnostic. The likelihood of a non-diagnostic examination by PM-MRI was calculated according to fetal gestational age and body weight. Full datasets were examined of 204 fetuses, with mean gestational age of 20.95 ± 3.82 weeks (range, 12.0-30.7 weeks) and body-weight range of 15.9-1872 g. Body weight was the most significant predictor of diagnostic yield of PM-MRI. There was 95% confidence that 90% of fetuses will show diagnostic images by PM-MRI for all five organ systems when fetal body weight is ≥ 535 g, but < 50% of fetuses will have all five systems diagnostic on PM-MRI when body weight is < 122 g. PM-MRI is highly likely to provide adequate diagnostic images for fetuses with a body weight > 500 g. Below this weight, the diagnostic yield of standard 1.5-T PM-MRI decreases significantly. These data should help inform parents and clinicians on the suitability of performing PM-MRI in fetuses with low body weight. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

  20. Intramuscular adipose tissue determined by T1-weighted MRI at 3T primarily reflects extramyocellular lipids.

    PubMed

    Akima, Hiroshi; Hioki, Maya; Yoshiko, Akito; Koike, Teruhiko; Sakakibara, Hisataka; Takahashi, Hideyuki; Oshida, Yoshiharu

    2016-05-01

    The purpose of this study was to assess relationships between intramuscular adipose tissue (IntraMAT) content determined by MRI and intramyocellular lipids (IMCL) and extramyocellular lipids (EMCL) determined by (1)H magnetic resonance spectroscopy ((1)H MRS) or echo intensity determined by B-mode ultrasonography of human skeletal muscles. Thirty young and elderly men and women were included. T1-weighted MRI was taken from the right mid-thigh to measure IntraMAT content of the vastus lateralis (VL) and biceps femoris (BF) using a histogram shape-based thresholding technique. IMCL and EMCL were measured from the VL and BF at the right mid-thigh using (1)H MRS. Ultrasonographic images were taken from the VL and BF of the right mid-thigh to measure echo intensity based on gray-scale level for quantitative analysis. There was a significant correlation between IntraMAT content by MRI and EMCL of the VL and BF (VL, r=0.506, P<0.01; BF, r=0.591, P<0.001) and between echo intensity and EMCL of the VL and BF (VL, r=0.485, P<0.05; BF, r=0.648, P<0.01). IntraMAT content was also significantly correlated with echo intensity of the VL and BF (VL, r=0.404, P<0.05; BF, r=0.493, P<0.01). Our study suggests that IntraMAT content determined by T1-weighted MRI at 3T primarily reflects extramyocellular lipids, not intramyocellular lipids, in human skeletal muscles. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Determining dark matter properties with a XENONnT/LZ signal and LHC Run 3 monojet searches

    NASA Astrophysics Data System (ADS)

    Baum, Sebastian; Catena, Riccardo; Conrad, Jan; Freese, Katherine; Krauss, Martin B.

    2018-04-01

    We develop a method to forecast the outcome of the LHC Run 3 based on the hypothetical detection of O (100 ) signal events at XENONnT. Our method relies on a systematic classification of renormalizable single-mediator models for dark matter-quark interactions and is valid for dark matter candidates of spin less than or equal to one. Applying our method to simulated data, we find that at the end of the LHC Run 3 only two mutually exclusive scenarios would be compatible with the detection of O (100 ) signal events at XENONnT. In the first scenario, the energy distribution of the signal events is featureless, as for canonical spin-independent interactions. In this case, if a monojet signal is detected at the LHC, dark matter must have spin 1 /2 and interact with nucleons through a unique velocity-dependent operator. If a monojet signal is not detected, dark matter interacts with nucleons through canonical spin-independent interactions. In a second scenario, the spectral distribution of the signal events exhibits a bump at nonzero recoil energies. In this second case, a monojet signal can be detected at the LHC Run 3; dark matter must have spin 1 /2 and interact with nucleons through a unique momentum-dependent operator. We therefore conclude that the observation of O (100 ) signal events at XENONnT combined with the detection, or the lack of detection, of a monojet signal at the LHC Run 3 would significantly narrow the range of possible dark matter-nucleon interactions. As we argued above, it can also provide key information on the dark matter particle spin.

  2. Little composite dark matter.

    PubMed

    Balkin, Reuven; Perez, Gilad; Weiler, Andreas

    2018-01-01

    We examine the dark matter phenomenology of a composite electroweak singlet state. This singlet belongs to the Goldstone sector of a well-motivated extension of the Littlest Higgs with T -parity. A viable parameter space, consistent with the observed dark matter relic abundance as well as with the various collider, electroweak precision and dark matter direct detection experimental constraints is found for this scenario. T -parity implies a rich LHC phenomenology, which forms an interesting interplay between conventional natural SUSY type of signals involving third generation quarks and missing energy, from stop-like particle production and decay, and composite Higgs type of signals involving third generation quarks associated with Higgs and electroweak gauge boson, from vector-like top-partners production and decay. The composite features of the dark matter phenomenology allows the composite singlet to produce the correct relic abundance while interacting weakly with the Higgs via the usual Higgs portal coupling [Formula: see text], thus evading direct detection.

  3. Dark energy and fate of the Universe

    NASA Astrophysics Data System (ADS)

    Li, XiaoDong; Wang, Shuang; Huang, QingGuo; Zhang, Xin; Li, Miao

    2012-07-01

    We explore the ultimate fate of the Universe by using a divergence-free parametrization for dark energy w( z)= w 0+ w a [ln(2 + z) / (1 + z) - ln 2]. Unlike the Chevallier-Polarski-Linder parametrization, this parametrization has well behaved, bounded behavior for both high redshifts and negative redshifts, and thus can genuinely cover many theoretical dark energy models. After constraining the parameter space of this parametrization by using the current cosmological observations, we find that, at the 95.4% confidence level, our Universe can still exist at least 16.7 Gyr before it ends in a big rip. Moreover, for the phantom energy dominated Universe, we find that a gravitationally bound system will be destroyed at a time {{t ˜eq Psqrt {2| {1 + 3w( - 1)} |} } {/ {{t ˜eq Psqrt {2| {1 + 3w( - 1)} |} } {[ {6π | {1 + w( - 1)} |} ]}}} . } {[ {6π | {1 + w( - 1)} |} ]}}, where P is the period of a circular orbit around this system, before the big rip.

  4. Ordinary matter, dark matter, and dark energy on normal Zeeman space-times

    NASA Astrophysics Data System (ADS)

    Imre Szabó, Zoltán

    2017-01-01

    Zeeman space-times are new, relativistic, and operator based Hamiltonian models representing multi-particle systems. They are established on Lorentzian pseudo Riemannian manifolds whose Laplacian immediately appears in the form of original quantum physical wave operators. In classical quantum theory they emerge, differently, from the Hamilton formalism and the correspondence principle. Nonetheless, this new model does not just reiterate the well known conceptions but holds the key to solving open problems of quantum theory. Most remarkably, it represents the dark matter, dark energy, and ordinary matter by the same ratios how they show up in experiments. Another remarkable agreement with reality is that the ordinary matter appears to be non-expanding and is described in consent with observations. The theory also explains gravitation, moreover, the Hamilton operators of all energy and matter formations, together with their physical properties, are solely derived from the Laplacian of the Zeeman space-time. By this reason, it is called Monistic Wave Laplacian which symbolizes an all-comprehensive unification of all matter and energy formations. This paper only outlines the normal case where the particles do not have proper spin but just angular momentum. The complete anomalous theory is detailed in [Sz2, Sz3, Sz4, Sz5, Sz6, Sz7].

  5. Proliferation of PD-1+ CD8 T cells in peripheral blood after PD-1-targeted therapy in lung cancer patients.

    PubMed

    Kamphorst, Alice O; Pillai, Rathi N; Yang, Shu; Nasti, Tahseen H; Akondy, Rama S; Wieland, Andreas; Sica, Gabriel L; Yu, Ke; Koenig, Lydia; Patel, Nikita T; Behera, Madhusmita; Wu, Hong; McCausland, Megan; Chen, Zhengjia; Zhang, Chao; Khuri, Fadlo R; Owonikoko, Taofeek K; Ahmed, Rafi; Ramalingam, Suresh S

    2017-05-09

    Exhausted T cells in chronic infections and cancer have sustained expression of the inhibitory receptor programmed cell death 1 (PD-1). Therapies that block the PD-1 pathway have shown promising clinical results in a significant number of advanced-stage cancer patients. Nonetheless, a better understanding of the immunological responses induced by PD-1 blockade in cancer patients is lacking. Identification of predictive biomarkers is a priority in the field, but whether peripheral blood analysis can provide biomarkers to monitor or predict patients' responses to treatment remains to be resolved. In this study, we analyzed longitudinal blood samples from advanced stage non-small cell lung cancer (NSCLC) patients ( n = 29) receiving PD-1-targeted therapies. We detected an increase in Ki-67+ PD-1+ CD8 T cells following therapy in ∼70% of patients, and most responses were induced after the first or second treatment cycle. This T-cell activation was not indiscriminate because we observed only minimal effects on EBV-specific CD8 T cells, suggesting that responding cells may be tumor specific. These proliferating CD8 T cells had an effector-like phenotype (HLA-DR + , CD38 + , Bcl-2 lo ), expressed costimulatory molecules (CD28, CD27, ICOS), and had high levels of PD-1 and coexpression of CTLA-4. We found that 70% of patients with disease progression had either a delayed or absent PD-1+ CD8 T-cell response, whereas 80% of patients with clinical benefit exhibited PD-1+ CD8 T-cell responses within 4 wk of treatment initiation. Our results suggest that peripheral blood analysis may provide valuable insights into NSCLC patients' responses to PD-1-targeted therapies.

  6. Designing a space-based galaxy redshift survey to probe dark energy

    NASA Astrophysics Data System (ADS)

    Wang, Yun; Percival, Will; Cimatti, Andrea; Mukherjee, Pia; Guzzo, Luigi; Baugh, Carlton M.; Carbone, Carmelita; Franzetti, Paolo; Garilli, Bianca; Geach, James E.; Lacey, Cedric G.; Majerotto, Elisabetta; Orsi, Alvaro; Rosati, Piero; Samushia, Lado; Zamorani, Giovanni

    2010-12-01

    A space-based galaxy redshift survey would have enormous power in constraining dark energy and testing general relativity, provided that its parameters are suitably optimized. We study viable space-based galaxy redshift surveys, exploring the dependence of the Dark Energy Task Force (DETF) figure-of-merit (FoM) on redshift accuracy, redshift range, survey area, target selection and forecast method. Fitting formulae are provided for convenience. We also consider the dependence on the information used: the full galaxy power spectrum P(k), P(k) marginalized over its shape, or just the Baryon Acoustic Oscillations (BAO). We find that the inclusion of growth rate information (extracted using redshift space distortion and galaxy clustering amplitude measurements) leads to a factor of ~3 improvement in the FoM, assuming general relativity is not modified. This inclusion partially compensates for the loss of information when only the BAO are used to give geometrical constraints, rather than using the full P(k) as a standard ruler. We find that a space-based galaxy redshift survey covering ~20000deg2 over with σz/(1 + z) <= 0.001 exploits a redshift range that is only easily accessible from space, extends to sufficiently low redshifts to allow both a vast 3D map of the universe using a single tracer population, and overlaps with ground-based surveys to enable robust modelling of systematic effects. We argue that these parameters are close to their optimal values given current instrumental and practical constraints.

  7. Vascular space occupancy (VASO) cerebral blood volume-weighted MRI identifies hemodynamic impairment in patients with carotid artery disease.

    PubMed

    Donahue, Manus J; van Laar, Peter Jan; van Zijl, Peter C M; Stevens, Robert D; Hendrikse, Jeroen

    2009-03-01

    To assess the role of vascular space occupancy (VASO) magnetic resonance imaging (MRI), a noninvasive cerebral blood volume (CBV)-weighted technique, for evaluating CBV reactivity in patients with internal carotid artery (ICA) stenosis. VASO reactivity, defined as a signal change in response to hypercapnic stimulus (4-second exhale, 14-second breath-hold), was measured in the left and right ICA flow territories in patients (n=10) with varying degrees of unilateral and bilateral ICA stenosis and in healthy volunteers (n=10). Percent VASO reactivity was more negative (P<0.01) bilaterally in patients (ipsilateral: -3.6+/-1.5%; contralateral: -3.4+/-1.2%) compared with age-matched controls (left: -1.9+/-0.6%; right: -1.9+/-0.8%). Owing to the nature of the VASO contrast mechanism, this more negative VASO reactivity was attributed to autoregulatory CBV effects in patients. A postbreath-hold overshoot, which was absent in healthy volunteers, was observed unilaterally in a subset of patients. More negative VASO reactivity was observed in patients with ICA stenosis and may be a marker of autoregulatory effects. Furthermore, the postbreath-hold overshoot observed in patients is consistent with compensatory microvascular vasoconstriction and may be a marker of hemodynamic impairment. Based on the results of this feasibility study, VASO should be useful for identifying CBV adjustments in patients with steno-occlusive disease of the ICA. Copyright (c) 2009 Wiley-Liss, Inc.

  8. Can tonne-scale direct detection experiments discover nuclear dark matter?

    NASA Astrophysics Data System (ADS)

    Butcher, Alistair; Kirk, Russell; Monroe, Jocelyn; West, Stephen M.

    2017-10-01

    Models of nuclear dark matter propose that the dark sector contains large composite states consisting of dark nucleons in analogy to Standard Model nuclei. We examine the direct detection phenomenology of a particular class of nuclear dark matter model at the current generation of tonne-scale liquid noble experiments, in particular DEAP-3600 and XENON1T. In our chosen nuclear dark matter scenario distinctive features arise in the recoil energy spectra due to the non-point-like nature of the composite dark matter state. We calculate the number of events required to distinguish these spectra from those of a standard point-like WIMP state with a decaying exponential recoil spectrum. In the most favourable regions of nuclear dark matter parameter space, we find that a few tens of events are needed to distinguish nuclear dark matter from WIMPs at the 3 σ level in a single experiment. Given the total exposure time of DEAP-3600 and XENON1T we find that at best a 2 σ distinction is possible by these experiments individually, while 3 σ sensitivity is reached for a range of parameters by the combination of the two experiments. We show that future upgrades of these experiments have potential to distinguish a large range of nuclear dark matter models from that of a WIMP at greater than 3 σ.

  9. Can tonne-scale direct detection experiments discover nuclear dark matter?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Butcher, Alistair; Kirk, Russell; Monroe, Jocelyn

    Models of nuclear dark matter propose that the dark sector contains large composite states consisting of dark nucleons in analogy to Standard Model nuclei. We examine the direct detection phenomenology of a particular class of nuclear dark matter model at the current generation of tonne-scale liquid noble experiments, in particular DEAP-3600 and XENON1T. In our chosen nuclear dark matter scenario distinctive features arise in the recoil energy spectra due to the non-point-like nature of the composite dark matter state. We calculate the number of events required to distinguish these spectra from those of a standard point-like WIMP state with amore » decaying exponential recoil spectrum. In the most favourable regions of nuclear dark matter parameter space, we find that a few tens of events are needed to distinguish nuclear dark matter from WIMPs at the 3 σ level in a single experiment. Given the total exposure time of DEAP-3600 and XENON1T we find that at best a 2 σ distinction is possible by these experiments individually, while 3 σ sensitivity is reached for a range of parameters by the combination of the two experiments. We show that future upgrades of these experiments have potential to distinguish a large range of nuclear dark matter models from that of a WIMP at greater than 3 σ .« less

  10. Mixed dark matter in left-right symmetric models

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Berlin, Asher; Fox, Patrick J.; Hooper, Dan

    Motivated by the recently reported diboson and dijet excesses in Run 1 data at ATLAS and CMS, we explore models of mixed dark matter in left-right symmetric theories. In this study, we calculate the relic abundance and the elastic scattering cross section with nuclei for a number of dark matter candidates that appear within the fermionic multiplets of left-right symmetric models. In contrast to the case of pure multiplets, WIMP-nucleon scattering proceeds at tree-level, and hence the projected reach of future direct detection experiments such as LUX-ZEPLIN and XENON1T will cover large regions of parameter space for TeV-scale thermal darkmore » matter. Decays of the heavy charged W' boson to particles in the dark sector can potentially shift the right-handed gauge coupling to larger values when fixed to the rate of the Run 1 excesses, moving towards the theoretically attractive scenario, g R = g L. Furthermore, this region of parameter space may be probed by future collider searches for new Higgs bosons or electroweak fermions.« less

  11. Mixed dark matter in left-right symmetric models

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Berlin, Asher; Fox, Patrick J.; Hooper, Dan

    Motivated by the recently reported diboson and dijet excesses in Run 1 data at ATLAS and CMS, we explore models of mixed dark matter in left-right symmetric theories. In this study, we calculate the relic abundance and the elastic scattering cross section with nuclei for a number of dark matter candidates that appear within the fermionic multiplets of left-right symmetric models. In contrast to the case of pure multiplets, WIMP-nucleon scattering proceeds at tree-level, and hence the projected reach of future direct detection experiments such as LUX-ZEPLIN and XENON1T will cover large regions of parameter space for TeV-scale thermal darkmore » matter. Decays of the heavy charged W{sup ′} boson to particles in the dark sector can potentially shift the right-handed gauge coupling to larger values when fixed to the rate of the Run 1 excesses, moving towards the theoretically attractive scenario, g{sub R}=g{sub L}. This region of parameter space may be probed by future collider searches for new Higgs bosons or electroweak fermions.« less

  12. Mixed dark matter in left-right symmetric models

    DOE PAGES

    Berlin, Asher; Fox, Patrick J.; Hooper, Dan; ...

    2016-06-08

    Motivated by the recently reported diboson and dijet excesses in Run 1 data at ATLAS and CMS, we explore models of mixed dark matter in left-right symmetric theories. In this study, we calculate the relic abundance and the elastic scattering cross section with nuclei for a number of dark matter candidates that appear within the fermionic multiplets of left-right symmetric models. In contrast to the case of pure multiplets, WIMP-nucleon scattering proceeds at tree-level, and hence the projected reach of future direct detection experiments such as LUX-ZEPLIN and XENON1T will cover large regions of parameter space for TeV-scale thermal darkmore » matter. Decays of the heavy charged W' boson to particles in the dark sector can potentially shift the right-handed gauge coupling to larger values when fixed to the rate of the Run 1 excesses, moving towards the theoretically attractive scenario, g R = g L. Furthermore, this region of parameter space may be probed by future collider searches for new Higgs bosons or electroweak fermions.« less

  13. The Effect of Theory Based Nutritional Education on Fat Intake, Weight and Blood Lipids.

    PubMed

    Kamran, Aziz; Sharifirad, Gholamreza; Heydari, Heshmatolah; Sharifian, Elham

    2016-12-01

    Though Nutrition plays a key role in the control of hypertension, it is often forgotten in Iranian patients' diet. In fact, dietary behavior can be regarded as unsatisfactory among Iranian patients. This study was aimed to assess the effectiveness of theory based educational intervention on fat intake, weight, and blood lipids among rural hypertensive patients. This quasi experimental study was conducted on 138 hypertensive patients who had referred to Ardabil rural health centers during 2014. The nutritional education based on DASH and Health Promotion Model (HPM) was treated for six sessions. The pre-test and post-test had intervals of two and six months. Data were analyzed using SPSS-18 and Chi-square, independent-samples t-test, paired-samples t-test and repeated measure ANOVA. After treating intervention, weight, dietary fat, LDL_C and Total cholesterol, systolic and diastolic blood pressures decreased significantly in the intervention group compared with the control group (p < 0.001). In contrast, HDL_C increased significantly in the intervention group. Educational intervention, provided based on Pender's health promotion model, affecting fat intake, blood lipids, and blood pressure, led to their decrease.

  14. Characterization of multifocal T2*-weighted MRI hypointensities in the basal ganglia of elderly, community-dwelling subjects☆

    PubMed Central

    Glatz, Andreas; Valdés Hernández, Maria C.; Kiker, Alexander J.; Bastin, Mark E.; Deary, Ian J.; Wardlaw, Joanna M.

    2013-01-01

    Multifocal T2*-weighted (T2*w) hypointensities in the basal ganglia, which are believed to arise predominantly from mineralized small vessels and perivascular spaces, have been proposed as a biomarker for cerebral small vessel disease. This study provides baseline data on their appearance on conventional structural MRI for improving and automating current manual segmentation methods. Using a published thresholding method, multifocal T2*w hypointensities were manually segmented from whole brain T2*w volumes acquired from 98 community-dwelling subjects in their early 70s. Connected component analysis was used to derive the average T2*w hypointensity count and load per basal ganglia nucleus, as well as the morphology of their connected components, while nonlinear spatial probability mapping yielded their spatial distribution. T1-weighted (T1w), T2-weighted (T2w) and T2*w intensity distributions of basal ganglia T2*w hypointensities and their appearance on T1w and T2w MRI were investigated to gain further insights into the underlying tissue composition. In 75/98 subjects, on average, 3 T2*w hypointensities with a median total volume per intracranial volume of 50.3 ppm were located in and around the globus pallidus. Individual hypointensities appeared smooth and spherical with a median volume of 12 mm3 and median in-plane area of 4 mm2. Spatial probability maps suggested an association between T2*w hypointensities and the point of entry of lenticulostriate arterioles into the brain parenchyma. T1w and T2w and especially the T2*w intensity distributions of these hypointensities, which were negatively skewed, were generally not normally distributed indicating an underlying inhomogeneous tissue structure. Globus pallidus T2*w hypointensities tended to appear hypo- and isointense on T1w and T2w MRI, whereas those from other structures appeared iso- and hypointense. This pattern could be explained by an increased mineralization of the globus pallidus. In conclusion, the

  15. Natural implementation of neutralino dark matter

    NASA Astrophysics Data System (ADS)

    King, Steve F.; Roberts, Jonathan P.

    2006-09-01

    The prediction of neutralino dark matter is generally regarded as one of the successes of the Minimal Supersymmetric Standard Model (MSSM). However the successful regions of parameter space allowed by WMAP and collider constraints are quite restricted. We discuss fine-tuning with respect to both dark matter and Electroweak Symmetry Breaking (EWSB) and explore regions of MSSM parameter space with non-universal gaugino and third family scalar masses in which neutralino dark matter may be implemented naturally. In particular allowing non-universal gauginos opens up the bulk region that allows Bino annihilation via t-channel slepton exchange, leading to ``supernatural dark matter'' corresponding to no fine-tuning at all with respect to dark matter. By contrast we find that the recently proposed ``well tempered neutralino'' regions involve substantial fine-tuning of MSSM parameters in order to satisfy the dark matter constraints, although the fine tuning may be ameliorated if several annihilation channels act simultaneously. Although we have identified regions of ``supernatural dark matter'' in which there is no fine tuning to achieve successful dark matter, the usual MSSM fine tuning to achieve EWSB always remains.

  16. Axion dark matter in a 3 -3 -1 model

    NASA Astrophysics Data System (ADS)

    Montero, J. C.; Romero Castellanos, Ana R.; Sánchez-Vega, B. L.

    2018-03-01

    Slightly extending a right-handed neutrino version of the 3 -3 -1 model, we show that it is not only possible to solve the strong C P problem but also to give the total dark matter abundance reported by the Planck collaboration. Specifically, we consider the possibility of introducing a 3 -3 -1 scalar singlet to implement a gravity stable Peccei-Quinn mechanism in this model. Remarkably, for allowed regions of the parameter space, the arising axions with masses ma≈meV can both make up the total dark matter relic density through nonthermal production mechanisms and be very close to the region to be explored by the IAXO helioscope.

  17. Unusual Light in Dark Space Revealed by Los Alamos, NASA

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Smidt, Joseph

    By looking at the dark spaces between visible galaxies and stars the NASA/JPL CIBER sounding rocket experiment has produced data that could redefine what constitutes a galaxy. CIBER, the Cosmic Infrared Background Experiment, is designed to understand the physics going on between visible stars and galaxies. The relatively small, sub-orbital rocket unloads a camera that snaps pictures of the night sky in near-infrared wavelengths, between 1.2 and 1.6 millionth of a meter. Scientists take the data and remove all the known visible stars and galaxies and quantify what is left.

  18. Unusual Light in Dark Space Revealed by Los Alamos, NASA

    ScienceCinema

    Smidt, Joseph

    2018-01-16

    By looking at the dark spaces between visible galaxies and stars the NASA/JPL CIBER sounding rocket experiment has produced data that could redefine what constitutes a galaxy. CIBER, the Cosmic Infrared Background Experiment, is designed to understand the physics going on between visible stars and galaxies. The relatively small, sub-orbital rocket unloads a camera that snaps pictures of the night sky in near-infrared wavelengths, between 1.2 and 1.6 millionth of a meter. Scientists take the data and remove all the known visible stars and galaxies and quantify what is left.

  19. Constraints on interacting dark energy models from Planck 2015 and redshift-space distortion data

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Costa, André A.; Abdalla, E.; Xu, Xiao-Dong

    2017-01-01

    We investigate phenomenological interactions between dark matter and dark energy and constrain these models by employing the most recent cosmological data including the cosmic microwave background radiation anisotropies from Planck 2015, Type Ia supernovae, baryon acoustic oscillations, the Hubble constant and redshift-space distortions. We find that the interaction in the dark sector parameterized as an energy transfer from dark matter to dark energy is strongly suppressed by the whole updated cosmological data. On the other hand, an interaction between dark sectors with the energy flow from dark energy to dark matter is proved in better agreement with the available cosmologicalmore » observations. This coupling between dark sectors is needed to alleviate the coincidence problem.« less

  20. Can a single-shot black-blood T2-weighted spin-echo echo-planar imaging sequence with sensitivity encoding replace the respiratory-triggered turbo spin-echo sequence for the liver? An optimization and feasibility study.

    PubMed

    Hussain, Shahid M; De Becker, Jan; Hop, Wim C J; Dwarkasing, Soendersing; Wielopolski, Piotr A

    2005-03-01

    To optimize and assess the feasibility of a single-shot black-blood T2-weighted spin-echo echo-planar imaging (SSBB-EPI) sequence for MRI of the liver using sensitivity encoding (SENSE), and compare the results with those obtained with a T2-weighted turbo spin-echo (TSE) sequence. Six volunteers and 16 patients were scanned at 1.5T (Philips Intera). In the volunteer study, we optimized the SSBB-EPI sequence by interactively changing the parameters (i.e., the resolution, echo time (TE), diffusion weighting with low b-values, and polarity of the phase-encoding gradient) with regard to distortion, suppression of the blood signal, and sensitivity to motion. The influence of each change was assessed. The optimized SSBB-EPI sequence was applied in patients (N = 16). A number of items, including the overall image quality (on a scale of 1-5), were used for graded evaluation. In addition, the signal-to-noise ratio (SNR) of the liver was calculated. Statistical analysis was carried out with the use of Wilcoxon's signed rank test for comparison of the SSBB-EPI and TSE sequences, with P = 0.05 considered the limit for significance. The SSBB-EPI sequence was improved by the following steps: 1) less frequency points than phase-encoding steps, 2) a b-factor of 20, and 3) a reversed polarity of the phase-encoding gradient. In patients, the mean overall image quality score for the optimized SSBB-EPI (3.5 (range: 1-4)) and TSE (3.6 (range: 3-4)), and the SNR of the liver on SSBB-EPI (mean +/- SD = 7.6 +/- 4.0) and TSE (8.9 +/- 4.6) were not significantly different (P > .05). Optimized SSBB-EPI with SENSE proved to be feasible in patients, and the overall image quality and SNR of the liver were comparable to those achieved with the standard respiratory-triggered T2-weighted TSE sequence. (c) 2005 Wiley-Liss, Inc.

  1. Diagnosis of hepatic metastasis: comparison of respiration-triggered diffusion-weighted echo-planar MRI and five t2-weighted turbo spin-echo sequences.

    PubMed

    Bruegel, Melanie; Gaa, Jochen; Waldt, Simone; Woertler, Klaus; Holzapfel, Konstantin; Kiefer, Berthold; Rummeny, Ernst J

    2008-11-01

    The purpose of this study was to compare the value of respiration-triggered diffusion-weighted (DW) single-shot echo-planar MRI (EPI) and five variants of T2-weighted turbo spin-echo (TSE) sequences in the diagnosis of hepatic metastasis. Fifty-two patients with extrahepatic primary malignant tumors underwent 1.5-T MRI that included DW EPI and the following variants of T2-weighted TSE techniques: breath-hold fat-suppressed HASTE, breath-hold fat-supressed TSE, respiration-triggered fat-suppressed TSE, breath-hold STIR, and respiration-triggered STIR. Images were reviewed independently by two blinded observers who used a 5-point confidence scale to identify lesions. Results were correlated with surgical and histopathologic findings and follow-up imaging findings. The accuracy of each technique was measured with free-response receiver operating characteristic analysis. A total of 118 hepatic metastatic lesions (mean diameter, 12.8 mm; range, 3-84 mm) were evaluated. Accuracy values were higher (p < 0.001) with DW EPI (0.91-0.92) than with the T2-weighted TSE techniques (0.47-0.67). Imaging with the HASTE sequence (0.47-0.52) was less accurate (p < 0.05) than imaging with the breath-hold TSE, breath-hold STIR, respiration-triggered TSE, and respiration-triggered STIR sequences (0.59-0.67). Sensitivity was higher (p < 0.001) with DW EPI (0.88-0.91) than with T2-weighted TSE techniques (0.45-0.62). For small (< or = 10 mm) metastatic lesions only, the differences in sensitivity between DW EPI (0.85) and T2-weighted TSE techniques (0.26-0.44) were even more pronounced. DW EPI was more sensitive and more accurate than imaging with T2-weighted TSE techniques. Because of the black-blood effect on vessels and low susceptibility to motion artifacts, DW EPI was particularly useful for the detection of small (< or = 10 mm) metastatic lesions.

  2. Purification for the XENONnT dark matter experiment

    NASA Astrophysics Data System (ADS)

    Brown, Ethan; Xenon Collaboration

    2017-01-01

    The XENON1T experiment uses 3.5 tons of liquid xenon in a cryogenic detector to search for dark matter. Its upgrade, XENONnT, will similarly house 7.5 tons of liquid xenon. Operation of these large detectors requires continual purification of the xenon in an external purifier, and the need for less than part per billion level oxygen in the xenon, coupled with the large quantity of xenon to be purified, places high demands on the rate of flow through this purification system. Building on the success of the XENON10 and XENON100 experiments, XENON1T circulates gaseous xenon through heated getters at a rate of up to 100 SLPM, pushing commercial pumps to their limits moving this large quantity of gas without interruption for several years. Two upgrades are considered for XENONnT. A custom high-capacity magnetic piston pump based on the one developed for the EXO200 experiment has been scaled up to support the high demands of this much larger experiment. Additionally, a liquid phase circulation and purification system that purifies the cryogenic liquid directly is being developed, which takes advantage of the much smaller volumetric flow demands of liquid relative to gas. The implementation of both upgrades will be presented. Supported by the National Science Foundation.

  3. Contrast-enhanced fluid-attenuated inversion recovery vs. contrast-enhanced spin echo T1-weighted brain imaging.

    PubMed

    Falzone, Cristian; Rossi, Federica; Calistri, Maurizio; Tranquillo, Massimo; Baroni, Massimo

    2008-01-01

    In humans, contrast-enhanced fluid-attenuated inversion recovery (FLAIR) imaging plays an important role in detecting brain disease. The aim of this study was to define the clinical utility of contrast-enhanced FLAIR imaging by comparing the results with those with contrast-enhanced spin echo T1-weighted images (SE T1WI) in animals with different brain disorders. Forty-one dogs and five cats with a clinical suspicion of brain disease and 30 normal animals (25 dogs and five cats) were evaluated using a 0.2 T permanent magnet. Before contrast medium injection, spin echo T1-weighted, SE T1WI, and FLAIR sequences were acquired in three planes. SE T1WI and FLAIR images were also acquired after gadolinium injection. Sensitivity in detecting the number, location, margin, and enhancement pattern and rate were evaluated. No lesions were found in a normal animal. In affected animals, 48 lesions in 34 patients were detected in contrast-enhanced SE T1WI whereas 81 lesions in 44 patients were detected in contrast-enhanced FLAIR images. There was no difference in the characteristics of the margins or enhancement pattern of the detected lesions. The objective enhancement rate, the mean value between lesion-to-white matter ratio and lesion-to-gray matter ratio, although representing an overlap of T1 and T2 effects and not pure contrast medium shortening of T1 relaxation, was better in contrast-enhanced FLAIR images. These results suggest a superiority of contrast-enhanced FLAIR images as compared with contrast-enhanced SE T1WI in detecting enhancing brain lesions.

  4. Revisiting the direct detection of dark matter in simplified models

    NASA Astrophysics Data System (ADS)

    Li, Tong

    2018-07-01

    In this work we numerically re-examine the loop-induced WIMP-nucleon scattering cross section for the simplified dark matter models and the constraint set by the latest direct detection experiment. We consider a fermion, scalar or vector dark matter component from five simplified models with leptophobic spin-0 mediators coupled only to Standard Model quarks and dark matter particles. The tree-level WIMP-nucleon cross sections in these models are all momentum-suppressed. We calculate the non-suppressed spin-independent WIMP-nucleon cross sections from loop diagrams and investigate the constrained space of dark matter mass and mediator mass by Xenon1T. The constraints from indirect detection and collider search are also discussed.

  5. WeightLifter: Visual Weight Space Exploration for Multi-Criteria Decision Making.

    PubMed

    Pajer, Stephan; Streit, Marc; Torsney-Weir, Thomas; Spechtenhauser, Florian; Muller, Torsten; Piringer, Harald

    2017-01-01

    A common strategy in Multi-Criteria Decision Making (MCDM) is to rank alternative solutions by weighted summary scores. Weights, however, are often abstract to the decision maker and can only be set by vague intuition. While previous work supports a point-wise exploration of weight spaces, we argue that MCDM can benefit from a regional and global visual analysis of weight spaces. Our main contribution is WeightLifter, a novel interactive visualization technique for weight-based MCDM that facilitates the exploration of weight spaces with up to ten criteria. Our technique enables users to better understand the sensitivity of a decision to changes of weights, to efficiently localize weight regions where a given solution ranks high, and to filter out solutions which do not rank high enough for any plausible combination of weights. We provide a comprehensive requirement analysis for weight-based MCDM and describe an interactive workflow that meets these requirements. For evaluation, we describe a usage scenario of WeightLifter in automotive engineering and report qualitative feedback from users of a deployed version as well as preliminary feedback from decision makers in multiple domains. This feedback confirms that WeightLifter increases both the efficiency of weight-based MCDM and the awareness of uncertainty in the ultimate decisions.

  6. Origins Space Telescope: Tracing Dark Molecular Gas in the Milky Way

    NASA Astrophysics Data System (ADS)

    Narayanan, Desika; Li, Qi; Krumholz, Mark; Dave, Romeel; Origins Space Telescope Science and Technology Definition Team

    2018-01-01

    We present theoretical models for quantifying the fraction of CO-dark molecular gas in galaxies. To do this, we combine novel thermal, chemical, and radiative equilibrium calculations with high-resolution cosmological zoom galaxy formation models. We discuss how this dark molecular gas will be uncovered by the Origins Space Telescope, one of the four science and technology definition studies of NASA Headquarters for the 2020 Astronomy and Astrophysics Decadal survey.

  7. Acoustic noise reduction in T 1- and proton-density-weighted turbo spin-echo imaging.

    PubMed

    Ott, Martin; Blaimer, Martin; Breuer, Felix; Grodzki, David; Heismann, Björn; Jakob, Peter

    2016-02-01

    To reduce acoustic noise levels in T 1-weighted and proton-density-weighted turbo spin-echo (TSE) sequences, which typically reach acoustic noise levels up to 100 dB(A) in clinical practice. Five acoustic noise reduction strategies were combined: (1) gradient ramps and shapes were changed from trapezoidal to triangular, (2) variable-encoding-time imaging was implemented to relax the phase-encoding gradient timing, (3) RF pulses were adapted to avoid the need for reversing the polarity of the slice-rewinding gradient, (4) readout bandwidth was increased to provide more time for gradient activity on other axes, (5) the number of slices per TR was reduced to limit the total gradient activity per unit time. We evaluated the influence of each measure on the acoustic noise level, and conducted in vivo measurements on a healthy volunteer. Sound recordings were taken for comparison. An overall acoustic noise reduction of up to 16.8 dB(A) was obtained by the proposed strategies (1-4) and the acquisition of half the number of slices per TR only. Image quality in terms of SNR and CNR was found to be preserved. The proposed measures in this study allowed a threefold reduction in the acoustic perception of T 1-weighted and proton-density-weighted TSE sequences compared to a standard TSE-acquisition. This could be achieved without visible degradation of image quality, showing the potential to improve patient comfort and scan acceptability.

  8. Diagnostic Utility of Contrast-enhanced 3D T1-weighted Imaging in Acute Cerebral Infarction Associated with Graves Disease.

    PubMed

    Gon, Yasufumi; Sakaguchi, Manabu; Oyama, Naoki; Mochizuki, Hideki

    2017-02-01

    Graves disease is rarely complicated with cerebrovascular steno-occlusive diseases. Previous studies have suggested several hypotheses for this occurrence, including excess thyroid hormone, which stimulates the sympathetic nervous system, which in turn causes an abnormal hemodynamic response with consequent atherosclerotic changes, and antithyroid antibodies cause local vascular inflammation in patients with Graves disease. However, radiological findings of vasculitis in patients with Graves disease and cerebral infarction remain less known. We report the case of a 30-year-old Japanese woman with acute cerebral infarction due to vasculitis associated with Graves disease. She was admitted to our hospital with a 4-day history of intermittent transient dysarthria and limb shaking of the left leg when standing. Three weeks before admission, she went to a local hospital because of general malaise and was diagnosed with Graves disease. Neurological examination revealed paralytic dysarthria, left central facial nerve palsy, and left hemiparesis (manual muscle testing, 4 of 5). Blood examinations showed hyperthyroidism (thyroid-stimulating hormone ≤.010 µU/mL; free T3 ≥25.0 pg/mL; free T4 ≥8.0 ng/dL) and elevation of antithyroid antibody levels (thyroid peroxidase antibody, 87 IU/mL). The vessel wall of the right internal carotid artery was markedly enhanced on contrast-enhanced three-dimensional T1-weighted magnetic resonance imaging, suggesting vasculitis. Magnetic resonance angiography revealed right internal carotid artery occlusion after the branching ophthalmic artery. Arterial stenosis due to vasculitis was considered the cause of hemodynamic ischemic stroke. Vessel wall imaging such as high-resolution contrast-enhanced T1-weighted imaging seems useful for assessing the underlying mechanism of stroke in patients with Graves disease. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  9. Impact of weight loss on ankle-brachial index and interartery blood pressures.

    PubMed

    Espeland, Mark A; Lewis, Cora E; Bahnson, Judy; Knowler, William C; Regensteiner, Judith G; Gaussoin, Sarah A; Beavers, Daniel; Johnson, Karen C

    2014-04-01

    To assess whether weight loss improves markers of peripheral artery disease and vascular stenosis. The Action for Health in Diabetes randomized clinical trial compared intensive lifestyle intervention (ILI) for weight loss to a control condition of diabetes support and education (DSE) in overweight or obese adults with type 2 diabetes. Annual ankle and brachial blood pressures over four years were used to compute ankle-brachial indices (ABIs) and to assess interartery blood pressure differences in 5018 participants. ILI, compared to DSE, produced 7.8% (Year 1) to 3.6% (Year 4) greater weight losses. These did not affect prevalence of low (<0.90) ABI (3.60% in DSE versus 3.14% in ILI; P = 0.20) or elevated (>1.40) ABI (7.52% in DSE versus 7.59% in ILI: P = 0.90), but produced smaller mean (SE) maximum interartery systolic blood pressure differences among ankle sites [19.7 (0.2) mmHg for ILI versus 20.6 (0.2) mmHg for DSE (P < 0.001)] and between arms [5.8 (0.1) mmHg for ILI versus 6.1 (0.1) mmHg for DSE (P = 0.01)]. Four years of intensive behavioral weight loss intervention did not significantly alter prevalence of abnormal ABI, however, it did reduce differences in systolic blood pressures among arterial sites. Copyright © 2013 The Obesity Society.

  10. Prevalence of human T-cell lymphotropic virus types 1 and 2 in blood donors of the Caruaru Blood Center (Hemope).

    PubMed

    de Lima, Waleska Mayara Gomes; Esteves, Fabrício Andrade Martins; Torres, Maria do Carmo Morais Rodrigues; Pires, Edna Suely Feitosa

    2013-01-01

    There is difficulty in gathering data on the prevalence of human T-cell lymphotropic virus in blood donors as confirmatory testing is not mandatory in Brazil. This suggests there may be an underreporting of the prevalence. To estimate the prevalence of human T-cell lymphotropic virus types 1 and 2 in donors of a blood bank in Caruaru, Brazil. This was an observational, epidemiological, descriptive, longitudinal and retrospective study with information about the serology of donors of the Caruaru Blood Center, Fundação de Hematologia e Hemoterapia de Pernambuco (Hemope) from May 2006 to December 2010. The data were analyzed using the Excel 2010 computer program (Microsoft Office(®)). Of 61,881 donors, 60 (0.096%) individuals were identified as potential carriers of human T-cell lymphotropic virus types 1 and 2. Of these, 28 (0.045%) were positive and 32 (0.051%) had inconclusive results in the serological screening. Forty-five (0.072%) were retested; 17 were positive (0.027%) and 3 inconclusive (0.005%). After confirmatory tests, 8 were positive (0.013%). Six (75%) of the confirmed cases were women. Epidemiological surveys like this are very important in order to create campaigns to attract donors and reduce the costs of laboratory tests.

  11. Prevalence of human T-cell lymphotropic virus types 1 and 2 in blood donors of the Caruaru Blood Center (Hemope)

    PubMed Central

    de Lima, Waleska Mayara Gomes; Esteves, Fabrício Andrade Martins; Torres, Maria do Carmo Morais Rodrigues; Pires, Edna Suely Feitosa

    2013-01-01

    Background There is difficulty in gathering data on the prevalence of human T-cell lymphotropic virus in blood donors as confirmatory testing is not mandatory in Brazil. This suggests there may be an underreporting of the prevalence. Objective To estimate the prevalence of human T-cell lymphotropic virus types 1 and 2 in donors of a blood bank in Caruaru, Brazil. Methods This was an observational, epidemiological, descriptive, longitudinal and retrospective study with information about the serology of donors of the Caruaru Blood Center, Fundação de Hematologia e Hemoterapia de Pernambuco (Hemope) from May 2006 to December 2010. The data were analyzed using the Excel 2010 computer program (Microsoft Office®). Results Of 61,881 donors, 60 (0.096%) individuals were identified as potential carriers of human T-cell lymphotropic virus types 1 and 2. Of these, 28 (0.045%) were positive and 32 (0.051%) had inconclusive results in the serological screening. Forty-five (0.072%) were retested; 17 were positive (0.027%) and 3 inconclusive (0.005%). After confirmatory tests, 8 were positive (0.013%). Six (75%) of the confirmed cases were women. Conclusion Epidemiological surveys like this are very important in order to create campaigns to attract donors and reduce the costs of laboratory tests. PMID:24106445

  12. Light chiral dark sector

    DOE PAGES

    Harigaya, Keisuke; Nomura, Yasunori

    2016-08-11

    An interesting possibility for dark matter is a scalar particle of mass of order 10 MeV-1 GeV, interacting with a U(1) gauge boson (dark photon) which mixes with the photon. We present a simple and natural model realizing this possibility. The dark matter arises as a composite pseudo-Nambu-Goldstone boson (dark pion) in a non-Abelian gauge sector, which also gives a mass to the dark photon. For a fixed non-Abelian gauge group, SU(N), and a U(1) charge of the constituent dark quarks, the model has only three free parameters: the dynamical scale of the non-Abelian gauge theory, the gauge coupling ofmore » the dark photon, and the mixing parameter between the dark and standard model photons. In particular, the gauge symmetry of the model does not allow any mass term for the dark quarks, and the stability of the dark pion is understood as a result of an accidental global symmetry. The model has a significant parameter space in which thermal relic dark pions comprise all of the dark matter, consistently with all experimental and cosmological constraints. In a corner of the parameter space, the discrepancy of the muon g-2 between experiments and the standard model prediction can also be ameliorated due to a loop contribution of the dark photon. Smoking-gun signatures of the model include a monophoton signal from the e +e - collision into a photon and a "dark rho meson." Observation of two processes in e +e - collision - the mode into the dark photon and that into the dark rho meson - would provide strong evidence for the model.« less

  13. Light chiral dark sector

    NASA Astrophysics Data System (ADS)

    Harigaya, Keisuke; Nomura, Yasunori

    2016-08-01

    An interesting possibility for dark matter is a scalar particle of mass of order 10 MeV-1 GeV, interacting with a U (1 ) gauge boson (dark photon) which mixes with the photon. We present a simple and natural model realizing this possibility. The dark matter arises as a composite pseudo-Nambu-Goldstone boson (dark pion) in a non-Abelian gauge sector, which also gives a mass to the dark photon. For a fixed non-Abelian gauge group, S U (N ) , and a U (1 ) charge of the constituent dark quarks, the model has only three free parameters: the dynamical scale of the non-Abelian gauge theory, the gauge coupling of the dark photon, and the mixing parameter between the dark and standard model photons. In particular, the gauge symmetry of the model does not allow any mass term for the dark quarks, and the stability of the dark pion is understood as a result of an accidental global symmetry. The model has a significant parameter space in which thermal relic dark pions comprise all of the dark matter, consistently with all experimental and cosmological constraints. In a corner of the parameter space, the discrepancy of the muon g -2 between experiments and the standard model prediction can also be ameliorated due to a loop contribution of the dark photon. Smoking-gun signatures of the model include a monophoton signal from the e+e- collision into a photon and a "dark rho meson." Observation of two processes in e+e- collision—the mode into the dark photon and that into the dark rho meson—would provide strong evidence for the model.

  14. Light chiral dark sector

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Harigaya, Keisuke; Nomura, Yasunori

    An interesting possibility for dark matter is a scalar particle of mass of order 10 MeV-1 GeV, interacting with a U(1) gauge boson (dark photon) which mixes with the photon. We present a simple and natural model realizing this possibility. The dark matter arises as a composite pseudo-Nambu-Goldstone boson (dark pion) in a non-Abelian gauge sector, which also gives a mass to the dark photon. For a fixed non-Abelian gauge group, SU(N), and a U(1) charge of the constituent dark quarks, the model has only three free parameters: the dynamical scale of the non-Abelian gauge theory, the gauge coupling ofmore » the dark photon, and the mixing parameter between the dark and standard model photons. In particular, the gauge symmetry of the model does not allow any mass term for the dark quarks, and the stability of the dark pion is understood as a result of an accidental global symmetry. The model has a significant parameter space in which thermal relic dark pions comprise all of the dark matter, consistently with all experimental and cosmological constraints. In a corner of the parameter space, the discrepancy of the muon g-2 between experiments and the standard model prediction can also be ameliorated due to a loop contribution of the dark photon. Smoking-gun signatures of the model include a monophoton signal from the e +e - collision into a photon and a "dark rho meson." Observation of two processes in e +e - collision - the mode into the dark photon and that into the dark rho meson - would provide strong evidence for the model.« less

  15. Proliferation of PD-1+ CD8 T cells in peripheral blood after PD-1–targeted therapy in lung cancer patients

    PubMed Central

    Kamphorst, Alice O.; Pillai, Rathi N.; Yang, Shu; Nasti, Tahseen H.; Sica, Gabriel L.; Yu, Ke; Koenig, Lydia; Patel, Nikita T.; Behera, Madhusmita; Wu, Hong; McCausland, Megan; Chen, Zhengjia; Zhang, Chao; Khuri, Fadlo R.; Owonikoko, Taofeek K.; Ahmed, Rafi; Ramalingam, Suresh S.

    2017-01-01

    Exhausted T cells in chronic infections and cancer have sustained expression of the inhibitory receptor programmed cell death 1 (PD-1). Therapies that block the PD-1 pathway have shown promising clinical results in a significant number of advanced-stage cancer patients. Nonetheless, a better understanding of the immunological responses induced by PD-1 blockade in cancer patients is lacking. Identification of predictive biomarkers is a priority in the field, but whether peripheral blood analysis can provide biomarkers to monitor or predict patients’ responses to treatment remains to be resolved. In this study, we analyzed longitudinal blood samples from advanced stage non–small cell lung cancer (NSCLC) patients (n = 29) receiving PD-1–targeted therapies. We detected an increase in Ki-67+ PD-1+ CD8 T cells following therapy in ∼70% of patients, and most responses were induced after the first or second treatment cycle. This T-cell activation was not indiscriminate because we observed only minimal effects on EBV-specific CD8 T cells, suggesting that responding cells may be tumor specific. These proliferating CD8 T cells had an effector-like phenotype (HLA-DR+, CD38+, Bcl-2lo), expressed costimulatory molecules (CD28, CD27, ICOS), and had high levels of PD-1 and coexpression of CTLA-4. We found that 70% of patients with disease progression had either a delayed or absent PD-1+ CD8 T-cell response, whereas 80% of patients with clinical benefit exhibited PD-1+ CD8 T-cell responses within 4 wk of treatment initiation. Our results suggest that peripheral blood analysis may provide valuable insights into NSCLC patients’ responses to PD-1–targeted therapies. PMID:28446615

  16. Quark seesaw mechanism, dark U (1 ) symmetry, and the baryon-dark matter coincidence

    NASA Astrophysics Data System (ADS)

    Gu, Pei-Hong; Mohapatra, Rabindra N.

    2017-09-01

    We attempt to understand the baryon-dark matter coincidence problem within the quark seesaw extension of the standard model where parity invariance is used to solve the strong C P problem. The S U (2 )L×S U (2 )R×U (1 )B -L gauge symmetry of this model is extended by a dark U (1 )X group plus inclusion of a heavy neutral vector-like fermion χL ,R charged under the dark group which plays the role of dark matter. All fermions are Dirac type in this model. Decay of heavy scalars charged under U (1 )X leads to simultaneous asymmetry generation of the dark matter and baryons after sphaleron effects are included. The U (1 )X group not only helps to stabilize the dark matter but also helps in the elimination of the symmetric part of the dark matter via χ -χ ¯ annihilation. For dark matter mass near the proton mass, it explains why the baryon and dark matter abundances are of similar magnitude (the baryon-dark matter coincidence problem). This model is testable in low threshold (sub-keV) direct dark matter search experiments.

  17. Comparison among T1-weighted magnetic resonance imaging, modified dixon method, and magnetic resonance spectroscopy in measuring bone marrow fat.

    PubMed

    Shen, Wei; Gong, Xiuqun; Weiss, Jessica; Jin, Ye

    2013-01-01

    An increasing number of studies are utilizing different magnetic resonance (MR) methods to quantify bone marrow fat due to its potential role in osteoporosis. Our aim is to compare the measurements of bone marrow fat among T1-weighted magnetic resonance imaging (MRI), modified Dixon method (also called fat fraction MRI (FFMRI)), and magnetic resonance spectroscopy (MRS). Contiguous MRI scans were acquired in 27 Caucasian postmenopausal women with a modified Dixon method (i.e., FFMRI). Bone marrow adipose tissue (BMAT) of T1-weighted MRI and bone marrow fat fraction of the L3 vertebra and femoral necks were quantified using SliceOmatic and Matlab. MRS was also acquired at the L3 vertebra. Correlation among the three MR methods measured bone marrow fat fraction and BMAT ranges from 0.78 to 0.88 (P < 0.001) in the L3 vertebra. Correlation between BMAT measured by T1-weighted MRI and bone marrow fat fraction measured by modified FFMRI is 0.86 (P < 0.001) in femoral necks. There are good correlations among T1-weighted MRI, FFMRI, and MRS for bone marrow fat quantification. The inhomogeneous distribution of bone marrow fat, the threshold segmentation of the T1-weighted MRI, and the ambiguity of the FFMRI may partially explain the difference among the three methods.

  18. Comparison among T1-Weighted Magnetic Resonance Imaging, Modified Dixon Method, and Magnetic Resonance Spectroscopy in Measuring Bone Marrow Fat

    PubMed Central

    Shen, Wei; Gong, Xiuqun; Weiss, Jessica; Jin, Ye

    2013-01-01

    Introduction. An increasing number of studies are utilizing different magnetic resonance (MR) methods to quantify bone marrow fat due to its potential role in osteoporosis. Our aim is to compare the measurements of bone marrow fat among T1-weighted magnetic resonance imaging (MRI), modified Dixon method (also called fat fraction MRI (FFMRI)), and magnetic resonance spectroscopy (MRS). Methods. Contiguous MRI scans were acquired in 27 Caucasian postmenopausal women with a modified Dixon method (i.e., FFMRI). Bone marrow adipose tissue (BMAT) of T1-weighted MRI and bone marrow fat fraction of the L3 vertebra and femoral necks were quantified using SliceOmatic and Matlab. MRS was also acquired at the L3 vertebra. Results. Correlation among the three MR methods measured bone marrow fat fraction and BMAT ranges from 0.78 to 0.88 (P < 0.001) in the L3 vertebra. Correlation between BMAT measured by T1-weighted MRI and bone marrow fat fraction measured by modified FFMRI is 0.86 (P < 0.001) in femoral necks. Conclusion. There are good correlations among T1-weighted MRI, FFMRI, and MRS for bone marrow fat quantification. The inhomogeneous distribution of bone marrow fat, the threshold segmentation of the T1-weighted MRI, and the ambiguity of the FFMRI may partially explain the difference among the three methods. PMID:23606951

  19. T2-Weighted intracranial vessel wall imaging at 7 Tesla using a DANTE-prepared variable flip angle turbo spin echo readout (DANTE-SPACE).

    PubMed

    Viessmann, Olivia; Li, Linqing; Benjamin, Philip; Jezzard, Peter

    2017-02-01

    To optimize intracranial vessel wall imaging (VWI) at 7T for sharp wall depiction and high boundary contrast. A variable flip angle turbo spin echo scheme (SPACE) was optimized for VWI. SPACE provides black-blood contrast, but has less crushing effect on cerebrospinal fluid (CSF). However, a delay alternating with nutation for tailored excitation (DANTE) preparation suppresses the signal from slowly moving spins of a few mm per second. Therefore, we optimized a DANTE-preparation module for 7T. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and signal ratio for vessel wall, CSF, and lumen were calculated for SPACE and DANTE-SPACE in 11 volunteers at the middle cerebral artery (MCA). An exemplar MCA stenosis patient was scanned with DANTE-SPACE. The 7T-optimized SPACE sequence improved the vessel wall point-spread function by 17%. The CNR between the wall and CSF was doubled (12.2 versus 5.6) for the DANTE-SPACE scans compared with the unprepared SPACE. This increase was significant in the right hemisphere (P = 0.016), but not in the left (P = 0.090). The CNR between wall and lumen was halved, but remained at a high value (24.9 versus 56.5). The optimized SPACE sequence improves VWI at 7T. Additional DANTE preparation increases the contrast between the wall and CSF. Increased outer boundary contrast comes at the cost of reduced inner boundary contrast. Magn Reson Med 77:655-663, 2017. © 2016 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 License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

  20. Mapping Human Cortical Areas in vivo Based on Myelin Content as Revealed by T1- and T2-weighted MRI

    PubMed Central

    Glasser, Matthew F.; Van Essen, David C.

    2011-01-01

    Non-invasively mapping the layout of cortical areas in humans is a continuing challenge for neuroscience. We present a new method of mapping cortical areas based on myelin content as revealed by T1-weighted (T1w) and T2-weighted (T2w) MRI. The method is generalizable across different 3T scanners and pulse sequences. We use the ratio of T1w/T2w image intensities to eliminate the MR-related image intensity bias and enhance the contrast to noise ratio for myelin. Data from each subject was mapped to the cortical surface and aligned across individuals using surface-based registration. The spatial gradient of the group average myelin map provides an observer-independent measure of sharp transitions in myelin content across the surface—i.e. putative cortical areal borders. We found excellent agreement between the gradients of the myelin maps and the gradients of published probabilistic cytoarchitectonically defined cortical areas that were registered to the same surface-based atlas. For other cortical regions, we used published anatomical and functional information to make putative identifications of dozens of cortical areas or candidate areas. In general, primary and early unimodal association cortices are heavily myelinated and higher, multi-modal, association cortices are more lightly myelinated, but there are notable exceptions in the literature that are confirmed by our results. The overall pattern in the myelin maps also has important correlations with the developmental onset of subcortical white matter myelination, evolutionary cortical areal expansion in humans compared to macaques, postnatal cortical expansion in humans, and maps of neuronal density in non-human primates. PMID:21832190

  1. Hubble Finds New Dark Spot on Neptune

    NASA Technical Reports Server (NTRS)

    1995-01-01

    NASA's Hubble Space Telescope has discovered a new great dark spot, located in the northern hemisphere of the planet Neptune. Because the planet's northern hemisphere is now tilted away from Earth, the new feature appears near the limb of the planet.

    The spot is a near mirror-image to a similar southern hemisphere dark spot that was discovered in 1989 by the Voyager 2 probe. In 1994, Hubble showed that the southern dark spot had disappeared.

    Like its predecessor, the new spot has high altitude clouds along its edge, caused by gasses that have been pushed to higher altitudes where they cool to form methane ice crystal clouds. The dark spot may be a zone of clear gas that is a window to a cloud deck lower in the atmosphere.

    Planetary scientists don t know how long lived this new feature might be. Hubble's high resolution will allow astronomers to follow the spot's evolution and other unexpected changes in Neptune's dynamic atmosphere.

    The image was taken on November 2, 1994 with Hubble's Wide Field Planetary Camera 2, when Neptune was 2.8 billion miles (4.5 billion kilometers) from Earth. Hubble can resolve features as small as 625 miles (1,000 kilometers) across in Neptune's cloud tops.

    The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.

    This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

  2. T1 weighted fat/water separated PROPELLER acquired with dual bandwidths.

    PubMed

    Rydén, Henric; Berglund, Johan; Norbeck, Ola; Avventi, Enrico; Skare, Stefan

    2018-04-24

    To describe a fat/water separated dual receiver bandwidth (rBW) spin echo PROPELLER sequence that eliminates the dead time associated with single rBW sequences. A nonuniform noise whitening by regularization of the fat/water inverse problem is proposed, to enable dual rBW reconstructions. Bipolar, flyback, and dual spin echo sequences were developed. All sequences acquire two echoes with different rBW without dead time. Chemical shift displacement was corrected by performing the fat/water separation in k-space, prior to gridding. The proposed sequences were compared to fat saturation, and single rBW sequences, in terms of SNR and CNR efficiency, using clinically relevant acquisition parameters. The impact of motion was investigated. Chemical shift correction greatly improved the image quality, especially at high resolution acquired with low rBW, and also improved motion estimates. SNR efficiency of the dual spin echo sequence was up to 20% higher than the single rBW acquisition, while CNR efficiency was 50% higher for the bipolar acquisition. Noise whitening was deemed necessary for all dual rBW acquisitions, rendering high image quality with strong and homogenous fat suppression. Dual rBW sequences eliminate the dead time present in single rBW sequences, which improves SNR efficiency. In combination with the proposed regularization, this enables highly efficient T1-weighted PROPELLER images without chemical shift displacement. © 2018 International Society for Magnetic Resonance in Medicine.

  3. Altered cytokine production by specific human peripheral blood cell subsets immediately following space flight

    NASA Technical Reports Server (NTRS)

    Crucian, B. E.; Cubbage, M. L.; Sams, C. F.

    2000-01-01

    In this study, flow cytometry was used to positively identify the specific lymphocyte subsets exhibiting space flight-induced alterations in cytokine production. Whole blood samples were collected from 27 astronauts at three points (one preflight, two postflight) surrounding four space shuttle missions. Assays performed included serum/urine stress hormones, white blood cell (WBC) phenotyping, and intracellular cytokine production following mitogenic stimulation. Absolute levels of peripheral granulocytes were significantly elevated following space flight, but the levels of circulating lymphocytes and monocytes were unchanged. Lymphocyte subset analysis demonstrated a decreased percentage of T cells, whereas percentages of B cells and natural killer (NK) cells remained unchanged after flight. Nearly all the astronauts exhibited an increased CD4/CD8 T cell ratio. Assessment of naive (CD45RA+) vs. memory (CD45RO+) CD4+ T cell subsets was ambiguous, and subjects tended to group within specific missions. Although no significant trend was seen in absolute monocyte levels, a significant decrease in the percentage of the CD14+ CD16+ monocytes was seen following space flight in all subjects tested. T cell (CD3+) production of interleukin-2 (IL-2) was significantly decreased after space flight, as was IL-2 production by both CD4+ and CD8+ T cell subsets. Production of interferon-gamma (IFN-gamma) was not altered by space flight for the CD8+ cell subset, but there was a significant decrease in IFN-gamma production for the CD4+ T cell subset. Serum and urine stress hormone analysis indicated significant physiologic stresses in astronauts following space flight. Altered peripheral leukocyte subsets, altered serum and urine stress hormone levels, and altered T cell cytokine secretion profiles were all observed postflight. In addition, there appeared to be differential susceptibility to space flight regarding cytokine secretion by T cell subsets. These alterations may be the

  4. Kiss High Blood Pressure Goodbye: The Relationship between Dark Chocolate and Hypertension

    ERIC Educational Resources Information Center

    Nordmoe, Eric D.

    2008-01-01

    This article reports on a delicious finding from a recent study claiming a causal link between dark chocolate consumption and blood pressure reductions. In the article, I provide ideas for using this study to whet student appetites for a discussion of statistical ideas, including experimental design, measurement error and inference methods.

  5. Effect of high protein vs high carbohydrate intake on insulin sensitivity, body weight, hemoglobin A1c, and blood pressure in patients with type 2 diabetes mellitus.

    PubMed

    Sargrad, Karin R; Homko, Carol; Mozzoli, Maria; Boden, Guenther

    2005-04-01

    Extremely low carbohydrate/high protein diets are popular methods of weight loss. Compliance with these diets is poor and long-term effectiveness and the safety of these diets for patients with type 2 diabetes is not known. The objective of the current study was to evaluate effects of less extreme changes in carbohydrate or protein diets on weight, insulin sensitivity, glycemic control, cardiovascular risk factors (blood pressure, lipid levels), and renal function in obese inner-city patients with type 2 diabetes. Study patients were admitted to the General Clinical Research Center for 24 hours for initial tests including a hyperinsulinemic-euglycemic clamp (for measurement of insulin sensitivity), bioelectrical impedance analysis (BIA) and anthropometric measurements (for assessment of body composition), indirect calorimetry (for measurement of REE), electronic blood pressure monitoring, and blood chemistries to measure blood lipids levels along with renal and hepatic functions. Six patients with type 2 diabetes (five women and one man) were randomly assigned to the high-protein diet (40% carbohydrate, 30% protein, 30% fat) and six patients (four women and two men) to the high-carbohydrate diet (55% carbohydrate, 15% protein, 30% fat). All patients returned to the General Clinical Research Center weekly for monitoring of food records; dietary compliance; and measurements of body weight, blood pressure, and blood glucose. After 8 weeks on these diets, all patients were readmitted to the General Clinical Research Center for the same series of tests. Twelve study patients were taught to select either the high-protein or high-carbohydrate diet and were followed for 8 weeks. Insulin sensitivity, hemoglobin A1c, weight, and blood pressure were measured. Statistical significance was assessed using two-tailed Student's t tests and two-way repeated measures analysis of variance. Both the high-carbohydrate and high-protein groups lost weight (-2.2+/-0.9 kg, -2.5+/-1.6 kg

  6. Sensitivity of Space Shuttle Weight and Cost to Structure Subsystem Weights

    NASA Technical Reports Server (NTRS)

    Wedge, T. E.; Williamson, R. P.

    1973-01-01

    Quantitative relationships between changes in space shuttle weights and costs with changes in weight of various portions of space shuttle structural subsystems are investigated. These sensitivity relationships, as they apply at each of three points in the development program (preliminary design phase, detail design phase, and test/operational phase) have been established for five typical space shuttle designs, each of which was responsive to the missions in the NASA Shuttle RFP, and one design was that selected by NASA.

  7. Dark-cycle monitoring of biological subjects on Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Chuang, Sherry; Mian, Arshad

    1992-01-01

    The operational environment for biological research on Space Station Freedom will incorporate video technology for monitoring plant and animal subjects. The video coverage must include dark-cycle monitoring because early experiments will use rodents that are nocturnal and therefore most active during the dark part of the daily cycle. Scientific requirements for monitoring during the dark cycle are exacting. Infrared (IR) or near-IR sensors are required. The trade-offs between these two types of sensors are based on engineering constraints, sensitivity spectra, and the quality of imagery possible from each type. This paper presents results of a study conducted by the Biological Flight Research Projects Office in conjunction with the Spacecraft Data Systems Branch at ARC to investigate the use of charged-coupled-device and IR cameras to meet the scientific requirements. Also examined is the effect of low levels of near-IR illumination on the circadian rhythm in rats.

  8. Giving pandas ROOT to chew on: experiences with the XENON1T Dark Matter experiment

    NASA Astrophysics Data System (ADS)

    Remenska, D.; Tunnell, C.; Aalbers, J.; Verhoeven, S.; Maassen, J.; Templon, J.

    2017-10-01

    In preparation for the XENON1T Dark Matter data acquisition, we have prototyped and implemented a new computing model. The XENON signal and data processing software is developed fully in Python 3, and makes extensive use of generic scientific data analysis libraries, such as the SciPy stack. A certain tension between modern “Big Data” solutions and existing HEP frameworks is typically experienced in smaller particle physics experiments. ROOT is still the “standard” data format in our field, defined by large experiments (ATLAS, CMS). To ease the transition, our computing model caters to both analysis paradigms, leaving the choice of using ROOT-specific C++ libraries, or alternatively, Python and its data analytics tools, as a front-end choice of developing physics algorithms. We present our path on harmonizing these two ecosystems, which allowed us to use off-the-shelf software libraries (e.g., NumPy, SciPy, scikit-learn, matplotlib) and lower the cost of development and maintenance. To analyse the data, our software allows researchers to easily create “mini-trees” small, tabular ROOT structures for Python analysis, which can be read directly into pandas DataFrame structures. One of our goals was making ROOT available as a cross-platform binary for an easy installation from the Anaconda Cloud (without going through the “dependency hell”). In addition to helping us discover dark matter interactions, lowering this barrier helps shift the particle physics toward non-domain-specific code.

  9. Local dark matter and dark energy as estimated on a scale of ~1 Mpc in a self-consistent way

    NASA Astrophysics Data System (ADS)

    Chernin, A. D.; Teerikorpi, P.; Valtonen, M. J.; Dolgachev, V. P.; Domozhilova, L. M.; Byrd, G. G.

    2009-12-01

    Context: Dark energy was first detected from large distances on gigaparsec scales. If it is vacuum energy (or Einstein's Λ), it should also exist in very local space. Here we discuss its measurement on megaparsec scales of the Local Group. Aims: We combine the modified Kahn-Woltjer method for the Milky Way-M 31 binary and the HST observations of the expansion flow around the Local Group in order to study in a self-consistent way and simultaneously the local density of dark energy and the dark matter mass contained within the Local Group. Methods: A theoretical model is used that accounts for the dynamical effects of dark energy on a scale of ~1 Mpc. Results: The local dark energy density is put into the range 0.8-3.7ρv (ρv is the globally measured density), and the Local Group mass lies within 3.1-5.8×1012 M⊙. The lower limit of the local dark energy density, about 4/5× the global value, is determined by the natural binding condition for the group binary and the maximal zero-gravity radius. The near coincidence of two values measured with independent methods on scales differing by ~1000 times is remarkable. The mass ~4×1012 M⊙ and the local dark energy density ~ρv are also consistent with the expansion flow close to the Local Group, within the standard cosmological model. Conclusions: One should take into account the dark energy in dynamical mass estimation methods for galaxy groups, including the virial theorem. Our analysis gives new strong evidence in favor of Einstein's idea of the universal antigravity described by the cosmological constant.

  10. Changes in blood manganese concentration and MRI t1 relaxation time during 180 days of stainless steel welding-fume exposure in cynomolgus monkeys.

    PubMed

    Sung, Jae Hyuck; Kim, Choong Yong; Yang, Seoung Oh; Khang, Hyun Soo; Cheong, Hae Kwan; Lee, Jong Seong; Song, Chang-Woo; Park, Jung Duck; Han, Jeong Hee; Chung, Yong Hyun; Choi, Byung Sun; Kwon, Il Hoon; Cho, Myung Haeng; Yu, Il Je

    2007-01-01

    Welders are at risk of being exposed to high concentrations of welding fumes and developing pneumoconiosis or other welding-fume exposure-related diseases. Among such diseases, manganism resulting from welding-fume exposure remains a controversial issue, as although the movement of manganese into specific brain regions has been established, the similar movement of manganese presented with other metals, such as welding fumes, has not been clearly demonstrated as being similar to that of manganese alone. Meanwhile, the competition between Mn and iron for iron transporters, such as transferrin and DMT-1, to the brain has also been implicated in the welding-fume exposure. Thus, the increased signal intensities in the basal ganglia, including the globus pallidus and subcortical frontal white matter, based on T1-weighted magnetic resonances in welders, require further examination as regards the correspondence with an increased manganese concentration. Accordingly, to investigate the movement of manganese after welding-fume exposure, 6 cynomolgus monkeys were acclimated for 1 mo and assigned to 3 dose groups: unexposed, low dose of (total suspended particulate [TSP] 31 mg/m3, 0.9 mg/m3 of Mn), and high dose of total suspended particulate (62 mg/m3 TSP, 1.95 mg/m3 of Mn). The primates were exposed to manual metal-arc stainless steel (MMA-SS) welding fumes for 2 h/day in an inhalation chamber system equipped with an automatic fume generator for 6 mo. Magnetic resonance imaging (MRI) studies of the basal ganglia were conducted before the initiation of exposure and thereafter every month. During the exposure, the blood chemistry was monitored every 2 wk and the concentrations of metal components in the blood were measured every 2 wk and compared with ambient manganese concentrations. The manganese concentrations in the blood did not show any significant increase until after 2 mo of exposure, and then reached a plateau after 90 days of exposure, showing that an exposure period

  11. Dirac dark matter and b →s ℓ+ℓ- with U(1) gauge symmetry

    NASA Astrophysics Data System (ADS)

    Celis, Alejandro; Feng, Wan-Zhe; Vollmann, Martin

    2017-02-01

    We revisit the possibility of a Dirac fermion dark matter candidate in the light of current b →s ℓ+ℓ- anomalies by investigating a minimal extension of the Standard Model with a horizontal U(1 ) ' local symmetry. Dark matter stability is protected by a remnant Z2 symmetry arising after spontaneous symmetry breaking of U(1 ) '. The associated Z' gauge boson can accommodate current hints of new physics in b →s ℓ+ℓ- decays, and acts as a vector portal between dark matter and the visible sector. We find that the model is severely constrained by a combination of precision measurements at flavor factories, LHC searches for dilepton resonances, as well as direct and indirect dark matter searches. Despite this, viable regions of the parameter space accommodating the observed dark matter relic abundance and the b →s ℓ+ℓ-anomalies still persist for dark matter and Z ' masses in the TeV range.

  12. SpaceCube Version 1.5

    NASA Technical Reports Server (NTRS)

    Geist, Alessandro; Lin, Michael; Flatley, Tom; Petrick, David

    2013-01-01

    SpaceCube 1.5 is a high-performance and low-power system in a compact form factor. It is a hybrid processing system consisting of CPU (central processing unit), FPGA (field-programmable gate array), and DSP (digital signal processor) processing elements. The primary processing engine is the Virtex- 5 FX100T FPGA, which has two embedded processors. The SpaceCube 1.5 System was a bridge to the SpaceCube 2.0 and SpaceCube 2.0 Mini processing systems. The SpaceCube 1.5 system was the primary avionics in the successful SMART (Small Rocket/Spacecraft Technology) Sounding Rocket mission that was launched in the summer of 2011. For SMART and similar missions, an avionics processor is required that is reconfigurable, has high processing capability, has multi-gigabit interfaces, is low power, and comes in a rugged/compact form factor. The original SpaceCube 1.0 met a number of the criteria, but did not possess the multi-gigabit interfaces that were required and is a higher-cost system. The SpaceCube 1.5 was designed with those mission requirements in mind. The SpaceCube 1.5 features one Xilinx Virtex-5 FX100T FPGA and has excellent size, weight, and power characteristics [4×4×3 in. (approx. = 10×10×8 cm), 3 lb (approx. = 1.4 kg), and 5 to 15 W depending on the application]. The estimated computing power of the two PowerPC 440s in the Virtex-5 FPGA is 1100 DMIPS each. The SpaceCube 1.5 includes two Gigabit Ethernet (1 Gbps) interfaces as well as two SATA-I/II interfaces (1.5 to 3.0 Gbps) for recording to data drives. The SpaceCube 1.5 also features DDR2 SDRAM (double data rate synchronous dynamic random access memory); 4- Gbit Flash for storing application code for the CPU, FPGA, and DSP processing elements; and a Xilinx Platform Flash XL to store FPGA configuration files or application code. The system also incorporates a 12 bit analog to digital converter with the ability to read 32 discrete analog sensor inputs. The SpaceCube 1.5 design also has a built

  13. Multidimensional Space-Time Methodology for Development of Planetary and Space Sciences, S-T Data Management and S-T Computational Tomography

    NASA Astrophysics Data System (ADS)

    Andonov, Zdravko

    This R&D represent innovative multidimensional 6D-N(6n)D Space-Time (S-T) Methodology, 6D-6nD Coordinate Systems, 6D Equations, new 6D strategy and technology for development of Planetary Space Sciences, S-T Data Management and S-T Computational To-mography. . . The Methodology is actual for brain new RS Microwaves' Satellites and Compu-tational Tomography Systems development, aimed to defense sustainable Earth, Moon, & Sun System evolution. Especially, extremely important are innovations for monitoring and protec-tion of strategic threelateral system H-OH-H2O Hydrogen, Hydroxyl and Water), correspond-ing to RS VHRS (Very High Resolution Systems) of 1.420-1.657-22.089GHz microwaves. . . One of the Greatest Paradox and Challenge of World Science is the "transformation" of J. L. Lagrange 4D Space-Time (S-T) System to H. Minkovski 4D S-T System (O-X,Y,Z,icT) for Einstein's "Theory of Relativity". As a global result: -In contemporary Advanced Space Sciences there is not real adequate 4D-6D Space-Time Coordinate System and 6D Advanced Cosmos Strategy & Methodology for Multidimensional and Multitemporal Space-Time Data Management and Tomography. . . That's one of the top actual S-T Problems. Simple and optimal nD S-T Methodology discovery is extremely important for all Universities' Space Sci-ences' Education Programs, for advances in space research and especially -for all young Space Scientists R&D!... The top ten 21-Century Challenges ahead of Planetary and Space Sciences, Space Data Management and Computational Space Tomography, important for successfully de-velopment of Young Scientist Generations, are following: 1. R&D of W. R. Hamilton General Idea for transformation all Space Sciences to Time Sciences, beginning with 6D Eukonal for 6D anisotropic mediums & velocities. Development of IERS Earth & Space Systems (VLBI; LLR; GPS; SLR; DORIS Etc.) for Planetary-Space Data Management & Computational Planetary & Space Tomography. 2. R&D of S. W. Hawking Paradigm for 2D

  14. T2‐Weighted intracranial vessel wall imaging at 7 Tesla using a DANTE‐prepared variable flip angle turbo spin echo readout (DANTE‐SPACE)

    PubMed Central

    Viessmann, Olivia; Li, Linqing; Benjamin, Philip

    2016-01-01

    Purpose To optimize intracranial vessel wall imaging (VWI) at 7T for sharp wall depiction and high boundary contrast. Methods A variable flip angle turbo spin echo scheme (SPACE) was optimized for VWI. SPACE provides black‐blood contrast, but has less crushing effect on cerebrospinal fluid (CSF). However, a delay alternating with nutation for tailored excitation (DANTE) preparation suppresses the signal from slowly moving spins of a few mm per second. Therefore, we optimized a DANTE‐preparation module for 7T. Signal‐to‐noise ratio (SNR), contrast‐to‐noise ratio (CNR), and signal ratio for vessel wall, CSF, and lumen were calculated for SPACE and DANTE‐SPACE in 11 volunteers at the middle cerebral artery (MCA). An exemplar MCA stenosis patient was scanned with DANTE‐SPACE. Results The 7T‐optimized SPACE sequence improved the vessel wall point‐spread function by 17%. The CNR between the wall and CSF was doubled (12.2 versus 5.6) for the DANTE‐SPACE scans compared with the unprepared SPACE. This increase was significant in the right hemisphere (P = 0.016), but not in the left (P = 0.090). The CNR between wall and lumen was halved, but remained at a high value (24.9 versus 56.5). Conclusion The optimized SPACE sequence improves VWI at 7T. Additional DANTE preparation increases the contrast between the wall and CSF. Increased outer boundary contrast comes at the cost of reduced inner boundary contrast. Magn Reson Med 77:655–663, 2017. © 2016 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 License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. PMID:26890988

  15. Impact of Dietary Acculturation on the Food Habits, Weight, Blood Pressure, and Fasting Blood Glucose Levels of International College Students.

    PubMed

    Almohanna, Amal; Conforti, Frank; Eigel, William; Barbeau, William

    2015-01-01

    This study was conducted to determine the impact of dietary acculturation on the health status of newly arrived international students at Virginia Tech in Fall 2010. Thirty-five international students, 18-36 years of age, completed the study. Data were collected at 3 different time periods (V1, V2, and V3) approximately 6 weeks apart. A food frequency- and dietary pattern-related questionnaire was administered and numerically coded responses were analyzed. Twenty-four-hour dietary recall data were also collected at V1, V2, and V3. Body weight, fasting blood glucose level, and blood pressure of study participants were also determined at each time period. Total sample population (TSP) had a significant increase in mean weight of 2.79 lb from visit 1 (V1) to visit 3 (V3) (p = .0082). Ten participants gained an average of 9.0 lb (participants who gained weight; n = 10). There was also an increase in the frequency of consumption of high-calorie American food items from V1 to V3. However, there were no significant changes in mean systolic blood pressure and mean fasting blood glucose was significantly lower at V3 than at V1. There was a gradual shift in the dietary patterns of international students towards the American diet. Dietary acculturation led to weight gain among some of the students, which may potentially have a negative impact on their health status if continued for longer time periods.

  16. Dark matter in NGC 4472

    NASA Technical Reports Server (NTRS)

    Loewenstein, Michael

    1992-01-01

    An attempt is made to constrain the total mass distribution of the giant elliptical galaxy NGC 4472 by constructing simultaneous equilibrium models for the gas and stars. Emphasis is given to reconciling the value of the emission-weighted average value of kT derived from the Ginga spectrum with the amount of dark matter needed to account for velocity dispersion observations.

  17. Diagnostic value of T1-weighted gradient-echo in-phase images added to MRCP in differentiation of hepatolithiasis and intrahepatic pneumobilia.

    PubMed

    Erden, Ayşe; Haliloğlu, Nuray; Genç, Yasemin; Erden, Ilhan

    2014-01-01

    The purpose of this article is to determine the added diagnostic value of T1-weighted gradient-echo in-phase images obtained during MRCP in the detection and differentiation of hepatolithiasis and intrahepatic pneumobilia. Intrahepatic bile ducts in 47 patients were scored in terms of their possibility of containing biliary stone and air. MRI was performed with a 1-T system for 32 patients and with a 3-T system for 15 patients. Two radiologists independently reviewed two sets of MRI scans: set 1 included T2-weighted MRCP images, and set 2 included T2-weighted MRCP images plus T1-weighted gradient-echo in-phase images. The diagnostic performances of set 1 and set 2 in the evaluation of the bile ducts containing air or stone and bile ducts containing neither of them were analyzed using the area under the receiver operating characteristic curve (AUC) for clustered data. The sensitivities and specificities of both image sets to detect intrahepatic stone or air were also calculated and compared. For the diagnosis of hepatolithiasis, the AUC obtained from set 2 (0.983) was significantly higher than that obtained from set 1 (0.879; p = 0.037). For the diagnosis of pneumobilia, the AUC obtained from set 2 (0.965) was also significantly higher than that of set 1 (0.765; p = 0.002). With use of percutaneous transhepatic cholangiography, ERCP, and CT as the reference standards, the sensitivity of set 2 (97.1%; 95% CI, 91.1-100%) was significantly higher than that of set 1 (74.3%; 95% CI, 56.7-91.9%) in detecting intrahepatic stones (p = 0.011). For the detection of pneumobilia, the sensitivity of set 2 (98.5%; 95% CI, 95.4-100%) was also significantly higher than that of set 1 (70.8%; 95% CI, 57.7-83.3%; p = 0.000). The addition of T1-weighted gradient-echo in-phase images to standard MRCP sequences improves the detection and differentiation of hepatolithiasis and intrahepatic pneumobilia.

  18. Two-dimensional T2 distribution mapping in rock core plugs with optimal k-space sampling.

    PubMed

    Xiao, Dan; Balcom, Bruce J

    2012-07-01

    Spin-echo single point imaging has been employed for 1D T(2) distribution mapping, but a simple extension to 2D is challenging since the time increase is n fold, where n is the number of pixels in the second dimension. Nevertheless 2D T(2) mapping in fluid saturated rock core plugs is highly desirable because the bedding plane structure in rocks often results in different pore properties within the sample. The acquisition time can be improved by undersampling k-space. The cylindrical shape of rock core plugs yields well defined intensity distributions in k-space that may be efficiently determined by new k-space sampling patterns that are developed in this work. These patterns acquire 22.2% and 11.7% of the k-space data points. Companion density images may be employed, in a keyhole imaging sense, to improve image quality. T(2) weighted images are fit to extract T(2) distributions, pixel by pixel, employing an inverse Laplace transform. Images reconstructed with compressed sensing, with similar acceleration factors, are also presented. The results show that restricted k-space sampling, in this application, provides high quality results. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Study on the mapping of dark matter clustering from real space to redshift space

    NASA Astrophysics Data System (ADS)

    Zheng, Yi; Song, Yong-Seon

    2016-08-01

    The mapping of dark matter clustering from real space to redshift space introduces the anisotropic property to the measured density power spectrum in redshift space, known as the redshift space distortion effect. The mapping formula is intrinsically non-linear, which is complicated by the higher order polynomials due to indefinite cross correlations between the density and velocity fields, and the Finger-of-God effect due to the randomness of the peculiar velocity field. Whilst the full higher order polynomials remain unknown, the other systematics can be controlled consistently within the same order truncation in the expansion of the mapping formula, as shown in this paper. The systematic due to the unknown non-linear density and velocity fields is removed by separately measuring all terms in the expansion directly using simulations. The uncertainty caused by the velocity randomness is controlled by splitting the FoG term into two pieces, 1) the ``one-point" FoG term being independent of the separation vector between two different points, and 2) the ``correlated" FoG term appearing as an indefinite polynomials which is expanded in the same order as all other perturbative polynomials. Using 100 realizations of simulations, we find that the Gaussian FoG function with only one scale-independent free parameter works quite well, and that our new mapping formulation accurately reproduces the observed 2-dimensional density power spectrum in redshift space at the smallest scales by far, up to k~ 0.2 Mpc-1, considering the resolution of future experiments.

  20. Study on the mapping of dark matter clustering from real space to redshift space

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zheng, Yi; Song, Yong-Seon, E-mail: yizheng@kasi.re.kr, E-mail: ysong@kasi.re.kr

    The mapping of dark matter clustering from real space to redshift space introduces the anisotropic property to the measured density power spectrum in redshift space, known as the redshift space distortion effect. The mapping formula is intrinsically non-linear, which is complicated by the higher order polynomials due to indefinite cross correlations between the density and velocity fields, and the Finger-of-God effect due to the randomness of the peculiar velocity field. Whilst the full higher order polynomials remain unknown, the other systematics can be controlled consistently within the same order truncation in the expansion of the mapping formula, as shown inmore » this paper. The systematic due to the unknown non-linear density and velocity fields is removed by separately measuring all terms in the expansion directly using simulations. The uncertainty caused by the velocity randomness is controlled by splitting the FoG term into two pieces, 1) the ''one-point' FoG term being independent of the separation vector between two different points, and 2) the ''correlated' FoG term appearing as an indefinite polynomials which is expanded in the same order as all other perturbative polynomials. Using 100 realizations of simulations, we find that the Gaussian FoG function with only one scale-independent free parameter works quite well, and that our new mapping formulation accurately reproduces the observed 2-dimensional density power spectrum in redshift space at the smallest scales by far, up to k ∼ 0.2 Mpc{sup -1}, considering the resolution of future experiments.« less

  1. ABCB1 C3435T polymorphism is associated with tetrahydrocannabinol blood levels in heavy cannabis users.

    PubMed

    Kebir, Oussama; Lafaye, Genevieve; Blecha, Lisa; Chaumette, Boris; Mouaffak, Fayçal; Laqueille, Xavier; Benyamina, Amine

    2018-04-01

    ABCB1 polymorphisms are known to modify drug pharmacokinetics but have yet to be studied for their role in generating and maintaining cannabis dependence. The objective of this study is to determine if ABCB1 C3435T (rs1045642) polymorphism may modulate Δ9-Tetrahydrocannabinol (THC) blood levels in a sample of heavy cannabis users. The study sample includes 39 Caucasian individuals, recruited in two French addictology centres, with isolated cannabis dependence and heavy use (defined as ≥ 7 joints per week). Each underwent clinical evaluation, cannabis blood metabolite dosage (THC, 11-OH-THC, and THC-COOH) and genotyping of ABCB1 C3435T polymorphism. In this population (males: 74.4%, average age 29.5 +/- 9), average cannabis use was 21 joints per week (median 12; range 7 - 80). T carriers (TT/CT) had significantly lower plasma THC levels (ng/ml) versus non T carriers (8 vs 15.70, significant), controlling for level of weekly use, 11-OH-THC and THC-COOH levels. Our results show that ABCB1 C3435T polymorphism may modulate serum THC levels in chronic heavy cannabis users. The exact mechanisms and roles that this may play in cannabis dependence genesis and evolution remain to be elucidated. These results should be controlled in a replication study using a larger population. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Closed-form expressions for flip angle variation that maximize total signal in T1-weighted rapid gradient echo MRI.

    PubMed

    Drobnitzky, Matthias; Klose, Uwe

    2017-03-01

    Magnetization-prepared rapid gradient-echo (MPRAGE) sequences are commonly employed for T1-weighted structural brain imaging. Following a contrast preparation radiofrequency (RF) pulse, the data acquisition proceeds under nonequilibrium conditions of the relaxing longitudinal magnetization. Variation of the flip angle can be used to maximize total available signal. Simulated annealing or greedy algorithms have so far been published to numerically solve this problem, with signal-to-noise ratios optimized for clinical imaging scenarios by adhering to a predefined shape of the signal evolution. We propose an unconstrained optimization of the MPRAGE experiment that employs techniques from resource allocation theory. A new dynamic programming solution is introduced that yields closed-form expressions for optimal flip angle variation. Flip angle series are proposed that maximize total transverse magnetization (Mxy) for a range of physiologic T1 values. A 3D MPRAGE sequence is modified to allow for a controlled variation of the excitation angle. Experiments employing a T1 contrast phantom are performed at 3T. 1D acquisitions without phase encoding permit measurement of the temporal development of Mxy. Image mean signal and standard deviation for reference flip angle trains are compared in 2D measurements. Signal profiles at sharp phantom edges are acquired to access image blurring related to nonuniform Mxy development. A novel closed-form expression for flip angle variation is found that constitutes the optimal policy to reach maximum total signal. It numerically equals previously published results of other authors when evaluated under their simplifying assumptions. Longitudinal magnetization (Mz) is exhaustively used without causing abrupt changes in the measured MR signal, which is a prerequisite for artifact free images. Phantom experiments at 3T verify the expected benefit for total accumulated k-space signal when compared with published flip angle series. Describing

  3. Spectral analysis of difference and differential operators in weighted spaces

    NASA Astrophysics Data System (ADS)

    Bichegkuev, M. S.

    2013-11-01

    This paper is concerned with describing the spectrum of the difference operator \\displaystyle \\mathscr{K}\\colon l_\\alpha^p( Z,X)\\to l_\\alpha^p( Z......athscr{K}x)(n)=Bx(n-1), \\ \\ n\\in{Z}, \\ \\ x\\in l_\\alpha^p( Z,X), with a constant operator coefficient B, which is a bounded linear operator in a Banach space X. It is assumed that \\mathscr{K} acts in the weighted space l_\\alpha^p( Z,X), 1\\leq p\\leq \\infty, of two-sided sequences of vectors from X. The main results are obtained in terms of the spectrum \\sigma(B) of the operator coefficient B and properties of the weight function. Applications to the study of the spectrum of a differential operator with an unbounded operator coefficient (the generator of a strongly continuous semigroup of operators) in weighted function spaces are given. Bibliography: 23 titles.

  4. The DarkSide awakens

    NASA Astrophysics Data System (ADS)

    Davini, S.; Agnes, P.; Agostino, L.; Albuquerque, I. F. M.; Alexander, T.; Alton, A. K.; Arisaka, K.; Back, H. O.; Baldin, B.; Biery, K.; Bonfini, G.; Bossa, M.; Bottino, B.; Brigatti, A.; Brodsky, J.; Budano, F.; Bussino, S.; Cadeddu, M.; Cadonati, L.; Cadoni, M.; Calaprice, F.; Canci, N.; Candela, A.; Cao, H.; Cariello, M.; Carlini, M.; Catalanotti, S.; Cavalcante, P.; Chepurnov, A.; Cocco, A. G.; Covone, G.; D'Angelo, D.; D'Incecco, M.; De Cecco, S.; De Deo, M.; De Vincenzi, M.; Derbin, A.; Devoto, A.; Di Eusanio, F.; Di Pietro, G.; Edkins, E.; Empl, A.; Fan, A.; Fiorillo, G.; Fomenko, K.; Foster, G.; Franco, D.; Gabriele, F.; Galbiati, C.; Giganti, C.; Goretti, A. M.; Granato, F.; Grandi, L.; Gromov, M.; Guan, M.; Guardincerri, Y.; Hackett, B. R.; Herner, K. R.; Hungerford, E. V.; Ianni, Aldo; Ianni, Andrea; James, I.; Jollet, C.; Keeter, K.; Kendziora, C. L.; Kobychev, V.; Koh, G.; Korablev, D.; Korga, G.; Kubankin, A.; Li, X.; Lissia, M.; Lombardi, P.; Luitz, S.; Ma, Y.; Machulin, I. N.; Mandarano, A.; Mari, S. M.; Maricic, J.; Marini, L.; Martoff, C. J.; Meregaglia, A.; Meyers, P. D.; Miletic, T.; Milincic, R.; Montanari, D.; Monte, A.; Montuschi, M.; Monzani, M. E.; Mosteiro, P.; Mount, B. J.; Muratova, V. N.; Musico, P.; Napolitano, J.; Orsini, M.; Ortica, F.; Pagani, L.; Pallavicini, M.; Pantic, E.; Parmeggiano, S.; Pelczar, K.; Pelliccia, N.; Perasso, S.; Pocar, A.; Pordes, S.; Pugachev, D. A.; Qian, H.; Randle, K.; Ranucci, G.; Razeto, A.; Reinhold, B.; Renshaw, A. L.; Romani, A.; Rossi, B.; Rossi, N.; Rountree, S. D.; Sablone, D.; Saggese, P.; Saldanha, R.; Sands, W.; Sangiorgio, S.; Savarese, C.; Segreto, E.; Semenov, D. A.; Shields, E.; Singh, P. N.; Skorokhvatov, M. D.; Smirnov, O.; Sotnikov, A.; Stanford, C.; Suvorov, Y.; Tartaglia, R.; Tatarowicz, J.; Testera, G.; Tonazzo, A.; Trinchese, P.; Unzhakov, E. V.; Vishneva, A.; Vogelaar, B.; Wada, M.; Walker, S.; Wang, H.; Wang, Y.; Watson, A. W.; Westerdale, S.; Wilhelmi, J.; Wojcik, M. M.; Xiang, X.; Xu, J.; Yang, C.; Yoo, J.; Zavatarelli, S.; Zec, A.; Zhong, W.; Zhu, C.; Zuzel, G.

    2016-05-01

    The DarkSide program at LNGS aims to perform background-free WIMP searches using two phase liquid argon time projection chambers, with the ultimate goal of covering all parameters down to the so-called neutrino floor. One of the distinct features of the program is the use of underground argon with has a reduced content of the radioactive 39Ar compared to atmospheric argon. The DarkSide Collaboration is currently operating the DarkSide-50 experiment, the first such WIMP detector using underground argon. Operations with underground argon indicate a suppression of 39Ar by a factor (1.4 ± 0.2) × 103 relative to atmospheric argon. The new results obtained with DarkSide-50 and the plans for the next steps of the DarkSide program, the 20t fiducial mass DarkSide-20k detector and the 200 t fiducial Argo, are reviewed in this proceedings.

  5. STrategically Acquired Gradient Echo (STAGE) imaging, part I: Creating enhanced T1 contrast and standardized susceptibility weighted imaging and quantitative susceptibility mapping.

    PubMed

    Chen, Yongsheng; Liu, Saifeng; Wang, Yu; Kang, Yan; Haacke, E Mark

    2018-02-01

    To provide whole brain grey matter (GM) to white matter (WM) contrast enhanced T1W (T1WE) images, multi-echo quantitative susceptibility mapping (QSM), proton density (PD) weighted images, T1 maps, PD maps, susceptibility weighted imaging (SWI), and R2* maps with minimal misregistration in scanning times <5min. Strategically acquired gradient echo (STAGE) imaging includes two fully flow compensated double echo gradient echo acquisitions with a resolution of 0.67×1.33×2.0mm 3 acquired in 5min for 64 slices. Ten subjects were recruited and scanned at 3 Tesla. The optimum pair of flip angles (6° and 24° with TR=25ms at 3T) were used for both T1 mapping with radio frequency (RF) transmit field correction and creating enhanced GM/WM contrast (the T1WE). The proposed T1WE image was created from a combination of the proton density weighted (6°, PDW) and T1W (24°) images and corrected for RF transmit field variations. Prior to the QSM calculation, a multi-echo phase unwrapping strategy was implemented using the unwrapped short echo to unwrap the longer echo to speed up computation. R2* maps were used to mask deep grey matter and veins during the iterative QSM calculation. A weighted-average sum of susceptibility maps was generated to increase the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR). The proposed T1WE image has a significantly improved CNR both for WM to deep GM and WM to cortical GM compared to the acquired T1W image (the first echo of 24° scan) and the T1MPRAGE image. The weighted-average susceptibility maps have 80±26%, 55±22%, 108±33% SNR increases across the ten subjects compared to the single echo result of 17.5ms for the putamen, caudate nucleus, and globus pallidus, respectively. STAGE imaging offers the potential to create a standardized brain imaging protocol providing four pieces of quantitative tissue property information and multiple types of qualitative information in just 5min. Published by Elsevier Inc.

  6. Evaluation of multimodal segmentation based on 3D T1-, T2- and FLAIR-weighted images - the difficulty of choosing.

    PubMed

    Lindig, Tobias; Kotikalapudi, Raviteja; Schweikardt, Daniel; Martin, Pascal; Bender, Friedemann; Klose, Uwe; Ernemann, Ulrike; Focke, Niels K; Bender, Benjamin

    2018-04-15

    Voxel-based morphometry is still mainly based on T1-weighted MRI scans. Misclassification of vessels and dura mater as gray matter has been previously reported. Goal of the present work was to evaluate the effect of multimodal segmentation methods available in SPM12, and their influence on identification of age related atrophy and lesion detection in epilepsy patients. 3D T1-, T2- and FLAIR-images of 77 healthy adults (mean age 35.8 years, 19-66 years, 45 females), 7 patients with malformation of cortical development (MCD) (mean age 28.1 years,19-40 years, 3 females), and 5 patients with left hippocampal sclerosis (LHS) (mean age 49.0 years, 25-67 years, 3 females) from a 3T scanner were evaluated. Segmentation based on T1-only, T1+T2, T1+FLAIR, T2+FLAIR, and T1+T2+FLAIR were compared in the healthy subjects. Clinical VBM results based on the different segmentation approaches for MCD and for LHS were compared. T1-only segmentation overestimated total intracranial volume by about 80ml compared to the other segmentation methods. This was due to misclassification of dura mater and vessels as GM and CSF. Significant differences were found for several anatomical regions: the occipital lobe, the basal ganglia/thalamus, the pre- and postcentral gyrus, the cerebellum, and the brainstem. None of the segmentation methods yielded completely satisfying results for the basal ganglia/thalamus and the brainstem. The best correlation with age could be found for the multimodal T1+T2+FLAIR segmentation. Highest T-scores for identification of LHS were found for T1+T2 segmentation, while highest T-scores for MCD were dependent on lesion and anatomical location. Multimodal segmentation is superior to T1-only segmentation and reduces the misclassification of dura mater and vessels as GM and CSF. Depending on the anatomical region and the pathology of interest (atrophy, lesion detection, etc.), different combinations of T1, T2 and FLAIR yield optimal results. Copyright © 2017 Elsevier

  7. Redshift space clustering of galaxies and cold dark matter model

    NASA Technical Reports Server (NTRS)

    Bahcall, Neta A.; Cen, Renyue; Gramann, Mirt

    1993-01-01

    The distorting effect of peculiar velocities on the power speturm and correlation function of IRAS and optical galaxies is studied. The observed redshift space power spectra and correlation functions of IRAS and optical the galaxies over the entire range of scales are directly compared with the corresponding redshift space distributions using large-scale computer simulations of cold dark matter (CDM) models in order to study the distortion effect of peculiar velocities on the power spectrum and correlation function of the galaxies. It is found that the observed power spectrum of IRAS and optical galaxies is consistent with the spectrum of an Omega = 1 CDM model. The problems that such a model currently faces may be related more to the high value of Omega in the model than to the shape of the spectrum. A low-density CDM model is also investigated and found to be consistent with the data.

  8. Λ(t)CDM model as a unified origin of holographic and agegraphic dark energy models

    NASA Astrophysics Data System (ADS)

    Chen, Yun; Zhu, Zong-Hong; Xu, Lixin; Alcaniz, J. S.

    2011-04-01

    Motivated by the fact that any nonzero Λ can introduce a length scale or a time scale into Einstein's theory, r=ct=3/|Λ|. Conversely, any cosmological length scale or time scale can introduce a Λ(t), Λ(t)=3/rΛ2(t)=3/(c2tΛ2(t)). In this Letter, we investigate the time varying Λ(t) corresponding to the length scales, including the Hubble horizon, the particle horizon and the future event horizon, and the time scales, including the age of the universe and the conformal time. It is found out that, in this scenario, the Λ(t)CDM model can be taken as the unified origin of the holographic and agegraphic dark energy models with interaction between the matter and the dark energy, where the interacting term is determined by Q=-ρ. We place observational constraints on the Λ(t)CDM models originating from different cosmological length scales and time scales with the recently compiled “Union2 compilation” which consists of 557 Type Ia supernovae (SNIa) covering a redshift range 0.015⩽z⩽1.4. In conclusion, an accelerating expansion universe can be derived in the cases taking the Hubble horizon, the future event horizon, the age of the universe and the conformal time as the length scale or the time scale.

  9. Effect of cold water and inverse lighting on growth performance of broiler chickens under extreme heat stress.

    PubMed

    Park, Sang-oh; Park, Byung-sung; Hwangbo, Jong

    2015-07-01

    The present study was carried out to investigate the effect of provision of extreme heat stress diet (EHD), inverse lighting, cold water on growth performance of broiler chickens exposed to extreme heat stress. The chickens were divided into four treatment groups, (T1, T2, T3, T4) as given below: Ti (EHD 1, 10:00-19:00 dark, 19:00-10:00 light, cool water 9 degrees C); T2 (EHD 2, 10:00-19:00 dark, 19:00-10:00 light, cool water 9 degrees C); T3 (EHD 1, 09:00-18:00 dark, 18:00-09:00 light, cool water 141C); T4 (EHD 2, 09:00-18:00 dark, 18:00-09:00 light, cool water 14 degrees C. EHD 1 contained soybean oil, molasses, methionine and lysine; EHD 2 contained the same ingredients as EHD 1 with addition of vitamin C. Groups T1 and T2 were given cooler water than the othertwo groups, and displayed higher body weight increase and diet intake as compared to T3 and T4 (p<0.05). The weights of their liver and gizzard were similar but the weights of the thymus and bursa of fabricius (F) were higher in groups T1 and T2 (p<0.05). It was observed that groups T1 and T2 displayed higher concentrations of blood triglyceride, total cholesterol, HDL-cholesterol and blood sugar as compared to T3 and T4; however LDL-cholesterol level was higher in groups T3 and T4 (p<0.05). T1 and T2 displayed higher levels of immunity substances such as IgG, IgAand IgM as compared to T3 and T4, but the blood level of corticosterone was lower in groups T1 and T2 (p<0.05). Ti and T2 contained higher amount of fecal Lactobacill as compared to T3 and T4; howeverT3 and T4 contained higher amount of fecal E. coli, total aerobic bacteria and coliform bacteria (p<0.05). Groups T1 and T2 displayed higher concentrations of cecal total short chain fatty acids, acetic acid and propionic acid but groups T3 and T4 displayed higher concentrations of butyric acid, isobutyric acid, valeric acid and isovaleric acid (p<0.05). The present study reports novel results such that the supply of extreme heat stress diet, inverse

  10. Accounting for the Confound of Meninges in Segmenting Entorhinal and Perirhinal Cortices in T1-Weighted MRI.

    PubMed

    Xie, Long; Wisse, Laura E M; Das, Sandhitsu R; Wang, Hongzhi; Wolk, David A; Manjón, Jose V; Yushkevich, Paul A

    2016-10-01

    Quantification of medial temporal lobe (MTL) cortices, including entorhinal cortex (ERC) and perirhinal cortex (PRC), from in vivo MRI is desirable for studying the human memory system as well as in early diagnosis and monitoring of Alzheimer's disease. However, ERC and PRC are commonly over-segmented in T1-weighted (T1w) MRI because of the adjacent meninges that have similar intensity to gray matter in T1 contrast. This introduces errors in the quantification and could potentially confound imaging studies of ERC/PRC. In this paper, we propose to segment MTL cortices along with the adjacent meninges in T1w MRI using an established multi-atlas segmentation framework together with super-resolution technique. Experimental results comparing the proposed pipeline with existing pipelines support the notion that a large portion of meninges is segmented as gray matter by existing algorithms but not by our algorithm. Cross-validation experiments demonstrate promising segmentation accuracy. Further, agreement between the volume and thickness measures from the proposed pipeline and those from the manual segmentations increase dramatically as a result of accounting for the confound of meninges. Evaluated in the context of group discrimination between patients with amnestic mild cognitive impairment and normal controls, the proposed pipeline generates more biologically plausible results and improves the statistical power in discriminating groups in absolute terms comparing to other techniques using T1w MRI. Although the performance of the proposed pipeline is inferior to that using T2-weighted MRI, which is optimized to image MTL sub-structures, the proposed pipeline could still provide important utilities in analyzing many existing large datasets that only have T1w MRI available.

  11. Make dark matter charged again

    NASA Astrophysics Data System (ADS)

    Agrawal, Prateek; Cyr-Racine, Francis-Yan; Randall, Lisa; Scholtz, Jakub

    2017-05-01

    We revisit constraints on dark matter that is charged under a U(1) gauge group in the dark sector, decoupled from Standard Model forces. We find that the strongest constraints in the literature are subject to a number of mitigating factors. For instance, the naive dark matter thermalization timescale in halos is corrected by saturation effects that slow down isotropization for modest ellipticities. The weakened bounds uncover interesting parameter space, making models with weak-scale charged dark matter viable, even with electromagnetic strength interaction. This also leads to the intriguing possibility that dark matter self-interactions within small dwarf galaxies are extremely large, a relatively unexplored regime in current simulations. Such strong interactions suppress heat transfer over scales larger than the dark matter mean free path, inducing a dynamical cutoff length scale above which the system appears to have only feeble interactions. These effects must be taken into account to assess the viability of darkly-charged dark matter. Future analyses and measurements should probe a promising region of parameter space for this model.

  12. Make dark matter charged again

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Agrawal, Prateek; Cyr-Racine, Francis-Yan; Randall, Lisa

    2017-05-01

    We revisit constraints on dark matter that is charged under a U(1) gauge group in the dark sector, decoupled from Standard Model forces. We find that the strongest constraints in the literature are subject to a number of mitigating factors. For instance, the naive dark matter thermalization timescale in halos is corrected by saturation effects that slow down isotropization for modest ellipticities. The weakened bounds uncover interesting parameter space, making models with weak-scale charged dark matter viable, even with electromagnetic strength interaction. This also leads to the intriguing possibility that dark matter self-interactions within small dwarf galaxies are extremely large,more » a relatively unexplored regime in current simulations. Such strong interactions suppress heat transfer over scales larger than the dark matter mean free path, inducing a dynamical cutoff length scale above which the system appears to have only feeble interactions. These effects must be taken into account to assess the viability of darkly-charged dark matter. Future analyses and measurements should probe a promising region of parameter space for this model.« less

  13. New Agegraphic Pilgrim Dark Energy in f(T, TG) Gravity

    NASA Astrophysics Data System (ADS)

    Jawad, Abdul; Debnath, Ujjal

    2015-08-01

    In this work, we briefly discuss a novel class of modified gravity like f(T, TG) gravity. In this background, we assume the new agegraphic version of pilgrim dark energy and reconstruct f(T, TG) models for two specific values of s. We also discuss the equation of state parameter, squared speed of sound and wDE-w‧DE plane for these reconstructed f(T, TG) models. The equation of state parameter provides phantom-like behavior of the universe. The wDE-w‧DE plane also corresponds to ΛCDM limit, thawing and freezing regions for both models.

  14. Heavily T2-weighted MR myelography vs CT myelography in spontaneous intracranial hypotension.

    PubMed

    Wang, Y-F; Lirng, J-F; Fuh, J-L; Hseu, S-S; Wang, S-J

    2009-12-01

    To assess the diagnostic accuracy of heavily T2-weighted magnetic resonance myelography (MRM) in patients with spontaneous intracranial hypotension (SIH). Patients with SIH were recruited prospectively, and first underwent MRM and then computed tomographic myelography (CTM). The results of MRM were validated with the gold standard, CTM, focusing on 1) CSF leaks along the nerve roots, 2) epidural CSF collections, and 3) high-cervical (C1-3) retrospinal CSF collections. Comparisons of these 3 findings between the 2 studies were made by kappa statistics and agreement rates. Targeted epidural blood patches (EBPs) were placed at the levels of CSF leaks if supportive treatment failed. Nineteen patients (6 men and 13 women, mean age 37.9 +/- 8.6 years) with SIH completed the study. MRM did not differ from CTM in the detection rates of CSF leaks along the nerve roots (84% vs 74%, p = 0.23), high-cervical retrospinal CSF collections (32% vs 16%, p = 0.13), and epidural CSF collections (89% vs 79%, p = 0.20). MRM demonstrated more spinal levels of CSF leaks (2.2 +/- 1.7 vs 1.5 +/- 1.5, p = 0.011) and epidural collections (12.2 +/- 5.9 vs 7.1 +/- 5.8, p < 0.001) than CTM. The overall level-by-level concordance was substantial for CSF leaks along the nerve roots (C1-L3) (kappa = 0.71, p < 0.001, agreement = 95%) and high-cervical retrospinal CSF collections (C1-3) (kappa = 0.73, p < 0.001, agreement = 92%), and moderate for epidural CSF collections (C1-L3) (kappa = 0.47, p < 0.001, agreement = 72%). Ten of the 14 patients (71%) receiving targeted EBPs experienced sustained symptomatic relief after a single attempt. Heavily T2-weighted magnetic resonance myelography was accurate in localizing CSF leaks for patients with spontaneous intracranial hypotension. This noninvasive technique may be an alternative to computed tomographic myelography before targeted epidural blood patches.

  15. Relaxivity of Ferumoxytol at 1.5 T and 3.0 T.

    PubMed

    Knobloch, Gesine; Colgan, Timothy; Wiens, Curtis N; Wang, Xiaoke; Schubert, Tilman; Hernando, Diego; Sharma, Samir D; Reeder, Scott B

    2018-05-01

    The aim of this study was to determine the relaxation properties of ferumoxytol, an off-label alternative to gadolinium-based contrast agents, under physiological conditions at 1.5 T and 3.0 T. Ferumoxytol was diluted in gradually increasing concentrations (0.26-4.2 mM) in saline, human plasma, and human whole blood. Magnetic resonance relaxometry was performed at 37°C at 1.5 T and 3.0 T. Longitudinal and transverse relaxation rate constants (R1, R2, R2*) were measured as a function of ferumoxytol concentration, and relaxivities (r1, r2, r2*) were calculated. A linear dependence of R1, R2, and R2* on ferumoxytol concentration was found in saline and plasma with lower R1 values at 3.0 T and similar R2 and R2* values at 1.5 T and 3.0 T (1.5 T: r1saline = 19.9 ± 2.3 smM; r1plasma = 19.0 ± 1.7 smM; r2saline = 60.8 ± 3.8 smM; r2plasma = 64.9 ± 1.8 smM; r2*saline = 60.4 ± 4.7 smM; r2*plasma = 64.4 ± 2.5 smM; 3.0 T: r1saline = 10.0 ± 0.3 smM; r1plasma = 9.5 ± 0.2 smM; r2saline = 62.3 ± 3.7 smM; r2plasma = 65.2 ± 1.8 smM; r2*saline = 57.0 ± 4.7 smM; r2*plasma = 55.7 ± 4.4 smM). The dependence of relaxation rates on concentration in blood was nonlinear. Formulas from second-order polynomial fittings of the relaxation rates were calculated to characterize the relationship between R1blood and R2 blood with ferumoxytol. Ferumoxytol demonstrates strong longitudinal and transverse relaxivities. Awareness of the nonlinear relaxation behavior of ferumoxytol in blood is important for ferumoxytol-enhanced magnetic resonance imaging applications and for protocol optimization.

  16. Generalized ghost pilgrim dark energy in F(T,TG) cosmology

    NASA Astrophysics Data System (ADS)

    Sharif, M.; Nazir, Kanwal

    2016-07-01

    This paper is devoted to study the generalized ghost pilgrim dark energy (PDE) model in F(T,TG) gravity with flat Friedmann-Robertson-Walker (FRW) universe. In this scenario, we reconstruct F(T,TG) models and evaluate the corresponding equation of state (EoS) parameter for different choices of the scale factors. We assume power-law scale factor, scale factor for unification of two phases, intermediate and bouncing scale factor. We study the behavior of reconstructed models and EoS parameters graphically. It is found that all the reconstructed models show decreasing behavior for PDE parameter u = -2. On the other hand, the EoS parameter indicates transition from dust-like matter to phantom era for all choices of the scale factor except intermediate for which this is less than - 1. We conclude that all the results are in agreement with PDE phenomenon.

  17. Diagnostic accuracy of automatic normalization of CBV in glioma grading using T1- weighted DCE-MRI.

    PubMed

    Sahoo, Prativa; Gupta, Rakesh K; Gupta, Pradeep K; Awasthi, Ashish; Pandey, Chandra M; Gupta, Mudit; Patir, Rana; Vaishya, Sandeep; Ahlawat, Sunita; Saha, Indrajit

    2017-12-01

    Aim of this retrospective study was to compare diagnostic accuracy of proposed automatic normalization method to quantify the relative cerebral blood volume (rCBV) with existing contra-lateral region of interest (ROI) based CBV normalization method for glioma grading using T1-weighted dynamic contrast enhanced MRI (DCE-MRI). Sixty patients with histologically confirmed gliomas were included in this study retrospectively. CBV maps were generated using T1-weighted DCE-MRI and are normalized by contralateral ROI based method (rCBV_contra), unaffected white matter (rCBV_WM) and unaffected gray matter (rCBV_GM), the latter two of these were generated automatically. An expert radiologist with >10years of experience in DCE-MRI and a non-expert with one year experience were used independently to measure rCBVs. Cutoff values for glioma grading were decided from ROC analysis. Agreement of histology with rCBV_WM, rCBV_GM and rCBV_contra respectively was studied using Kappa statistics and intra-class correlation coefficient (ICC). The diagnostic accuracy of glioma grading using the measured rCBV_contra by expert radiologist was found to be high (sensitivity=1.00, specificity=0.96, p<0.001) compared to the non-expert user (sensitivity=0.65, specificity=0.78, p<0.001). On the other hand, both the expert and non-expert user showed similar diagnostic accuracy for automatic rCBV_WM (sensitivity=0.89, specificity=0.87, p=0.001) and rCBV_GM (sensitivity=0.81, specificity=0.78, p=0.001) measures. Further, it was also observed that, contralateral based method by expert user showed highest agreement with histological grading of tumor (kappa=0.96, agreement 98.33%, p<0.001), however; automatic normalization method showed same percentage of agreement for both expert and non-expert user. rCBV_WM showed an agreement of 88.33% (kappa=0.76,p<0.001) with histopathological grading. It was inferred from this study that, in the absence of expert user, automated normalization of CBV using the

  18. "Black butterfly" sign on T2*-weighted and susceptibility-weighted imaging: A novel finding of chronic venous congestion of the brain stem and spinal cord associated with dural arteriovenous fistulas.

    PubMed

    Enokizono, Mikako; Sato, Noriko; Morikawa, Minoru; Kimura, Yukio; Sugiyama, Atsuhiko; Maekawa, Tomoko; Sone, Daichi; Takewaki, Daiki; Okamoto, Tomoko; Takahashi, Yuji; Horie, Nobutaka; Matsuo, Takayuki

    2017-08-15

    A dural arteriovenous fistula (DAVF) with spinal perimedullary venous drainage can cause progressive myelopathy, and it is sometimes incorrectly diagnosed as another spinal cord disease. Here we report the cases of three individuals with a DAVF (one craniocervical junction DAVF and two tentorial DAVFs) with progressive myelopathy showing unique magnetic resonance (MR) imaging findings. MR T2*WI or susceptibility-weighted imaging (SWI) demonstrated symmetrical dark signal intensity lesions predominantly in the dorsal aspect of medulla and the central gray matter of cervical spinal cord that showed the "black butterfly" silhouette. Cerebral angiography revealed DAVFs draining into anterior and posterior spinal veins. Dark signals on T2*WI and SWI were presumed to be hemorrhages, which were probably caused by prolonged venous congestion. Identifying this "black butterfly" sign can facilitate the diagnosis of DAVF, differentiating DAVF from other spinal cord diseases such as demyelinating lesions and neoplasms. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Spectral analysis of difference and differential operators in weighted spaces

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bichegkuev, M S

    2013-11-30

    This paper is concerned with describing the spectrum of the difference operator K:l{sub α}{sup p}(Z,X)→l{sub α}{sup p}(Z......athscrKx)(n)=Bx(n−1),  n∈Z,  x∈l{sub α}{sup p}(Z,X), with a constant operator coefficient B, which is a bounded linear operator in a Banach space X. It is assumed that K acts in the weighted space l{sub α}{sup p}(Z,X), 1≤p≤∞, of two-sided sequences of vectors from X. The main results are obtained in terms of the spectrum σ(B) of the operator coefficient B and properties of the weight function. Applications to the study of the spectrum of a differential operator with an unbounded operator coefficient (the generator of a strongly continuous semigroup of operators) in weighted function spaces aremore » given. Bibliography: 23 titles.« less

  20. The DarkSide awakens

    DOE PAGES

    Davini, S.; Agnes, P.; Agostino, L.; ...

    2016-06-09

    Here, the DarkSide program at LNGS aims to perform background-free WIMP searches using two phase liquid argon time projection chambers, with the ultimate goal of covering all parameters down to the so-called neutrino floor. One of the distinct features of the program is the use of underground argon with has a reduced content of the radioactive 39Ar compared to atmospheric argon. The DarkSide Collaboration is currently operating the DarkSide-50 experiment, the first such WIMP detector using underground argon. Operations with underground argon indicate a suppression of 39Ar by a factor (1.4 ± 0.2) × 10 3 relative to atmospheric argon.more » The new results obtained with DarkSide-50 and the plans for the next steps of the DarkSide program, the 20t fiducial mass DarkSide-20k detector and the 200 t fiducial Argo, are reviewed in this proceedings.« less

  1. Targeting Angiotensin II Type-1 Receptor (AT1R) Inhibits the Harmful Phenotype of Plasmodium-Specific CD8+ T Cells during Blood-Stage Malaria.

    PubMed

    Silva-Filho, João L; Caruso-Neves, Celso; Pinheiro, Ana A S

    2017-01-01

    CD8 + T-cell response is critical in the pathogenesis of cerebral malaria during blood-stage. Our group and other have been shown that angiotensin II (Ang II) and its receptor AT 1 (AT 1 R), a key effector axis of renin-angiotensin system (RAS), have immune regulatory effects on T cells. Previously, we showed that inhibition of AT 1 R signaling protects mice against the lethal disease induced by Plasmodium berghei ANKA infection However, most of the Ang II/AT 1 R actions were characterized by using only pharmacological approaches, the effects of which may not always be due to a specific receptor blockade. In addition, the mechanisms of action of the AT 1 R in inducing the pathogenic activity of Plasmodium -specific CD8 + T cells during blood-stage were not determined. Here, we examined how angiotensin II/AT 1 R axis promotes the harmful response of Plasmodium -specific CD8 + T-cell during blood-stage by using genetic and pharmacological approaches. We evaluated the response of wild-type (WT) and AT 1 R -/- Plasmodium -specific CD8 + T cells in mice infected with a transgenic PbA lineage expressing ovalbumin; and in parallel infected mice receiving WT Plasmodium -specific CD8 + T cells were treated with losartan (AT 1 R antagonist) or captopril (ACE inhibitor). Both, AT 1 R -/- OT-I cells and WT OT-I cells from losartan- or captopril-treated mice showed lower expansion, reduced IL-2 production and IL-2Rα expression, lower activation (lower expression of CD69, CD44 and CD160) and lower exhaustion profiles. AT 1 R -/- OT-I cells also exhibit lower expression of the integrin LFA-1 and the chemokine receptors CCR5 and CXCR3, known to play a key role in the development of cerebral malaria. Moreover, AT 1 R -/- OT-I cells produce lower amounts of IFN-γ and TNF-α and show lower degranulation upon restimulation. In conclusion, our results show the pivotal mechanisms of AT 1 R-induced harmful phenotype of Plasmodium -specific CD8 + T cells during blood-stage malaria.

  2. RGD-functionalized ultrasmall iron oxide nanoparticles for targeted T1-weighted MR imaging of gliomas

    NASA Astrophysics Data System (ADS)

    Luo, Yu; Yang, Jia; Yan, Yu; Li, Jingchao; Shen, Mingwu; Zhang, Guixiang; Mignani, Serge; Shi, Xiangyang

    2015-08-01

    We report a convenient approach to prepare ultrasmall Fe3O4 nanoparticles (NPs) functionalized with an arginylglycylaspartic acid (RGD) peptide for in vitro and in vivo magnetic resonance (MR) imaging of gliomas. In our work, stable sodium citrate-stabilized Fe3O4 NPs were prepared by a solvothermal route. Then, the carboxylated Fe3O4 NPs stabilized with sodium citrate were conjugated with polyethylene glycol (PEG)-linked RGD. The formed ultrasmall RGD-functionalized nanoprobe (Fe3O4-PEG-RGD) was fully characterized using different techniques. We show that these Fe3O4-PEG-RGD particles with a size of 2.7 nm are water-dispersible, stable, cytocompatible and hemocompatible in a given concentration range, and display targeting specificity to glioma cells overexpressing αvβ3 integrin in vitro. With the relatively high r1 relaxivity (r1 = 1.4 mM-1 s-1), the Fe3O4-PEG-RGD particles can be used as an efficient nanoprobe for targeted T1-weighted positive MR imaging of glioma cells in vitro and the xenografted tumor model in vivo via an active RGD-mediated targeting pathway. The developed RGD-functionalized Fe3O4 NPs may hold great promise to be used as a nanoprobe for targeted T1-weighted MR imaging of different αvβ3 integrin-overexpressing cancer cells or biological systems.We report a convenient approach to prepare ultrasmall Fe3O4 nanoparticles (NPs) functionalized with an arginylglycylaspartic acid (RGD) peptide for in vitro and in vivo magnetic resonance (MR) imaging of gliomas. In our work, stable sodium citrate-stabilized Fe3O4 NPs were prepared by a solvothermal route. Then, the carboxylated Fe3O4 NPs stabilized with sodium citrate were conjugated with polyethylene glycol (PEG)-linked RGD. The formed ultrasmall RGD-functionalized nanoprobe (Fe3O4-PEG-RGD) was fully characterized using different techniques. We show that these Fe3O4-PEG-RGD particles with a size of 2.7 nm are water-dispersible, stable, cytocompatible and hemocompatible in a given concentration

  3. Longitudinal T1 relaxation rate (R1) captures changes in short-term Mn exposure in welders

    PubMed Central

    Lewis, Mechelle M.; Flynn, Michael R.; Lee, Eun-Young; Van Buren, Scott; Van Buren, Eric; Du, Guangwei; Fry, Rebecca C.; Herring, Amy H.; Kong, Lan; Mailman, Richard B.; Huang, Xuemei

    2016-01-01

    Objectives We demonstrated recently that the T1 relaxation rate (R1) captured short-term Mn exposure in welders with chronic, relatively low exposure levels in a cross-sectional study. In the current study, we used a longitudinal design to examine whether R1 values reflect the short-term dynamics of Mn exposure. Methods Twenty-nine welders were evaluated at baseline and 12 months. Occupational questionnaires estimated short-term welding exposure using welding hours in the 90 days prior to each study visit (HrsW90). In addition, blood Mn levels, the pallidal index (PI; globus pallidus T1-weighted intensity (T1WI)/frontal white matter T1WI), and R1 values in brain regions of interest (ROIs) were determined as Mn biomarkers at each visit. Associations between changes in estimated welding exposure and changes in purported Mn biomarkers were assessed by Spearman’s correlations with adjustment for age and baseline R1, HrsW90, and blood Mn values. Results Changes in welding hours (HrsW90: the short-term welding exposure estimate), was associated significantly with changes in R1 values in the putamen (r=0.541, p=0.005), caudate (R=0.453, p=0.023), globus pallidus (R=0.430, p=0.032), amygdala (R=0.461, p=0.020), and hippocampus (R=0.447, p=0.025), but not with changes in blood Mn levels or the PI. Discussion Changes in R1 values correlated with changes in the short-term welding exposure estimate, but not with more traditional measures of Mn exposure (blood Mn levels or PI). These results suggest that R1 may serve as a useful marker to capture the short-term dynamics in Mn brain accumulation related to welding exposure. PMID:27567731

  4. Transverse water relaxation in whole blood and erythrocytes at 3T, 7T, 9.4T, 11.7T and 16.4T; determination of intracellular hemoglobin and extracellular albumin relaxivities.

    PubMed

    Grgac, Ksenija; Li, Wenbo; Huang, Alan; Qin, Qin; van Zijl, Peter C M

    2017-05-01

    Blood is a physiological substance with multiple water compartments, which contain water-binding proteins such as hemoglobin in erythrocytes and albumin in plasma. Knowing the water transverse (R 2 ) relaxation rates from these different blood compartments is a prerequisite for quantifying the blood oxygenation level-dependent (BOLD) effect. Here, we report the Carr-Purcell-Meiboom-Gill (CPMG) based transverse (R 2CPMG ) relaxation rates of water in bovine blood samples circulated in a perfusion system at physiological temperature in order to mimic blood perfusion in humans. R 2CPMG values of blood plasma, lysed packed erythrocytes, lysed plasma/erythrocyte mixtures, and whole blood at 3 T, 7 T, 9.4 T, 11.7 T and 16.4 T were measured as a function of hematocrit or hemoglobin concentration, oxygenation, and CPMG inter-echo spacing (τ cp ). R 2CPMG in lysed cells showed a small τ cp dependence, attributed to the water exchange rate between free and hemoglobin-bound water to be much faster than τ cp . This was contrary to the tangential dependence in whole blood, where a much slower exchange between cells and blood plasma applies. Whole blood data were fitted as a function of τ cp using a general tangential correlation time model applicable for exchange as well as diffusion contributions to R 2CPMG , and the intercept R 20blood at infinitely short τ cp was determined. The R 20blood values at different hematocrit and the R 2CPMG values of lysed erythrocyte/plasma mixtures at different hemoglobin concentration were used to determine the relaxivity of hemoglobin inside the erythrocyte (r 2Hb ) and albumin (r 2Alb ) in plasma. The r 2Hb values obtained from lysed erythrocytes and whole blood were comparable at full oxygenation. However, while r 2Hb determined from lysed cells showed a linear dependence on oxygenation, this dependence became quadratic in whole blood. This possibly suggests an additional relaxation effect inside intact cells, perhaps due to hemoglobin

  5. Beyond birth-weight: early growth and adolescent blood pressure in a Peruvian population.

    PubMed

    Sterling, Robie; Checkley, William; Gilman, Robert H; Cabrera, Lilia; Sterling, Charles R; Bern, Caryn; Miranda, J Jaime

    2014-01-01

    Background. Longitudinal investigations into the origins of adult essential hypertension have found elevated blood pressure in children to accurately track into adulthood, however the direct causes of essential hypertension in adolescence and adulthood remains unclear. Methods. We revisited 152 Peruvian adolescents from a birth cohort tracked from 0 to 30 months of age, and evaluated growth via monthly anthropometric measurements between 1995 and 1998, and obtained anthropometric and blood pressure measurements 11-14 years later. We used multivariable regression models to study the effects of infantile and childhood growth trends on blood pressure and central obesity in early adolescence. Results. In regression models adjusted for interim changes in weight and height, each 0.1 SD increase in weight for length from 0 to 5 months of age, and 1 SD increase from 6 to 30 months of age, was associated with decreased adolescent systolic blood pressure by 1.3 mm Hg (95% CI -2.4 to -0.1) and 2.5 mm Hg (95% CI -4.9 to 0.0), and decreased waist circumference by 0.6 (95% CI -1.1 to 0.0) and 1.2 cm (95% CI -2.3 to -0.1), respectively. Growth in infancy and early childhood was not significantly associated with adolescent waist-to-hip ratio. Conclusions. Rapid compensatory growth in early life has been posited to increase the risk of long-term cardiovascular morbidities such that nutritional interventions may do more harm than good. However, we found increased weight growth during infancy and early childhood to be associated with decreased systolic blood pressure and central adiposity in adolescence.

  6. Indirect detection constraints on s- and t-channel simplified models of dark matter

    NASA Astrophysics Data System (ADS)

    Carpenter, Linda M.; Colburn, Russell; Goodman, Jessica; Linden, Tim

    2016-09-01

    Recent Fermi-LAT observations of dwarf spheroidal galaxies in the Milky Way have placed strong limits on the gamma-ray flux from dark matter annihilation. In order to produce the strongest limit on the dark matter annihilation cross section, the observations of each dwarf galaxy have typically been "stacked" in a joint-likelihood analysis, utilizing optical observations to constrain the dark matter density profile in each dwarf. These limits have typically been computed only for singular annihilation final states, such as b b ¯ or τ+τ- . In this paper, we generalize this approach by producing an independent joint-likelihood analysis to set constraints on models where the dark matter particle annihilates to multiple final-state fermions. We interpret these results in the context of the most popular simplified models, including those with s- and t-channel dark matter annihilation through scalar and vector mediators. We present our results as constraints on the minimum dark matter mass and the mediator sector parameters. Additionally, we compare our simplified model results to those of effective field theory contact interactions in the high-mass limit.

  7. High-resolution T1-weighted 3D real IR imaging of the temporal bone using triple-dose contrast material.

    PubMed

    Naganawa, Shinji; Koshikawa, Tokiko; Nakamura, Tatsuya; Fukatsu, Hiroshi; Ishigaki, Takeo; Aoki, Ikuo

    2003-12-01

    The small structures in the temporal bone are surrounded by bone and air. The objectives of this study were (a) to compare contrast-enhanced T1-weighted images acquired by fast spin-echo-based three-dimensional real inversion recovery (3D rIR) against those acquired by gradient echo-based 3D SPGR in the visualization of the enhancement of small structures in the temporal bone, and (b) to determine whether either 3D rIR or 3D SPGR is useful for visualizing enhancement of the cochlear lymph fluid. Seven healthy men (age range 27-46 years) volunteered to participate in this study. All MR imaging was performed using a dedicated bilateral quadrature surface phased-array coil for temporal bone imaging at 1.5 T (Visart EX, Toshiba, Tokyo, Japan). The 3D rIR images (TR/TE/TI: 1800 ms/10 ms/500 ms) and flow-compensated 3D SPGR images (TR/TE/FA: 23 ms/10 ms/25 degrees) were obtained with a reconstructed voxel size of 0.6 x 0.7 x 0.8 mm3. Images were acquired before and 1, 90, 180, and 270 min after the administration of triple-dose Gd-DTPA-BMA (0.3 mmol/kg). In post-contrast MR images, the degree of enhancement of the cochlear aqueduct, endolymphatic sac, subarcuate artery, geniculate ganglion of the facial nerve, and cochlear lymph fluid space was assessed by two radiologists. The degree of enhancement was scored as follows: 0 (no enhancement); 1 (slight enhancement); 2 (intermediate between 1 and 3); and 3 (enhancement similar to that of vessels). Enhancement scores for the endolymphatic sac, subarcuate artery, and geniculate ganglion were higher in 3D rIR than in 3D SPGR. Washout of enhancement in the endolymphatic sac appeared to be delayed compared with that in the subarcuate artery, suggesting that the enhancement in the endolymphatic sac may have been due in part to non-vascular tissue enhancement. Enhancement of the cochlear lymph space was not observed in any of the subjects in 3D rIR and 3D SPGR. The 3D rIR sequence may be more sensitive than the 3D SPGR sequence

  8. Physics reach of the XENON1T dark matter experiment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Aprile, E.; Anthony, M.; Aalbers, J.

    2016-04-01

    The XENON1T experiment is currently in the commissioning phase at the Laboratori Nazionali del Gran Sasso, Italy. In this article we study the experiment's expected sensitivity to the spin-independent WIMP-nucleon interaction cross section, based on Monte Carlo predictions of the electronic and nuclear recoil backgrounds. The total electronic recoil background in 1 tonne fiducial volume and (1, 12) keV electronic recoil equivalent energy region, before applying any selection to discriminate between electronic and nuclear recoils, is (1.80 ± 0.15) · 10{sup −4} (kg·day·keV){sup −1}, mainly due to the decay of {sup 222}Rn daughters inside the xenon target. The nuclear recoil background in the correspondingmore » nuclear recoil equivalent energy region (4, 50) keV, is composed of (0.6 ± 0.1) (t·y){sup −1} from radiogenic neutrons, (1.8 ± 0.3) · 10{sup −2} (t·y){sup −1} from coherent scattering of neutrinos, and less than 0.01 (t·y){sup −1} from muon-induced neutrons. The sensitivity of XENON1T is calculated with the Profile Likelihood Ratio method, after converting the deposited energy of electronic and nuclear recoils into the scintillation and ionization signals seen in the detector. We take into account the systematic uncertainties on the photon and electron emission model, and on the estimation of the backgrounds, treated as nuisance parameters. The main contribution comes from the relative scintillation efficiency L{sub eff}, which affects both the signal from WIMPs and the nuclear recoil backgrounds. After a 2 y measurement in 1 t fiducial volume, the sensitivity reaches a minimum cross section of 1.6 · 10{sup −47} cm{sup 2} at m{sub χ} = 50 GeV/c{sup 2}.« less

  9. Restrained dark U (1 )d at low energies

    NASA Astrophysics Data System (ADS)

    Correia, Fagner C.; Fajfer, Svjetlana

    2016-12-01

    We investigate a spontaneously broken U (1 )d gauge symmetry with a muon-specific dark Higgs. Our first goal is to verify how the presence of a new dark Higgs, ϕ , and a dark gauge boson, V , can simultaneously face the anomalies from the muon magnetic moment and the proton charge radius. Second, by assuming that V must decay to an electron-positron pair, we explore the corresponding parameter space determined with the low-energy constraints coming from K →μ X , electron (g -2 )e, K →μ νμe+e-, K →μ νμμ+μ-, and τ →ντμ νμe+e-. We focus on the scenario where the V mass is below ˜2 mμ and the ϕ mass runs from few MeV to 250 MeV, with V -photon mixing of the order ˜O (10-3). Among weak process at low energies, we check the influence of the new light vector on kaon decays as well as on the scattering e+e-→μ+μ-e+e- and discuss the impact of the dark Higgs on e+e-→μ+μ-μ+μ-. Finally, we consider contributions of the V -photon mixing in the decays π0→γ e+e-, η →γ e+e-, ρ →π e+e-, K*→K e+e-, and ϕ (1020 )→η e+e-.

  10. Integrability of geodesics and action-angle variables in Sasaki-Einstein space T^{1,1}

    NASA Astrophysics Data System (ADS)

    Visinescu, Mihai

    2016-09-01

    We briefly describe the construction of Stäkel-Killing and Killing-Yano tensors on toric Sasaki-Einstein manifolds without working out intricate generalized Killing equations. The integrals of geodesic motions are expressed in terms of Killing vectors and Killing-Yano tensors of the homogeneous Sasaki-Einstein space T^{1,1}. We discuss the integrability of geodesics and construct explicitly the action-angle variables. Two pairs of frequencies of the geodesic motions are resonant giving way to chaotic behavior when the system is perturbed.

  11. Whole-brain intracranial vessel wall imaging at 3 Tesla using cerebrospinal fluid-attenuated T1-weighted 3D turbo spin echo.

    PubMed

    Fan, Zhaoyang; Yang, Qi; Deng, Zixin; Li, Yuxia; Bi, Xiaoming; Song, Shlee; Li, Debiao

    2017-03-01

    Although three-dimensional (3D) turbo spin echo (TSE) with variable flip angles has proven to be useful for intracranial vessel wall imaging, it is associated with inadequate suppression of cerebrospinal fluid (CSF) signals and limited spatial coverage at 3 Tesla (T). This work aimed to modify the sequence and develop a protocol to achieve whole-brain, CSF-attenuated T 1 -weighted vessel wall imaging. Nonselective excitation and a flip-down radiofrequency pulse module were incorporated into a commercial 3D TSE sequence. A protocol based on the sequence was designed to achieve T 1 -weighted vessel wall imaging with whole-brain spatial coverage, enhanced CSF-signal suppression, and isotropic 0.5-mm resolution. Human volunteer and pilot patient studies were performed to qualitatively and quantitatively demonstrate the advantages of the sequence. Compared with the original sequence, the modified sequence significantly improved the T 1 -weighted image contrast score (2.07 ± 0.19 versus 3.00 ± 0.00, P = 0.011), vessel wall-to-CSF contrast ratio (0.14 ± 0.16 versus 0.52 ± 0.30, P = 0.007) and contrast-to-noise ratio (1.69 ± 2.18 versus 4.26 ± 2.30, P = 0.022). Significant improvement in vessel wall outer boundary sharpness was observed in several major arterial segments. The new 3D TSE sequence allows for high-quality T 1 -weighted intracranial vessel wall imaging at 3 T. It may potentially aid in depicting small arteries and revealing T 1 -mediated high-signal wall abnormalities. Magn Reson Med 77:1142-1150, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  12. Weight changes in children in foster care for 1 year.

    PubMed

    Schneiderman, Janet U; Smith, Caitlin; Arnold-Clark, Janet S; Fuentes, Jorge; Duan, Lei

    2013-10-01

    The aims of this study of predominately racial/ethnic minority children in foster care (N=360, birth to 19 years old) in Los Angeles, CA were to examine the (1) prevalence of obesity (≥ 95 percentile) and overweight/obese (≥ 85 percentile) upon entrance to foster care (T1) and after 1 year in foster care (T2); (2) comparison of high weight categories to national statistics; (3) relationship of changes in weight status to age, reason for entry into foster care, and placement. Chi-square test and McNemar test comparing paired proportions were used to determine whether there were significant changes in the proportion of high weight categories between T1 and T2. Chi-square test or Fisher's exact test were used to evaluate the association between age, placement, and reason for foster care with the change in weight category. Changes in weight were categorized as (1) decreased in weight, (2) remained at overweight or obese, (3) increased in weight, or (4) remained normal. The proportion of obese and obese/overweight children between ages 2 and 5 were significantly lower at T2 than T1. There were no significant changes in the prevalence of obesity for the total population at T2. Children age 6 or older had a higher prevalence of obesity and overweight/obesity compared to national statistics. Of children at all ages, 64.7% of children of all ages entered foster care with a normal weight and stayed in the normal range during their first year in foster care, 12.2% decreased their weight, 15.4% remained overweight or obese, and 7.7% increased their weight. Age and parental substance use was related to change in weight category from T1 to T2. Children did not become more overweight or obese in foster care; however 28% of the children were obese or overweight upon entry into foster care. Children who are 6 years or older and obese upon entering foster care should be targeted for weight reduction. The pediatric community and child welfare system need to work together by

  13. A voxel based comparative analysis using magnetization transfer imaging and T1-weighted magnetic resonance imaging in progressive supranuclear palsy

    PubMed Central

    Sandhya, Mangalore; Saini, Jitender; Pasha, Shaik Afsar; Yadav, Ravi; Pal, Pramod Kumar

    2014-01-01

    Aims: In progressive supranuclear palsy (PSP) tissue damage occurs in specific cortical and subcortical regions. Voxel based analysis using T1-weighted images depict quantitative gray matter (GM) atrophy changes. Magnetization transfer (MT) imaging depicts qualitative changes in the brain parenchyma. The purpose of our study was to investigate whether MT imaging could indicate abnormalities in PSP. Settings and Design: A total of 10 patients with PSP (9 men and 1 woman) and 8 controls (5 men and 3 women) were studied with T1-weighted magnetic resonance imaging (MRI) and 3DMT imaging. Voxel based analysis of T1-weighted MRI was performed to investigate brain atrophy while MT was used to study qualitative abnormalities in the brain tissue. We used SPM8 to investigate group differences (with two sample t-test) using the GM and white matter (WM) segmented data. Results: T1-weighted imaging and MT are equally sensitive to detect changes in GM and WM in PSP. Magnetization transfer ratio images and magnetization-prepared rapid acquisition of gradient echo revealed extensive bilateral volume and qualitative changes in the orbitofrontal, prefrontal cortex and limbic lobe and sub cortical GM. The prefrontal structures involved were the rectal gyrus, medial, inferior frontal gyrus (IFG) and middle frontal gyrus (MFG). The anterior cingulate, cingulate gyrus and lingual gyrus of limbic lobe and subcortical structures such as caudate, thalamus, insula and claustrum were also involved. Cerebellar involvement mainly of anterior lobe was also noted. Conclusions: The findings suggest that voxel based MT imaging permits a whole brain unbiased investigation of central nervous system structural integrity in PSP. PMID:25024571

  14. Preliminary design and cost of a 1-megawatt solar-pumped iodide laser space-to-space transmission station

    NASA Technical Reports Server (NTRS)

    Deyoung, R. J.; Walker, G. H.; Williams, M. D.; Schuster, G. L.; Conway, E. J.

    1987-01-01

    A preliminary conceptual design of a space-based solar pumped iodide laser emitting 1 megawatt of laser power for space-to-space power transmission is described. A near parabolic solar collector focuses sunlight onto the t-C4F9I (perfluoro-t butyl iodide) lasant within a transverse flow optical cavity. Using waste heat, a thermal system was designed to supply compressor and auxiliary power. System components were designed with weight and cost estimates assigned. Although cost is very approximate, the cost comparison of individual system components leads to valuable insights for future research. In particular, it was found that laser efficiency was not a dominant cost or weight factor, the dominant factor being the laser cavity and laser transmission optics. The manufacturing cost was approx. two thirds of the total cost with transportation to orbit the remainder. The flowing nonrenewable lasant comprised 20% of the total life cycle cost of the system and thus was not a major cost factor. The station mass was 92,000 kg without lasant, requiring approx. four shuttle flights to low Earth orbit where an orbital transfer vehicle will transport it to the final altitude of 6378 km.

  15. Quantitative T1 and T2* carotid atherosclerotic plaque imaging using a three-dimensional multi-echo phase-sensitive inversion recovery sequence: a feasibility study.

    PubMed

    Fujiwara, Yasuhiro; Maruyama, Hirotoshi; Toyomaru, Kanako; Nishizaka, Yuri; Fukamatsu, Masahiro

    2018-06-01

    Magnetic resonance imaging (MRI) is widely used to detect carotid atherosclerotic plaques. Although it is important to evaluate vulnerable carotid plaques containing lipids and intra-plaque hemorrhages (IPHs) using T 1 -weighted images, the image contrast changes depending on the imaging settings. Moreover, to distinguish between a thrombus and a hemorrhage, it is useful to evaluate the iron content of the plaque using both T 1 -weighted and T 2 *-weighted images. Therefore, a quantitative evaluation of carotid atherosclerotic plaques using T 1 and T 2 * values may be necessary for the accurate evaluation of plaque components. The purpose of this study was to determine whether the multi-echo phase-sensitive inversion recovery (mPSIR) sequence can improve T 1 contrast while simultaneously providing accurate T 1 and T 2 * values of an IPH. T 1 and T 2 * values measured using mPSIR were compared to values from conventional methods in phantom and in vivo studies. In the phantom study, the T 1 and T 2 * values estimated using mPSIR were linearly correlated with those of conventional methods. In the in vivo study, mPSIR demonstrated higher T 1 contrast between the IPH phantom and sternocleidomastoid muscle than the conventional method. Moreover, the T 1 and T 2 * values of the blood vessel wall and sternocleidomastoid muscle estimated using mPSIR were correlated with values measured by conventional methods and with values reported previously. The mPSIR sequence improved T 1 contrast while simultaneously providing accurate T 1 and T 2 * values of the neck region. Although further study is required to evaluate the clinical utility, mPSIR may improve carotid atherosclerotic plaque detection and provide detailed information about plaque components.

  16. Comparison of hindlimb unloading and partial weight suspension models for spaceflight-type condition induced effects on white blood cells

    NASA Astrophysics Data System (ADS)

    Wilson, Jolaine M.; Krigsfeld, Gabriel S.; Sanzari, Jenine K.; Wagner, Erika B.; Mick, Rosemarie; Kennedy, Ann R.

    2012-01-01

    Animal models are frequently used to assist in the determination of the long- and short-term effects of space flight. The space environment, including microgravity, can impact many physiological and immunological system parameters. It has been found that ground based models of microgravity produce changes in white blood cell counts, which negatively affects immunologic function. As part of the Center of Acute Radiation Research (CARR), we compared the acute effects on white blood cell parameters induced by the more traditionally used animal model of hindlimb unloading (HU) with a recently developed reduced weightbearing analog known as partial weight suspension (PWS). Female ICR mice were either hindlimb unloaded or placed in the PWS system at 16% quadrupedal weightbearing for 4 h, 1, 2, 7 or 10 days, at which point complete blood counts were obtained. Control animals (jacketed and non-jacketed) were exposed to identical conditions without reduced weightbearing. Results indicate that significant changes in total white blood cell (WBC), neutrophil, lymphocyte, monocyte and eosinophil counts were observed within the first 2 days of exposure to each system. These differences in blood cell counts normalized by day 7 in both systems. The results of these studies indicate that there are some statistically significant changes observed in the blood cell counts for animals exposed to both the PWS and HU simulated microgravity systems.

  17. 46 CFR 32.40-40 - Other spaces-T/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Other spaces-T/ALL. 32.40-40 Section 32.40-40 Shipping... REQUIREMENTS Accommodations for Officers and Crew § 32.40-40 Other spaces—T/ALL. Each vessel must have— (a... with hot and cold fresh water; (b) Recreation spaces; and (c) A space or spaces of adequate size...

  18. 46 CFR 32.40-40 - Other spaces-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Other spaces-T/ALL. 32.40-40 Section 32.40-40 Shipping... REQUIREMENTS Accommodations for Officers and Crew § 32.40-40 Other spaces—T/ALL. Each vessel must have— (a... with hot and cold fresh water; (b) Recreation spaces; and (c) A space or spaces of adequate size...

  19. 46 CFR 32.40-40 - Other spaces-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Other spaces-T/ALL. 32.40-40 Section 32.40-40 Shipping... REQUIREMENTS Accommodations for Officers and Crew § 32.40-40 Other spaces—T/ALL. Each vessel must have— (a... with hot and cold fresh water; (b) Recreation spaces; and (c) A space or spaces of adequate size...

  20. 46 CFR 32.40-40 - Other spaces-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Other spaces-T/ALL. 32.40-40 Section 32.40-40 Shipping... REQUIREMENTS Accommodations for Officers and Crew § 32.40-40 Other spaces—T/ALL. Each vessel must have— (a... with hot and cold fresh water; (b) Recreation spaces; and (c) A space or spaces of adequate size...

  1. 46 CFR 32.40-40 - Other spaces-T/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Other spaces-T/ALL. 32.40-40 Section 32.40-40 Shipping... REQUIREMENTS Accommodations for Officers and Crew § 32.40-40 Other spaces—T/ALL. Each vessel must have— (a... with hot and cold fresh water; (b) Recreation spaces; and (c) A space or spaces of adequate size...

  2. T-cell receptor transfer for boosting HIV-1-specific T-cell immunity in HIV-1-infected patients.

    PubMed

    Mummert, Christiane; Hofmann, Christian; Hückelhoven, Angela G; Bergmann, Silke; Mueller-Schmucker, Sandra M; Harrer, Ellen G; Dörrie, Jan; Schaft, Niels; Harrer, Thomas

    2016-09-10

    Strategies to cure HIV-1 infection require the eradication of viral reservoirs. An innovative approach for boosting the cytotoxic T-lymphocyte response is the transfer of T-cell receptors (TCRs). Previously, we have shown that electroporation of TCR-encoding mRNA is able to reprogram CD8 T cells derived from healthy donors. So far, it is unknown whether the transfer of HIV-1-specific TCRs is capable to reprogram CD8 T cells of HIV-1-infected patients. To assess the efficiency of TCR-transfer by mRNA electroporation and the functionality of reprogramed T cells in HIV-1-infected patients, we performed an in-vitro analysis of TCR-transfer into T cells from HIV-1-infected patients in various stages of disease and from healthy controls. Peripheral blood mononuclear cells from 16 HIV-1-infected patients (nine HLA-A02-positive, seven HLA-A02-negative) and from five healthy controls were electroporated with mRNA-constructs encoding TCRs specific for the HLA-A02/HIV-1-gag p17 epitope SLYNTVATL (SL9). Functionality of the TCRs was measured by γIFN-ELISpot assays. SL9/TCR transfection into peripheral blood mononuclear cells from both HLA-A02-positive and HLA-A02-negative HIV-1-infected patients and from healthy blood donors reprogramed T cells for recognition of SL9-presenting HLA-A02-positive cells in γIFN-ELISpot assays. SL9/TCR-transfer into T cells from an immunodeficient AIDS patient could induce recognition of SL9-expressing target cells only after reversion of T-cell dysfunction by antiretroviral therapy. The transfer of HIV-1-p17-specific TCRs into T cells is functional both in HIV-1-infected patients as well as in healthy blood donors. TCR-transfer is a promising method to boost the immune system against HIV-1.

  3. Disruptive chemical doping in a ferritin-based iron oxide nanoparticle to decrease r2 and enhance detection with T1-weighted MRI.

    PubMed

    Clavijo Jordan, M Veronica; Beeman, Scott C; Baldelomar, Edwin J; Bennett, Kevin M

    2014-01-01

    Inorganic doping was used to create flexible, paramagnetic nanoparticle contrast agents for in vivo molecular magnetic resonance imaging (MRI) with low transverse relaxivity (r2). Most nanoparticle contrast agents formed from superparamagnetic metal oxides are developed with high r2. While sensitive, they can have limited in vivo detection due to a number of constraints with T2 or T2*-weighted imaging. T1-weighted imaging is often preferred for molecular MRI, but most T1-shortening agents are small chelates with low metal payload or are nanoparticles that also shorten T2 and limit the range of concentrations detectable with T1-weighting. Here we used tungsten and iron deposition to form doped iron oxide crystals inside the apoferritin cavity to form a WFe nanoparticle with a disordered crystal and un-coupled atomic magnetic moments. The atomic magnetic moments were thus localized, resulting in a principally paramagnetic nanoparticle. The WFe nanoparticles had no coercivity or saturation magnetization at 5 K and sweeping up to ± 20,000 Oe, while native ferritin had a coercivity of 3000 Oe and saturation at ± 20,000 Oe. This tungsten-iron crystal paramagnetism resulted in an increased WFe particle longitudinal relaxivity (r1) of 4870 mm(-1) s(-1) and a reduced transverse relaxivity (r2) of 9076 mm(-1) s(-1) compared with native ferritin. The accumulation of the particles was detected with T1-weighted MRI in concentrations from 20 to 400 nm in vivo, both injected in the rat brain and targeted to the rat kidney glomerulus. The WFe apoferritin nanoparticles were not cytotoxic up to 700 nm particle concentrations, making them potentially important for targeted molecular MRI. Copyright © 2014 John Wiley & Sons, Ltd.

  4. Charming dark matter

    NASA Astrophysics Data System (ADS)

    Jubb, Thomas; Kirk, Matthew; Lenz, Alexander

    2017-12-01

    We have considered a model of Dark Minimal Flavour Violation (DMFV), in which a triplet of dark matter particles couple to right-handed up-type quarks via a heavy colour-charged scalar mediator. By studying a large spectrum of possible constraints, and assessing the entire parameter space using a Markov Chain Monte Carlo (MCMC), we can place strong restrictions on the allowed parameter space for dark matter models of this type.

  5. Effect of ground cinnamon on postprandial blood glucose concentration in normal-weight and obese adults.

    PubMed

    Magistrelli, Ashley; Chezem, Jo Carol

    2012-11-01

    In healthy normal-weight adults, cinnamon reduces blood glucose concentration and enhances insulin sensitivity. Insulin resistance, resulting in increased fasting and postprandial blood glucose and insulin levels, is commonly observed in obese individuals. The objective of the study was to compare declines in postprandial glycemic response in normal-weight and obese subjects with ingestion of 6 g ground cinnamon. In a crossover study, subjects consumed 50 g available carbohydrate in instant farina cereal, served plain or with 6 g ground cinnamon. Blood glucose concentration, the main outcome measure, was assessed at minutes 0, 15, 30, 45, 60, 90, and 120. Repeated-measures analysis of variance evaluated the effects of body mass index (BMI) group, dietary condition, and time on blood glucose. Paired t-test assessed blood glucose at individual time points and glucose area under the curve (AUC) between dietary conditions. Thirty subjects between the ages of 18 and 30 years, 15 with BMIs between 18.5 and 24.9 and 15 with BMIs of 30.0 or more, completed the study. There was no significant difference in blood glucose between the two BMI groups at any time point. However, in a combined analysis of all subjects, the addition of cinnamon to the cereal significantly reduced 120-minute glucose AUC (P=0.008) and blood glucose at 15 (P=0.001), 30 (P<0.001), 45 (P<0.001), and 60 (P=0.001) minutes. At 120 minutes, blood glucose was significantly higher with cinnamon consumption (P<0.001). These results suggest cinnamon may be effective in moderating postprandial glucose response in normal weight and obese adults. Copyright © 2012 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  6. New limits on coupled dark energy model after Planck 2015

    NASA Astrophysics Data System (ADS)

    Li, Hang; Yang, Weiqiang; Wu, Yabo; Jiang, Ying

    2018-06-01

    We used the Planck 2015 cosmic microwave background anisotropy, baryon acoustic oscillation, type-Ia supernovae, redshift-space distortions, and weak gravitational lensing to test the model parameter space of coupled dark energy. We assumed the constant and time-varying equation of state parameter for dark energy, and treated dark matter and dark energy as the fluids whose energy transfer was proportional to the combined term of the energy densities and equation of state, such as Q = 3 Hξ(1 +wx) ρx and Q = 3 Hξ [ 1 +w0 +w1(1 - a) ] ρx, the full space of equation of state could be measured when we considered the term (1 +wx) in the energy exchange. According to the joint observational constraint, the results showed that wx = - 1.006-0.027+0.047 and ξ = 0.098-0.098>+0.026 for coupled dark energy with a constant equation of state, w0 = -1.076-0.076+0.085, w1 = - 0.069-0.319+0.361, and ξ = 0.210-0.210+0.048 for a variable equation of state. We did not get any clear evidence for the coupling in the dark fluids at 1 σ region.

  7. Direct reconstruction of dark energy.

    PubMed

    Clarkson, Chris; Zunckel, Caroline

    2010-05-28

    An important issue in cosmology is reconstructing the effective dark energy equation of state directly from observations. With so few physically motivated models, future dark energy studies cannot only be based on constraining a dark energy parameter space. We present a new nonparametric method which can accurately reconstruct a wide variety of dark energy behavior with no prior assumptions about it. It is simple, quick and relatively accurate, and involves no expensive explorations of parameter space. The technique uses principal component analysis and a combination of information criteria to identify real features in the data, and tailors the fitting functions to pick up trends and smooth over noise. We find that we can constrain a large variety of w(z) models to within 10%-20% at redshifts z≲1 using just SNAP-quality data.

  8. Contrast-enhanced MR imaging of the brain using T1-weighted FLAIR with BLADE compared with a conventional spin-echo sequence.

    PubMed

    Naganawa, Shinji; Satake, Hiroko; Iwano, Shingo; Kawai, Hisashi; Kubota, Seiji; Komada, Tomohiro; Kawamura, Minako; Sakurai, Yasuo; Fukatsu, Hiroshi

    2008-02-01

    The BLADE and PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction) techniques have been proposed to reduce the effect of head motion. Preliminary results have shown that BLADE also reduces pulsation artifacts from venous sinuses. The purpose of this study was to compare T1-weighted FLAIR acquired with BLADE (T1W-FLAIR BLADE) and T1-weighted spin-echo (T1W-SE) for the detection of contrast enhancement in a phantom and in patients with suspected brain lesions and to compare the degree of flow-related artifacts in the patients. A phantom filled with diluted Gd-DTPA was scanned in addition to 27 patients. In the phantom study, the peak contrast-to-noise ratio of T1W-FLAIR BLADE was larger than that of T1W-SE, and the position of the peak was shifted to a lower concentration. In patients, the degree of flow-related artifacts was significantly higher in T1W-SE. Among the 27 patients, 9 had metastatic tumor, and 18 did not. On a patient-by-patient basis, the sensitivity and specificity for the detection of metastatic lesions on axial T1W-SE were 100% and 55.6% respectively, while on axial T1W-FLAIR BLADE they were 100% and 100%. T1W-FLAIR BLADE seems to be capable of replacing T1W-SE, at least for axial post-contrast imaging to detect brain metastases.

  9. Long-term changes in body weight are associated with changes in blood pressure levels.

    PubMed

    Markus, M R P; Ittermann, T; Baumeister, S E; Troitzsch, P; Schipf, S; Lorbeer, R; Aumannn, N; Wallaschofski, H; Dörr, M; Rettig, R; Völzke, H

    2015-03-01

    Hypertension and obesity are highly prevalent in Western societies. We investigated the associations of changes in body weight with changes in blood pressure and with incident hypertension, incident cardiovascular events, or incident normalization of blood pressure in patients who were hypertensive at baseline, over a 5-year period. Data of men and women aged 20-81 years of the Study of Health in Pomerania were used. Changes in body weight were related to changes in blood pressure by linear regression (n = 1875) adjusted for cofounders. Incident hypertension, incident cardiovascular events, or incident blood pressure normalization in patients who were hypertensive at baseline were investigated using Poisson regression (n = 3280) models. A change of 1 kg in body weight was positively associated with a change of 0.45 mm Hg (95% confidence interval (CI): 0.34-0.55 mm Hg) in systolic blood pressure, 0.32 mm Hg (95% CI: 0.25-0.38 mm Hg) in diastolic blood pressure, and 0.36 mm Hg (95% CI: 0.29-0.43 mm Hg) in mean arterial pressure (all p-values <0.001). A 5% weight loss reduced the relative risk (RR) of incident hypertension (RRs 0.84 (95% CI: 0.79-0.89)) and incident cardiovascular events (RRs 0.81 (95% CI: 0.68-0.98)) and increased the chance of incident blood pressure normalization in patients who were hypertensive at baseline by 15% (95% CI: 7-23%). Absolute and relative changes in body weight are positively associated with changes in blood pressure levels and also affect the risk of cardiovascular events. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Twin Higgs Asymmetric Dark Matter.

    PubMed

    García García, Isabel; Lasenby, Robert; March-Russell, John

    2015-09-18

    We study asymmetric dark matter (ADM) in the context of the minimal (fraternal) twin Higgs solution to the little hierarchy problem, with a twin sector with gauged SU(3)^{'}×SU(2)^{'}, a twin Higgs doublet, and only third-generation twin fermions. Naturalness requires the QCD^{'} scale Λ_{QCD}^{'}≃0.5-20  GeV, and that t^{'} is heavy. We focus on the light b^{'} quark regime, m_{b^{'}}≲Λ_{QCD}^{'}, where QCD^{'} is characterized by a single scale Λ_{QCD}^{'} with no light pions. A twin baryon number asymmetry leads to a successful dark matter (DM) candidate: the spin-3/2 twin baryon, Δ^{'}∼b^{'}b^{'}b^{'}, with a dynamically determined mass (∼5Λ_{QCD}^{'}) in the preferred range for the DM-to-baryon ratio Ω_{DM}/Ω_{baryon}≃5. Gauging the U(1)^{'} group leads to twin atoms (Δ^{'}-τ^{'}[over ¯] bound states) that are successful ADM candidates in significant regions of parameter space, sometimes with observable changes to DM halo properties. Direct detection signatures satisfy current bounds, at times modified by dark form factors.

  11. IVIM diffusion-weighted imaging of the liver at 3.0 T: Comparison with 1.5 T

    PubMed Central

    Cui, Yong; Dyvorne, Hadrien; Besa, Cecilia; Cooper, Nancy; Taouli, Bachir

    2015-01-01

    Purpose To compare intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) of the liver between 1.5 T and 3.0 T in terms of parameter quantification and inter-platform reproducibility. Materials and methods In this IRB approved prospective study, 19 subjects (17 patients with chronic liver disease and 2 healthy volunteers) underwent two repeat scans at 1.5 T and 3.0 T. Each scan included IVIM DWI using 16 b values from 0 to 800 s/mm2. A single observer measured IVIM parameters for each platform and estimated signal to noise ratio (eSNR) at b0, 200, 400 and 800 s/mm2. Wilcoxon paired tests were used to compare liver eSNR and IVIM parameters. Inter-platform reproducibility was assessed by calculating within-subject coefficient of variation (CV) and Bland–Altman limits of agreement. An ice water phantom was used to test ADC variability between the two MRI systems. Results The mean invitro difference in ADC between the two platforms was 6.8%. eSNR was significantly higher at 3.0T for all selected b values (p = 0.006–0.020), except for b0 (p = 0.239). Liver IVIM parameters were significantly different between 1.5 T and 3.0 T (p = 0.005–0.044), except for ADC (p = 0.748). The inter-platform reproducibility of true diffusion coefficient (D) and ADC were good, with mean CV of 10.9% and 11.1%, respectively. Perfusion fraction (PF) and pseudodiffusion coefficient (D*) showed more limited inter-platform reproducibility (mean CV of 22.6% for PF and 46.9% for D*). Conclusion Liver D and ADC values showed good reproducibility between 1.5 T and 3.0 T platforms; while there was more variability in PF, and large variability in D* parameters between the two platforms. These findings may have implications for drug trials assessing the role of IVIM DWI in tumor response and liver fibrosis. PMID:26393236

  12. Impairment of T-regulatory cells in cord blood of atopic mothers.

    PubMed

    Schaub, Bianca; Liu, Jing; Höppler, Sabine; Haug, Severine; Sattler, Christine; Lluis, Anna; Illi, Sabina; von Mutius, Erika

    2008-06-01

    Maternal atopy is a strong predictor for the development of childhood allergic diseases. The underlying mechanisms are ill defined, yet regulatory T (Treg) and T(H)17 cells may play a key role potentially shaping the early immune system toward a proallergic or antiallergic immune regulation. We examined T(H)1/T(H)2, Treg, and T(H)17 cell responses to innate (lipid A/peptidoglycan) and mitogen/adaptive (phytohemagglutinin/Dermatophagoides pteronyssinus 1) immune stimulation in cord blood from offspring of atopic/nonatopic mothers. Cord blood mononuclear cells from 161 healthy neonates (59% nonatopic, 41% atopic mothers) were investigated regarding Treg and T(H)17 cells (mRNA/surface markers), suppressive function, and proliferation/cytokine secretion. Cord blood from offspring of atopic mothers showed fewer innate-induced Treg cells (CD4(+)CD25(+)high), lower mRNA expression of associated markers (glucocorticoid-induced tumor necrosis factor receptor-related protein/lymphocyte activation gene 3; P < .05), and a trend toward lower Forkhead box transcription factor 3 (Foxp3) expression. Treg cell function was impaired in mitogen-induced suppression of T effector cells in cord blood of offspring from atopic mothers (P = .03). Furthermore, IL-10 and IFN-gamma secretion were decreased in innate-stimulated cord blood of offspring from atopic mothers (P = .04/.05). Innate-induced IL-17 was independent of maternal atopy and highly correlated with IL-13 secretion. In offspring of atopic mothers, Treg cell numbers, expression, and function were impaired at birth. T(H)17 cells were correlated with T(H)2 cells, independently of maternal atopy.

  13. ChLae1 and ChVel1 Regulate T-toxin Production, Virulence, Oxidative Stress Response, and Development of the Maize Pathogen Cochliobolus heterostrophus

    PubMed Central

    Wu, Dongliang; Oide, Shinichi; Zhang, Ning; Choi, May Yee; Turgeon, B. Gillian

    2012-01-01

    LaeA and VeA coordinate secondary metabolism and differentiation in response to light signals in Aspergillus spp. Their orthologs, ChLae1 and ChVel1, were identified in the maize pathogen Cochliobolus heterostrophus, known to produce a wealth of secondary metabolites, including the host selective toxin, T-toxin. Produced by race T, T-toxin promotes high virulence to maize carrying Texas male sterile cytoplasm (T-cms). T-toxin production is significantly increased in the dark in wild type (WT), whereas Chvel1 and Chlae1 mutant toxin levels are much reduced in the dark compared to WT. Correspondingly, expression of T-toxin biosynthetic genes (Tox1) is up-regulated in the dark in WT, while dark-induced expression is much reduced/minimal in Chvel1 and Chlae1 mutants. Toxin production and Tox1 gene expression are increased in ChVEL1 overexpression (OE) strains grown in the dark and in ChLAE1 strains grown in either light or dark, compared to WT. These observations establish ChLae1 and ChVel1 as the first factors known to regulate host selective toxin production. Virulence of Chlae1 and Chvel1 mutants and OE strains is altered on both T-cms and normal cytoplasm maize, indicating that both T-toxin mediated super virulence and basic pathogenic ability are affected. Deletion of ChLAE1 or ChVEL1 reduces tolerance to H2O2. Expression of CAT3, one of the three catalase genes, is reduced in the Chvel1 mutant. Chlae1 and Chvel1 mutants also show decreased aerial hyphal growth, increased asexual sporulation and female sterility. ChLAE1 OE strains are female sterile, while ChVEL1 OE strains are more fertile than WT. ChLae1 and ChVel1 repress expression of 1,8-dihydroxynaphthalene (DHN) melanin biosynthesis genes, and, accordingly, melanization is enhanced in Chlae1 and Chvel1 mutants, and reduced in OE strains. Thus, ChLae1 and ChVel1 positively regulate T-toxin biosynthesis, pathogenicity and super virulence, oxidative stress responses, sexual development, and aerial hyphal

  14. 46 CFR 32.56-55 - Control spaces-T/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Control spaces-T/ALL. 32.56-55 Section 32.56-55 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS SPECIAL EQUIPMENT, MACHINERY, AND HULL....56-55 Control spaces—T/ALL. Bulkheads and decks that separate control spaces from adjacent spaces...

  15. 46 CFR 32.56-55 - Control spaces-T/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Control spaces-T/ALL. 32.56-55 Section 32.56-55 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS SPECIAL EQUIPMENT, MACHINERY, AND HULL....56-55 Control spaces—T/ALL. Bulkheads and decks that separate control spaces from adjacent spaces...

  16. 46 CFR 32.56-55 - Control spaces-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Control spaces-T/ALL. 32.56-55 Section 32.56-55 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS SPECIAL EQUIPMENT, MACHINERY, AND HULL....56-55 Control spaces—T/ALL. Bulkheads and decks that separate control spaces from adjacent spaces...

  17. 46 CFR 32.56-55 - Control spaces-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Control spaces-T/ALL. 32.56-55 Section 32.56-55 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS SPECIAL EQUIPMENT, MACHINERY, AND HULL....56-55 Control spaces—T/ALL. Bulkheads and decks that separate control spaces from adjacent spaces...

  18. 46 CFR 32.56-55 - Control spaces-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Control spaces-T/ALL. 32.56-55 Section 32.56-55 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS SPECIAL EQUIPMENT, MACHINERY, AND HULL....56-55 Control spaces—T/ALL. Bulkheads and decks that separate control spaces from adjacent spaces...

  19. Direct visualization of antigen-specific T cells: HTLV-1 Tax11-19- specific CD8(+) T cells are activated in peripheral blood and accumulate in cerebrospinal fluid from HAM/TSP patients.

    PubMed

    Greten, T F; Slansky, J E; Kubota, R; Soldan, S S; Jaffee, E M; Leist, T P; Pardoll, D M; Jacobson, S; Schneck, J P

    1998-06-23

    Human T lymphotropic virus type 1 (HTLV-1) -associated myelopathy/tropic spastic paraparesis is a demyelinating inflammatory neurologic disease associated with HTLV-1 infection. HTLV-1 Tax11-19-specific cytotoxic T cells have been isolated from HLA-A2-positive patients. We have used a peptide-loaded soluble HLA-A2-Ig complex to directly visualize HTLV-1 Tax11-19-specific T cells from peripheral blood and cerebrospinal fluid without in vitro stimulation. Five of six HTLV-1-associated myelopathy/tropic spastic paraparesis patients carried a significant number (up to 13.87%) of CD8(+) lymphocytes specific for the HTLV-1 Tax11-19 peptide in their peripheral blood, which were not found in healthy controls. Simultaneous comparison of peripheral blood and cerebrospinal fluid from one patient revealed 2.5-fold more Tax11-19-specific T cells in the cerebrospinal fluid (23.7% vs. 9.4% in peripheral blood lymphocyte). Tax11-19-specific T cells were seen consistently over a 9-yr time course in one patient as far as 19 yrs after the onset of clinical symptoms. Further analysis of HTLV-1 Tax11-19-specific CD8(+) T lymphocytes in HAM/TSP patients showed different expression patterns of activation markers, intracellular TNF-alpha and gamma-interferon depending on the severity of the disease. Thus, visualization of antigen-specific T cells demonstrates that HTLV-1 Tax11-19-specific CD8(+) T cells are activated, persist during the chronic phase of the disease, and accumulate in cerebrospinal fluid, showing their pivotal role in the pathogenesis of this neurologic disease.

  20. Macroscopic theory of dark sector

    NASA Astrophysics Data System (ADS)

    Meierovich, Boris

    A simple Lagrangian with squared covariant divergence of a vector field as a kinetic term turned out an adequate tool for macroscopic description of the dark sector. The zero-mass field acts as the dark energy. Its energy-momentum tensor is a simple additive to the cosmological constant [1]. Space-like and time-like massive vector fields describe two different forms of dark matter. The space-like massive vector field is attractive. It is responsible for the observed plateau in galaxy rotation curves [2]. The time-like massive field displays repulsive elasticity. In balance with dark energy and ordinary matter it provides a four parametric diversity of regular solutions of the Einstein equations describing different possible cosmological and oscillating non-singular scenarios of evolution of the universe [3]. In particular, the singular big bang turns into a regular inflation-like transition from contraction to expansion with the accelerate expansion at late times. The fine-tuned Friedman-Robertson-Walker singular solution corresponds to the particular limiting case at the boundary of existence of regular oscillating solutions in the absence of vector fields. The simplicity of the general covariant expression for the energy-momentum tensor allows to analyse the main properties of the dark sector analytically and avoid unnecessary model assumptions. It opens a possibility to trace how the additional attraction of the space-like dark matter, dominating in the galaxy scale, transforms into the elastic repulsion of the time-like dark matter, dominating in the scale of the Universe. 1. B. E. Meierovich. "Vector fields in multidimensional cosmology". Phys. Rev. D 84, 064037 (2011). 2. B. E. Meierovich. "Galaxy rotation curves driven by massive vector fields: Key to the theory of the dark sector". Phys. Rev. D 87, 103510, (2013). 3. B. E. Meierovich. "Towards the theory of the evolution of the Universe". Phys. Rev. D 85, 123544 (2012).

  1. High-resolution T2-weighted cervical cancer imaging: a feasibility study on ultra-high-field 7.0-T MRI with an endorectal monopole antenna.

    PubMed

    Hoogendam, Jacob P; Kalleveen, Irene M L; de Castro, Catalina S Arteaga; Raaijmakers, Alexander J E; Verheijen, René H M; van den Bosch, Maurice A A J; Klomp, Dennis W J; Zweemer, Ronald P; Veldhuis, Wouter B

    2017-03-01

    We studied the feasibility of high-resolution T 2 -weighted cervical cancer imaging on an ultra-high-field 7.0-T magnetic resonance imaging (MRI) system using an endorectal antenna of 4.7-mm thickness. A feasibility study on 20 stage IB1-IIB cervical cancer patients was conducted. All underwent pre-treatment 1.5-T MRI. At 7.0-T MRI, an external transmit/receive array with seven dipole antennae and a single endorectal monopole receive antenna were used. Discomfort levels were assessed. Following individualised phase-based B 1 + shimming, T 2 -weighted turbo spin echo sequences were completed. Patients had stage IB1 (n = 9), IB2 (n = 4), IIA1 (n = 1) or IIB (n = 6) cervical cancer. Discomfort (ten-point scale) was minimal at placement and removal of the endorectal antenna with a median score of 1 (range, 0-5) and 0 (range, 0-2) respectively. Its use did not result in adverse events or pre-term session discontinuation. To demonstrate feasibility, T 2 -weighted acquisitions from 7.0-T MRI are presented in comparison to 1.5-T MRI. Artefacts on 7.0-T MRI were due to motion, locally destructive B 1 interference, excessive B 1 under the external antennae and SENSE reconstruction. High-resolution T 2 -weighted 7.0-T MRI of stage IB1-IIB cervical cancer is feasible. The addition of an endorectal antenna is well tolerated by patients. • High resolution T 2 -weighted 7.0-T MRI of the inner female pelvis is challenging • We demonstrate a feasible approach for T 2 -weighted 7.0-T MRI of cervical cancer • An endorectal monopole receive antenna is well tolerated by participants • The endorectal antenna did not lead to adverse events or session discontinuation.

  2. Diffusion-weighted and T2-weighted MR imaging for colorectal liver metastases detection in a rat model at 7 T: a comparative study using histological examination as reference.

    PubMed

    Wagner, Mathilde; Maggiori, Léon; Ronot, Maxime; Paradis, Valérie; Vilgrain, Valérie; Panis, Yves; Van Beers, Bernard E

    2013-08-01

    To compare diffusion-weighted (DW) and T2-weighted MR imaging in detecting colorectal liver metastases in a rat model, using histological examination as a reference method. Eighteen rats had four liver injections of colon cancer cells. MR examinations at 7 T included FSE-T2-weighted imaging and SE-DW MR imaging (b = 0, 20 and 150 s/mm(2)) and were analysed by two independent readers. Histological examination was performed on 0.4-mm slices. McNemar's test was used to compare the sensitivities and the Wilcoxon matched pairs test to compare the average number of false-positives per rat. One hundred and sixty-six liver metastases were identified on histological examination. The sensitivity in detecting liver metastases was significantly higher on DW MR than on T2-weighted images (99/166 (60 %) (reader 1) and 92/166 (55 %) (reader 2) versus 77/166 (46 %), P ≤ 0.001), without an increase in false-positives per rat (P = 0.773/P = 0.850). After stratification according to metastasis diameter, DW MR imaging had a significantly higher sensitivity than T2-weighted imaging only for metastases with a diameter (0.6-1.2 mm) similar to that of the spatial resolution of MR imaging in the current study. This MR study with histological correlations shows the higher sensitivity of DW relative to T2-weighted imaging at 7 T for detecting liver metastases, especially small ones. • Diffusion weighted (DW) sequences are increasingly used in magnetic resonance imaging (MRI). • DW has higher sensitivity for liver metastases than T2-weighted imaging at 7 T. • This increase in sensitivity is especially marked for small liver metastasis detection. • This higher sensitivity is confirmed in an animal model with histological correlation. • DW imaging has the potential for earlier diagnosis of small liver metastases.

  3. Molecular weight dependent glucose lowering effect of low molecular weight Chitosan Oligosaccharide (GO2KA1) on postprandial blood glucose level in SD rats model.

    PubMed

    Jo, Sung-Hoon; Ha, Kyoung-Soo; Moon, Kyoung-Sik; Kim, Jong-Gwan; Oh, Chen-Gum; Kim, Young-Cheul; Apostolidis, Emmanouil; Kwon, Young-In

    2013-07-09

    This research investigated the effect of enzymatically digested low molecular weight (MW) chitosan oligosaccharide on type 2 diabetes prevention. Three different chitosan oligosaccharide samples with varying MW were evaluated in vitro for inhibition of rat small intestinal α-glucosidase and porcine pancreatic α-amylase (GO2KA1; <1000 Da, GO2KA2; 1000-10,000 Da, GO2KA3; MW > 10,000 Da). The in vitro results showed that all tested samples had similar rat α-glucosidase inhibitory and porcine α-amylase inhibitory activity. Based on these observations, we decided to further investigate the effect of all three samples at a dose of 0.1 g/kg, on reducing postprandial blood glucose levels in Sprague-Dawley (SD) rat model after sucrose loading test. In the animal trial, all tested samples had postprandial blood glucose reduction effect, when compared to control, however GO2KA1 supplementation had the strongest effect. The glucose peak (Cmax) for GO2KA1 and control was 152 mg/dL and 193 mg/dL, respectively. The area under the blood glucose-time curve (AUC) for GO2KA1 and control was 262 h mg/dL and 305 h mg/dL, respectively. Furthermore, the time of peak plasma concentration of blood glucose (Tmax) for GO2KA1 was significantly delayed (0.9 h) compared to control (0.5 h). These results suggest that GO2KA1 could have a beneficial effect for blood glucose management relevant to diabetes prevention in normal and pre-diabetic individuals. The suggested mechanism of action is via inhibition of the carbohydrate hydrolysis enzyme α-glucosidase and since GO2KA1 (MW < 1000 Da) had higher in vivo effect, we hypothesize that it is more readily absorbed and might exert further biological effect once it is absorbed in the blood stream, relevant to blood glucose management.

  4. Quantitative Retinal and Choroidal Blood Flow During Light, Dark Adaptation and Flicker Light Stimulation in Rats Using Fluorescent Microspheres

    PubMed Central

    Shih, Yen-Yu I.; Wang, Lin; De La Garza, Bryan H.; Li, Guang; Cull, Grant; Kiel, Jeffery W.; Duong, Timothy Q.

    2013-01-01

    Purpose The present study aimed to quantify retinal and choroidal blood flow (BF) during light, dark adaptation and flicker light stimulation using the microsphere technique. Materials and Methods Adult male Sprague–Dawley rats were anesthetized with isoflurane. Eyes were dark (Group I, n = 8), light (Group II, n = 8) adapted or stimulated with 10Hz flicker light (Group III, n = 10). Retinal and choroidal BF were measured by a previously established method, using a mixture of 8 μm yellow-green and 10 μm red fluorescent microspheres. The microspheres were counted ex vivo in the dissected retina and choroid and in the reference arterial blood under a fluorescent microscope. Results The choroidal BF was 64.8 ± 29 μl/min (mean ± SD) during dark adaptation, not significantly different from that during light adaptation (66.0 ± 17.8 μl/min). The retinal BF was 13.5 ± 3.2 μl/min during 10 Hz flickering light stimulation, significantly higher than that during dark adaptation in the control fellow eyes (9.9 ± 2.9 μl/min). The choroidal BF values were not statistically different between flicker stimulation and dark adaptation. Retinal BF was 11.6 ± 2.9 μl/min during light adaptation. Dark adaptation did not increase retinal BF (Group I, 8.2 ± 2.4 μl/min; Group II, 9.9 ± 2.9 μl/min). Conclusions These findings argue against a dark-induced or flicker-induced functional hyperemia in the choroid as a result of the demands of the outer retina. Retinal BF was not higher during dark adaptation. Our data support the conclusion that the inner retina has a higher energy demand in flicker conditions relative to dark. PMID:23317112

  5. Quantitative retinal and choroidal blood flow during light, dark adaptation and flicker light stimulation in rats using fluorescent microspheres.

    PubMed

    Shih, Yen-Yu I; Wang, Lin; De La Garza, Bryan H; Li, Guang; Cull, Grant; Kiel, Jeffery W; Duong, Timothy Q

    2013-02-01

    The present study aimed to quantify retinal and choroidal blood flow (BF) during light, dark adaptation and flicker light stimulation using the microsphere technique. Adult male Sprague-Dawley rats were anesthetized with isoflurane. Eyes were dark (Group I, n = 8), light (Group II, n = 8) adapted or stimulated with 10 Hz flicker light (Group III, n = 10). Retinal and choroidal BF were measured by a previously established method, using a mixture of 8 µm yellow-green and 10 µm red fluorescent microspheres. The microspheres were counted ex vivo in the dissected retina and choroid and in the reference arterial blood under a fluorescent microscope. The choroidal BF was 64.8 ± 29 µl/min (mean ± SD) during dark adaptation, not significantly different from that during light adaptation (66.0 ± 17.8 µl/min). The retinal BF was 13.5 ± 3.2 µl/min during 10 Hz flickering light stimulation, significantly higher than that during dark adaptation in the control fellow eyes (9.9 ± 2.9 µl/min). The choroidal BF values were not statistically different between flicker stimulation and dark adaptation. Retinal BF was 11.6 ± 2.9 µl/min during light adaptation. Dark adaptation did not increase retinal BF (Group I, 8.2 ± 2.4 µl/min; Group II, 9.9 ± 2.9 µl/min). These findings argue against a dark-induced or flicker-induced functional hyperemia in the choroid as a result of the demands of the outer retina. Retinal BF was not higher during dark adaptation. Our data support the conclusion that the inner retina has a higher energy demand in flicker conditions relative to dark.

  6. Dark Matter's secret liaisons: phenomenology of a dark U(1) sector with bound states

    NASA Astrophysics Data System (ADS)

    Cirelli, Marco; Panci, Paolo; Petraki, Kalliopi; Sala, Filippo; Taoso, Marco

    2017-05-01

    Dark matter (DM) charged under a dark U(1) force appears in many extensions of the Standard Model, and has been invoked to explain anomalies in cosmic-ray data, as well as a self-interacting DM candidate. In this paper, we perform a comprehensive phenomenological analysis of such a model, assuming that the DM abundance arises from the thermal freeze-out of the dark interactions. We include, for the first time, bound-state effects both in the DM production and in the indirect detection signals, and quantify their importance for FERMI, AMS-02, and CMB experiments. We find that DM in the mass range 1 GeV to 100 TeV, annihilating into dark photons of MeV to GeV mass, is in conflict with observations. Instead, DM annihilation into heavier dark photons is viable. We point out that the late decays of multi-GeV dark photons can produce significant entropy and thus dilute the DM density. This can lower considerably the dark coupling needed to obtain the DM abundance, and in turn relax the existing constraints.

  7. Blood troponin levels in acute cardiac events depends on space weather activity components (a correlative study).

    PubMed

    Stoupel, Eliiyahu; Radishauskas, Richardas; Bernotiene, Gailute; Tamoshiunas, Abdonas; Virvichiute, Daiva

    2018-02-05

    Many biological processes are influenced by space weather activity components such as solar activity (SA), geomagnetic activity (GMA) and cosmic ray activity (CRA). Examples are total mortality, acute myocardial infarction (AMI), stroke (cerebrovascular accident), sudden cardiac death, some congenital maladies (congenital heart disease and Down syndrome), many events in neonatology, ophtalmology, blood pressure regulation, blood coagulation, inflammation, etc. The aim of this study was to check if the level of blood troponins (Tns) - markers of myocardial damage and recognized components of modern description of AMI - is connected with the mentioned space weather parameters. Patients admitted to a 3000-bed tertiary university hospital in Kaunas, Lithuania, with suspected AMI were the object of the study. Data for the time between 2008 and 2013 - 72 consecutive months - were studied. Of the patients, 1896 (1398 male, 498 female) had elevated troponin I (Tn I) or troponin T (Tn T, sensitive Tn) levels. Normal values were 0.00-0.03 ng/mL for Tn I and 0.00-14.00 ng/mL for Tn T. Monthly means and standard deviation of Tn I and Tn T were compared with monthly markers of SA, GMA and CRA. Pearson correlation coefficients and their probabilities were established (in addition to the consecutive graphs of both comparing physical and biological data). The cosmophysical data came from space service institutions in the United States, Russia and Finland. AMI was diagnosed in 1188 patients (62.66%), and intermediate coronary syndrome in 698 patients (36.81%). There were significant links of the Tn blood levels with four SA indices and CRA (neutron activity in imp/min); there was no significant correlation with GMA indices Ap and Cp (p=0.27 and p=0.235). Tn T levels significantly correlated with the GMA indices and not with the SA and CRA levels (Ap: r=0.77, p=0.0021; Cp: r=0.729, p=0.0047). First, the monthly level of blood Tn I in ACS is significantly correlated with the indices

  8. Destruction of newly released red blood cells in space flight

    NASA Technical Reports Server (NTRS)

    Alfrey, C. P.; Udden, M. M.; Huntoon, C. L.; Driscoll, T.

    1996-01-01

    Space flight results in a rapid change in total blood volume, plasma volume, and red blood cell mass because the space to contain blood is decreased. The plasma volume and total blood volume decreases during the first hours in space and remain at a decreased level for the remainder of the flight. During the first several hours following return to earth, plasma volume and total blood volume increase to preflight levels. During the first few days in space recently produced red blood cells disappear from the blood resulting in a decrease in red blood cell mass of 10-15%. Red cells 12 d old or older survive normally and production of new cells continues at near preflight levels. After the first few days in space, the red cell mass is stable at the decreased level. Following return to earth the hemoglobin and red blood cell mass concentrations decrease reflecting the increase in plasma volume. The erythropoietin levels increase responding to "postflight anemia"; red cell production increases, and the red cell mass is restored to preflight levels after several weeks.

  9. [The value of low-molecular-weight DNA of blood plasma in the diagnostic of the patological processes of different genesis].

    PubMed

    Vasil'eva, I N; Zinkin, V N

    2013-01-01

    The low-molecular-weight DNA appears in blood plasma of irradiated rats, and its content correlates directly with the irradiation dose. Cloning has shown, that enrichment of low-molecular-weight DNA with G+C content and features of its nucleotide sequences point to its ability to form rather stable nucleosomes. DNA obtained after irradiation of rats with principally different doses 8 and 100 Gy differed not only quantitatively, but also by content of the dinucleotides CpG and CpT; this suggests their origin from different sites of genome. For the first time it has been shown that exposure to low-frequency noise results in an increase of the contents of blood plasma low-molecular-weight DNA. In stroke patients blood concentrations of this DNA increased 3 days after the beginning of the acute period, and dynamics of its excretion differs in ischemic and hemorrhagic forms; in the case of ischemia low-molecular-weight DNA appears in cerebrospinal fluid. The chronic obstructive pulmonary disease in the state of remission is characterized by the decline of the level of low-molecular-weight DNA in the blood plasma unlike in the case of the chronic nonobstructive bronchitis. The clear dependence between formation and special features of the low-molecular-weight DNA fraction in blood plasma makes it possible to consider the low-molecular fraction as an universal index of apoptosis, which allows to distinguish basically different conditions of the body.

  10. Assessment of cerebral venous sinus thrombosis using T2*-weighted gradient echo magnetic resonance imaging sequences

    PubMed Central

    Bidar, Fatemeh; Faeghi, Fariborz; Ghorbani, Askar

    2016-01-01

    Background: The purpose of this study is to demonstrate the advantages of gradient echo (GRE) sequences in the detection and characterization of cerebral venous sinus thrombosis compared to conventional magnetic resonance sequences. Methods: A total of 17 patients with cerebral venous thrombosis (CVT) were evaluated using different magnetic resonance imaging (MRI) sequences. The MRI sequences included T1-weighted spin echo (SE) imaging, T*2-weighted turbo SE (TSE), fluid attenuated inversion recovery (FLAIR), T*2-weighted conventional GRE, and diffusion weighted imaging (DWI). MR venography (MRV) images were obtained as the golden standard. Results: Venous sinus thrombosis was best detectable in T*2-weighted conventional GRE sequences in all patients except in one case. Venous thrombosis was undetectable in DWI. T*2-weighted GRE sequences were superior to T*2-weighted TSE, T1-weighted SE, and FLAIR. Enhanced MRV was successful in displaying the location of thrombosis. Conclusion: T*2-weighted conventional GRE sequences are probably the best method for the assessment of cerebral venous sinus thrombosis. The mentioned method is non-invasive; therefore, it can be employed in the clinical evaluation of cerebral venous sinus thrombosis. PMID:27326365

  11. Blood lead levels and bone turnover with weight reduction in women.

    PubMed

    Riedt, Claudia S; Buckley, Brian T; Brolin, Robert E; Ambia-Sobhan, Hasina; Rhoads, George G; Shapses, Sue A

    2009-01-01

    High bone turnover states are known to raise blood lead levels (BPb). Caloric restriction will increase bone turnover, yet it remains unknown if weight reduction increases BPb due to mobilization of skeletal stores. We measured whole blood Pb levels ((206)Pb) by inductively coupled plasma mass spectrometry in 73 women (age 24-75 years; BMI 23- 61 kg/m(2)) before and after 6 months of severe weight loss (S-WL), moderate weight loss (M-WL), or weight maintenance (WM). Baseline BPb levels were relatively low at 0.2-6.0 microg/dl, and directly associated with age (r=0.49, P<0.0001). After severe WL (-37.4+/-9.3 kg, n=17), BPb increased by 2.1+/-3.9 microg/dl (P<0.05), resulting in BPb levels of 1.3-12.5 microg/dl. M-WL (-5.6+/-2.7 kg, n=39) and WM (0.3+/-1.3 kg, n=17) did not result in an increase in BPb levels (0.5+/-3.2 and 0.0+/-0.7 microg/dl, M-WL and WM, respectively). BPb levels increased more with greater WL (r=0.24, P<0.05). Bone turnover markers increased only with severe WL and were directly correlated with WL. At baseline, higher calcium intake was associated with lower BPb (r=-0.273, P<0.02), however, this association was no longer present after 6 months. Severe weight reduction in obese women increases skeletal bone mobilization and BPb, but values remain well below levels defined as Pb overexposure.

  12. Impact of body weight on the relationship between alcohol intake and blood pressure.

    PubMed

    Wakabayashi, Ichiro

    2009-01-01

    The reduction of habitual alcohol drinking is recommended for the prevention of hypertension. Daily or weekly alcohol consumption, which is used for evaluation of the effects of alcohol drinking on blood pressure, is usually not corrected by body weight. In this study, the influence of body weight on the relationship between alcohol intake and blood pressure was investigated. The subjects (27,005 healthy men at ages of 35-54 years) were divided into four groups by average daily ethanol intake [non-, light (<15 g per day), moderate (>or=15 and <30 g per day) and heavy (>or=30 g per day) drinkers]. The subjects were also divided into four quartile groups by body weight. Alcohol intake and the percentage of drinkers were not different in the four quartile groups of body weight. In the first and second quartiles of body weight, systolic and diastolic blood pressures were significantly higher in moderate and heavy drinkers than in non-drinkers, while systolic and diastolic blood pressures in the fourth quartile of body weight were significantly higher in heavy drinkers than in non-drinkers but were not significantly different in moderate drinkers and non-drinkers. The differences in systolic or diastolic blood pressure between non-drinkers and moderate drinkers and between non-drinkers and heavy drinkers became greater as body weight decreased. These results were not altered when age and smoking history were adjusted. The results suggest that body weight modifies the relationship between alcohol consumption and blood pressure and thus should be taken into account when effects of alcohol on blood pressure are considered.

  13. Effect of Renal Function on Gadolinium-Related Signal Increases on Unenhanced T1-Weighted Brain Magnetic Resonance Imaging.

    PubMed

    Cao, Yan; Zhang, Yang; Shih, George; Zhang, Yan; Bohmart, Andrew; Hecht, Elizabeth M; Prince, Martin R

    2016-11-01

    The purpose of this study was to determine if renal function affects signal changes in the deep brain nuclei on unenhanced T1-weighted images after administration of linear gadolinium-based contrast agents (GBCAs). An electronic medical records search of 2 large medical centers identified 25 patients who received linear GBCA while on hemodialysis and had unenhanced T1-weighted images of the brain before and after. The dentate-to-cerebellar peduncle (DCP) ratio, globus pallidus-to-mid thalamus (GPT) ratio, and choroid plexus-to-nearby white matter ratio were measured and compared with 25 age/sex/GBCA exposure-matched control patients with normal or near-normal renal function (estimated glomerular filtration rate >60 mL/min per 1.73 m). Two additional control groups included 13 patients on hemodialysis without GBCA exposure and 13 age/sex-matched patients with estimated glomerular filtration rate greater than 60 mL/min per 1.73 m. Hemodialysis patients (n = 25) with an average of 1.8 linear GBCA administrations had a 4.9% mean increase (1.00 ± 0.04 vs 1.05 ± 0.05; P < 0.001) in DCP, which was greater than the 1.6% change (0.99 ± 0.04 vs 1.00 ± 0.05; P = 0.08) observed in matched controls (P = 0.01). There was no significant signal change in the DCP ratio in the 13 hemodialysis patients (0.99 ± 0.04 vs 0.99 ± 0.04; P = 0.78) and 13 age/sex-matched patients (0.99 ± 0.02 vs 0.99 ± 0.03; P = 0.78) who did not receive GBCA. The hemodialysis patients had a baseline GPT that was higher than nondialysis patients (P < 0.001). However, the GPT change after GBCA administration was not significantly different from controls. Increased signal in the choroid plexus on unenhanced T1-weighted images after GBCA administration was noted in hemodialysis patients (0.72 ± 0.20 vs 0.86 ± 0.23; P = 0.006); however, a multivariate analysis showed this to be primarily related to hemodialysis (P = 0.003) with only a trend toward relating to GBCA exposure (P = 0.07). Hemodialysis

  14. Gadolinium-based magnetic resonance contrast agents at 7 Tesla: in vitro T1 relaxivities in human blood plasma.

    PubMed

    Noebauer-Huhmann, Iris M; Szomolanyi, Pavol; Juras, Vladimír; Kraff, Oliver; Ladd, Mark E; Trattnig, Siegfried

    2010-09-01

    PURPOSE/INTRODUCTION: The aim of this study was to determine the T1 relaxivities (r1) of 8 gadolinium (Gd)-based MR contrast agents in human blood plasma at 7 Tesla, compared with 3 Tesla. Eight commercially available Gd-based MR contrast agents were diluted in human blood plasma to concentrations of 0, 0.25, 0.5, 1, and 2 mmol/L. In vitro measurements were performed at 37 degrees C, on a 7 Tesla and on a 3 Tesla whole-body magnetic resonance imaging scanner. For the determination of T1 relaxation times, Inversion Recovery Sequences with inversion times from 0 to 3500 ms were used. The relaxivities were calculated. The r1 relaxivities of all agents, diluted in human blood plasma at body temperature, were lower at 7 Tesla than at 3 Tesla. The values at 3 Tesla were comparable to those published earlier. Notably, in some agents, a minor negative correlation of r1 with a concentration of up to 2 mmol/L could be observed. This was most pronounced in the agents with the highest protein-binding capacity. At 7 Tesla, the in vitro r1 relaxivities of Gd-based contrast agents in human blood plasma are lower than those at 3 Tesla. This work may serve as a basis for the application of Gd-based MR contrast agents at 7 Tesla. Further studies are required to optimize the contrast agent dose in vivo.

  15. 3D T2-weighted imaging to shorten multiparametric prostate MRI protocols.

    PubMed

    Polanec, Stephan H; Lazar, Mathias; Wengert, Georg J; Bickel, Hubert; Spick, Claudio; Susani, Martin; Shariat, Shahrokh; Clauser, Paola; Baltzer, Pascal A T

    2018-04-01

    To determine whether 3D acquisitions provide equivalent image quality, lesion delineation quality and PI-RADS v2 performance compared to 2D acquisitions in T2-weighted imaging of the prostate at 3 T. This IRB-approved, prospective study included 150 consecutive patients (mean age 63.7 years, 35-84 years; mean PSA 7.2 ng/ml, 0.4-31.1 ng/ml). Two uroradiologists (R1, R2) independently rated image quality and lesion delineation quality using a five-point ordinal scale and assigned a PI-RADS score for 2D and 3D T2-weighted image data sets. Data were compared using visual grading characteristics (VGC) and receiver operating characteristics (ROC)/area under the curve (AUC) analysis. Image quality was similarly good to excellent for 2D T2w (mean score R1, 4.3 ± 0.81; R2, 4.7 ± 0.83) and 3D T2w (mean score R1, 4.3 ± 0.82; R2, 4.7 ± 0.69), p = 0.269. Lesion delineation was rated good to excellent for 2D (mean score R1, 4.16 ± 0.81; R2, 4.19 ± 0.92) and 3D T2w (R1, 4.19 ± 0.94; R2, 4.27 ± 0.94) without significant differences (p = 0.785). ROC analysis showed an equivalent performance for 2D (AUC 0.580-0.623) and 3D (AUC 0.576-0.629) T2w (p > 0.05, respectively). Three-dimensional acquisitions demonstrated equivalent image and lesion delineation quality, and PI-RADS v2 performance, compared to 2D in T2-weighted imaging of the prostate. Three-dimensional T2-weighted imaging could be used to considerably shorten prostate MRI protocols in clinical practice. • 3D shows equivalent image quality and lesion delineation compared to 2D T2w. • 3D T2w and 2D T2w image acquisition demonstrated comparable diagnostic performance. • Using a single 3D T2w acquisition may shorten the protocol by 40%. • Combined with short DCE, multiparametric protocols of 10 min are feasible.

  16. 46 CFR 32.40-35 - Hospital space-T/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Hospital space-T/ALL. 32.40-35 Section 32.40-35 Shipping... REQUIREMENTS Accommodations for Officers and Crew § 32.40-35 Hospital space—T/ALL. (a) Each vessel which in the... crew of 12 or more, must be provided with a hospital space. This space must be situated with due regard...

  17. 46 CFR 32.40-35 - Hospital space-T/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Hospital space-T/ALL. 32.40-35 Section 32.40-35 Shipping... REQUIREMENTS Accommodations for Officers and Crew § 32.40-35 Hospital space—T/ALL. (a) Each vessel which in the... crew of 12 or more, must be provided with a hospital space. This space must be situated with due regard...

  18. 46 CFR 32.40-35 - Hospital space-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Hospital space-T/ALL. 32.40-35 Section 32.40-35 Shipping... REQUIREMENTS Accommodations for Officers and Crew § 32.40-35 Hospital space—T/ALL. (a) Each vessel which in the... crew of 12 or more, must be provided with a hospital space. This space must be situated with due regard...

  19. 46 CFR 32.40-35 - Hospital space-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Hospital space-T/ALL. 32.40-35 Section 32.40-35 Shipping... REQUIREMENTS Accommodations for Officers and Crew § 32.40-35 Hospital space—T/ALL. (a) Each vessel which in the... crew of 12 or more, must be provided with a hospital space. This space must be situated with due regard...

  20. 46 CFR 32.40-35 - Hospital space-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Hospital space-T/ALL. 32.40-35 Section 32.40-35 Shipping... REQUIREMENTS Accommodations for Officers and Crew § 32.40-35 Hospital space—T/ALL. (a) Each vessel which in the... crew of 12 or more, must be provided with a hospital space. This space must be situated with due regard...

  1. Protective Misperception? Prospective Study of Weight Self-Perception and Blood Pressure in Adolescents With Overweight and Obesity.

    PubMed

    Unger, Emily S; Kawachi, Ichiro; Milliren, Carly E; Sonneville, Kendrin R; Thurston, Idia B; Gooding, Holly C; Richmond, Tracy K

    2017-06-01

    Underestimating one's weight is often seen as a barrier to weight loss. However, recent research has shown that weight underperception may be beneficial, with lower future weight gain and fewer depressive symptoms. Here, we examine the relationship between adolescent weight underperception and future blood pressure. Using data from the National Longitudinal Study of Adolescent to Adult Health, we obtained a nationally representative sample of 2,463 adolescents with overweight and obesity (students in grades 8-12 in 1996). We used multivariable linear regression to prospectively examine the relationship between weight self-perception in adolescence and blood pressure in adulthood (year 2008; follow-up rate 80.3%), controlling for age, gender, race/ethnicity, smoking, alcohol consumption, education level, household income, and body mass index. Additional analyses were stratified by gender and race/ethnicity. Youth with overweight/obesity who underperceived their weight had lower blood pressure in adulthood than those who perceived themselves to be overweight. The decrease in systolic blood pressure was -2.5 mm Hg (95% confidence interval: -4.3, -0.7; p = .006). Although the interaction by gender was statistically insignificant (p = .289), important differences appeared upon stratification by gender. Young men showed no significant difference in adult blood pressure related to weight self-perception. Conversely, in young women, weight underperception was associated with an average decrease in systolic blood pressure of -4.3 mm Hg (95% confidence interval: -7.0, -1.7; p = .002). Contrary to conventional wisdom, weight underperception is associated with improved health markers in young women. The observed differences in blood pressure are clinically relevant in magnitude, and interventions to correct weight underperception should be re-examined for unintended consequences. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc

  2. Effects of Enterococcus faecium SLB 120 on growth performance, blood parameters, relative organ weight, breast muscle meat quality, excreta microbiota shedding, and noxious gas emission in broilers.

    PubMed

    Lan, R X; Lee, S I; Kim, I H

    2017-09-01

    This 5-week study was conducted to determine the effects of Enterococcus faecium (SLB 120) on growth performance, blood parameters, relative organ weight, breast muscle meat quality, excreta microbiota shedding, and noxious gas emission in broilers. A total of 816 one-day-old male broilers were allocated to 4 groups with 12 replications (17 broilers/pen) according to body weight (43.2 ± 0.32 g). Dietary treatment groups were: (1) CON, basal diet, (2) T1, CON + 0.05% E. faecium, (3) T2, CON + 0.10% E. faecium, (4) T3, CON + 0.20% E. faecium. From day 1 to 21, dietary E. faecium supplementation showed linear increase (P < 0.05) in gain:feed ratio. From day 21 to 35 and the overall period, dietary E. faecium supplementation showed a linear increase (P < 0.05) in body weight gain and gain:feed ratio. On day 35, dietary E. faecium supplementation showed a linear increase (P < 0.05) in the apparent total tract digestibility of dry matter and nitrogen, and the relative weight of bursa of Fabricius; no differences were observed in white blood cells, red blood cells or lymphocyte counts. Dietary E. faecium supplementation showed a linear decrease (P < 0.05) in excreta E.coli counts on day 7 and 35, while excreta Lactobacillus counts were linearly increased (P < 0.05) on day 35. On day 35, dietary E. faecium supplementation linearly decreased (P < 0.05) excreta NH3, H2S, and total mercaptans emission, but only H2S emission was linearly decreased (P < 0.05) on day 7. In conclusion, the supplementation of E. faecium improved growth performance, the digestibility of dry matter and nitrogen, the relative weight of bursa of Fabricius, and shifted excreta microbiota by increasing Lactobacillus and decreasing E.coli counts, as well as decreased excreta NH3, H2S, and total mercaptans gas emission. © 2017 Poultry Science Association Inc.

  3. Dark Matter's secret liaisons: phenomenology of a dark U(1) sector with bound states

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cirelli, Marco; Petraki, Kalliopi; Sala, Filippo

    Dark matter (DM) charged under a dark U(1) force appears in many extensions of the Standard Model, and has been invoked to explain anomalies in cosmic-ray data, as well as a self-interacting DM candidate. In this paper, we perform a comprehensive phenomenological analysis of such a model, assuming that the DM abundance arises from the thermal freeze-out of the dark interactions. We include, for the first time, bound-state effects both in the DM production and in the indirect detection signals, and quantify their importance for FERMI, AMS-02, and CMB experiments. We find that DM in the mass range 1 GeVmore » to 100 TeV, annihilating into dark photons of MeV to GeV mass, is in conflict with observations. Instead, DM annihilation into heavier dark photons is viable. We point out that the late decays of multi-GeV dark photons can produce significant entropy and thus dilute the DM density. This can lower considerably the dark coupling needed to obtain the DM abundance, and in turn relax the existing constraints.« less

  4. Dark chocolate: an obesity paradox or a culprit for weight gain?

    PubMed

    Farhat, Grace; Drummond, Sandra; Fyfe, Lorna; Al-Dujaili, E A S

    2014-06-01

    Obesity remains a major public health challenge, and its prevalence is dramatically increasing. Diet and exercise are typically recommended to prevent and manage obesity; however, the results are often conflicting. Polyphenols, a class of phytochemicals that have been shown to reduce the risk factors for diabetes type II and cardiovascular diseases, are recently suggested as complementary agents in the management of obesity through several mechanisms such as decreasing fat absorption and/or fat synthesis. Dark chocolate, a high source of polyphenols, and flavanols in particular, has lately received attention for its possible role in modulating obesity because of its potential effect on fat and carbohydrate metabolism, as well as on satiety. This outcome was investigated in animal models of obesity, cell cultures and few human observational and clinical studies. The research undertaken to date has shown promising results, with the possible implication of cocoa/dark chocolate in the modulation of obesity and body weight through several mechanisms including decreasing the expression of genes involved in fatty acid synthesis, reducing the digestion and absorption of fats and carbohydrates and increasing satiety. Copyright © 2013 John Wiley & Sons, Ltd.

  5. NLO+NLL collider bounds, Dirac fermion and scalar dark matter in the B–L model

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Klasen, Michael; Lyonnet, Florian; Queiroz, Farinaldo S.

    Baryon and lepton numbers being accidental global symmetries of the Standard Model (SM), it is natural to promote them to local symmetries. However, to preserve anomaly-freedom, only combinations of B–L are viable. In this spirit, we investigate possible dark matter realizations in the context of the U(1) B-L model: (i) Dirac fermion with unbroken B–L; (ii) Dirac fermion with broken B–L; (iii) scalar dark matter; (iv) two-component dark matter.We compute the relic abundance, direct and indirect detection observables and confront them with recent results from Planck, LUX-2016, and Fermi-LAT and prospects from XENON1T. In addition to the well-known LEP boundmore » M Z' /g BL 7 TeV, we include often ignored LHC bounds using 13 TeV dilepton (dimuon + dielectron) data at next-to-leading order plus nextto- leading logarithmic accuracy. We show that, for gauge couplings smaller than 0.4, theLHCgives rise to the strongest collider limit. In particular, we find M Z' /g BL > 8.7 TeV for g BL = 0.3. We conclude that the NLO+NLL corrections improve the dilepton bounds on the Z mass and that both dark matter candidates are only viable in the Z' resonance region, with the parameter space for scalar dark matter being fully probed by XENON1T. Lastly, we show that one can successfully have a minimal two-component dark matter model.« less

  6. NLO+NLL collider bounds, Dirac fermion and scalar dark matter in the B-L model

    NASA Astrophysics Data System (ADS)

    Klasen, Michael; Lyonnet, Florian; Queiroz, Farinaldo S.

    2017-05-01

    Baryon and lepton numbers being accidental global symmetries of the Standard Model (SM), it is natural to promote them to local symmetries. However, to preserve anomaly-freedom, only combinations of B-L are viable. In this spirit, we investigate possible dark matter realizations in the context of the U(1)_B{-L} model: (i) Dirac fermion with unbroken B-L; (ii) Dirac fermion with broken B-L; (iii) scalar dark matter; (iv) two-component dark matter. We compute the relic abundance, direct and indirect detection observables and confront them with recent results from Planck, LUX-2016, and Fermi-LAT and prospects from XENON1T. In addition to the well-known LEP bound M_{Z^' }}/g_BL ≳ 7 TeV, we include often ignored LHC bounds using 13 TeV dilepton (dimuon + dielectron) data at next-to-leading order plus next-to-leading logarithmic accuracy. We show that, for gauge couplings smaller than 0.4, the LHC gives rise to the strongest collider limit. In particular, we find M_{Z^' }}/g_BL > 8.7 TeV for g_BL=0.3. We conclude that the NLO+NLL corrections improve the dilepton bounds on the Z^' } mass and that both dark matter candidates are only viable in the Z^' } resonance region, with the parameter space for scalar dark matter being fully probed by XENON1T. Lastly, we show that one can successfully have a minimal two-component dark matter model.

  7. NLO+NLL collider bounds, Dirac fermion and scalar dark matter in the B–L model

    DOE PAGES

    Klasen, Michael; Lyonnet, Florian; Queiroz, Farinaldo S.

    2017-05-25

    Baryon and lepton numbers being accidental global symmetries of the Standard Model (SM), it is natural to promote them to local symmetries. However, to preserve anomaly-freedom, only combinations of B–L are viable. In this spirit, we investigate possible dark matter realizations in the context of the U(1) B-L model: (i) Dirac fermion with unbroken B–L; (ii) Dirac fermion with broken B–L; (iii) scalar dark matter; (iv) two-component dark matter.We compute the relic abundance, direct and indirect detection observables and confront them with recent results from Planck, LUX-2016, and Fermi-LAT and prospects from XENON1T. In addition to the well-known LEP boundmore » M Z' /g BL 7 TeV, we include often ignored LHC bounds using 13 TeV dilepton (dimuon + dielectron) data at next-to-leading order plus nextto- leading logarithmic accuracy. We show that, for gauge couplings smaller than 0.4, theLHCgives rise to the strongest collider limit. In particular, we find M Z' /g BL > 8.7 TeV for g BL = 0.3. We conclude that the NLO+NLL corrections improve the dilepton bounds on the Z mass and that both dark matter candidates are only viable in the Z' resonance region, with the parameter space for scalar dark matter being fully probed by XENON1T. Lastly, we show that one can successfully have a minimal two-component dark matter model.« less

  8. Human T-Lymphotropic Virus Type 1 and 2 Seroprevalence among first-time blood donors in Chile, 2011-2013.

    PubMed

    San Martín, Héctor; Balanda, Monserrat; Vergara, Nicolás; Valenzuela, María Antonieta; Cartier, Luis; Ayala, Salvador; Ramírez, Eugenio

    2016-06-01

    Infection with human T-lymphotropic virus type 1/2 (HTLV-1/2) is a major health problem. HTLV-1/2 infection is endemic in Chile but representative donor prevalence data are lacking. Data on all blood donors in a large network of Chilean blood centers were examined during 2011-2013. Screening of HTLV-1/2 antibodies were measured by enzyme immunoassay (EIA) at all blood banks. Blood samples with anticoagulants from initially reactive blood donors were analyzed by serological confirmation tests (immunofluorescence or recombinant immunoblot) at the HTLV National Reference Laboratory of the Public Health Institute of Chile. Additionally, detection of HTLV-1 and HTLV-2 provirus in peripheral blood mononuclear cells (PBMCs) was performed in all blood donors as confirmatory test. Prevalence rates were calculated. Among 694,016 donors, 706 were seropositive for HTLV-1 (prevalence, 1.02 cases per 1,000; 95% confidence interval [CI], 0.94-1.09), and 97 were seropositive for HTLV-2 (prevalence, 0.14 cases per 1,000; 95%CI, 0.11-0.17). Prevalence of HTLV-1 differed considerably by region, from 0.51 to 1.69 per 1,000. Prevalence of HTLV-2 was similar across the country (0.12-0.16). HTLV-1 prevalence was associated with female sex, older age, and residence in the north of Chile. HTVL-2 prevalence was associated with older age. The HTLV-1 prevalence among Chilean blood donors was relatively high and could be reduced by improving donor recruitment and selection in high prevalence areas. Blood center data may contribute to surveillance for HTLV-1 and HTLV-2 infections. © 2015 Wiley Periodicals, Inc.

  9. Drugs as habitable planets in the space of dark chemical matter.

    PubMed

    Siramshetty, Vishal B; Preissner, Robert

    2018-03-01

    A recent study demonstrated antifungal activity of dark chemical matter (DCM) compounds that were otherwise inactive in more than 100 HTS assays. These compounds were proposed to possess unique activity and 'clean' safety profiles. Here, we present an outlook of the promiscuity and safety of these compounds by retrospectively comparing their chemical and biological spaces with those of drugs. Significant amounts of marketed drugs (16%), withdrawn drugs (16.5%) and natural compounds (3.5%) share structural identity with DCM. Compound promiscuity assessment indicates that dark matter compounds could potentially interact with multiple biological targets. Further, thousands of DCM compounds showed presence of frequent-hitting pan-assay interference compound (PAINS) substructures. In light of these observations, filtering these compounds from screening libraries can be an irrevocable loss. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. [Optimal scan parameters for a method of k-space trajectory (radial scan method) in evaluation of carotid plaque characteristics].

    PubMed

    Nakamura, Manami; Makabe, Takeshi; Tezuka, Hideomi; Miura, Takahiro; Umemura, Takuma; Sugimori, Hiroyuki; Sakata, Motomichi

    2013-04-01

    The purpose of this study was to optimize scan parameters for evaluation of carotid plaque characteristics by k-space trajectory (radial scan method), using a custom-made carotid plaque phantom. The phantom was composed of simulated sternocleidomastoid muscle and four types of carotid plaque. The effect of chemical shift artifact was compared using T1 weighted images (T1WI) of the phantom obtained with and without fat suppression, and using two types of k-space trajectory (the radial scan method and the Cartesian method). The ratio of signal intensity of simulated sternocleidomastoid muscle to the signal intensity of hematoma, blood (including heparin), lard, and mayonnaise was compared among various repetition times (TR) using T1WI and T2 weighted imaging (T2WI). In terms of chemical shift artifacts, image quality was improved using fat suppression for both the radial scan and Cartesian methods. In terms of signal ratio, the highest values were obtained for the radial scan method with TR of 500 ms for T1WI, and TR of 3000 ms for T2WI. For evaluation of carotid plaque characteristics using the radial scan method, chemical shift artifacts were reduced with fat suppression. Signal ratio was improved by optimizing the TR settings for T1WI and T2WI. These results suggest the potential for using magnetic resonance imaging for detailed evaluation of carotid plaque.

  11. EDITORIAL: Focus on Dark Matter and Particle Physics

    NASA Astrophysics Data System (ADS)

    Aprile, Elena; Profumo, Stefano

    2009-10-01

    The quest for the nature of dark matter has reached a historical point in time, with several different and complementary experiments on the verge of conclusively exploring large portions of the parameter space of the most theoretically compelling particle dark matter models. This focus issue on dark matter and particle physics brings together a broad selection of invited articles from the leading experimental and theoretical groups in the field. The leitmotif of the collection is the need for a multi-faceted search strategy that includes complementary experimental and theoretical techniques with the common goal of a sound understanding of the fundamental particle physical nature of dark matter. These include theoretical modelling, high-energy colliders and direct and indirect searches. We are confident that the works collected here present the state of the art of this rapidly changing field and will be of interest to both experts in the topic of dark matter as well as to those new to this exciting field. Focus on Dark Matter and Particle Physics Contents DARK MATTER AND ASTROPHYSICS Scintillator-based detectors for dark matter searches I S K Kim, H J Kim and Y D Kim Cosmology: small-scale issues Joel R Primack Big Bang nucleosynthesis and particle dark matter Karsten Jedamzik and Maxim Pospelov Particle models and the small-scale structure of dark matter Torsten Bringmann DARK MATTER AND COLLIDERS Dark matter in the MSSM R C Cotta, J S Gainer, J L Hewett and T G Rizzo The role of an e+e- linear collider in the study of cosmic dark matter M Battaglia Collider, direct and indirect detection of supersymmetric dark matter Howard Baer, Eun-Kyung Park and Xerxes Tata INDIRECT PARTICLE DARK MATTER SEARCHES:EXPERIMENTS PAMELA and indirect dark matter searches M Boezio et al An indirect search for dark matter using antideuterons: the GAPS experiment C J Hailey Perspectives for indirect dark matter search with AMS-2 using cosmic-ray electrons and positrons B Beischer, P von

  12. Neptune's New Dark Vortex: Imaging with HST/WFC3

    NASA Astrophysics Data System (ADS)

    Wong, M. H.; Tollefson, J.; De Pater, I.; de Kleer, K.; Hammel, H. B.; Luszcz-Cook, S.; Hueso, R.; Sanchez-Lavega, A.; Simon, A. A.; Delcroix, M.; Sromovsky, L. A.; Fry, P. M.; Orton, G. S.; Baranec, C.

    2016-12-01

    A bright, unusually long-lived outburst of cloud activity on Neptune was observed in 2015 (Hueso et al. 2015, DPS 400.02). This led to speculation about whether the clouds were convective in nature, or bright companions to an unseen dark vortex (similar to the Great Dark Spot studied in detail by Voyager 2: Smith et al. 1989, Science 246, 1422). HST OPAL images at blue wavelengths finally answered this question by discovering a new dark vortex at 45 deg S. We call this feature SDS-2015, for "southern dark spot discovered in 2015" (Wong et al. 2016, CBET 4278). Dark vortices on Neptune are rare; SDS-2015 is only the fifth ever seen. All five were diverse in terms of size and shape, the distribution of bright companion clouds, and horizontal motions (oscillations and drifts). The drift of these vortices is highly sensitive to horizontal and vertical wind shear, making them valuable probes into the structure of Neptune's atmospheric jets. We will present imaging observations of SDS-2015 obtained with the WFC3/UVIS camera on the Hubble Space Telescope, covering the discovery of the vortex in September 2015 and follow-up observations in May 2016. No significant latitudinal drift was seen over this time span. We will compare size estimates, which are complicated by the continual presence of companion clouds, and by the low contrast between the vortex and its surroundings. The 2015 observations included 7 filters spanning 467-845 nm, weighted toward longer wavelengths to study general cloud motions and vertical distributions. The 2016 observations included 7 filters spanning 336-763 nm, weighted toward shorter wavelengths where the dark spot itself can be detected. A companion abstract (Tollefson et al., this meeting) will present results from radiative transfer modeling of the multispectral data. [This conference abstract is based on observations made with the NASA/ESA Hubble Space Telescope, associated with programs GO-13937 ("OPAL") and GO-14492.

  13. Blood Glucose Monitoring Before and After Type 1 Diabetes Clinic Visits.

    PubMed

    Driscoll, Kimberly A; Johnson, Suzanne Bennett; Wang, Yuxia; Wright, Nancy; Deeb, Larry C

    2017-12-23

    To determine patterns of blood glucose monitoring in children and adolescents with type 1 diabetes (T1D) before and after routine T1D clinic visits. Blood glucose monitoring data were downloaded at four consecutive routine clinic visits from children and adolescents aged 5-18 years. Linear mixed models were used to analyze patterns of blood glucose monitoring in patients who had at least 28 days of data stored in their blood glucose monitors. In general, the frequency of blood glucose monitoring decreased across visits, and younger children engaged in more frequent blood glucose monitoring. Blood glucose monitoring increased before the T1D clinic visits in younger children, but not in adolescents. It declined after the visit regardless of age. Members of the T1D care team need to consider that a T1D clinic visit may prompt an increase in blood glucose monitoring when making treatment changes and recommendations. Tailored interventions are needed to maintain that higher level of adherence across time. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  14. Dark energy in systems of galaxies

    NASA Astrophysics Data System (ADS)

    Chernin, A. D.

    2013-11-01

    The precise observational data of the Hubble Space Telescope have been used to study nearby galaxy systems. The main result is the detection of dark energy in groups, clusters, and flows of galaxies on a spatial scale of about 1-10 Mpc. The local density of dark energy in these systems, which is determined by various methods, is close to the global value or even coincides with it. A theoretical model of the nearby Universe has been constructed, which describes the Local Group of galaxies with the flow of dwarf galaxies receding from this system. The key physical parameter of the group-flow system is zero gravity radius, which is the distance at which the gravity of dark matter is compensated by dark-energy antigravity. The model predicts the existence of local regions of space where Einstein antigravity is stronger than Newton gravity. Six such regions have been revealed in the data of the Hubble space telescope. The nearest of these regions is at a distance of 1-3 Mpc from the center of the Milky Way. Antigravity in this region is several times stronger than gravity. Quasiregular flows of receding galaxies, which are accelerated by the dark-energy antigravity, exist in these regions. The model of the nearby Universe at the scale of groups of galaxies (˜1 Mpc) can be extended to the scale of clusters (˜10 Mpc). The systems of galaxies with accelerated receding flows constitute a new and probably widespread class of metagalactic populations. Strong dynamic effects of local dark energy constitute the main characteristic feature of these systems.

  15. T1-weighted dynamic contrast-enhanced brain magnetic resonance imaging: A preliminary study with low infusion rate in pediatric patients.

    PubMed

    Rochetams, Bruno-Bernard; Marechal, Bénédicte; Cottier, Jean-Philippe; Gaillot, Kathleen; Sembely-Taveau, Catherine; Sirinelli, Dominique; Morel, Baptiste

    2017-10-01

    Background The aim of this preliminary study is to evaluate the results of T1-weighted dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) in pediatric patients at 1.5T, with a low peripheral intravenous gadoteric acid injection rate of 1 ml/s. Materials and methods Children with neurological symptoms were examined prospectively with conventional MRI and T1-weighted DCE MRI. An magnetic resonance perfusion analysis method was used to obtain time-concentration curves (persistent pattern, type-I; plateau pattern, type-II; washout pattern, type-III) and to calculate pharmacokinetic parameters. A total of two radiologists manually defined regions of interest (ROIs) in the part of the lesion exhibiting the greatest contrast enhancement and in the surrounding normal or contralateral tissue. Lesion/surrounding tissue or contralateral tissue pharmacokinetic parameter ratios were calculated. Tumors were categorized by grade (I-IV) using the World Health Organization (WHO) Grade. Mann-Whitney testing and receiver-operating characteristic (ROC) curves were performed. Results A total of nine boys and nine girls (mean age 10.5 years) were included. Lesions consisted of 10 brain tumors, 3 inflammatory lesions, 3 arteriovenous malformations and 2 strokes. We obtained analyzable concentration-time curves for all patients (6 type-I, 9 type-II, 3 type-III). K trans between tumor tissue and surrounding or contralateral tissue was significantly different ( p = 0.034). K trans ratios were significantly different between grade I tumors and grade IV tumors ( p = 0.027) and a K trans ratio value superior to 0.63 appeared to be discriminant to determine a grade IV of malignancy. Conclusions Our results confirm the feasibility of pediatric T1-weighted DCE MRI at 1.5T with a low injection rate, which could be of great value in differentiating brain tumor grades.

  16. Evaluation of MRI sequences for quantitative T1 brain mapping

    NASA Astrophysics Data System (ADS)

    Tsialios, P.; Thrippleton, M.; Glatz, A.; Pernet, C.

    2017-11-01

    T1 mapping constitutes a quantitative MRI technique finding significant application in brain imaging. It allows evaluation of contrast uptake, blood perfusion, volume, providing a more specific biomarker of disease progression compared to conventional T1-weighted images. While there are many techniques for T1-mapping there is a wide range of reported T1-values in tissues, raising the issue of protocols reproducibility and standardization. The gold standard for obtaining T1-maps is based on acquiring IR-SE sequence. Widely used alternative sequences are IR-SE-EPI, VFA (DESPOT), DESPOT-HIFI and MP2RAGE that speed up scanning and fitting procedures. A custom MRI phantom was used to assess the reproducibility and accuracy of the different methods. All scans were performed using a 3T Siemens Prisma scanner. The acquired data processed using two different codes. The main difference was observed for VFA (DESPOT) which grossly overestimated T1 relaxation time by 214 ms [126 270] compared to the IR-SE sequence. MP2RAGE and DESPOT-HIFI sequences gave slightly shorter time than IR-SE (~20 to 30ms) and can be considered as alternative and time-efficient methods for acquiring accurate T1 maps of the human brain, while IR-SE-EPI gave identical result, at a cost of a lower image quality.

  17. Probing the Dark Sector with Dark Matter Bound States

    NASA Astrophysics Data System (ADS)

    An, Haipeng; Echenard, Bertrand; Pospelov, Maxim; Zhang, Yue

    2016-04-01

    A model of the dark sector where O (few GeV ) mass dark matter particles χ couple to a lighter dark force mediator V , mV≪mχ, is motivated by the recently discovered mismatch between simulated and observed shapes of galactic halos. Such models, in general, provide a challenge for direct detection efforts and collider searches. We show that for a large range of coupling constants and masses, the production and decay of the bound states of χ , such as 0-+ and 1-- states, ηD and ϒD, is an important search channel. We show that e+e-→ηD+V or ϒD+γ production at B factories for αD>0.1 is sufficiently strong to result in multiple pairs of charged leptons and pions via ηD→2 V →2 (l+l-) and ϒD→3 V →3 (l+l-) (l =e ,μ ,π ). The absence of such final states in the existing searches performed at BABAR and Belle sets new constraints on the parameter space of the model. We also show that a search for multiple bremsstrahlung of dark force mediators, e+e-→χ χ ¯+n V , resulting in missing energy and multiple leptons, will further improve the sensitivity to self-interacting dark matter.

  18. Whole brain myelin mapping using T1- and T2-weighted MR imaging data

    PubMed Central

    Ganzetti, Marco; Wenderoth, Nicole; Mantini, Dante

    2014-01-01

    Despite recent advancements in MR imaging, non-invasive mapping of myelin in the brain still remains an open issue. Here we attempted to provide a potential solution. Specifically, we developed a processing workflow based on T1-w and T2-w MR data to generate an optimized myelin enhanced contrast image. The workflow allows whole brain mapping using the T1-w/T2-w technique, which was originally introduced as a non-invasive method for assessing cortical myelin content. The hallmark of our approach is a retrospective calibration algorithm, applied to bias-corrected T1-w and T2-w images, that relies on image intensities outside the brain. This permits standardizing the intensity histogram of the ratio image, thereby allowing for across-subject statistical analyses. Quantitative comparisons of image histograms within and across different datasets confirmed the effectiveness of our normalization procedure. Not only did the calibrated T1-w/T2-w images exhibit a comparable intensity range, but also the shape of the intensity histograms was largely corresponding. We also assessed the reliability and specificity of the ratio image compared to other MR-based techniques, such as magnetization transfer ratio (MTR), fractional anisotropy (FA), and fluid-attenuated inversion recovery (FLAIR). With respect to these other techniques, T1-w/T2-w had consistently high values, as well as low inter-subject variability, in brain structures where myelin is most abundant. Overall, our results suggested that the T1-w/T2-w technique may be a valid tool supporting the non-invasive mapping of myelin in the brain. Therefore, it might find important applications in the study of brain development, aging and disease. PMID:25228871

  19. Reference-tissue correction of T2-weighted signal intensity for prostate cancer detection

    NASA Astrophysics Data System (ADS)

    Peng, Yahui; Jiang, Yulei; Oto, Aytekin

    2014-03-01

    The purpose of this study was to investigate whether correction with respect to reference tissue of T2-weighted MRimage signal intensity (SI) improves its effectiveness for classification of regions of interest (ROIs) as prostate cancer (PCa) or normal prostatic tissue. Two image datasets collected retrospectively were used in this study: 71 cases acquired with GE scanners (dataset A), and 59 cases acquired with Philips scanners (dataset B). Through a consensus histology- MR correlation review, 175 PCa and 108 normal-tissue ROIs were identified and drawn manually. Reference-tissue ROIs were selected in each case from the levator ani muscle, urinary bladder, and pubic bone. T2-weighted image SI was corrected as the ratio of the average T2-weighted image SI within an ROI to that of a reference-tissue ROI. Area under the receiver operating characteristic curve (AUC) was used to evaluate the effectiveness of T2-weighted image SIs for differentiation of PCa from normal-tissue ROIs. AUC (+/- standard error) for uncorrected T2-weighted image SIs was 0.78+/-0.04 (datasets A) and 0.65+/-0.05 (datasets B). AUC for corrected T2-weighted image SIs with respect to muscle, bladder, and bone reference was 0.77+/-0.04 (p=1.0), 0.77+/-0.04 (p=1.0), and 0.75+/-0.04 (p=0.8), respectively, for dataset A; and 0.81+/-0.04 (p=0.002), 0.78+/-0.04 (p<0.001), and 0.79+/-0.04 (p<0.001), respectively, for dataset B. Correction in reference to the levator ani muscle yielded the most consistent results between GE and Phillips images. Correction of T2-weighted image SI in reference to three types of extra-prostatic tissue can improve its effectiveness for differentiation of PCa from normal-tissue ROIs, and correction in reference to the levator ani muscle produces consistent T2-weighted image SIs between GE and Phillips MR images.

  20. Does Ramadan fasting alter body weight and blood lipids and fasting blood glucose in a healthy population? A meta-analysis.

    PubMed

    Kul, Seval; Savaş, Esen; Öztürk, Zeynel Abidin; Karadağ, Gülendam

    2014-06-01

    In this study, we conducted a meta-analysis of self-controlled cohort studies comparing body weights, blood levels of lipids and fasting blood glucose levels before and after Ramadan taking into account gender differences. Several databases were searched up to June 2012 for studies showing an effect of Ramadan fasting in healthy subjects, yielding 30 articles. The primary finding of this meta-analysis was that after Ramadan fasting, low-density lipoprotein (SMD = -1.67, 95 % CI = -2.48 to -0.86) and fasting blood glucose levels (SMD = -1.10, 95 % CI = -1.62 to -0.58) were decreased in both sex groups and also in the entire group compared to levels prior to Ramadan. In addition, in the female subgroup, body weight (SMD = -0.04, 95 % CI = -0.20, 0.12), total cholesterol (SMD = 0.05, 95 % CI = -0.51 to 0.60), and triglyceride levels (SMD = 0.03, 95 % CI = -0.31, 0.36) remained unchanged, while HDL levels (SMD = 0.86, 95 % CI = 0.11 to 1.61, p = 0.03) were increased. In males, Ramadan fasting resulted in weight loss (SMD = -0.24, 95 % CI = -0.36, -0.12, p = 0.001). Also, a substantial reduction in total cholesterol (SMD = -0.44, 95 % CI = -0.77 to -0.11) and LDL levels (SMD = -2.22, 95 % CI = -3.47 to -0.96) and a small decrease in triglyceride levels (SMD = -0.35, 95 % CI = -0.67 to -0.02) were observed in males. In conclusion, by looking at this data, it is evident that Ramadan fasting can effectively change body weight and some biochemical parameters in healthy subjects especially in males compared to pre-Ramadan period.

  1. Comparison of 3T and 7T susceptibility-weighted angiography of the substantia nigra in diagnosing Parkinson disease.

    PubMed

    Cosottini, M; Frosini, D; Pesaresi, I; Donatelli, G; Cecchi, P; Costagli, M; Biagi, L; Ceravolo, R; Bonuccelli, U; Tosetti, M

    2015-03-01

    Standard neuroimaging fails in defining the anatomy of the substantia nigra and has a marginal role in the diagnosis of Parkinson disease. Recently 7T MR target imaging of the substantia nigra has been useful in diagnosing Parkinson disease. We performed a comparative study to evaluate whether susceptibility-weighted angiography can diagnose Parkinson disease with a 3T scanner. Fourteen patients with Parkinson disease and 13 healthy subjects underwent MR imaging examination at 3T and 7T by using susceptibility-weighted angiography. Two expert blinded observers and 1 neuroradiology fellow evaluated the 3T and 7T images of the sample to identify substantia nigra abnormalities indicative of Parkinson disease. Diagnostic accuracy and intra- and interobserver agreement were calculated separately for 3T and 7T acquisitions. Susceptibility-weighted angiography 7T MR imaging can diagnose Parkinson disease with a mean sensitivity of 93%, specificity of 100%, and diagnostic accuracy of 96%. 3T MR imaging diagnosed Parkinson disease with a mean sensitivity of 79%, specificity of 94%, and diagnostic accuracy of 86%. Intraobserver and interobserver agreement was excellent at 7T. At 3T, intraobserver agreement was excellent for experts, and interobserver agreement ranged between good and excellent. The less expert reader obtained a diagnostic accuracy of 89% at 3T. Susceptibility-weighted angiography images obtained at 3T and 7T differentiate controls from patients with Parkinson disease with a higher diagnostic accuracy at 7T. The capability of 3T in diagnosing Parkinson disease might encourage its use in clinical practice. The use of the more accurate 7T should be supported by a dedicated cost-effectiveness study. © 2015 by American Journal of Neuroradiology.

  2. Correlation of cord blood telomere length with birth weight.

    PubMed

    Lee, Siew-Peng; Hande, Prakash; Yeo, George Sh; Tan, Ene-Choo

    2017-09-08

    Intrauterine growth restriction affects 3% of newborns; and the lightest 10% of whom are classified as small for gestational age (SGA). These low-birth weight newborns are at increased risk of neonatal morbidity such as hypoxia and hypoglycaemia. In later life, they are at higher risk of several age-related diseases such as cardiovascular and metabolic disorders and dementia. As having short telomeres is also associated with these diseases, we tested if these newborns might already start with shorter telomeres at birth. Relative telomere lengths were determined using quantitative real-time PCR in cord blood samples from 195 newborns of Chinese ancestry. Based on the telomere length normalised to a single copy gene and a reference DNA sample as internal control, we found statistically significant correlations between relative telomere length and both unadjusted and gestational age-adjusted birth weight, with the lighter newborns having shorter telomeres. The SGA birth weight group comprising the bottom 10% of the samples also had the shortest telomeres compared to the medium and heaviest birth weight groups. Our results indicate that there is reduction of cord blood telomere length for newborns with lower birth weight.

  3. Prostate Postbrachytherapy Seed Distribution: Comparison of High-Resolution, Contrast-Enhanced, T1- and T2-Weighted Endorectal Magnetic Resonance Imaging Versus Computed Tomography: Initial Experience

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bloch, B. Nicolas; Department of Radiology, General Hospital Vienna, Medical University Vienna, Vienna; Lenkinski, Robert E.

    2007-09-01

    Purpose: To compare contrast-enhanced, T1-weighted, three-dimensional magnetic resonance imaging (CEMR) and T2-weighted magnetic resonance imaging (T2MR) with computed tomography (CT) for prostate brachytherapy seed location for dosimetric calculations. Methods and Materials: Postbrachytherapy prostate MRI was performed on a 1.5 Tesla unit with combined surface and endorectal coils in 13 patients. Both CEMR and T2MR used a section thickness of 3 mm. Spiral CT used a section thickness of 5 mm with a pitch factor of 1.5. All images were obtained in the transverse plane. Two readers using CT and MR imaging assessed brachytherapy seed distribution independently. The dependency of datamore » read by both readers for a specific subject was assessed with a linear mixed effects model. Results: The mean percentage ({+-} standard deviation) values of the readers for seed detection and location are presented. Of 1205 implanted seeds, CEMR, T2MR, and CT detected 91.5% {+-} 4.8%, 78.5% {+-} 8.5%, and 96.1% {+-} 2.3%, respectively, with 11.8% {+-} 4.5%, 8.5% {+-} 3.5%, 1.9% {+-} 1.0% extracapsular, respectively. Assignment to periprostatic structures was not possible with CT. Periprostatic seed assignments for CEMR and T2MR, respectively, were as follows: neurovascular bundle, 3.5% {+-} 1.6% and 2.1% {+-} 0.9%; seminal vesicles, 0.9% {+-} 1.8% and 0.3% {+-} 0.7%; periurethral, 7.1% {+-} 3.3% and 5.8% {+-} 2.9%; penile bulb, 0.6% {+-} 0.8% and 0.3% {+-} 0.6%; Denonvillier's Fascia/rectal wall, 0.5% {+-} 0.6% and 0%; and urinary bladder, 0.1% {+-} 0.3% and 0%. Data dependency analysis showed statistical significance for the type of imaging but not for reader identification. Conclusion: Both enumeration and localization of implanted seeds are readily accomplished with CEMR. Calculations with MRI dosimetry do not require CT data. Dose determinations to specific extracapsular sites can be obtained with MRI but not with CT.« less

  4. Physiological noise in murine solid tumours using T2*-weighted gradient-echo imaging: a marker of tumour acute hypoxia?

    PubMed

    Baudelet, Christine; Ansiaux, Réginald; Jordan, Bénédicte F; Havaux, Xavier; Macq, Benoit; Gallez, Bernard

    2004-08-07

    T2*-weighted gradient-echo magnetic resonance imaging (T2*-weighted GRE MRI) was used to investigate spontaneous fluctuations in tumour vasculature non-invasively. FSa fibrosarcomas, implanted intramuscularly (i.m.) in the legs of mice, were imaged at 4.7 T, over a 30 min or 1 h sampling period. On a voxel-by-voxel basis, time courses of signal intensity were analysed using a power spectrum density (PSD) analysis to isolate voxels for which signal changes did not originate from Gaussian white noise or linear drift. Under baseline conditions, the tumours exhibited spontaneous signal fluctuations showing spatial and temporal heterogeneity over the tumour. Statistically significant fluctuations occurred at frequencies ranging from 1 cycle/3 min to 1 cycle/h. The fluctuations were independent of the scanner instabilities. Two categories of signal fluctuations were reported: (i) true fluctuations (TFV), i.e., sequential signal increase and decrease, and (ii) profound drop in signal intensity with no apparent signal recovery (SDV). No temporal correlation between tumour and contralateral muscle fluctuations was observed. Furthermore, treatments aimed at decreasing perfusion-limited hypoxia, such as carbogen combined with nicotinamide and flunarizine, decreased the incidence of tumour T2*-weighted GRE fluctuations. We also tracked dynamic changes in T2* using multiple GRE imaging. Fluctuations of T2* were observed; however, fluctuation maps using PSD analysis could not be generated reliably. An echo-time dependency of the signal fluctuations was observed, which is typical to physiological noise. Finally, at the end of T2*-weighted GRE MRI acquisition, a dynamic contrast-enhanced MRI was performed to characterize the microenvironment in which tumour signal fluctuations occurred in terms of vessel functionality, vascularity and microvascular permeability. Our data showed that TFV were predominantly located in regions with functional vessels, whereas SDV occurred in regions

  5. Early Weight Gain, Linear Growth, and Mid-Childhood Blood Pressure: A Prospective Study in Project Viva.

    PubMed

    Perng, Wei; Rifas-Shiman, Sheryl L; Kramer, Michael S; Haugaard, Line K; Oken, Emily; Gillman, Matthew W; Belfort, Mandy B

    2016-02-01

    In recent years, the prevalence of hypertension and prehypertension increased markedly among children and adolescents, highlighting the importance of identifying determinants of elevated blood pressure early in life. Low birth weight and rapid early childhood weight gain are associated with higher future blood pressure. However, few studies have examined the timing of postnatal weight gain in relation to later blood pressure, and little is known regarding the contribution of linear growth. We studied 957 participants in Project Viva, an ongoing US prebirth cohort. We examined the relations of gains in body mass index z-score and length/height z-score during 4 early life age intervals (birth to 6 months, 6 months to 1 year, 1 to 2 years, and 2 to 3 years) with blood pressure during mid-childhood (6-10 years) and evaluated whether these relations differed by birth size. After accounting for confounders, each additional z-score gain in body mass index during birth to 6 months and 2 to 3 years was associated with 0.81 (0.15, 1.46) and 1.61 (0.33, 2.89) mm Hg higher systolic blood pressure, respectively. Length/height gain was unrelated to mid-childhood blood pressure, and there was no evidence of effect modification by birth size for body mass index or length/height z-score gain. Our findings suggest that more rapid gain in body mass index during the first 6 postnatal months and in the preschool years may lead to higher systolic blood pressure in mid-childhood, regardless of size at birth. Strategies to reduce accrual of excess adiposity during early life may reduce mid-childhood blood pressure, which may also impact adult blood pressure and cardiovascular health. © 2015 American Heart Association, Inc.

  6. DarkSide-20k: A 20 tonne two-phase LAr TPC for direct dark matter detection at LNGS

    NASA Astrophysics Data System (ADS)

    Aalseth, C. E.; Acerbi, F.; Agnes, P.; Albuquerque, I. F. M.; Alexander, T.; Alici, A.; Alton, A. K.; Antonioli, P.; Arcelli, S.; Ardito, R.; Arnquist, I. J.; Asner, D. M.; Ave, M.; Back, H. O.; Barrado Olmedo, A. I.; Batignani, G.; Bertoldo, E.; Bettarini, S.; Bisogni, M. G.; Bocci, V.; Bondar, A.; Bonfini, G.; Bonivento, W.; Bossa, M.; Bottino, B.; Boulay, M.; Bunker, R.; Bussino, S.; Buzulutskov, A.; Cadeddu, M.; Cadoni, M.; Caminata, A.; Canci, N.; Candela, A.; Cantini, C.; Caravati, M.; Cariello, M.; Carlini, M.; Carpinelli, M.; Castellani, A.; Catalanotti, S.; Cataudella, V.; Cavalcante, P.; Cavuoti, S.; Cereseto, R.; Chepurnov, A.; Cicalò, C.; Cifarelli, L.; Citterio, M.; Cocco, A. G.; Colocci, M.; Corgiolu, S.; Covone, G.; Crivelli, P.; D'Antone, I.; D'Incecco, M.; D'Urso, D.; Da Rocha Rolo, M. D.; Daniel, M.; Davini, S.; de Candia, A.; De Cecco, S.; De Deo, M.; De Filippis, G.; De Guido, G.; De Rosa, G.; Dellacasa, G.; Della Valle, M.; Demontis, P.; Derbin, A.; Devoto, A.; Di Eusanio, F.; Di Pietro, G.; Dionisi, C.; Dolgov, A.; Dormia, I.; Dussoni, S.; Empl, A.; Fernandez Diaz, M.; Ferri, A.; Filip, C.; Fiorillo, G.; Fomenko, K.; Franco, D.; Froudakis, G. E.; Gabriele, F.; Gabrieli, A.; Galbiati, C.; Garcia Abia, P.; Gendotti, A.; Ghisi, A.; Giagu, S.; Giampa, P.; Gibertoni, G.; Giganti, C.; Giorgi, M. A.; Giovanetti, G. K.; Gligan, M. L.; Gola, A.; Gorchakov, O.; Goretti, A. M.; Granato, F.; Grassi, M.; Grate, J. W.; Grigoriev, G. Y.; Gromov, M.; Guan, M.; Guerra, M. B. B.; Guerzoni, M.; Gulino, M.; Haaland, R. K.; Hallin, A.; Harrop, B.; Hoppe, E. W.; Horikawa, S.; Hosseini, B.; Hughes, D.; Humble, P.; Hungerford, E. V.; Ianni, An.; Jillings, C.; Johnson, T. N.; Keeter, K.; Kendziora, C. L.; Kim, S.; Koh, G.; Korablev, D.; Korga, G.; Kubankin, A.; Kuss, M.; Kuźniak, M.; La Commara, M.; Lehnert, B.; Li, X.; Lissia, M.; Lodi, G. U.; Loer, B.; Longo, G.; Loverre, P.; Lussana, R.; Luzzi, L.; Ma, Y.; Machado, A. A.; Machulin, I. N.; Mandarano, A.; Mapelli, L.; Marcante, M.; Margotti, A.; Mari, S. M.; Mariani, M.; Maricic, J.; Martoff, C. J.; Mascia, M.; Mayer, M.; McDonald, A. B.; Messina, A.; Meyers, P. D.; Milincic, R.; Moggi, A.; Moioli, S.; Monroe, J.; Monte, A.; Morrocchi, M.; Mount, B. J.; Mu, W.; Muratova, V. N.; Murphy, S.; Musico, P.; Nania, R.; Navrer Agasson, A.; Nikulin, I.; Nosov, V.; Nozdrina, A. O.; Nurakhov, N. N.; Oleinik, A.; Oleynikov, V.; Orsini, M.; Ortica, F.; Pagani, L.; Pallavicini, M.; Palmas, S.; Pandola, L.; Pantic, E.; Paoloni, E.; Paternoster, G.; Pavletcov, V.; Pazzona, F.; Peeters, S.; Pelczar, K.; Pellegrini, L. A.; Pelliccia, N.; Perotti, F.; Perruzza, R.; Pesudo, V.; Piemonte, C.; Pilo, F.; Pocar, A.; Pollmann, T.; Portaluppi, D.; Pugachev, D. A.; Qian, H.; Radics, B.; Raffaelli, F.; Ragusa, F.; Razeti, M.; Razeto, A.; Regazzoni, V.; Regenfus, C.; Reinhold, B.; Renshaw, A. L.; Rescigno, M.; Retière, F.; Riffard, Q.; Rivetti, A.; Rizzardini, S.; Romani, A.; Romero, L.; Rossi, B.; Rossi, N.; Rubbia, A.; Sablone, D.; Salatino, P.; Samoylov, O.; Sánchez García, E.; Sands, W.; Sanfilippo, S.; Sant, M.; Santorelli, R.; Savarese, C.; Scapparone, E.; Schlitzer, B.; Scioli, G.; Segreto, E.; Seifert, A.; Semenov, D. A.; Shchagin, A.; Shekhtman, L.; Shemyakina, E.; Sheshukov, A.; Simeone, M.; Singh, P. N.; Skensved, P.; Skorokhvatov, M. D.; Smirnov, O.; Sobrero, G.; Sokolov, A.; Sotnikov, A.; Speziale, F.; Stainforth, R.; Stanford, C.; Suffritti, G. B.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Tonazzo, A.; Tosi, A.; Trinchese, P.; Unzhakov, E. V.; Vacca, A.; Vázquez-Jáuregui, E.; Verducci, M.; Viant, T.; Villa, F.; Vishneva, A.; Vogelaar, B.; Wada, M.; Wahl, J.; Walding, J.; Wang, H.; Wang, Y.; Watson, A. W.; Westerdale, S.; Williams, R.; Wojcik, M. M.; Wu, S.; Xiang, X.; Xiao, X.; Yang, C.; Ye, Z.; Yllera de Llano, A.; Zappa, F.; Zappalà, G.; Zhu, C.; Zichichi, A.; Zullo, M.; Zullo, A.; Zuzel, G.

    2018-03-01

    Building on the successful experience in operating the DarkSide-50 detector, the DarkSide Collaboration is going to construct DarkSide-20k, a direct WIMP search detector using a two-phase Liquid Argon Time Projection Chamber (LAr TPC) with an active (fiducial) mass of 23 t (20 t). This paper describes a preliminary design for the experiment, in which the DarkSide-20k LAr TPC is deployed within a shield/veto with a spherical Liquid Scintillator Veto (LSV) inside a cylindrical Water Cherenkov Veto (WCV). This preliminary design provides a baseline for the experiment to achieve its physics goals, while further development work will lead to the final optimization of the detector parameters and an eventual technical design. Operation of DarkSide-50 demonstrated a major reduction in the dominant 39Ar background when using argon extracted from an underground source, before applying pulse shape analysis. Data from DarkSide-50, in combination with MC simulation and analytical modeling, shows that a rejection factor for discrimination between electron and nuclear recoils of >3 × 109 is achievable. This, along with the use of the veto system and utilizing silicon photomultipliers in the LAr TPC, are the keys to unlocking the path to large LAr TPC detector masses, while maintaining an experiment in which less than < 0.1 events (other than ν-induced nuclear recoils) is expected to occur within the WIMP search region during the planned exposure. DarkSide-20k will have ultra-low backgrounds than can be measured in situ, giving sensitivity to WIMP-nucleon cross sections of 1.2 × 10^{-47} cm2 (1.1 × 10^{-46} cm2) for WIMPs of 1 TeV/c 2 (10 TeV/c 2) mass, to be achieved during a 5 yr run producing an exposure of 100 t yr free from any instrumental background.

  7. NASA and Dark Energy

    NASA Astrophysics Data System (ADS)

    Rhodes, Jason

    2014-03-01

    Dark energy, the name given to the cause of the accelerating expansion of the Universe, is one of the most profound mysteries in modern science. Current cosmological models hold that dark energy is currently the dominant component of the Universe, but the exact nature of dark energy remains poorly understood. There are ambitious ground-based surveys underway that seek to understand dark energy and NASA is participating in the development of significantly more ambitious space-based surveys planned for the next decade. NASA has provided mission enabling technology to the European Space Agency's (ESA) Euclid mission in exchange for US scientists to participate in the Euclid mission. NASA is also developing the Wide Field Infrared Survey Telescope-Astrophysics Focused Telescope Asset (WFIRST-AFTA) mission for possible launch in ~2023. WFIRST was the highest ranked space mission in the Astro2010 Decadal Survey and the AFTA incarnation of the WFIRST design uses a 2.4 m space telescope to go beyond what the Decadal Survey envisioned for WFIRST. Understanding dark energy is one of the primary science goals of WFIRST-AFTA. I'll discuss the status of Euclid and WFIRST and comment on the complementarity of the two missions.

  8. Meta-regression analysis to evaluate relationships between maternal blood levels of placentation biomarkers and low delivery weight.

    PubMed

    Goto, Eita

    2018-05-03

    Caution is required for women at increased risk of low neonatal delivery weight. To evaluate relationships between maternal placentation biomarkers and the odds of low delivery weight. Databases including PubMed/MEDLINE were searched up to May 2017 using keywords involving biomarker names and "low birthweight." English language studies providing true- and false-positive, and true- and false-negative results of low delivery weight classified by maternal blood levels of placentation biomarkers (in units of multiple of the mean [MoM]) were included. Coefficients representing changes in log odds ratio for low delivery weight per 1 MoM increase in maternal blood placentation biomarkers, and those adjusted for race, sampling period, and/or study quality were calculated. Adjusted coefficients representing changes in log odds ratio for low delivery weight per 1 MoM increase in maternal blood levels of α-fetoprotein (AFP) and β-human chorionic gonadotropin (β-hCG) were significantly greater than 0 (both P<0.001), whereas that for pregnancy-associated plasma protein A (PAPP-A) was significantly less than 0 (P=0.028). Adjusted models explained the higher proportion of between-study variance better than non-adjusted models. Elevated AFP and β-hCG, and reduced PAPP-A in maternal blood were positively associated with odds of low delivery weight. © 2018 International Federation of Gynecology and Obstetrics.

  9. Prevalence of Human T-lymphotropic virus type 1 and 2 among blood donors in Manaus, Amazonas State, Brazil

    PubMed Central

    de Morais, Márcia Poinho EncarnaçÃo; Gato, Cynara Melo; Maciel, Lucinei Alves; Lalwani, Pritesh; Costa, Cristóvão Alves; Lalwani, Jaila Dias Borges

    2017-01-01

    ABSTRACT Introduction: Human T-lymphotropic virus type 1 and 2 (HTLV-1/2) is endemic in Brazil, but few studies have investigated the seroprevalence of HTLV and its subtypes among blood donors in the capital city Manaus, Amazonas State, Brazil. Aim: To estimate the seroprevalence of HTLV-1/2 and to identify circulating subtypes among blood donors in Manaus. Materials and Methods: Blood donors (2001-2003) were screened for HTLV-1/2 antibodies by ELISA. Positive results were confirmed and subtyped by Western blot assays. Prevalence rates were calculated and compared with demographic data. Results: Among the 87,402 individuals screened, 116 (0.13%) were seropositive for HTLV-1/2. A second sample (76/116) was collected and retested by HTLV-1/2 ELISA, of which only 41/76 were positive. Western blot confirmed HTLV infection in 24/41 retested blood donors [HTLV-1 (n=16), HTLV-2 (n=5) and HTLV-untypable (n=3)]. Discussion: HTLV-1 and HTLV-2 are prevalent among blood donors in Manaus. However, additional studies are needed to comprehend the epidemiology of HTLV-1/2 in Amazonas not only to understand the pathophysiology of the disease providing adequate medical assistance, but also to reduce or block virus transmission. PMID:29267588

  10. Walnut consumption in a weight reduction intervention: effects on body weight, biological measures, blood pressure and satiety.

    PubMed

    Rock, Cheryl L; Flatt, Shirley W; Barkai, Hava-Shoshana; Pakiz, Bilge; Heath, Dennis D

    2017-12-04

    Dietary strategies that help patients adhere to a weight reduction diet may increase the likelihood of weight loss maintenance and improved long-term health outcomes. Regular nut consumption has been associated with better weight management and less adiposity. The objective of this study was to compare the effects of a walnut-enriched reduced-energy diet to a standard reduced-energy-density diet on weight, cardiovascular disease risk factors, and satiety. Overweight and obese men and women (n = 100) were randomly assigned to a standard reduced-energy-density diet or a walnut-enriched (15% of energy) reduced-energy diet in the context of a behavioral weight loss intervention. Measurements were obtained at baseline and 3- and 6-month clinic visits. Participants rated hunger, fullness and anticipated prospective consumption at 3 time points during the intervention. Body measurements, blood pressure, physical activity, lipids, tocopherols and fatty acids were analyzed using repeated measures mixed models. Both study groups reduced body weight, body mass index and waist circumference (time effect p < 0.001 for each). Change in weight was -9.4 (0.9)% vs. -8.9 (0.7)% (mean [SE]), for the standard vs. walnut-enriched diet groups, respectively. Systolic blood pressure decreased in both groups at 3 months, but only the walnut-enriched diet group maintained a lower systolic blood pressure at 6 months. The walnut-enriched diet group, but not the standard reduced-energy-density diet group, reduced total cholesterol and low-density lipoprotein cholesterol (LDL-C) at 6 months, from 203 to 194 mg/dL and 121 to 112 mg/dL, respectively (p < 0.05). Self-reported satiety was similar in the groups. These findings provide further evidence that a walnut-enriched reduced-energy diet can promote weight loss that is comparable to a standard reduced-energy-density diet in the context of a behavioral weight loss intervention. Although weight loss in response to both dietary

  11. Effect of dark chocolate on plasma epicatechin levels, DNA resistance to oxidative stress and total antioxidant activity in healthy subjects.

    PubMed

    Spadafranca, A; Martinez Conesa, C; Sirini, S; Testolin, G

    2010-04-01

    Dark chocolate (DC) may be cardioprotective by antioxidant properties of flavonoids. We investigated the effect of DC (860 mg polyphenols, of which 58 mg epicatechin) compared with white chocolate (WC; 5 mg polyphenols, undetectable epicatechin) on plasma epicatechin levels, mononuclear blood cells (MNBC) DNA damage and plasma total antioxidant activity (TAA). Twenty healthy subjects followed a balanced diet (55 % of energy from carbohydrates, 30 % from fat and 1 g protein/kg body weight) for 4 weeks. Since the 14th day until the 27th day, they introduced daily 45 g of either WC (n 10) or DC (n 10). Whole experimental period was standardised in antioxidant intake. Blood samples were collected at T(0), after 2 weeks (T(14)), 2 h and 22 h after the first chocolate intake (T(14+2 h) and T(14+22 h)), and at 27th day, before chocolate intake (T(27)), 2 h and 22 h after (T(27+2 h) and T(27+22 h)). Samples, except for T(14+2 h) and T(27+2 h), were fasting collected. Detectable epicatechin levels were observed exclusively 2 h after DC intake (T(14+2 h) = 0.362 (se 0.052) micromol/l and T(27+2 h) = 0.369 (se 0.041) micromol/l); at the same times corresponded lower MNBC DNA damages (T(14+2 h) = - 19.4 (se 3.4) % v. T(14), P < 0.05; T(27+2 h) = - 24 (se 7.4) % v. T(27), P < 0.05; T(14+2 h) v. T(27+2 h), P = 0.7). Both effects were no longer evident after 22 h. No effect was observed on TAA. WC did not affect any variable. DC may transiently improve DNA resistance to oxidative stress, probably for flavonoid kinetics.

  12. The phase-space structure of nearby dark matter as constrained by the SDSS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Leclercq, Florent; Percival, Will; Jasche, Jens

    Previous studies using numerical simulations have demonstrated that the shape of the cosmic web can be described by studying the Lagrangian displacement field. We extend these analyses, showing that it is now possible to perform a Lagrangian description of cosmic structure in the nearby Universe based on large-scale structure observations. Building upon recent Bayesian large-scale inference of initial conditions, we present a cosmographic analysis of the dark matter distribution and its evolution, referred to as the dark matter phase-space sheet, in the nearby universe as probed by the Sloan Digital Sky Survey main galaxy sample. We consider its stretchings andmore » foldings using a tetrahedral tessellation of the Lagrangian lattice. The method provides extremely accurate estimates of nearby density and velocity fields, even in regions of low galaxy density. It also measures the number of matter streams, and the deformation and parity reversals of fluid elements, which were previously thought inaccessible using observations. We illustrate the approach by showing the phase-space structure of known objects of the nearby Universe such as the Sloan Great Wall, the Coma cluster and the Boötes void. We dissect cosmic structures into four distinct components (voids, sheets, filaments, and clusters), using the Lagrangian classifiers DIVA, ORIGAMI, and a new scheme which we introduce and call LICH. Because these classifiers use information other than the sheer local density, identified structures explicitly carry physical information about their formation history. Accessing the phase-space structure of dark matter in galaxy surveys opens the way for new confrontations of observational data and theoretical models. We have made our data products publicly available.« less

  13. The phase-space structure of nearby dark matter as constrained by the SDSS

    NASA Astrophysics Data System (ADS)

    Leclercq, Florent; Jasche, Jens; Lavaux, Guilhem; Wandelt, Benjamin; Percival, Will

    2017-06-01

    Previous studies using numerical simulations have demonstrated that the shape of the cosmic web can be described by studying the Lagrangian displacement field. We extend these analyses, showing that it is now possible to perform a Lagrangian description of cosmic structure in the nearby Universe based on large-scale structure observations. Building upon recent Bayesian large-scale inference of initial conditions, we present a cosmographic analysis of the dark matter distribution and its evolution, referred to as the dark matter phase-space sheet, in the nearby universe as probed by the Sloan Digital Sky Survey main galaxy sample. We consider its stretchings and foldings using a tetrahedral tessellation of the Lagrangian lattice. The method provides extremely accurate estimates of nearby density and velocity fields, even in regions of low galaxy density. It also measures the number of matter streams, and the deformation and parity reversals of fluid elements, which were previously thought inaccessible using observations. We illustrate the approach by showing the phase-space structure of known objects of the nearby Universe such as the Sloan Great Wall, the Coma cluster and the Boötes void. We dissect cosmic structures into four distinct components (voids, sheets, filaments, and clusters), using the Lagrangian classifiers DIVA, ORIGAMI, and a new scheme which we introduce and call LICH. Because these classifiers use information other than the sheer local density, identified structures explicitly carry physical information about their formation history. Accessing the phase-space structure of dark matter in galaxy surveys opens the way for new confrontations of observational data and theoretical models. We have made our data products publicly available.

  14. Perfusion weighted imaging and its application in stroke

    NASA Astrophysics Data System (ADS)

    Li, Enzhong; Tian, Jie; Han, Ying; Wang, Huifang; Li, Xingfeng; Zhu, Fuping

    2003-05-01

    To study the technique and application of perfusion weighted imaging (PWI) in the diagnosis and medical treatment of acute stroke, 25 patients were examined by 1.5 T or 1.0 T MRI scanner. The Data analysis was done with "3D Med System" developed by our Lab to process the data and obtain apparent diffusion coefficient (ADC) map, cerebral blood volume (CBV) map, cerebral blood flow (CBF) map as well as mean transit time (MTT) map. In accute stage of stroke, normal or slightly hypointensity in T1-, hyperintensity in T2- and diffusion-weighted images were seen in the cerebral infarction areas. There were hypointensity in CBV map, CBF map and ADC map; and hyperintensity in MTT map that means this infarct area could be saved. If the hyperintensity area in MTT map was larger than the area in diffusion weighted imaging (DWI), the larger part was called penumbra and could be cured by an appropriate thrombolyitic or other therapy. The CBV, CBF and MTT maps are very important in the diagnosis and medical treatment of acute especially hyperacute stroke. Comparing with DWI, we can easily know the situation of penumbra and the effect of curvative therapy. Besides, we can also make a differential diagnosis with this method.

  15. Dark photons from the center of the Earth: Smoking-gun signals of dark matter

    NASA Astrophysics Data System (ADS)

    Feng, Jonathan L.; Smolinsky, Jordan; Tanedo, Philip

    2016-01-01

    Dark matter may be charged under dark electromagnetism with a dark photon that kinetically mixes with the Standard Model photon. In this framework, dark matter will collect at the center of the Earth and annihilate into dark photons, which may reach the surface of the Earth and decay into observable particles. We determine the resulting signal rates, including Sommerfeld enhancements, which play an important role in bringing the Earth's dark matter population to their maximal, equilibrium value. For dark matter masses mX˜100 GeV - 10 TeV , dark photon masses mA'˜MeV -GeV , and kinetic mixing parameters ɛ ˜1 0-9- 1 0-7 , the resulting electrons, muons, photons, and hadrons that point back to the center of the Earth are a smoking-gun signal of dark matter that may be detected by a variety of experiments, including neutrino telescopes, such as IceCube, and space-based cosmic ray detectors, such as Fermi-LAT and AMS. We determine the signal rates and characteristics and show that large and striking signals—such as parallel muon tracks—are possible in regions of the (mA',ɛ ) plane that are not probed by direct detection, accelerator experiments, or astrophysical observations.

  16. Levitating dark matter

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kaloper, Nemanja; Padilla, Antonio, E-mail: kaloper@physics.ucdavis.edu, E-mail: antonio.padilla@nottingham.ac.uk

    2009-10-01

    A sizable fraction of the total energy density of the universe may be in heavy particles with a net dark U(1)' charge comparable to its mass. When the charges have the same sign the cancellation between their gravitational and gauge forces may lead to a mismatch between different measures of masses in the universe. Measuring galactic masses by orbits of normal matter, such as galaxy rotation curves or lensing, will give the total mass, while the flows of dark matter agglomerates may yield smaller values if the gauge repulsion is not accounted for. If distant galaxies which house light beaconsmore » like SNe Ia contain such dark particles, the observations of their cosmic recession may mistake the weaker forces for an extra 'antigravity', and infer an effective dark energy equation of state smaller than the real one. In some cases, including that of a cosmological constant, these effects can mimic w < −1. They can also lead to a local variation of galaxy-galaxy forces, yielding a larger 'Hubble Flow' in those regions of space that could be taken for a dynamical dark energy, or superhorizon effects.« less

  17. Levitating dark matter

    NASA Astrophysics Data System (ADS)

    Kaloper, Nemanja; Padilla, Antonio

    2009-10-01

    A sizable fraction of the total energy density of the universe may be in heavy particles with a net dark U(1)' charge comparable to its mass. When the charges have the same sign the cancellation between their gravitational and gauge forces may lead to a mismatch between different measures of masses in the universe. Measuring galactic masses by orbits of normal matter, such as galaxy rotation curves or lensing, will give the total mass, while the flows of dark matter agglomerates may yield smaller values if the gauge repulsion is not accounted for. If distant galaxies which house light beacons like SNe Ia contain such dark particles, the observations of their cosmic recession may mistake the weaker forces for an extra `antigravity', and infer an effective dark energy equation of state smaller than the real one. In some cases, including that of a cosmological constant, these effects can mimic w < -1. They can also lead to a local variation of galaxy-galaxy forces, yielding a larger `Hubble Flow' in those regions of space that could be taken for a dynamical dark energy, or superhorizon effects.

  18. Codecaying Dark Matter.

    PubMed

    Dror, Jeff Asaf; Kuflik, Eric; Ng, Wee Hao

    2016-11-18

    We propose a new mechanism for thermal dark matter freeze-out, called codecaying dark matter. Multicomponent dark sectors with degenerate particles and out-of-equilibrium decays can codecay to obtain the observed relic density. The dark matter density is exponentially depleted through the decay of nearly degenerate particles rather than from Boltzmann suppression. The relic abundance is set by the dark matter annihilation cross section, which is predicted to be boosted, and the decay rate of the dark sector particles. The mechanism is viable in a broad range of dark matter parameter space, with a robust prediction of an enhanced indirect detection signal. Finally, we present a simple model that realizes codecaying dark matter.

  19. Designing future dark energy space missions. II. Photometric redshift of space weak lensing optimized surveys

    NASA Astrophysics Data System (ADS)

    Jouvel, S.; Kneib, J.-P.; Bernstein, G.; Ilbert, O.; Jelinsky, P.; Milliard, B.; Ealet, A.; Schimd, C.; Dahlen, T.; Arnouts, S.

    2011-08-01

    Context. With the discovery of the accelerated expansion of the universe, different observational probes have been proposed to investigate the presence of dark energy, including possible modifications to the gravitation laws by accurately measuring the expansion of the Universe and the growth of structures. We need to optimize the return from future dark energy surveys to obtain the best results from these probes. Aims: A high precision weak-lensing analysis requires not an only accurate measurement of galaxy shapes but also a precise and unbiased measurement of galaxy redshifts. The survey strategy has to be defined following both the photometric redshift and shape measurement accuracy. Methods: We define the key properties of the weak-lensing instrument and compute the effective PSF and the overall throughput and sensitivities. We then investigate the impact of the pixel scale on the sampling of the effective PSF, and place upper limits on the pixel scale. We then define the survey strategy computing the survey area including in particular both the Galactic absorption and Zodiacal light variation accross the sky. Using the Le Phare photometric redshift code and realistic galaxy mock catalog, we investigate the properties of different filter-sets and the importance of the u-band photometry quality to optimize the photometric redshift and the dark energy figure of merit (FoM). Results: Using the predicted photometric redshift quality, simple shape measurement requirements, and a proper sky model, we explore what could be an optimal weak-lensing dark energy mission based on FoM calculation. We find that we can derive the most accurate the photometric redshifts for the bulk of the faint galaxy population when filters have a resolution ℛ ~ 3.2. We show that an optimal mission would survey the sky through eight filters using two cameras (visible and near infrared). Assuming a five-year mission duration, a mirror size of 1.5 m and a 0.5 deg2 FOV with a visible pixel

  20. Profiling MHC II immunopeptidome of blood-stage malaria reveals that cDC1 control the functionality of parasite-specific CD4 T cells.

    PubMed

    Draheim, Marion; Wlodarczyk, Myriam F; Crozat, Karine; Saliou, Jean-Michel; Alayi, Tchilabalo Dilezitoko; Tomavo, Stanislas; Hassan, Ali; Salvioni, Anna; Demarta-Gatsi, Claudia; Sidney, John; Sette, Alessandro; Dalod, Marc; Berry, Antoine; Silvie, Olivier; Blanchard, Nicolas

    2017-11-01

    In malaria, CD4 Th1 and T follicular helper (T FH ) cells are important for controlling parasite growth, but Th1 cells also contribute to immunopathology. Moreover, various regulatory CD4 T-cell subsets are critical to hamper pathology. Yet the antigen-presenting cells controlling Th functionality, as well as the antigens recognized by CD4 T cells, are largely unknown. Here, we characterize the MHC II immunopeptidome presented by DC during blood-stage malaria in mice. We establish the immunodominance hierarchy of 14 MHC II ligands derived from conserved parasite proteins. Immunodominance is shaped differently whether blood stage is preceded or not by liver stage, but the same ETRAMP-specific dominant response develops in both contexts. In naïve mice and at the onset of cerebral malaria, CD8α + dendritic cells (cDC1) are superior to other DC subsets for MHC II presentation of the ETRAMP epitope. Using in vivo depletion of cDC1, we show that cDC1 promote parasite-specific Th1 cells and inhibit the development of IL-10 + CD4 T cells. This work profiles the P. berghei blood-stage MHC II immunopeptidome, highlights the potency of cDC1 to present malaria antigens on MHC II, and reveals a major role for cDC1 in regulating malaria-specific CD4 T-cell responses. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

  1. ERTS-1 anomalous dark patches

    NASA Technical Reports Server (NTRS)

    Strong, A. E. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Through combined use of imagery from ERTS-1 and NOAA-2 satellites was found that when the sun elevation exceeds 55 degrees, the ERTS-1 imagery is subject to considerable contamination by sunlight even though the actual specular point is nearly 300 nautical miles from nadir. Based on sea surface wave slope information, a wind speed of 10 knots will theoretically provide approximately 0.5 percent incident solar reflectance under observed ERTS multispectral scanner detectors. This reflectance nearly doubles under the influence of a 20 knot wind. The most pronounced effect occurs in areas of calm water where anomalous dark patches are observed. Calm water at distances from the specular point found in ERTS scenes will reflect no solar energy to the multispectral scanner, making these regions stand out as dark areas in all bands in an ocean scene otherwise comprosed by a general diffuse sunlight from rougher ocean surfaces. Anomalous dark patches in the outer parts of the glitter zones may explain the unusual appearance of some scenes.

  2. Breast Lesions: Diagnosis Using Diffusion Weighted Imaging at 1.5T and 3.0T-Systematic Review and Meta-analysis.

    PubMed

    Shi, Ruo-Yang; Yao, Qiu-Ying; Wu, Lian-Ming; Xu, Jian-Rong

    2018-06-01

    We compared the diagnostic performance of diffusion weighted imaging (DWI) acquired with 1.5T and 3.0T magnetic resonance (MR) units in differentiating malignant breast lesions from benign ones. A comprehensive search of the PubMed and Embase databases was performed for studies reported from January 1, 2000 to February 19, 2016. The quality of the included studies was assessed. Statistical analysis included pooling of diagnostic sensitivity and specificity and assessing data inhomogeneity and publication bias. A total of 61 studies were included after a full-text review. These included 4778 patients and 5205 breast lesions. The overall sensitivity and specificity were 90% (95% confidence interval [CI], 88%-92%) and 86% (95% CI, 82%-89%), respectively. The pooled diagnostic odds ratio was 53 (95% CI, 37-74). For breast cancer versus benign lesions, the area under the curve was 0.94 (95% CI, 0.92-0.96). For the 44 studies that used a 1.5T MR unit, the pooled sensitivity and specificity were 91% (95% CI, 89%-92%) and 86% (95% CI, 81%-90%), respectively. For the 17 studies that used a 3.0T MR unit, the pooled sensitivity and specificity were 88% (95% CI, 83%-91%) and 84% (95% CI, 0.78-0.89), respectively. Publication bias and significant heterogeneity were observed; however, no threshold was found among the 61 studies. No significant difference was found in the sensitivity or specificity between the subgroups. The results of the comparison between the subgroups that had used either a 1.5T or 3.0T MR unit suggest that the diagnostic accuracy for breast cancer compared with benign lesions is not significantly different. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. The dark side of cosmology: dark matter and dark energy.

    PubMed

    Spergel, David N

    2015-03-06

    A simple model with only six parameters (the age of the universe, the density of atoms, the density of matter, the amplitude of the initial fluctuations, the scale dependence of this amplitude, and the epoch of first star formation) fits all of our cosmological data . Although simple, this standard model is strange. The model implies that most of the matter in our Galaxy is in the form of "dark matter," a new type of particle not yet detected in the laboratory, and most of the energy in the universe is in the form of "dark energy," energy associated with empty space. Both dark matter and dark energy require extensions to our current understanding of particle physics or point toward a breakdown of general relativity on cosmological scales. Copyright © 2015, American Association for the Advancement of Science.

  4. Wideband Arrhythmia-Insensitive-Rapid (AIR) Pulse Sequence for Cardiac T1 mapping without Image Artifacts induced by ICD

    PubMed Central

    Hong, KyungPyo; Jeong, Eun-Kee; Wall, T. Scott; Drakos, Stavros G.; Kim, Daniel

    2015-01-01

    Purpose To develop and evaluate a wideband arrhythmia-insensitive-rapid (AIR) pulse sequence for cardiac T1 mapping without image artifacts induced by implantable-cardioverter-defibrillator (ICD). Methods We developed a wideband AIR pulse sequence by incorporating a saturation pulse with wide frequency bandwidth (8.9 kHz), in order to achieve uniform T1 weighting in the heart with ICD. We tested the performance of original and “wideband” AIR cardiac T1 mapping pulse sequences in phantom and human experiments at 1.5T. Results In 5 phantoms representing native myocardium and blood and post-contrast blood/tissue T1 values, compared with the control T1 values measured with an inversion-recovery pulse sequence without ICD, T1 values measured with original AIR with ICD were considerably lower (absolute percent error >29%), whereas T1 values measured with wideband AIR with ICD were similar (absolute percent error <5%). Similarly, in 11 human subjects, compared with the control T1 values measured with original AIR without ICD, T1 measured with original AIR with ICD was significantly lower (absolute percent error >10.1%), whereas T1 measured with wideband AIR with ICD was similar (absolute percent error <2.0%). Conclusion This study demonstrates the feasibility of a wideband pulse sequence for cardiac T1 mapping without significant image artifacts induced by ICD. PMID:25975192

  5. Supergravity, dark energy, and the fate of the universe

    NASA Astrophysics Data System (ADS)

    Kallosh, Renata; Linde, Andrei; Prokushkin, Sergey; Shmakova, Marina

    2002-12-01

    We propose a description of dark energy and acceleration of the universe in extended supergravities with de Sitter (dS) solutions. Some of them are related to M theory with noncompact internal spaces. Masses of ultralight scalars in these models are quantized in units of the Hubble constant: m2=nH2. If the dS solution corresponds to a minimum of the effective potential, the universe eventually becomes dS space. If the dS solution corresponds to a maximum or a saddle point, which is the case in all known models based on N=8 supergravity, the flat universe eventually stops accelerating and collapses to a singularity. We show that in these models, as well as in the simplest models of dark energy based on N=1 supergravity, the typical time remaining before the global collapse is comparable to the present age of the universe, t=O(1010) yr. We discuss the possibility of distinguishing between various models and finding our destiny using cosmological observations.

  6. Comparison of axial T1 spin-echo and T1 fat-saturation magnetic resonance imaging techniques in the diagnosis of chondromalacia patellae.

    PubMed

    Vanarthos, W J; Pope, T L; Monu, J U

    1994-12-01

    To test the diagnostic value of T1 spin-echo and T1 fat-saturated magnetic resonance images (MRIs), we reviewed axial T1-weighted images with and without fat saturation in 20 patients with clinically suspected chondromalacia of the patella. All scans were obtained on 1.5-MR units. The scans were randomly ordered and reviewed independently at different times by two radiologists without knowledge of the arthroscopy results. The sensitivity of the individual techniques for detecting grade 3 or 4 chondromalacia patellae was 92% for fat-saturated axial T1-weighted images alone, and 67% for axial T1-weighted images without fat saturation. The sensitivity of the combined techniques was 100% for grades 3 and 4 and 90% for all grades (0 to 4). Chondromalacia patellae is diagnosed more accurately by using T1 fat saturation than by using T1 spin-echo images. With a combination of the two techniques, accuracy is 90% to 100%.

  7. Single-Cell RNA Sequencing Reveals Expanded Clones of Islet Antigen-Reactive CD4+ T Cells in Peripheral Blood of Subjects with Type 1 Diabetes.

    PubMed

    Cerosaletti, Karen; Barahmand-Pour-Whitman, Fariba; Yang, Junbao; DeBerg, Hannah A; Dufort, Matthew J; Murray, Sara A; Israelsson, Elisabeth; Speake, Cate; Gersuk, Vivian H; Eddy, James A; Reijonen, Helena; Greenbaum, Carla J; Kwok, William W; Wambre, Erik; Prlic, Martin; Gottardo, Raphael; Nepom, Gerald T; Linsley, Peter S

    2017-07-01

    The significance of islet Ag-reactive T cells found in peripheral blood of type 1 diabetes (T1D) subjects is unclear, partly because similar cells are also found in healthy control (HC) subjects. We hypothesized that key disease-associated cells would show evidence of prior Ag exposure, inferred from expanded TCR clonotypes, and essential phenotypic properties in their transcriptomes. To test this, we developed single-cell RNA sequencing procedures for identifying TCR clonotypes and transcript phenotypes in individual T cells. We applied these procedures to analysis of islet Ag-reactive CD4 + memory T cells from the blood of T1D and HC individuals after activation with pooled immunodominant islet peptides. We found extensive TCR clonotype sharing in Ag-activated cells, especially from individual T1D subjects, consistent with in vivo T cell expansion during disease progression. The expanded clonotype from one T1D subject was detected at repeat visits spanning >15 mo, demonstrating clonotype stability. Notably, we found no clonotype sharing between subjects, indicating a predominance of "private" TCR specificities. Expanded clones from two T1D subjects recognized distinct IGRP peptides, implicating this molecule as a trigger for CD4 + T cell expansion. Although overall transcript profiles of cells from HC and T1D subjects were similar, profiles from the most expanded clones were distinctive. Our findings demonstrate that islet Ag-reactive CD4 + memory T cells with unique Ag specificities and phenotypes are expanded during disease progression and can be detected by single-cell analysis of peripheral blood. Copyright © 2017 by The American Association of Immunologists, Inc.

  8. Modelling non-linear effects of dark energy

    NASA Astrophysics Data System (ADS)

    Bose, Benjamin; Baldi, Marco; Pourtsidou, Alkistis

    2018-04-01

    We investigate the capabilities of perturbation theory in capturing non-linear effects of dark energy. We test constant and evolving w models, as well as models involving momentum exchange between dark energy and dark matter. Specifically, we compare perturbative predictions at 1-loop level against N-body results for four non-standard equations of state as well as varying degrees of momentum exchange between dark energy and dark matter. The interaction is modelled phenomenologically using a time dependent drag term in the Euler equation. We make comparisons at the level of the matter power spectrum and the redshift space monopole and quadrupole. The multipoles are modelled using the Taruya, Nishimichi and Saito (TNS) redshift space spectrum. We find perturbation theory does very well in capturing non-linear effects coming from dark sector interaction. We isolate and quantify the 1-loop contribution coming from the interaction and from the non-standard equation of state. We find the interaction parameter ξ amplifies scale dependent signatures in the range of scales considered. Non-standard equations of state also give scale dependent signatures within this same regime. In redshift space the match with N-body is improved at smaller scales by the addition of the TNS free parameter σv. To quantify the importance of modelling the interaction, we create mock data sets for varying values of ξ using perturbation theory. This data is given errors typical of Stage IV surveys. We then perform a likelihood analysis using the first two multipoles on these sets and a ξ=0 modelling, ignoring the interaction. We find the fiducial growth parameter f is generally recovered even for very large values of ξ both at z=0.5 and z=1. The ξ=0 modelling is most biased in its estimation of f for the phantom w=‑1.1 case.

  9. Heavy weight vehicle traffic and its relationship with antimony content in human blood.

    PubMed

    Quiroz, Waldo; De Gregori, Ida; Basilio, Paola; Bravo, Manuel; Pinto, Marcela; Lobos, Maria Gabriela

    2009-05-01

    Brake pads systems are nowadays considered as one of the most important sources of antimony in airborne particulate matter. One way that antimony can enter the body is through the lungs and specially by the interaction of antimony with -SH groups present in erythrocyte membrane cells. In spite of that, there are no studies about antimony enrichment in blood of workers exposed to high vehicle traffic. Port workers are generally exposed to heavy weight vehicle traffic. In Chile the biggest marine port is found in Valparaíso City. In this study antimony in whole blood and its fractions (erythrocytes-plasma and erythrocytes membranes-cytoplasm) of 45 volunteers were determined. The volunteers were port workers from Valparaíso city, and two control groups, one from Valparaíso and another from Quebrada Alvarado, the latter being a rural area located about 100 Km away from Valparaíso. The results demonstrate that port workers are highly impacted by antimony emissions from heavy weight vehicle traffic showing an average concentration of 27 +/- 9 ng Sb kg(-1), 5-10 times higher than the concentration of antimony in the blood of control groups. These are the highest antimony levels in blood ever reported in the literature. The highest antimony percentages (>60%) were always found in the erythrocyte fractions. However, the exposure degree to vehicle traffic is significant over antimony distribution in plasma, erythrocytes and cytoplasm. This results shows that the antimony mass in the erythrocyte membranes, was approximately constant at 1.0 +/- 0.1 ng Sb g(-1) of whole blood in all blood samples analyzed.

  10. Blood pressure, excess weight and level of physical activity in students of a public university.

    PubMed

    Martins, Maria do Carmo de Carvalho e; Ricarte, Irapuá Ferreira; Rocha, Cláudio Henrique Lima; Maia, Rodrigo Batista; Silva, Vitor Brito da; Veras, André Bastos; Filho, Manoel Dias de Souza

    2010-08-01

    High blood pressure, excess weight and sedentary lifestyle are important risk factors for cardiovascular diseases, and they are closely associated. To evaluate the nutritional status, level of physical activity and blood pressure levels of students of Universidade Federal do Piauí, Teresina, Brazil. Cross-sectional study with a sample of 605 students (46.1% males and 53.9% females), with a mean age of 21.7 ± 3.7 years. The nutritional status was classified according to body mass index (BMI), and central adiposity according to waist circumference (WC). The level of physical activity was evaluated using the short version of the International Physical Activity Questionnaire (IPAQ). Elevated blood pressure was defined as systolic blood pressure > 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg. The prevalence of elevated blood pressure was 9.7%, and was higher among men. Excess weight (BMI > 25 kg/m(2)) was found in 18.2% of the students, with overweight and obesity rates of 15.2% and 3%, respectively. Abdominal obesity was found in 2.4% of the students regardless of gender, and sedentary lifestyle in 52%. The mean blood pressure increased with increasing BMI and WC. No association was found between the levels of physical activity and blood pressure. An association of increased body weight and waist circumference with higher blood pressure levels was observed among the participants. Instruments for an early assessment of the cardiovascular risk and preventive advice should be established for these young individuals.

  11. Renormalization group equation analysis of a pseudoscalar portal dark matter model

    NASA Astrophysics Data System (ADS)

    Ghorbani, Karim

    2017-10-01

    We investigate the vacuum stability and perturbativity of a pseudoscalar portal dark matter (DM) model with a Dirac DM candidate, through the renormalization group equation analysis at one-loop order. The model has a particular feature which can evade the direct detection upper bounds measured by XENON100 and even that from planned experiment XENON1T. We first find the viable regions in the parameter space which will give rise to correct DM relic density and comply with the constraints from Higgs physics. We show that for a given mass of the pseudoscalar, the mixing angle plays no significant role in the running of the couplings. Then we study the running of the couplings for various pseudoscalar masses at mixing angle θ =6^\\circ , and find the scale of validity in terms of the dark coupling, {λ }d. Depending on our choice of the cutoff scale, the resulting viable parameter space will be determined.

  12. Development of PEGylated KMnF3 nanoparticles as a T1-weighted contrast agent: chemical synthesis, in vivo brain MR imaging, and accounting for high relaxivity

    NASA Astrophysics Data System (ADS)

    Liu, Zhi-Jun; Song, Xiao-Xia; Tang, Qun

    2013-05-01

    Magnetic nanoparticles consisting of manganese-based T1-weighted contrast agents have rapidly achieved clinical application, however low proton relaxivity impedes further development. In this report, by analyzing nanoparticles' surface oxidation states we propose the possible reason for the low r1 relaxivity of common MnO nanoparticles and develop PEGylated fluoroperovskite KMnF3 nanoparticles as new T1-weighted contrast agents, which exhibit the highest longitudinal relaxivity (r1 = 23.15 mM-1 s-1) among all the reported manganese-based T1-weighted contrast agents. We, for the first time, illustrate a typical example showing that the surface oxidation states of metal ions exposed on the nanoparticles' surfaces are able to influence not only the optical, magnetic, electronic or catalytic properties but also water proton longitudinal relaxivity when applied as an MRI contrast agent. Cytotoxicity tests demonstrate that the PEGylated KMnF3 nanoparticles are free from toxicity. Further in vivo MRI experiments distinctively depict fine anatomical features in brain imaging at a low dose of 5 mg of Mn per kg and possible removal from the kidneys due to their small size and biocompatibility.Magnetic nanoparticles consisting of manganese-based T1-weighted contrast agents have rapidly achieved clinical application, however low proton relaxivity impedes further development. In this report, by analyzing nanoparticles' surface oxidation states we propose the possible reason for the low r1 relaxivity of common MnO nanoparticles and develop PEGylated fluoroperovskite KMnF3 nanoparticles as new T1-weighted contrast agents, which exhibit the highest longitudinal relaxivity (r1 = 23.15 mM-1 s-1) among all the reported manganese-based T1-weighted contrast agents. We, for the first time, illustrate a typical example showing that the surface oxidation states of metal ions exposed on the nanoparticles' surfaces are able to influence not only the optical, magnetic, electronic or

  13. Umbilical Arterial Blood Sampling Alters Cerebral Tissue Oxygenation in Very Low Birth Weight Neonates.

    PubMed

    Mintzer, Jonathan P; Parvez, Boriana; La Gamma, Edmund F

    2015-11-01

    To evaluate the magnitude, consistency, and natural history of reductions in cerebral regional tissue oxygenation (CrSO2) during umbilical arterial (UA) blood sampling in very low birth weight neonates. Data were collected during a prospective observational near-infrared spectroscopy survey conducted on a convenience sample of 500-1250 g neonates during the first 10 postnatal days. A before-after analysis of UA blood sampling effects on CrSO2 absolute values and variability was performed. The present analysis was not designed a priori and was conducted following the bedside observation of CrSO2 decrements contiguous with UA blood draws. Fifteen very low birth weight neonates had 201 UA blood draws. Baseline CrSO2 (mean ± SEM) decreased following UA blood sampling, from 70 ± 1% to a nadir of 63 ± 1% (P < .001) occurring 4 ± 3 (range 2-24) minutes following blood draws. CrSO2 subsequently increased to 70 ± 1% (P < .001 compared with nadir) at 10 ± 4 (range 4-28) minutes following UA blood sampling. Coefficients of variation (mean ± SEM) increased from 0.02 ± 0.001 at baseline to 0.05 ± 0.004 (P < .001), followed by a decrease to 0.03 ± 0.003 (P < .001 for all comparisons), thus denoting increased CrSO2 variability following UA blood sampling. UA blood sampling is associated with significant CrSO2 decrements with increased variability over clinically significant intervals. Whether these changes impact complications of prematurity, including intraventricular hemorrhage and periventricular leukomalacia, remain unknown. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Crystallographic analysis of ground and space thermostable T1 lipase crystal obtained via counter diffusion method approach.

    PubMed

    Mohamad Aris, Sayangku Nor Ariati; Thean Chor, Adam Leow; Mohamad Ali, Mohd Shukuri; Basri, Mahiran; Salleh, Abu Bakar; Raja Abd Rahman, Raja Noor Zaliha

    2014-01-01

    Three-dimensional structure of thermostable lipase is much sought after nowadays as it is important for industrial application mainly found in the food, detergent, and pharmaceutical sectors. Crystallization utilizing the counter diffusion method in space was performed with the aim to obtain high resolution diffracting crystals with better internal order to improve the accuracy of the structure. Thermostable T1 lipase enzyme has been crystallized in laboratory on earth and also under microgravity condition aboard Progress spacecraft to the ISS in collaboration with JAXA (Japanese Aerospace Exploration Agency). This study is conducted with the aims of improving crystal packing and structure resolution. The diffraction data set for ground grown crystal was collected to 1.3 Å resolution and belonged to monoclinic C2 space group with unit cell parameters a = 117.40 Å, b = 80.95 Å, and c = 99.81 Å, whereas the diffraction data set for space grown crystal was collected to 1.1 Å resolution and belonged to monoclinic C2 space group with unit cell parameters a = 117.31 Å, b = 80.85 Å, and c = 99.81 Å. The major difference between the two crystal growth systems is the lack of convection and sedimentation in microgravity environment resulted in the growth of much higher quality crystals of T1 lipase.

  15. Normalization of white matter intensity on T1-weighted images of patients with acquired central nervous system demyelination.

    PubMed

    Ghassemi, Rezwan; Brown, Robert; Narayanan, Sridar; Banwell, Brenda; Nakamura, Kunio; Arnold, Douglas L

    2015-01-01

    Intensity variation between magnetic resonance images (MRI) hinders comparison of tissue intensity distributions in multicenter MRI studies of brain diseases. The available intensity normalization techniques generally work well in healthy subjects but not in the presence of pathologies that affect tissue intensity. One such disease is multiple sclerosis (MS), which is associated with lesions that prominently affect white matter (WM). To develop a T1-weighted (T1w) image intensity normalization method that is independent of WM intensity, and to quantitatively evaluate its performance. We calculated median intensity of grey matter and intraconal orbital fat on T1w images. Using these two reference tissue intensities we calculated a linear normalization function and applied this to the T1w images to produce normalized T1w (NT1) images. We assessed performance of our normalization method for interscanner, interprotocol, and longitudinal normalization variability, and calculated the utility of the normalization method for lesion analyses in clinical trials. Statistical modeling showed marked decreases in T1w intensity differences after normalization (P < .0001). We developed a WM-independent T1w MRI normalization method and tested its performance. This method is suitable for longitudinal multicenter clinical studies for the assessment of the recovery or progression of disease affecting WM. Copyright © 2014 by the American Society of Neuroimaging.

  16. Depiction of pneumothoraces in a large animal model using x-ray dark-field radiography.

    PubMed

    Hellbach, Katharina; Baehr, Andrea; De Marco, Fabio; Willer, Konstantin; Gromann, Lukas B; Herzen, Julia; Dmochewitz, Michaela; Auweter, Sigrid; Fingerle, Alexander A; Noël, Peter B; Rummeny, Ernst J; Yaroshenko, Andre; Maack, Hanns-Ingo; Pralow, Thomas; van der Heijden, Hendrik; Wieberneit, Nataly; Proksa, Roland; Koehler, Thomas; Rindt, Karsten; Schroeter, Tobias J; Mohr, Juergen; Bamberg, Fabian; Ertl-Wagner, Birgit; Pfeiffer, Franz; Reiser, Maximilian F

    2018-02-08

    The aim of this study was to assess the diagnostic value of x-ray dark-field radiography to detect pneumothoraces in a pig model. Eight pigs were imaged with an experimental grating-based large-animal dark-field scanner before and after induction of a unilateral pneumothorax. Image contrast-to-noise ratios between lung tissue and the air-filled pleural cavity were quantified for transmission and dark-field radiograms. The projected area in the object plane of the inflated lung was measured in dark-field images to quantify the collapse of lung parenchyma due to a pneumothorax. Means and standard deviations for lung sizes and signal intensities from dark-field and transmission images were tested for statistical significance using Student's two-tailed t-test for paired samples. The contrast-to-noise ratio between the air-filled pleural space of lateral pneumothoraces and lung tissue was significantly higher in the dark-field (3.65 ± 0.9) than in the transmission images (1.13 ± 1.1; p = 0.002). In case of dorsally located pneumothoraces, a significant decrease (-20.5%; p > 0.0001) in the projected area of inflated lung parenchyma was found after a pneumothorax was induced. Therefore, the detection of pneumothoraces in x-ray dark-field radiography was facilitated compared to transmission imaging in a large animal model.

  17. Effect of Intensive Statin Therapy on Coronary High-Intensity Plaques Detected by Noncontrast T1-Weighted Imaging: The AQUAMARINE Pilot Study.

    PubMed

    Noguchi, Teruo; Tanaka, Atsushi; Kawasaki, Tomohiro; Goto, Yoichi; Morita, Yoshiaki; Asaumi, Yasuhide; Nakao, Kazuhiro; Fujiwara, Reiko; Nishimura, Kunihiro; Miyamoto, Yoshihiro; Ishihara, Masaharu; Ogawa, Hisao; Koga, Nobuhiko; Narula, Jagat; Yasuda, Satoshi

    2015-07-21

    Coronary high-intensity plaques detected by noncontrast T1-weighted imaging may represent plaque instability. High-intensity plaques can be quantitatively assessed by a plaque-to-myocardium signal-intensity ratio (PMR). This pilot, hypothesis-generating study sought to investigate whether intensive statin therapy would lower PMR. Prospective serial noncontrast T1-weighted magnetic resonance imaging and computed tomography angiography were performed in 48 patients with coronary artery disease at baseline and after 12 months of intensive pitavastatin treatment with a target low-density lipoprotein cholesterol level <80 mg/dl. The control group consisted of coronary artery disease patients not treated with statins that were matched by propensity scoring (n = 48). The primary endpoint was the 12-month change in PMR. Changes in computed tomography angiography parameters and high-sensitivity C-reactive protein levels were analyzed. In the statin group, 12 months of statin therapy significantly improved low-density lipoprotein cholesterol levels (125 to 70 mg/dl; p < 0.001), PMR (1.38 to 1.11, an 18.9% reduction; p < 0.001), low-attenuation plaque volume, and the percentage of total atheroma volume on computed tomography. In the control group, the PMR increased significantly (from 1.22 to 1.49, a 19.2% increase; p < 0.001). Changes in PMR were correlated with changes in low-density lipoprotein cholesterol (r = 0.533; p < 0.001), high-sensitivity C-reactive protein (r = 0.347; p < 0.001), percentage of atheroma volume (r = 0.477; p < 0.001), and percentage of low-attenuation plaque volume (r = 0.416; p < 0.001). Statin treatment significantly reduced the PMR of high-intensity plaques. Noncontrast T1-weighted magnetic resonance imaging could become a useful technique for repeated quantitative assessment of plaque composition. (Attempts at Plaque Vulnerability Quantification with Magnetic Resonance Imaging Using Noncontrast T1-weighted Technique [AQUAMARINE

  18. Serum zinc levels of cord blood: relation to birth weight and gestational period.

    PubMed

    Gómez, Tahiry; Bequer, Leticia; Mollineda, Angel; González, Olga; Diaz, Mireisy; Fernández, Douglas

    2015-04-01

    Zn-deficiency has been associated with numerous alterations during pregnancy including low birth weight; however, the research relating neonatal zinc status and birth weight has not produced reliable results. To compare the serum Zn-levels of cord blood in healthy newborns and low birth weight newborns, and to assess a possible relationship between zinc concentration and neonatal birth weight and gestational age. 123 newborns divided in "study group" (n=50) with <2500g birth weight neonates and "control group" (n=73) with ≥2500g birth weight neonates were enrolled. Study group was subdivided according to gestational age in preterm (<37 weeks) and full-term (≥37 weeks). Serum cord blood samples were collected and the Zn-levels were analyzed using flame Atomic Absorption Spectrophotometry method and the result was expressed in μmol/L. The Zn-levels were compared between the groups (Mann-Whitney-U test) and the Zn-levels were correlated with the birth weight and gestational age (Spearman's rank correlations). Statistically significant low positive correlation between Zn-levels and birth weight (ρ=0.283; p=0.005) was found. No statistically significant difference between Zn-levels of study and control groups [17.00±0.43 vs. 18.16±0.32 (p=0.053)] was found. Statistically significant low positive correlation between Zn-levels and gestational age (ρ=0.351; p=0.001) was found. No statistically significant difference between Zn-levels of preterm as compare to full-term newborns [16.33±0.42 vs. 18.43±0.93 (p=0.079)] was found. Zn-level of preterm subgroup was significantly lower compared to control group (p=0.001). Despite low birth weight preterm neonates had significantly lower serum zinc levels of cord blood than healthy term neonates, the correlation between cord blood zinc levels and birth weight and gestational age was lower. The results are not enough to relate the change in cord blood zinc concentration to the birth weight values or gestational period. In

  19. Probing the Dark Sector with Dark Matter Bound States.

    PubMed

    An, Haipeng; Echenard, Bertrand; Pospelov, Maxim; Zhang, Yue

    2016-04-15

    A model of the dark sector where O(few  GeV) mass dark matter particles χ couple to a lighter dark force mediator V, m_{V}≪m_{χ}, is motivated by the recently discovered mismatch between simulated and observed shapes of galactic halos. Such models, in general, provide a challenge for direct detection efforts and collider searches. We show that for a large range of coupling constants and masses, the production and decay of the bound states of χ, such as 0^{-+} and 1^{--} states, η_{D} and ϒ_{D}, is an important search channel. We show that e^{+}e^{-}→η_{D}+V or ϒ_{D}+γ production at B factories for α_{D}>0.1 is sufficiently strong to result in multiple pairs of charged leptons and pions via η_{D}→2V→2(l^{+}l^{-}) and ϒ_{D}→3V→3(l^{+}l^{-}) (l=e,μ,π). The absence of such final states in the existing searches performed at BABAR and Belle sets new constraints on the parameter space of the model. We also show that a search for multiple bremsstrahlung of dark force mediators, e^{+}e^{-}→χχ[over ¯]+nV, resulting in missing energy and multiple leptons, will further improve the sensitivity to self-interacting dark matter.

  20. Oral administration of Dictyostelium differentiation-inducing factor 1 lowers blood glucose levels in streptozotocin-induced diabetic rats.

    PubMed

    Kawaharada, Ritsuko; Nakamura, Akio; Takahashi, Katsunori; Kikuchi, Haruhisa; Oshima, Yoshiteru; Kubohara, Yuzuru

    2016-06-15

    Differentiation-inducing factor 1 (DIF-1), originally discovered in the cellular slime mold Dictyostelium discoideum, and its derivatives possess pharmacological activities, such as the promotion of glucose uptake in non-transformed mammalian cells in vitro. Accordingly, DIFs are considered promising lead candidates for novel anti-diabetic drugs. The aim of this study was to assess the anti-diabetic and toxic effects of DIF-1 in mouse 3T3-L1 fibroblast cells in vitro and in diabetic rats in vivo. Main methods We investigated the in vitro effects of DIF-1 and DIF-1(3M), a derivative of DIF-1, on glucose metabolism in 3T3-L1 cells by using capillary electrophoresis time-of-flight mass spectrometry (CE-TOF-MS). We also examined the effects of DIF-1 on blood glucose levels in streptozotocin (STZ)-induced rats. CE-TOF-MS revealed that 20μM DIF-1 and 20μM DIF-1(3M) promoted glucose uptake and metabolism in 3T3-L1 cells. Oral administration of DIF-1 (30mg/kg) significantly lowered basal blood glucose levels in STZ-treated rats and promoted a decrease in blood glucose levels after oral glucose loading (2.5g/kg) in the rats. In addition, daily oral administration of DIF-1 (30mg/kg/day) for 1wk significantly lowered the blood glucose levels in STZ-treated rats but did not affect their body weight and caused only minor alterations in the levels of other blood analytes. These results indicate that DIF-1 may be a good lead compound for the development of anti-diabetic drugs. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Effects of multiple concurrent stressors on rectal temperature, blood acid-base status, and longissimus muscle glycolytic potential in market-weight pigs.

    PubMed

    Ritter, M J; Ellis, M; Anderson, D B; Curtis, S E; Keffaber, K K; Killefer, J; McKeith, F K; Murphy, C M; Peterson, B A

    2009-01-01

    Sixty-four market-weight (130.0 +/- 0.65 kg) barrows (n = 16) and gilts (n = 48) were used in a split-plot design with a 2 x 2 x 2 factorial arrangement of treatments: 1) handling intensity (gentle vs. aggressive), 2) transport floor space (0.39 vs. 0.49 m(2)/pig), and 3) distance moved during handling (25 vs. 125 m) to determine the effects of multiple concurrent stressors on metabolic responses. For the handling intensity treatment, pigs were moved individually approximately 50 m through a handling course with either 0 (gentle) or 8 (aggressive) shocks from an electric goad. Pigs were loaded onto a trailer and transported for approximately 1 h at floor spaces of either 0.39 or 0.49 m(2)/pig. After transport, pigs were unloaded, and the distance moved treatment was applied; pigs were moved 25 or 125 m through a handling course using livestock paddles. Rectal temperature was measured, and blood samples (to measure blood acid-base status) were collected 2 h before the handling intensity treatment was applied and immediately after the distance moved treatment was applied. A LM sample to measure glycolytic potential was collected after the distance moved treatments on a subset of 32 pigs. There were handling intensity x distance moved interactions (P < 0.05) for several blood acid-base measurements. In general, there was no effect of distance moved on these traits when pigs were previously handled gently. However, when pigs were previously handled aggressively, pigs moved 125 compared with 25 m had greater (P < 0.05) blood lactate and less (P < 0.05) blood pH, bicarbonate, and base-excess. Pigs transported at 0.39 compared with 0.49 m(2)/pig had a greater (P < 0.01) increase in creatine kinase values; however, transport floor space did not affect any other measurements. Data were analyzed by the number of stressors (the aggressive handling, restricted transport floor space, and 125-m distance moved treatments) experienced by each pig (0, 1, 2, or 3). As the number of

  2. Comparative study of standard space and real space analysis of quantitative MR brain data.

    PubMed

    Aribisala, Benjamin S; He, Jiabao; Blamire, Andrew M

    2011-06-01

    To compare the robustness of region of interest (ROI) analysis of magnetic resonance imaging (MRI) brain data in real space with analysis in standard space and to test the hypothesis that standard space image analysis introduces more partial volume effect errors compared to analysis of the same dataset in real space. Twenty healthy adults with no history or evidence of neurological diseases were recruited; high-resolution T(1)-weighted, quantitative T(1), and B(0) field-map measurements were collected. Algorithms were implemented to perform analysis in real and standard space and used to apply a simple standard ROI template to quantitative T(1) datasets. Regional relaxation values and histograms for both gray and white matter tissues classes were then extracted and compared. Regional mean T(1) values for both gray and white matter were significantly lower using real space compared to standard space analysis. Additionally, regional T(1) histograms were more compact in real space, with smaller right-sided tails indicating lower partial volume errors compared to standard space analysis. Standard space analysis of quantitative MRI brain data introduces more partial volume effect errors biasing the analysis of quantitative data compared to analysis of the same dataset in real space. Copyright © 2011 Wiley-Liss, Inc.

  3. Near-infrared light-activated red-emitting upconverting nanoplatform for T1-weighted magnetic resonance imaging and photodynamic therapy.

    PubMed

    Tang, Xiang-Long; Wu, Jun; Lin, Ben-Lan; Cui, Sheng; Liu, Hong-Mei; Yu, Ru-Tong; Shen, Xiao-Dong; Wang, Ting-Wei; Xia, Wei

    2018-05-12

    Photodynamic therapy (PDT) has increasingly become an efficient and attractive cancer treatment modality based on reactive oxygen species (ROS) that can induce tumor death after irradiation with ultraviolet or visible light. Herein, to overcome the limited tissue penetration in traditional PDT, a novel near-infrared (NIR) light-activated NaScF 4 : 40% Yb, 2% Er@CaF 2 upconversion nanoparticle (rUCNP) is successfully designed and synthesized. Chlorin e6, a photosensitizer and a chelating agent for Mn 2+ , is loaded into human serum albumin (HSA) that further conjugates onto rUCNPs. To increase the ability to target glioma tumor, an acyclic Arg-Gly-Asp peptide (cRGDyK) is linked to rUCNPs@HSA(Ce6-Mn). This nanoplatform enables efficient adsorption and conversion of NIR light (980 nm) into bright red emission (660 nm), which can trigger the photosensitizer Ce6-Mn complex for PDT and T 1 -weighted magnetic resonance imaging (T 1 -weighted MRI) for glioma diagnosis. Our in vitro and in vivo experiments demonstrate that NIR light-activated and glioma tumor-targeted PDT can generate large amounts of intracellular ROS that induce U87 cell apoptosis and suppress glioma tumor growth owing to the deep tissue penetration of irradiated light and excellent tumor-targeting ability. Thus, this nanoplatform holds potential for applications in T 1 -weighted MRI diagnosis and PDT of glioma for antitumor therapy. A near-infrared (NIR) light-activated nanoplatform for photodynamic therapy (PDT) was designed and synthesized. The Red-to-Green (R/G) ratio of NaScF 4 : 40% Yb, 2% Er almost reached 9, a value that was much higher than that of a traditional Yb/Er-codoped upconversion nanoparticle (rUCNP). By depositing a CaF 2 shell, the red-emission intensities of the rUCNPs were seven times strong as that of NaScF 4 : 40% Yb, 2% Er. The enhanced red-emitting rUCNPs could be applied in many fields such as bioimaging, controlled release, and real-time diagnosis. The nanoplatform had a

  4. Topological T-duality, automorphisms and classifying spaces

    NASA Astrophysics Data System (ADS)

    Pande, Ashwin S.

    2014-08-01

    We extend the formalism of Topological T-duality to spaces which are the total space of a principal S1-bundle p:E→W with an H-flux in H3(E,Z) together with an automorphism of the continuous-trace algebra on E determined by H. The automorphism is a ‘topological approximation’ to a gerby gauge transformation of spacetime. We motivate this physically from Buscher’s Rules for T-duality. Using the Equivariant Brauer Group, we connect this problem to the C∗-algebraic formalism of Topological T-duality of Mathai and Rosenberg (2005). We show that the study of this problem leads to the study of a purely topological problem, namely, Topological T-duality of triples (p,b,H) consisting of isomorphism classes of a principal circle bundle p:X→B and classes b∈H2(X,Z) and H∈H3(X,Z). We construct a classifying space R for triples in a manner similar to the work of Bunke and Schick (2005). We characterize R up to homotopy and study some of its properties. We show that it possesses a natural self-map which induces T-duality for triples. We study some properties of this map.

  5. Influence of sibutramine in addition to diet and exercise on the relationship between weight loss and blood glucose changes.

    PubMed

    Kamil, Sadaf; Finer, Nicholas; James, William Philip T; Caterson, Ian D; Andersson, Charlotte; Torp-Pedersen, Christian

    2017-07-01

    Weight loss is expected to improve glycaemic control in patients with diabetes or at high risk hereof. Sibutramine causes weight loss and is associated with an increased risk of myocardial infarction and stroke in high-risk patients. We examined the impact of sibutramine-induced weight loss on glycaemic control. In total, 8192 obese patients with diabetes were randomized to sibutramine or placebo plus diet and exercise after a preliminary 6 weeks in which all patients received sibutramine. Patients were classified into four groups of weight change. A total of 1582 patients had a weight loss >5.7 kg; 2047 patients lost 3.7-5.7 kg; 2432 patients lost <3.7 kg, and 1875 patients gained weight. Patients on sibutramine lost slightly more weight than those on placebo (-0.2 kg on average, P < 0.0001). Mean blood glucose changes in the placebo group were -0.6 mmol/L (±3.1, P = 0.0002), -0.2  mmol/L (±2.7, P = 0.04), and -0.1  mmol/L (±3.0, P = 0.01) in the moderate, modest, and mild weight loss groups, respectively; in the weight gain group blood glucose levels increased by +0.2 mmol/L (±3.1, P = 0.003). Corresponding mean blood glucose changes in the sibutramine-treated patients were -0.4 mmol/L (±3.2, P = 0.0002), +0.1 mmol/L (±3.0, P = 0.04), +0.4 mmol/L (±2.8, P = 0.01), and +0.2 mmol/L (±3.4, P = 0.003). Mean values of HbA1c followed the same pattern though the HbA1c changes were smaller with weight loss and greater with weight gain in the sibutramine group. All results were statistically significant (P < 0.0001). Weight loss induced by sibutramine, diet, and exercise attenuates falls in blood glucose levels and HbA1c compared with similar weight loss with placebo, diet, and exercise. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For Permissions, please email: journals.permissions@oup.com.

  6. Automated segmentation of multifocal basal ganglia T2*-weighted MRI hypointensities

    PubMed Central

    Glatz, Andreas; Bastin, Mark E.; Kiker, Alexander J.; Deary, Ian J.; Wardlaw, Joanna M.; Valdés Hernández, Maria C.

    2015-01-01

    Multifocal basal ganglia T2*-weighted (T2*w) hypointensities, which are believed to arise mainly from vascular mineralization, were recently proposed as a novel MRI biomarker for small vessel disease and ageing. These T2*w hypointensities are typically segmented semi-automatically, which is time consuming, associated with a high intra-rater variability and low inter-rater agreement. To address these limitations, we developed a fully automated, unsupervised segmentation method for basal ganglia T2*w hypointensities. This method requires conventional, co-registered T2*w and T1-weighted (T1w) volumes, as well as region-of-interest (ROI) masks for the basal ganglia and adjacent internal capsule generated automatically from T1w MRI. The basal ganglia T2*w hypointensities were then segmented with thresholds derived with an adaptive outlier detection method from respective bivariate T2*w/T1w intensity distributions in each ROI. Artefacts were reduced by filtering connected components in the initial masks based on their standardised T2*w intensity variance. The segmentation method was validated using a custom-built phantom containing mineral deposit models, i.e. gel beads doped with 3 different contrast agents in 7 different concentrations, as well as with MRI data from 98 community-dwelling older subjects in their seventies with a wide range of basal ganglia T2*w hypointensities. The method produced basal ganglia T2*w hypointensity masks that were in substantial volumetric and spatial agreement with those generated by an experienced rater (Jaccard index = 0.62 ± 0.40). These promising results suggest that this method may have use in automatic segmentation of basal ganglia T2*w hypointensities in studies of small vessel disease and ageing. PMID:25451469

  7. Evaluation of hydrocephalus patients with 3D-SPACE technique using variant FA mode at 3T.

    PubMed

    Algin, Oktay

    2018-06-01

    The major advantages of three-dimensional sampling perfection with application optimized contrasts using different flip-angle evolution (3D-SPACE) technique are its high resistance to artifacts that occurs as a result of radiofrequency or static field, the ability of providing images with sub-millimeter voxel size which allows obtaining reformatted images in any plane due to isotropic three-dimensional data with lower specific absorption rate values. That is crucial during examination of cerebrospinal-fluid containing complex structures, and the acquisition time, which is approximately 5 min for scanning of entire cranium. Recent data revealed that T2-weighted (T2W) 3D-SPACE with variant flip-angle mode (VFAM) imaging allows fast and accurate evaluation of the hydrocephalus patients during both pre- and post-operative period for monitoring the treatment. For a better assessment of these patients; radiologists and neurosurgeons should be aware of the details and implications regarding to the 3D-SPACE technique, and they should follow the updates in this field. There could be a misconception about the difference between T2W-VFAM and routine heavily T2W 3D-SPACE images. T2W 3D-SPACE with VFAM imaging is only a subtype of 3D-SPACE technique. In this review, we described the details of T2W 3D-SPACE with VFAM imaging and comprehensively reviewed its recent applications.

  8. Dark forces in the sky: signals from Z{sup ′} and the dark Higgs

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bell, Nicole F.; Cai, Yi; Leane, Rebecca K.

    2016-08-01

    We consider the indirect detection signals for a self-consistent hidden U(1) model containing a Majorana dark matter candidate, χ, a dark gauge boson, Z{sup ′}, and a dark Higgs, s. Compared with a model containing only a dark matter candidate and Z{sup ′} mediator, the addition of the scalar provides a mass generation mechanism for the dark sector particles and is required in order to avoid unitarity violation at high energies. We find that the inclusion of the two mediators opens up a new two-body s-wave annihilation channel, χχ→sZ{sup ′}. This new process, which is missed in the usual single-mediatormore » simplified model approach, can be the dominant annihilation channel. This provides rich phenomenology for indirect detection searches, allows indirect searches to explore regions of parameter space not accessible with other commonly considered s-wave annihilation processes, and enables both the Z{sup ′} and scalar couplings to be probed. We examine the phenomenology of the sector with a focus on this new process, and determine the limits on the model parameter space from Fermi data on dwarf spheriodal galaxies and other relevant experiments.« less

  9. HUBBLE FINDS NEW DARK SPOT ON NEPTUNE

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NASA's Hubble Space Telescope has discovered a new great dark spot, located in the northern hemisphere of the planet Neptune. Because the planet's northern hemisphere is now tilted away from Earth, the new feature appears near the limb of the planet. The spot is a near mirror-image to a similar southern hemisphere dark spot that was discovered in 1989 by the Voyager 2 probe. In 1994, Hubble showed that the southern dark spot had disappeared. Like its predecessor, the new spot has high altitude clouds along its edge, caused by gasses that have been pushed to higher altitudes where they cool to form methane ice crystal clouds. The dark spot may be a zone of clear gas that is a window to a cloud deck lower in the atmosphere. Planetary scientists don t know how long lived this new feature might be. Hubble's high resolution will allow astronomers to follow the spot's evolution and other unexpected changes in Neptune's dynamic atmosphere. The image was taken on November 2, 1994 with Hubble's Wide Field Planetary Camera 2, when Neptune was 2.8 billion miles (4.5 billion kilometers) from Earth. Hubble can resolve features as small as 625 miles (1,000 kilometers) across in Neptune's cloud tops. Credit: H. Hammel (Massachusetts Institute of Technology) and NASA

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

    PubMed

    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.

  11. Holographic dark energy in braneworld models with moving branes and the w = -1 crossing

    NASA Astrophysics Data System (ADS)

    Saridakis, E. N.

    2008-04-01

    We apply the bulk holographic dark energy in general 5D two-brane models. We extract the Friedmann equation on the physical brane and we show that in the general moving-brane case the effective 4D holographic dark energy behaves as a quintom for a large parameter-space area of a simple solution subclass. We find that wΛ was larger than -1 in the past while its present value is wΛ0≈-1.05, and the phantom bound wΛ = -1 was crossed at zp≈0.41, a result in agreement with observations. Such a behavior arises naturally, without the inclusion of special fields or potential terms, but a fine-tuning between the 4D Planck mass and the brane tension has to be imposed.

  12. 1. Dyea Dock looking south. Note faint evenly spaced circular ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Dyea Dock looking south. Note faint evenly spaced circular dark pieces of grass up through the middle of the picture indicating posts making up the pier. Photograph made from park service cherry picker. - Dyea Dock & Association (Ruins), Skagway, Skagway, AK

  13. Dark Energy and Dark Matter from Emergent Gravity Picture

    NASA Astrophysics Data System (ADS)

    Seok Yang, Hyun

    2018-01-01

    We suggest that dark energy and dark matter may be a cosmic uroboros of quantum gravity due to the coherent vacuum structure of spacetime. We apply the emergent gravity to a large N matrix model by considering the vacuum in the noncommutative (NC) Coulomb branch satisfying the Heisenberg algebra. We observe that UV fluctuations in the NC Coulomb branch are always paired with IR fluctuations and these UV/IR fluctuations can be extended to macroscopic scales. We show that space-like fluctuations give rise to the repulsive gravitational force while time-like fluctuations generate the attractive gravitational force. When considering the fact that the fluctuations are random in nature and we are living in the (3+1)-dimensional spacetime, the ratio of the repulsive and attractive components will end in ¾ : ¼= 75 : 25 and this ratio curiously coincides with the dark composition of our current Universe. If one includes ordinary matters which act as the attractive gravitational force, the emergent gravity may explain the dark sector of our Universe more precisely.

  14. Time-resolved 3D pulmonary perfusion MRI: comparison of different k-space acquisition strategies at 1.5 and 3 T.

    PubMed

    Attenberger, Ulrike I; Ingrisch, Michael; Dietrich, Olaf; Herrmann, Karin; Nikolaou, Konstantin; Reiser, Maximilian F; Schönberg, Stefan O; Fink, Christian

    2009-09-01

    Time-resolved pulmonary perfusion MRI requires both high temporal and spatial resolution, which can be achieved by using several nonconventional k-space acquisition techniques. The aim of this study is to compare the image quality of time-resolved 3D pulmonary perfusion MRI with different k-space acquisition techniques in healthy volunteers at 1.5 and 3 T. Ten healthy volunteers underwent contrast-enhanced time-resolved 3D pulmonary MRI on 1.5 and 3 T using the following k-space acquisition techniques: (a) generalized autocalibrating partial parallel acquisition (GRAPPA) with an internal acquisition of reference lines (IRS), (b) GRAPPA with a single "external" acquisition of reference lines (ERS) before the measurement, and (c) a combination of GRAPPA with an internal acquisition of reference lines and view sharing (VS). The spatial resolution was kept constant at both field strengths to exclusively evaluate the influences of the temporal resolution achieved with the different k-space sampling techniques on image quality. The temporal resolutions were 2.11 seconds IRS, 1.31 seconds ERS, and 1.07 VS at 1.5 T and 2.04 seconds IRS, 1.30 seconds ERS, and 1.19 seconds VS at 3 T.Image quality was rated by 2 independent radiologists with regard to signal intensity, perfusion homogeneity, artifacts (eg, wrap around, noise), and visualization of pulmonary vessels using a 3 point scale (1 = nondiagnostic, 2 = moderate, 3 = good). Furthermore, the signal-to-noise ratio in the lungs was assessed. At 1.5 T the lowest image quality (sum score: 154) was observed for the ERS technique and the highest quality for the VS technique (sum score: 201). In contrast, at 3 T images acquired with VS were hampered by strong artifacts and image quality was rated significantly inferior (sum score: 137) compared with IRS (sum score: 180) and ERS (sum score: 174). Comparing 1.5 and 3 T, in particular the overall rating of the IRS technique (sum score: 180) was very similar at both field

  15. WIMP dark matter and unitarity-conserving inflation via a gauge singlet scalar

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kahlhoefer, Felix; McDonald, John, E-mail: felix.kahlhoefer@desy.de, E-mail: j.mcdonald@lancaster.ac.uk

    2015-11-01

    A gauge singlet scalar with non-minimal coupling to gravity can drive inflation and later freeze out to become cold dark matter. We explore this idea by revisiting inflation in the singlet direction (S-inflation) and Higgs Portal Dark Matter in light of the Higgs discovery, limits from LUX and observations by Planck. We show that large regions of parameter space remain viable, so that successful inflation is possible and the dark matter relic abundance can be reproduced. Moreover, the scalar singlet can stabilise the electroweak vacuum and at the same time overcome the problem of unitarity-violation during inflation encountered by Higgsmore » Inflation, provided the singlet is a real scalar. The 2-σ Planck upper bound on n{sub s} imposes that the singlet mass is below 2 TeV, so that almost the entire allowed parameter range can be probed by XENON1T.« less

  16. Blood pressure changes during pregnancy: impact of race, body mass index, and weight gain.

    PubMed

    Magriples, Urania; Boynton, Marcella H; Kershaw, Trace S; Duffany, Kathleen O; Rising, Sharon Schindler; Ickovics, Jeannette R

    2013-05-01

    To investigate the effect of race, body mass index (BMI), and weight gain on blood pressure in pregnancy and postpartum. Secondary analysis of pregnant women aged 14 to 25 who received prenatal care at a university-affiliated public clinic in New Haven, Connecticut and delivered singleton term infants (n = 418). Longitudinal multivariate analysis was used to evaluate blood pressure trajectories from pregnancy through 12 weeks postpartum. Obese and overweight women had significantly higher blood pressure readings as compared with women with normal BMI (all p < 0.05). African American women who had high pregnancy weight gain had the greatest increase in mean arterial and diastolic blood pressures in pregnancy and postpartum. Blood pressure trajectories in pregnancy and postpartum are significantly affected by race, BMI, and weight gain. Given the young age of this cohort, targeted efforts must be made for postpartum weight reduction to reduce cardiovascular risk. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  17. Right-handed neutrino dark matter in a U(1) extension of the Standard Model

    NASA Astrophysics Data System (ADS)

    Cox, Peter; Han, Chengcheng; Yanagida, Tsutomu T.

    2018-01-01

    We consider minimal U(1) extensions of the Standard Model in which one of the right-handed neutrinos is charged under the new gauge symmetry and plays the role of dark matter. In particular, we perform a detailed phenomenological study for the case of a U(1)(B‑L)3 flavoured B‑L symmetry. If perturbativity is required up to high-scales, we find an upper bound on the dark matter mass of mχlesssim2 TeV, significantly stronger than that obtained in simplified models. Furthermore, if the U(1)(B‑L)3 breaking scalar has significant mixing with the SM Higgs, there are already strong constraints from direct detection. On the other hand, there remains significant viable parameter space in the case of small mixing, which may be probed in the future via LHC Z' searches and indirect detection. We also comment on more general anomaly-free symmetries consistent with a TeV-scale RH neutrino dark matter candidate, and show that if two heavy RH neutrinos for leptogenesis are also required, one is naturally led to a single-parameter class of U(1) symmetries.

  18. Persistence of Space Radiation Induced Cytogenetic Damage in the Blood Lymphocytes of Astronauts

    NASA Technical Reports Server (NTRS)

    George, Kerry; Cucinotta, Francis A.

    2008-01-01

    Cytogenetic damage in astronaut's peripheral blood lymphocytes is a useful in vivo marker of space radiation induced damage. Moreover, if radiation induced chromosome translocations persist in peripheral blood lymphocytes for many years, as has been assumed, they could potentially be used to measure retrospective doses or prolonged low dose rate exposures. However, as more data becomes available, evidence suggests that the yield of translocations may decline with time after exposure, at least in the case of space radiation exposures. We present our latest follow-up measurements of chromosome aberrations in astronauts blood lymphocytes assessed by FISH painting and collected a various times beginning directly after return from space to several years after flight. For most individuals the analysis of individual time-courses for translocations revealed a temporal decline of yields with different half-lives. Since the level of stable aberrations depends on the interplay between natural loss of circulating T-lymphocytes and replenishment from the stem or progenitor cells, the differences in the rates of decay could be explained by inter-individual variation in lymphocyte turn over. Biodosimetry estimates derived from cytogenetic analysis of samples collected a few days after return to earth lie within the range expected from physical dosimetry. However, a temporal decline in yields may indicate complications with the use of stable aberrations for retrospective dose reconstruction, and the differences in the decay time may reflect individual variability in risk from space radiation exposure. In addition, limited data on multiple flights show a lack of correlation between time in space and translocation yields. Data from one crewmember who has participated in two separate long-duration space missions and has been followed up for over 10 years provides limited information on the effect of repeat flights and show a possible adaptive response to space radiation exposure.

  19. On conditions for invertibility of difference and differential operators in weight spaces

    NASA Astrophysics Data System (ADS)

    Bichegkuev, Mairbek S.

    2011-08-01

    We obtain necessary and sufficient conditions for the invertibility of the difference operator D_E\\colon D(D_E)\\subset l^p_\\alpha \\to l^p_\\alpha, (D_E x)(n)=x(n+1)-Bx(n), n\\in {Z}_+, whose domain D(D_E) is given by the condition x(0)\\in E, where l^p_\\alpha=l^p_\\alpha({Z}_+,X), p\\in \\lbrack 1,\\infty \\rbrack , is the Banach space of sequences (of vectors in a Banach space X) summable with weight \\alpha\\colon{Z}_+\\to (0,\\infty) for p\\in \\lbrack 1,\\infty) and bounded with respect to \\alpha for p=\\infty, B\\colon X\\to X is a bounded linear operator, and E is a closed B-invariant subspace of X. We give applications to the invertibility of differential operators with an unbounded operator coefficient (the generator of a strongly continuous operator semigroup) in weight spaces of functions.

  20. Molecular Dynamic Simulation of Space and Earth-Grown Crystal Structures of Thermostable T1 Lipase Geobacillus zalihae Revealed a Better Structure.

    PubMed

    Ishak, Siti Nor Hasmah; Aris, Sayangku Nor Ariati Mohamad; Halim, Khairul Bariyyah Abd; Ali, Mohd Shukuri Mohamad; Leow, Thean Chor; Kamarudin, Nor Hafizah Ahmad; Masomian, Malihe; Rahman, Raja Noor Zaliha Raja Abd

    2017-09-25

    Less sedimentation and convection in a microgravity environment has become a well-suited condition for growing high quality protein crystals. Thermostable T1 lipase derived from bacterium Geobacillus zalihae has been crystallized using the counter diffusion method under space and earth conditions. Preliminary study using YASARA molecular modeling structure program for both structures showed differences in number of hydrogen bond, ionic interaction, and conformation. The space-grown crystal structure contains more hydrogen bonds as compared with the earth-grown crystal structure. A molecular dynamics simulation study was used to provide insight on the fluctuations and conformational changes of both T1 lipase structures. The analysis of root mean square deviation (RMSD), radius of gyration, and root mean square fluctuation (RMSF) showed that space-grown structure is more stable than the earth-grown structure. Space-structure also showed more hydrogen bonds and ion interactions compared to the earth-grown structure. Further analysis also revealed that the space-grown structure has long-lived interactions, hence it is considered as the more stable structure. This study provides the conformational dynamics of T1 lipase crystal structure grown in space and earth condition.

  1. Detection of Felis catus gammaherpesvirus 1 (FcaGHV1) in peripheral blood B- and T-lymphocytes in asymptomatic, naturally-infected domestic cats

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    McLuckie, Alicia J.; Barrs, Vanessa R.

    The domestic cat is natural host to both feline immunodeficiency virus and Felis catus gammaherpesvirus 1 (FcaGHV1). Comparative data suggest that these agents might act as synergistic copathogens in feline AIDS-related lymphoma. To identify leucocyte subsets harbouring gammaherpesvirus DNA, whole blood from 5 healthy, FcaGHV1-infected cats was labelled with monoclonal antibodies to feline CD21, CD4, CD8 and CD14 for 4-way fluorescence-activated cell sorting. FcaGHV1gB qPCR was performed on DNA extracted from purified fractions and whole blood longitudinally. FcaGHV1 DNA was detected in CD21+, CD4+, CD8+, but not CD14+ cells. Variation in whole blood load, up to 19,788 copies/10{sup 6}cells, wasmore » detected in individual cats over time. FcaGHV1 DNA was undetectable in one cat on one occasion highlighting that qPCR of whole blood from a single time point will not detect all cases of FcaGHV1 infection. Further investigation of the role of FcaGHV1 in feline lymphoid malignancies is warranted. -- Highlights: •FcaGHV1 DNA detected in circulating B and T lymphocytes in domestic cats. •Peripheral FcaGHV1 load fluctuates widely in healthy, chronically-infected cats. •qPCR of blood taken at a single time-point will fail to detect some FcaGHV-infected cats. •A role for FcaGHV1 in FIV-associated lymphoid malignancies is supported.« less

  2. High-resolution myocardial stress perfusion at 3 T in patients with suspected coronary artery disease.

    PubMed

    Meyer, Carsten; Strach, Katharina; Thomas, Daniel; Litt, Harold; Nähle, Claas P; Tiemann, Klaus; Schwenger, Ulrich; Schild, Hans H; Sommer, Torsten

    2008-02-01

    To implement a high-resolution first-pass myocardial perfusion imaging protocol (HRPI) at 3 T, and to evaluate the feasibility, image quality and accuracy of this approach prospectively in patients with suspected CAD. We hypothesized that utilizing the gain in SNR at 3 T to increase spatial resolution would reduce partial volume effects and subendocardial dark rim artifacts in comparison to 1.5 T. HRPI studies were performed on 60 patients using a segmented k-space gradient echo sequence (in plane resolution 1.97 x 1.94 mm(2)). Semiquantitative assessment of dark rim artifacts was performed for the stress studies on a slice-by-slice basis. Qualitative visual analysis was compared to quantitative coronary angiography (QCA) results; hemodynamically significant CAD was defined as stenosis >or=70% at QCA. Dark rim artifacts appeared in 108 of 180 slices (average extent 1.3 +/- 1.2 mm representing 11.8 +/- 10.8% of the transmural myocardial thickness). Sensitivity, specifity, and test accuracy for the detection of significant CAD were 89%,79%, and 85%. HRPI studies at 3 T are feasible in a clinical setting, providing good image quality and high accuracy for detection of significant CAD. The presence of dark rim artifacts does not appear to represent a diagnostic problem when using a HRPI approach.

  3. Sub-MeV bosonic dark matter, misalignment mechanism, and galactic dark matter halo luminosities

    NASA Astrophysics Data System (ADS)

    Yang, Qiaoli; Di, Haoran

    2017-04-01

    We explore a scenario that dark matter is a boson condensate created by the misalignment mechanism, in which a spin 0 boson (an axionlike particle) and a spin 1 boson (the dark photon) are considered, respectively. We find that although the sub-MeV dark matter boson is extremely stable, the huge number of dark matter particles in a galaxy halo makes the decaying signal detectable. A galaxy halo is a large structure bounded by gravity with a typical ˜1 012 solar mass, and the majority of its components are made of dark matter. For the axionlike particle case, it decays via ϕ →γ γ , therefore the photon spectrum is monochromatic. For the dark photon case, it is a three body decay A'→γ γ γ . However, we find that the photon spectrum is heavily peaked at M /2 and thus can facilitate observation. We also suggest a physical explanation for the three body decay spectrum by comparing the physics in the decay of orthopositronium. In addition, for both cases, the decaying photon flux can be measured for some regions of parameter space using current technologies.

  4. Annihilation cross section of Kaluza Klien dark matter

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sharma, Rakesh, E-mail: rakesh-sharma-ujn@yahoo.co.in; Upadhyaya, G. K., E-mail: gopalujjain@yahoo.co.in; Sharma, S.

    2015-07-31

    The question as to how this universe came into being and as to how it has evolved to its present stage, is an old question. The answer to this question unfolds many secrets regarding fundamental particles and forces between them. Theodor Kaluza proposed the concept that the universe is composed of more than four space-time dimensions. In his work, electromagnetism is united with gravity. Various extra dimension formulations have been proposed to solve a variety of problems. Recently, the idea of more than four space time dimensions is applied to the search for particle identity of dark matter (DM). Signaturemore » of dark matter can be revealed by analysis of very high energy electrons which are coming from outer space. We investigate recent advancement in the field of dark matter search with reference to very high energy electrons from outer space [1-8].« less

  5. DarkSide-20k: A 20 Tonne Two-Phase LAr TPC for Direct Dark Matter Detection at LNGS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Aalseth, C.E.; et al.

    Building on the successful experience in operating the DarkSide-50 detector, the DarkSide Collaboration is going to construct DarkSide-20k, a direct WIMP search detector using a two-phase Liquid Argon Time Projection Chamber (LArTPC) with an active (fiducial) mass of 23 t (20 t). The DarkSide-20k LArTPC will be deployed within a shield/veto with a spherical Liquid Scintillator Veto (LSV) inside a cylindrical Water Cherenkov Veto (WCV). Operation of DarkSide-50 demonstrated a major reduction in the dominantmore » $$^{39}$$Ar background when using argon extracted from an underground source, before applying pulse shape analysis. Data from DarkSide-50, in combination with MC simulation and analytical modeling, shows that a rejection factor for discrimination between electron and nuclear recoils of $$\\gt3\\times10^9$$ is achievable. This, along with the use of the veto system, is the key to unlocking the path to large LArTPC detector masses, while maintaining an "instrumental background-free" experiment, an experiment in which less than 0.1 events (other than $$\

  6. Dark stars: a review

    NASA Astrophysics Data System (ADS)

    Freese, Katherine; Rindler-Daller, Tanja; Spolyar, Douglas; Valluri, Monica

    2016-06-01

    Dark stars are stellar objects made (almost entirely) of hydrogen and helium, but powered by the heat from dark matter annihilation, rather than by fusion. They are in hydrostatic and thermal equilibrium, but with an unusual power source. Weakly interacting massive particles (WIMPs), among the best candidates for dark matter, can be their own antimatter and can annihilate inside the star, thereby providing a heat source. Although dark matter constitutes only ≲ 0.1% of the stellar mass, this amount is sufficient to power the star for millions to billions of years. Thus, the first phase of stellar evolution in the history of the Universe may have been dark stars. We review how dark stars come into existence, how they grow as long as dark matter fuel persists, and their stellar structure and evolution. The studies were done in two different ways, first assuming polytropic interiors and more recently using the MESA stellar evolution code; the basic results are the same. Dark stars are giant, puffy (˜10 AU) and cool (surface temperatures  ˜10 000 K) objects. We follow the evolution of dark stars from their inception at  ˜1{{M}⊙} as they accrete mass from their surroundings to become supermassive stars, some even reaching masses  >{{10}6}{{M}⊙} and luminosities  >{{10}10}{{L}⊙} , making them detectable with the upcoming James Webb Space Telescope. Once the dark matter runs out and the dark star dies, it may collapse to a black hole; thus dark stars may provide seeds for the supermassive black holes observed throughout the Universe and at early times. Other sites for dark star formation may exist in the Universe today in regions of high dark matter density such as the centers of galaxies. The current review briefly discusses dark stars existing today, but focuses on the early generation of dark stars.

  7. Diagnosis of complications associated with acute cholecystitis using computed tomography and diffusion-weighted imaging with background body signal suppression/T2 image fusion.

    PubMed

    Tomizawa, Minoru; Shinozaki, Fuminobu; Tanaka, Satomi; Sunaoshi, Takafumi; Kano, Daisuke; Sugiyama, Eriko; Shite, Misaki; Haga, Ryouta; Fukamizu, Yoshiya; Fujita, Toshiyuki; Kagayama, Satoshi; Hasegawa, Rumiko; Shirai, Yoshinori; Motoyoshi, Yasufumi; Sugiyama, Takao; Yamamoto, Shigenori; Ishige, Naoki

    2017-07-01

    In a clinical setting, it is important to diagnose complications of acute cholecystitis accurately. Diffusion-weighted whole body imaging with background body signal suppression/T2-weighted image fusion (DWIBS/T2) provides high signal intensity with a strong contrast against surrounding tissues in anatomical settings. In the present study, patients who were being treated for acute cholecystitis and underwent DWIBS/T2 in the National Hospital Organization Shimoshizu Hospital between December 2012 and August 2015 were enrolled. A total of 10 men and 4 women underwent DWIBS/T2. Records, including DWIBS/T2 and computed tomography (CT) imaging, were retrospectively analyzed for patients with acute cholecystitis. CT images revealed thickened gallbladder walls in patients with acute cholecystitis, and high signal intensity was observed in DWIBS/T2 images for the thickened gallbladder wall. Inflammation of the pericholecystic space and the liver resulted in high intensity signals with DWIBS/T2 imaging, whereas CT imaging revealed a low-density area in the cholecystic space. Plain CT scanning identified a low-density area in the liver, which became more obvious with contrast-enhanced CT. DWIBS/T2 imaging showed the inflammation of the liver and pericholesyctic space as an area of high signal intensity. Detectability of inflammation of the pericholecystic space and the liver was the same for DWIBS/T2 and CT, which suggests that DWIBS/T2 has the same sensitivity as CT scanning for the diagnosis of complicated acute cholecystitis. However, the strong contrast shown by DWIBS/T2 allows for easier evaluation of acute cholecystitis than CT scanning.

  8. Gravitational wave from dark sector with dark pion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tsumura, Koji; Yamada, Masatoshi; Yamaguchi, Yuya, E-mail: ko2@gauge.scphys.kyoto-u.ac.jp, E-mail: m.yamada@thphys.uni-heidelberg.de, E-mail: yy@particle.sci.hokudai.ac.jp

    In this work, we investigate the spectra of gravitational waves produced by chiral symmetry breaking in dark quantum chromodynamics (dQCD) sector. The dark pion (π) can be a dark matter candidate as weakly interacting massive particle (WIMP) or strongly interacting massive particle (SIMP). For a WIMP scenario, we introduce the dQCD sector coupled to the standard model (SM) sector with classical scale invariance and investigate the annihilation process of the dark pion via the 2π → 2 SM process. For a SIMP scenario, we investigate the 3π → 2π annihilation process of the dark pion as a SIMP using chiralmore » perturbation theory. We find that in the WIMP scenario the gravitational wave background spectra can be observed by future space gravitational wave antennas. On the other hand, when the dark pion is the SIMP dark matter with the constraints for the chiral perturbative limit and pion-pion scattering cross section, the chiral phase transition becomes crossover and then the gravitational waves are not produced.« less

  9. High-resolution heavily T2-weighted magnetic resonance imaging for evaluation of the pituitary stalk in children with ectopic neurohypophysis.

    PubMed

    El Sanharawi, Imane; Tzarouchi, Loukia; Cardoen, Liesbeth; Martinerie, Laetitia; Leger, Juliane; Carel, Jean-Claude; Elmaleh-Berges, Monique; Alison, Marianne

    2017-05-01

    In anterior pituitary deficiency, patients with non visible pituitary stalk have more often multiple deficiencies and persistent deficiency than patients with visible pituitary stalk. To compare the diagnostic value of a high-resolution heavily T2-weighted sequence to 1.5-mm-thick unenhanced and contrast-enhanced sagittal T1-weighted sequences to assess the presence of the pituitary stalk in children with ectopic posterior pituitary gland. We retrospectively evaluated the MRI data of 14 children diagnosed with ectopic posterior pituitary gland between 2010 and 2014. We evaluated the presence of a pituitary stalk using a sagittal high-resolution heavily T2-weighted sequence and a 1.5-mm sagittal T1-weighted turbo spin-echo sequence before and after contrast medium administration. A pituitary stalk was present on at least one of the sequences in 10 of the 14 children (71%). T2-weighted sequence depicted the pituitary stalk in all 10 children, whereas the 1.5-mm-thick T1-weighted sequence depicted 2/10 (20%) before contrast injection and 8/10 (80%) after contrast injection (P=0.007). Compared with 1.5-mm-thick contrast-enhanced T1-weighted sequences, high-resolution heavily T2-weighted sequence demonstrates better sensitivity in detecting the pituitary stalk in children with ectopic posterior pituitary gland, suggesting that contrast injection is unnecessary to assess the presence of a pituitary stalk in this setting.

  10. Associations of Infant Feeding and Timing of Weight Gain and Linear Growth during Early Life with Childhood Blood Pressure: Findings from a Prospective Population Based Cohort Study

    PubMed Central

    Vrijkotte, Tanja G. M.; van Eijsden, Manon; Gemke, Reinoud J. B. J.

    2016-01-01

    Objective Small birth size and rapid postnatal growth have been associated with higher future blood pressure. The timing of these effects, the relative importance of weight gain and linear growth and the role of infant feeding need to be clarified. Methods We assessed how blood pressure relates to birth weight, infant and childhood growth and infant feeding (duration of exclusive breastfeeding and timing of introduction of complementary feeding) in 2227 children aged 5 years from a prospective cohort study (Amsterdam Born Children and their Development). Postnatal growth was represented by statistically independent measures of relative weight gain (weight gain independent of height) and linear growth in four age periods during infancy (0–1 month; 1–3 months; 3–6 months; 6–12 months) and from 12 months to 5 years. Results Lower birth weight was associated with higher childhood diastolic blood pressure (-0.38 mm Hg.SD-1; P = 0.007). Faster relative weight gain and linear growth after 1 month were positively associated with systolic and diastolic blood pressure. Associations of linear growth with systolic blood pressure ranged from 0.47 to 1.49 mm Hg.SD-1; P<0.01 for all. Coefficients were similar for different periods of infancy and also for relative weight gain and linear growth. Compared to breastfeeding <1 month, breastfeeding >1 month was associated with lower blood pressure (e.g. >6 months -1.56 mm Hg systolic blood pressure; P<0.001). Compared to >6 months, introduction of complementary feeding <6 months was associated with higher blood pressure (e.g. 4–6 months 0.91 mm Hg systolic blood pressure; P = 0.004). Conclusions After the age of one month faster growth in either weight or height is associated with higher childhood blood pressure. It is unknown whether faster weight gain and linear growth carry the same risk for adult hypertension and cardiovascular morbidity. Longer breastfeeding and delayed introduction of complementary feeding may be

  11. Associations of Infant Feeding and Timing of Weight Gain and Linear Growth during Early Life with Childhood Blood Pressure: Findings from a Prospective Population Based Cohort Study.

    PubMed

    de Beer, Marieke; Vrijkotte, Tanja G M; Fall, Caroline H D; van Eijsden, Manon; Osmond, Clive; Gemke, Reinoud J B J

    2016-01-01

    Small birth size and rapid postnatal growth have been associated with higher future blood pressure. The timing of these effects, the relative importance of weight gain and linear growth and the role of infant feeding need to be clarified. We assessed how blood pressure relates to birth weight, infant and childhood growth and infant feeding (duration of exclusive breastfeeding and timing of introduction of complementary feeding) in 2227 children aged 5 years from a prospective cohort study (Amsterdam Born Children and their Development). Postnatal growth was represented by statistically independent measures of relative weight gain (weight gain independent of height) and linear growth in four age periods during infancy (0-1 month; 1-3 months; 3-6 months; 6-12 months) and from 12 months to 5 years. Lower birth weight was associated with higher childhood diastolic blood pressure (-0.38 mm Hg.SD-1; P = 0.007). Faster relative weight gain and linear growth after 1 month were positively associated with systolic and diastolic blood pressure. Associations of linear growth with systolic blood pressure ranged from 0.47 to 1.49 mm Hg.SD-1; P<0.01 for all. Coefficients were similar for different periods of infancy and also for relative weight gain and linear growth. Compared to breastfeeding <1 month, breastfeeding >1 month was associated with lower blood pressure (e.g. >6 months -1.56 mm Hg systolic blood pressure; P<0.001). Compared to >6 months, introduction of complementary feeding <6 months was associated with higher blood pressure (e.g. 4-6 months 0.91 mm Hg systolic blood pressure; P = 0.004). After the age of one month faster growth in either weight or height is associated with higher childhood blood pressure. It is unknown whether faster weight gain and linear growth carry the same risk for adult hypertension and cardiovascular morbidity. Longer breastfeeding and delayed introduction of complementary feeding may be associated with lower adult blood pressure.

  12. Investigation of cyano-bridged coordination nanoparticles Gd3+/[Fe(CN)6]3-/d-mannitol as T1-weighted MRI contrast agents

    NASA Astrophysics Data System (ADS)

    Perrier, M.; Gallud, A.; Ayadi, A.; Kennouche, S.; Porredon, C.; Gary-Bobo, M.; Larionova, J.; Goze-Bac, Ch.; Zanca, M.; Garcia, M.; Basile, I.; Long, J.; de Lapuente, J.; Borras, M.; Guari, Y.

    2015-07-01

    Cyano-bridged Gd3+/[Fe(CN)6]3- coordination polymer nanoparticles of 3-4 nm stabilized with d-mannitol presenting a high r1 relaxivity value of 11.4 mM-1 s-1 were investigated in vivo as contrast agents (CA) for Magnetic Resonance Imaging (MRI). They allow an increase of the MR image contrast and can act as an efficient intravascular T1 CA with a relatively long blood-circulation lifetime (60 min) without specific toxicity.Cyano-bridged Gd3+/[Fe(CN)6]3- coordination polymer nanoparticles of 3-4 nm stabilized with d-mannitol presenting a high r1 relaxivity value of 11.4 mM-1 s-1 were investigated in vivo as contrast agents (CA) for Magnetic Resonance Imaging (MRI). They allow an increase of the MR image contrast and can act as an efficient intravascular T1 CA with a relatively long blood-circulation lifetime (60 min) without specific toxicity. Electronic supplementary information (ESI) available: Experimental details and procedures, toxicological data, physical characterization. See DOI: 10.1039/c5nr01557j

  13. T-cell phenotypes in bronchoalveolar lavage fluid, blood and lymph nodes in pulmonary sarcoidosis--indication for an airborne antigen as the triggering factor in sarcoidosis.

    PubMed

    Darlington, P; Haugom-Olsen, H; von Sivers, K; Wahlström, J; Runold, M; Svjatoha, V; Porwit, A; Eklund, A; Grunewald, J

    2012-11-01

    An increased percentage of CD4+ T cells is usually observed in bronchoalveolar lavage fluid (BALF) from patients with sarcoidosis. In HLA-DRB1*03-positive patients, such T cells express the T-cell receptor (TCR) AV2S3+ gene segment. It is not known whether cells found in BALF reflect those in enlarged regional lymph nodes (LNs). Therefore, the aim of this study was to compare T-cell phenotypes in BALF, blood and mediastinal LNs. Fifteen patients underwent clinical investigation including bronchoscopy with bronchoalveolar lavage. Blood samples were drawn, and endoscopic ultrasound-guided fine-needle aspiration of enlarged mediastinal LNs was performed via the oesophagus. T cells from all three compartments were analysed by flow cytometry for markers of activity, differentiation and T regulatory function. The CD4/CD8 ratio was significantly higher in BALF compared with regional LNs and was also significantly higher in LNs than in blood. The CD4+ T cells were recently activated and more differentiated in BALF than in blood and LNs. There was an accumulation of T regulatory cells (FOXP3+) in LNs and a correlation between high levels of FOXP3+ cells in BALF and in LNs. In HLA-DRB1*03-positive patients, TCR AV2S3+ CD4+ T cells were predominantly localized within BALF. The CD4+ T-cell phenotype in BALF indicates an active ongoing specific immune response primarily localized to the alveolar space. © 2012 The Association for the Publication of the Journal of Internal Medicine.

  14. Hidden gauged U (1 ) model: Unifying scotogenic neutrino and flavor dark matter

    NASA Astrophysics Data System (ADS)

    Yu, Jiang-Hao

    2016-06-01

    In both scotogenic neutrino and flavor dark matter models, the dark sector communicates with the standard model fermions via Yukawa portal couplings. We propose an economic scenario where the scotogenic neutrino and a flavored mediator share the same inert Higgs doublet and all are charged under a hidden gauged U (1 ) symmetry. The dark Z2 symmetry in the dark sector is regarded as the remnant of this hidden U (1 ) symmetry breaking. In particular, we investigate a dark U (1 )D [and also U (1 )B-L] model which unifies the scotogenic neutrino and top-flavored mediator. Thus dark tops and dark neutrinos are the standard model fermion partners, and the dark matter could be the inert Higgs or the lightest dark neutrino. We note that this model has rich collider signatures on dark tops, the inert Higgs and the Z' gauge boson. Moreover, the scalar associated to the U (1 )D [and also U (1 )B -L ] symmetry breaking could explain the 750 GeV diphoton excess reported by ATLAS and CMS recently.

  15. Skew-flavored dark matter

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Agrawal, Prateek; Chacko, Zackaria; Fortes, Elaine C. F. S.

    We explore a novel flavor structure in the interactions of dark matter with the Standard Model. We consider theories in which both the dark matter candidate, and the particles that mediate its interactions with the Standard Model fields, carry flavor quantum numbers. The interactions are skewed in flavor space, so that a dark matter particle does not directly couple to the Standard Model matter fields of the same flavor, but only to the other two flavors. This framework respects minimal flavor violation and is, therefore, naturally consistent with flavor constraints. We study the phenomenology of a benchmark model in whichmore » dark matter couples to right-handed charged leptons. In large regions of parameter space, the dark matter can emerge as a thermal relic, while remaining consistent with the constraints from direct and indirect detection. The collider signatures of this scenario include events with multiple leptons and missing energy. In conclusion, these events exhibit a characteristic flavor pattern that may allow this class of models to be distinguished from other theories of dark matter.« less

  16. Skew-flavored dark matter

    DOE PAGES

    Agrawal, Prateek; Chacko, Zackaria; Fortes, Elaine C. F. S.; ...

    2016-05-10

    We explore a novel flavor structure in the interactions of dark matter with the Standard Model. We consider theories in which both the dark matter candidate, and the particles that mediate its interactions with the Standard Model fields, carry flavor quantum numbers. The interactions are skewed in flavor space, so that a dark matter particle does not directly couple to the Standard Model matter fields of the same flavor, but only to the other two flavors. This framework respects minimal flavor violation and is, therefore, naturally consistent with flavor constraints. We study the phenomenology of a benchmark model in whichmore » dark matter couples to right-handed charged leptons. In large regions of parameter space, the dark matter can emerge as a thermal relic, while remaining consistent with the constraints from direct and indirect detection. The collider signatures of this scenario include events with multiple leptons and missing energy. In conclusion, these events exhibit a characteristic flavor pattern that may allow this class of models to be distinguished from other theories of dark matter.« less

  17. Cord blood leptin and gains in body weight and fat mass during infancy.

    PubMed

    Chaoimh, Carol Ní; Murray, Deirdre M; Kenny, Louise C; Irvine, Alan D; Hourihane, Jonathan O'B; Kiely, Mairead

    2016-11-01

    Low early-life leptin concentrations may promote faster weight gain in infancy. We aimed to examine the associations between cord blood leptin concentrations and changes in weight and body composition during infancy. Serum leptin was measured at 15 weeks gestation, in umbilical cord blood collected at delivery and at 2 years in 334 children from the Cork Baseline Birth Cohort Study. Body composition was measured at 2 days and 2 months using air displacement plethysmography. Conditional change in weight standard deviation scores over a number of age intervals in the first 2 years and conditional change in fat mass index (FMI) and fat-free mass index (FFMI) (kg/(length)m(2)) between birth and 2 months were calculated and associations with cord blood leptin were examined using linear regression. At birth, cord blood leptin was positively correlated with FMI (r = 0.48, P < 0.001) and showed a weaker correlation with FFMI (r = 0.12, P = 0.05). After adjustment for confounders, higher cord blood leptin (per ng/mL) was associated with slower conditional weight gain between birth and 2 months (β (95% CI): -0.024 (-0.035, -0.013), P < 0.001) but not over subsequent age intervals. Cord blood leptin was also inversely associated with conditional change in FMI (-0.021 (-0.034, -0.007, P = 0.003) but not FFMI between birth and 2 months. These are the first data to show that associations between higher cord blood leptin and slower weight gain during infancy are driven by lower increases in adiposity, at least in early infancy. © 2016 European Society of Endocrinology.

  18. MR of Toxoplasma encephalitis: Signal characteristics on T2-weighted images and pathologic correlation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Brightbill, T.C.; Hensley, G.T.; Ruiz, A.

    1996-05-01

    Our goal was to determine if there are any T2-weighted MR signal characteristics of Toxoplasma encephalitis that might be useful in diagnosis and/or in gauging the effectiveness of medical therapy. We retrospectively analyzed the MR, CT, thallium-201 SPECT brain scans, and medical records of 27 patients with medically proven (26) and biopsy proven (1) Toxoplasma encephalitis, supplemented by autopsy findings in 4 additional patients, 2 of whom had postmortem MR correlation. The neuropathologic literature was also reviewed. Among the 27 patients, we discovered three distinct imaging patterns. Ten (37%) patients had predominantly T2-weighted hyperintense lesions and had been on medicalmore » therapy an average of 3 days (excluding one outlier). Ten (37%) patients had T2-weighted isointense lesions and had received medical therapy an average of 61 days. Seven (26%) patients had lesions with mixed signal on T2-weighted images and bad been on treatment an average of 6 days. Analysis of autopsy material from the four additional patients revealed the presence of organizing abscesses in three and necrotizing encephalitis in one, while the patient who had a brain biopsy demonstrated both types of pathologic lesions. In both cases having postmortem MRI, organizing abscesses appeared isointense to hypointense on T2-weighted images. There is a definite variation in the appearance of lesions of Toxoplasma encephalitis on T2-weighted images that precludes a definitive diagnosis based on signal characteristics alone. Pathologically, our data suggest that T2-weighted hyperintensity correlates with necrotizing encephalitis and T2-weighted isointensity with organizing abscesses. Furthermore, in patients on medical therapy the T2-weighted MR appearance may be a transition from hyperintensity to isointensity as a function of a positive response to antibiotic treatment, indicating that the signal change might be used to gauge the effectiveness of medical therapy. 15 refs., 6 figs.« less

  19. A review of technical aspects of T1-weighted dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in human brain tumors.

    PubMed

    Bergamino, M; Bonzano, L; Levrero, F; Mancardi, G L; Roccatagliata, L

    2014-09-01

    In the last few years, several imaging methods, such as magnetic resonance imaging (MRI) and computed tomography, have been used to investigate the degree of blood-brain barrier (BBB) permeability in patients with neurological diseases including multiple sclerosis, ischemic stroke, and brain tumors. One promising MRI method for assessing the BBB permeability of patients with neurological diseases in vivo is T1-weighted dynamic contrast-enhanced (DCE)-MRI. Here we review the technical issues involved in DCE-MRI in the study of human brain tumors. In the first part of this paper, theoretical models for the DCE-MRI analysis will be described, including the Toft-Kety models, the adiabatic approximation to the tissue homogeneity model and the two-compartment exchange model. These models can be used to estimate important kinetic parameters related to BBB permeability. In the second part of this paper, details of the data acquisition, issues related to the arterial input function, and procedures for DCE-MRI image analysis are illustrated. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  20. [Correlation analysis of the pre-pregnant body mass index, the gestational weight gain and umbilical cord blood C peptide].

    PubMed

    Chen, X L; Han, Y; Zhao, X M; Liu, Y; Lü, J J

    2017-01-03

    Objective: To explore the correlation among the pre-pregnant body mass index (BMI), gestational weight gain (GWG) and umbilical cord blood C peptide, and to investigate the influence of maternal weight management on the incidence of baby long-term metabolic syndrome. Methods: During May to Aug.2015, 485 pregnant women in Zhejiang Taizhou first people's hospital and Taizhou Huangyan maternal &child care service centre were selected in random and divided into four groups according to pre-pregnant BMI: low body mass, normal body mass, over body mass and obese group, and also divided into two groups for getting gestational diabetes mellitus (GDM) or not. According to the gestational weight gain (GWG), all the cases were divided into two groups: above the Institute Of Medicine (IMO) 2009 recommendations or not. According to the outcome, the GDM group which had received weight control treatment, was divided into successful treat group or not. At last, we tested the umbilical cord blood C peptide and birth weight of each newborn and compared the difference in all subgroups. The correlation between the umbilical cord blood C peptide and birth weight were analysed. Results: (1) In the pre-pregnant BMI groups, there were significant differences of incidence of GDM ( P <0.05). But, there were no significant differences of incidence of GWG in four groups ( P >0.05). (2) Newborn birth weight and the umbilical cord blood C peptide were positively correlated ( r =0.673, P <0.05). (3) Umbilical cord blood C peptide showed the correlation in all subgroups for different pre-pregnant BMI, GDM or not, overweight or not ( P <0.05), but only the GDM or not group had relation to newborn birth weight in all subgroups. (4) All groups showed correlations with neonatal umbilical cord blood C peptide, the GDM mostly (β=0.58), pre-pregnant BMI secondly (β: 0.36, 0.38) , and GWG weakly (β=0.17). (5) By stratification analysis, in GDM group, low body mass was negatively correlated with

  1. t-topology on the n-dimensional Minkowski space

    NASA Astrophysics Data System (ADS)

    Agrawal, Gunjan; Shrivastava, Sampada

    2009-05-01

    In this paper, a topological study of the n-dimensional Minkowski space, n >1, with t-topology, denoted by Mt, has been carried out. This topology, unlike the usual Euclidean one, is more physically appealing being defined by means of the Lorentzian metric. It shares many topological properties with similar candidate topologies and it has the advantage of being first countable. Compact sets of Mt and continuous maps into Mt are studied using the notion of Zeno sequences besides characterizing those sets that have the same subspace topologies induced from the Euclidean and t-topologies on n-dimensional Minkowski space. A necessary and sufficient condition for a compact set in the Euclidean n-space to be compact in Mt is obtained, thereby proving that the n-cube, n >1, as a subspace of Mt, is not compact, while a segment on a timelike line is compact in Mt. This study leads to the nonsimply connectedness of Mt, for n =2. Further, Minkowski space with s-topology has also been dealt with.

  2. Interleukin-1β (IL-1β) increases pain behavior and the blood glucose level: possible involvement of sympathetic nervous system.

    PubMed

    Sim, Yun-Beom; Park, Soo-Hyun; Kang, Yu-Jung; Jung, Jun-Sub; Ryu, Ohk-Hyun; Choi, Moon-Gi; Suh, Hong-Won

    2012-07-01

    The relationship between interleukin-1β (IL-1β)-induced nociception and the blood glucose level was studied in ICR mice. We found in the present study that intrathecal (i.t.) injection of IL-1β increased pain behavior. In addition, i.t. IL-1β injection caused an elevation of the blood glucose level. The time-course study showed that maximal blood glucose level was observed 30 and 60 min after i.t. IL-1β administration. Furthermore, i.t. injection of IL-1β enhanced the blood glucose level when mice were orally fed with d-glucose. The i.t. administration of IL-1β antagonist (AF12198) inhibited the hyperglycemia and pain behaviors induced by IL-1β. We found in the present study that adrenal tyrosine hydroxylase (TH) mRNA level was also increased by i.t. IL-1β injection. Furthermore, intraperitoneal (i.p.) pretreatment with phentolamine (an α(1)-adrenergic blocker) or yohimbine (an α(2)-adrenergic blocker) significantly attenuated the blood glucose level and pain behavior induced by IL-1β administered i.t. However, the blood glucose level and pain behavior were not affected by butoxamine (a β(2)-adrenergic blocker), whereas metoprolol (a β(2)-adrenergic blocker) enhanced IL-1β-induced blood glucose level and pain behavior in mice fed with d-glucose. However, its effect was not statistically significant. Our results suggest that IL-1β administered i.t. increases the blood glucose level via an activation of α adrenergic nervous system. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Gauge coupling unification and nonequilibrium thermal dark matter.

    PubMed

    Mambrini, Yann; Olive, Keith A; Quevillon, Jérémie; Zaldívar, Bryan

    2013-06-14

    We study a new mechanism for the production of dark matter in the Universe which does not rely on thermal equilibrium. Dark matter is populated from the thermal bath subsequent to inflationary reheating via a massive mediator whose mass is above the reheating scale T(RH). To this end, we consider models with an extra U(1) gauge symmetry broken at some intermediate scale (M(int) ≃ 10(10)-10(12) GeV). We show that not only does the model allow for gauge coupling unification (at a higher scale associated with grand unification) but it can provide a dark matter candidate which is a standard model singlet but charged under the extra U(1). The intermediate scale gauge boson(s) which are predicted in several E6/SO(10) constructions can be a natural mediator between dark matter and the thermal bath. We show that the dark matter abundance, while never having achieved thermal equilibrium, is fixed shortly after the reheating epoch by the relation T(RH)(3)/M(int)(4). As a consequence, we show that the unification of gauge couplings which determines M(int) also fixes the reheating temperature, which can be as high as T(RH) ≃ 10(11) GeV.

  4. NASA Find Clues that May Help Identify Dark Matter

    NASA Image and Video Library

    2015-03-26

    Using observations from NASA’s Hubble Space Telescope and Chandra X-ray Observatory, astronomers have found that dark matter does not slow down when colliding with itself, meaning it interacts with itself less than previously thought. Researchers say this finding narrows down the options for what this mysterious substance might be. Dark matter is an invisible matter that makes up most of the mass of the universe. Because dark matter does not reflect, absorb or emit light, it can only be traced indirectly by, such as by measuring how it warps space through gravitational lensing, during which the light from a distant source is magnified and distorted by the gravity of dark matter. Read more: 1.usa.gov/1E5LcpO Caption: Here are images of six different galaxy clusters taken with NASA's Hubble Space Telescope (blue) and Chandra X-ray Observatory (pink) in a study of how dark matter in clusters of galaxies behaves when the clusters collide. A total of 72 large cluster collisions were studied. Credit: NASA and ESA mage Credit: NASA and ESA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  5. Abdominal MRI at 3.0 T: LAVA-Flex compared with conventional fat suppression T1-weighted images.

    PubMed

    Li, Xing Hui; Zhu, Jiang; Zhang, Xiao Ming; Ji, Yi Fan; Chen, Tian Wu; Huang, Xiao Hua; Yang, Lin; Zeng, Nan Lin

    2014-07-01

    To study liver imaging with volume acceleration-flexible (LAVA-Flex) for abdominal magnetic resonance imaging (MRI) at 3.0 T and compare the image quality of abdominal organs between LAVA-Flex and fast spoiled gradient-recalled (FSPGR) T1-weighted imaging. Our Institutional Review Board approval was obtained in this retrospective study. Sixty-nine subjects had both FSPGR and LAVA-Flex sequences. Two radiologists independently scored the acquisitions for image quality, fat suppression quality, and artifacts and the values obtained were compared with the Wilcoxon signed rank test. According to the signal intensity (SI) measurements, the uniformity of fat suppression, the contrast between muscle and fat and normal liver and liver lesions were compared by the paired t-test. The liver and spleen SI on the fat-only phase were analyzed in the fatty liver patients. Compared with FSPGR imaging, LAVA-Flex images had better and more homogenous fat suppression and lower susceptibility artifact (qualitative scores: 4.70 vs. 4.00, 4.86% vs. 7.14%, 4.60 and 4.10, respectively). The contrast between muscle and fat and between the liver and pathologic lesions was significantly improved on the LAVA-Flex sequence. The contrast value of the fatty liver and spleen was higher than that of the liver and spleen. The LAVA-Flex sequence offers superior and more homogenous fat suppression of the abdomen than does the FSPGR sequence. The fat-only phase can be a simple and effective method of assessing fatty liver. © 2013 Wiley Periodicals, Inc.

  6. Breast MRI at 7 Tesla with a bilateral coil and T1-weighted acquisition with robust fat suppression: image evaluation and comparison with 3 Tesla.

    PubMed

    Brown, Ryan; Storey, Pippa; Geppert, Christian; McGorty, KellyAnne; Leite, Ana Paula Klautau; Babb, James; Sodickson, Daniel K; Wiggins, Graham C; Moy, Linda

    2013-11-01

    To evaluate the image quality of T1-weighted fat-suppressed breast MRI at 7 T and to compare 7-T and 3-T images. Seventeen subjects were imaged using a 7-T bilateral transmit-receive coil and 3D gradient echo sequence with adiabatic inversion-based fat suppression (FS). Images were graded on a five-point scale and quantitatively assessed through signal-to-noise ratio (SNR), fibroglandular/fat contrast and signal uniformity measurements. Image scores at 7 and 3 T were similar on standard-resolution images (1.1 × 1.1 × 1.1-1.6 mm(3)), indicating that high-quality breast imaging with clinical parameters can be performed at 7 T. The 7-T SNR advantage was underscored on 0.6-mm isotropic images, where image quality was significantly greater than at 3 T (4.2 versus 3.1, P ≤ 0.0001). Fibroglandular/fat contrast was more than two times higher at 7 T than at 3 T, owing to effective adiabatic inversion-based FS and the inherent 7-T signal advantage. Signal uniformity was comparable at 7 and 3 T (P < 0.05). Similar 7-T image quality was observed in all subjects, indicating robustness against anatomical variation. The 7-T bilateral transmit-receive coil and adiabatic inversion-based FS technique produce image quality that is as good as or better than at 3 T. • High image quality bilateral breast MRI is achievable with clinical parameters at 7 T. • 7-T high-resolution imaging improves delineation of subtle soft tissue structures. • Adiabatic-based fat suppression provides excellent fibroglandular/fat contrast at 7 T. • 7- and 3-T 3D T1-weighted gradient-echo images have similar signal uniformity. • The 7-T dual solenoid coil enables bilateral imaging without compromising uniformity.

  7. A general model to calculate the spin-lattice (T1) relaxation time of blood, accounting for haematocrit, oxygen saturation and magnetic field strength.

    PubMed

    Hales, Patrick W; Kirkham, Fenella J; Clark, Christopher A

    2016-02-01

    Many MRI techniques require prior knowledge of the T1-relaxation time of blood (T1bl). An assumed/fixed value is often used; however, T1bl is sensitive to magnetic field (B0), haematocrit (Hct), and oxygen saturation (Y). We aimed to combine data from previous in vitro measurements into a mathematical model, to estimate T1bl as a function of B0, Hct, and Y. The model was shown to predict T1bl from in vivo studies with a good accuracy (± 87 ms). This model allows for improved estimation of T1bl between 1.5-7.0 T while accounting for variations in Hct and Y, leading to improved accuracy of MRI-derived perfusion measurements. © The Author(s) 2015.

  8. Local T1-T2 distribution measurements in porous media

    NASA Astrophysics Data System (ADS)

    Vashaee, S.; Li, M.; Newling, B.; MacMillan, B.; Marica, F.; Kwak, H. T.; Gao, J.; Al-harbi, A. M.; Balcom, B. J.

    2018-02-01

    A novel slice-selective T1-T2 measurement is proposed to measure spatially resolved T1-T2 distributions. An adiabatic inversion pulse is employed for slice-selection. The slice-selective pulse is able to select a quasi-rectangular slice, on the order of 1 mm, at an arbitrary position within the sample. The method does not employ conventional selective excitation in which selective excitation is often accomplished by rotation of the longitudinal magnetization in the slice of interest into the transverse plane, but rather a subtraction based on CPMG data acquired with and without adiabatic inversion slice selection. T1 weighting is introduced during recovery from the inversion associated with slice selection. The local T1-T2 distributions measured are of similar quality to bulk T1-T2 measurements. The new method can be employed to characterize oil-water mixtures and other fluids in porous media. The method is beneficial when a coarse spatial distribution of the components is of interest.

  9. Therapeutic potential of umbilical cord blood cells for type 1 diabetes mellitus.

    PubMed

    He, Binbin; Li, Xia; Yu, Haibo; Zhou, Zhiguang

    2015-11-01

    Type 1 diabetes mellitus (T1DM) is a chronic disorder that results from autoimmune-mediated destruction of pancreatic islet β-cells. However, to date, no conventional intervention has successfully treated the disease. The optimal therapeutic method for T1DM should effectively control the autoimmunity, restore immune homeostasis, preserve residual β-cells, reverse β-cell destruction, and protect the regenerated insulin-producing cells against re-attack. Umbilical cord blood is rich in regulatory T (T(reg)) cells and multiple types of stem cells that exhibit immunomodulating potential and hold promise in their ability to restore peripheral tolerance towards pancreatic islet β-cells through remodeling of immune responses and suppression of autoreactive T cells. Recently, reinfusion of autologous umbilical cord blood or immune cells from cord blood has been proposed as a novel therapy for T1DM, with the advantages of no risk to the donors, minimal ethical concerns, a low incidence of graft-versus-host disease and easy accessibility. In this review, we revisit the role of autologous umbilical cord blood or immune cells from cord blood-based applications for the treatment of T1DM. © 2015 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

  10. Figures of merit for present and future dark energy probes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mortonson, Michael J.; Huterer, Dragan; Hu, Wayne

    2010-09-15

    We compare current and forecasted constraints on dynamical dark energy models from Type Ia supernovae and the cosmic microwave background using figures of merit based on the volume of the allowed dark energy parameter space. For a two-parameter dark energy equation of state that varies linearly with the scale factor, and assuming a flat universe, the area of the error ellipse can be reduced by a factor of {approx}10 relative to current constraints by future space-based supernova data and CMB measurements from the Planck satellite. If the dark energy equation of state is described by a more general basis ofmore » principal components, the expected improvement in volume-based figures of merit is much greater. While the forecasted precision for any single parameter is only a factor of 2-5 smaller than current uncertainties, the constraints on dark energy models bounded by -1{<=}w{<=}1 improve for approximately 6 independent dark energy parameters resulting in a reduction of the total allowed volume of principal component parameter space by a factor of {approx}100. Typical quintessence models can be adequately described by just 2-3 of these parameters even given the precision of future data, leading to a more modest but still significant improvement. In addition to advances in supernova and CMB data, percent-level measurement of absolute distance and/or the expansion rate is required to ensure that dark energy constraints remain robust to variations in spatial curvature.« less

  11. Weight minimization of structural components for launch in space shuttle

    NASA Technical Reports Server (NTRS)

    Patnaik, Surya N.; Gendy, Atef S.; Hopkins, Dale A.; Berke, Laszlo

    1994-01-01

    Minimizing the weight of structural components of the space station launched into orbit in a space shuttle can save cost, reduce the number of space shuttle missions, and facilitate on-orbit fabrication. Traditional manual design of such components, although feasible, cannot represent a minimum weight condition. At NASA Lewis Research Center, a design capability called CometBoards (Comparative Evaluation Test Bed of Optimization and Analysis Routines for the Design of Structures) has been developed especially for the design optimization of such flight components. Two components of the space station - a spacer structure and a support system - illustrate the capability of CometBoards. These components are designed for loads and behavior constraints that arise from a variety of flight accelerations and maneuvers. The optimization process using CometBoards reduced the weights of the components by one third from those obtained with traditional manual design. This paper presents a brief overview of the design code CometBoards and a description of the space station components, their design environments, behavior limitations, and attributes of their optimum designs.

  12. Evolution of the phase-space density and the Jeans scale for dark matter derived from the Vlasov-Einstein equation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Piattella, O.F.; Rodrigues, D.C.; Fabris, J.C.

    2013-11-01

    We discuss solutions of Vlasov-Einstein equation for collisionless dark matter particles in the context of a flat Friedmann universe. We show that, after decoupling from the primordial plasma, the dark matter phase-space density indicator Q = ρ/(σ{sub 1D}{sup 2}){sup 3/2} remains constant during the expansion of the universe, prior to structure formation. This well known result is valid for non-relativistic particles and is not ''observer dependent'' as in solutions derived from the Vlasov-Poisson system. In the linear regime, the inclusion of velocity dispersion effects permits to define a physical Jeans length for collisionless matter as function of the primordial phase-spacemore » density indicator: λ{sub J} = (5π/G){sup 1/2}Q{sup −1/3}ρ{sub dm}{sup −1/6}. The comoving Jeans wavenumber at matter-radiation equality is smaller by a factor of 2-3 than the comoving wavenumber due to free-streaming, contributing to the cut-off of the density fluctuation power spectrum at the lowest scales. We discuss the physical differences between these two scales. For dark matter particles of mass equal to 200 GeV, the derived Jeans mass is 4.3 × 10{sup −6}M{sub ⊙}.« less

  13. Time to Detection with BacT/Alert FA Plus Compared to BacT/Alert FA Blood Culture Media.

    PubMed

    Nutman, A; Fisher Even-Tsur, S; Shapiro, G; Braun, T; Schwartz, D; Carmeli, Y

    2016-09-01

    Rapid identification of the causative pathogen in patients with bacteremia allows adjustment of antibiotic therapy and improves patient outcomes. We compared in vitro and real-life time to detection (TTD) of two blood culture media, BacT/Alert FA (FA) and BacT/Alert FA Plus (FA Plus), for the nine most common species of bacterial pathogens recovered from blood samples. Experimental data from simulated cultures was compared with microbiology records of TTD for both culture media with growth of the species of interest in clinical blood cultures. In the experimental conditions, median TTD was 3.8 hours (23.9 %) shorter using FA Plus media. The magnitude of reduction differed between species. Similarly, in real life data, FA Plus had shorter TTD than FA media; however, the difference between culture media was smaller, and median TTD was only 1 hour (8.5 %) less. We found shorter TTD with BacT/Alert FA Plus culture media, both experimentally and in real-life conditions and unrelated to antibiotic neutralization, highlighting the importance of appropriate blood culture media selection.

  14. Time-varying q-deformed dark energy interacts with dark matter

    NASA Astrophysics Data System (ADS)

    Dil, Emre; Kolay, Erdinç

    We propose a new model for studying the dark constituents of the universe by regarding the dark energy as a q-deformed scalar field interacting with the dark matter, in the framework of standard general relativity. Here we assume that the number of particles in each mode of the q-deformed scalar field varies in time by the particle creation and annihilation. We first describe the q-deformed scalar field dark energy quantum-field theoretically, then construct the action and the dynamical structure of these interacting dark sectors, in order to study the dynamics of the model. We perform the phase space analysis of the model to confirm and interpret our proposal by searching the stable attractor solutions implying the late-time accelerating phase of the universe. We then obtain the result that when interaction and equation-of-state parameter of the dark matter evolve from the present day values into a particular value, the dark energy turns out to be a q-deformed scalar field.

  15. Histogram Profiling of Postcontrast T1-Weighted MRI Gives Valuable Insights into Tumor Biology and Enables Prediction of Growth Kinetics and Prognosis in Meningiomas.

    PubMed

    Gihr, Georg Alexander; Horvath-Rizea, Diana; Kohlhof-Meinecke, Patricia; Ganslandt, Oliver; Henkes, Hans; Richter, Cindy; Hoffmann, Karl-Titus; Surov, Alexey; Schob, Stefan

    2018-06-14

    Meningiomas are the most frequently diagnosed intracranial masses, oftentimes requiring surgery. Especially procedure-related morbidity can be substantial, particularly in elderly patients. Hence, reliable imaging modalities enabling pretherapeutic prediction of tumor grade, growth kinetic, realistic prognosis, and-as a consequence-necessity of surgery are of great value. In this context, a promising diagnostic approach is advanced analysis of magnetic resonance imaging data. Therefore, our study investigated whether histogram profiling of routinely acquired postcontrast T1-weighted images is capable of separating low-grade from high-grade lesions and whether histogram parameters reflect Ki-67 expression in meningiomas. Pretreatment T1-weighted postcontrast volumes of 44 meningioma patients were used for signal intensity histogram profiling. WHO grade, tumor volume, and Ki-67 expression were evaluated. Comparative and correlative statistics investigating the association between histogram profile parameters and neuropathology were performed. None of the investigated histogram parameters revealed significant differences between low-grade and high-grade meningiomas. However, significant correlations were identified between Ki-67 and the histogram parameters skewness and entropy as well as between entropy and tumor volume. Contrary to previously reported findings, pretherapeutic postcontrast T1-weighted images can be used to predict growth kinetics in meningiomas if whole tumor histogram analysis is employed. However, no differences between distinct WHO grades were identifiable in out cohort. As a consequence, histogram analysis of postcontrast T1-weighted images is a promising approach to obtain quantitative in vivo biomarkers reflecting the proliferative potential in meningiomas. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Pediatric Patients Demonstrate Progressive T1-Weighted Hyperintensity in the Dentate Nucleus following Multiple Doses of Gadolinium-Based Contrast Agent.

    PubMed

    Roberts, D R; Chatterjee, A R; Yazdani, M; Marebwa, B; Brown, T; Collins, H; Bolles, G; Jenrette, J M; Nietert, P J; Zhu, X

    2016-12-01

    While there have been recent reports of brain retention of gadolinium following gadolinium-based contrast agent administration in adults, a retrospective series of pediatric patients has not previously been reported, to our knowledge. We investigated the relationship between the number of prior gadolinium-based contrast agent doses and increasing T1 signal in the dentate nucleus on unenhanced T1-weighted MR imaging. We hypothesized that despite differences in pediatric physiology and the smaller gadolinium-based contrast agent doses that pediatric patients are typically administered based on weighted-adjusted dosing, the pediatric brain would also demonstrate dose-dependent increasing T1 signal in the dentate nucleus. We included children with multiple gadolinium-based contrast agent administrations at our institution. A blinded reader placed ROIs within the dentate nucleus and adjacent cerebellar white matter. To eliminate reader bias, we also performed automated ROI delineation of the dentate nucleus, cerebellar white matter, and pons. Dentate-to-cerebellar white matter and dentate-to pons ratios were compared with the number of gadolinium-based contrast agent administrations. During 20 years at our institution, 280 patients received at least 5 gadolinium-based contrast agent doses, with 1 patient receiving 38 doses. Sixteen patients met the inclusion/exclusion criteria for ROI analysis. Blinded reader dentate-to-cerebellar white matter ratios were significantly associated with gadolinium-based contrast agent doses (r s = 0.77, P = .001). The dentate-to-pons ratio and dentate-to-cerebellar white matter ratios based on automated ROI placement were also significantly correlated with gadolinium-based contrast agent doses (t = 4.98, P < .0001 and t = 2.73, P < .02, respectively). In pediatric patients, the number of prior gadolinium-based contrast agent doses is significantly correlated with progressive T1-weighted dentate hyperintensity. Definitive confirmation of

  17. [IL-1beta and PGE2 production in whole blood and gingival fluid in women with periodontitis and preterm low birth weight].

    PubMed

    Konopka, Tomasz; Rutkowska, Monika; Hirnle, Lidia; Kopeć, Wacław

    2004-05-01

    The aim of the investigation was to evaluate of IL-1beta and PGE2 concentrations in gingival fluid, whole blood as well as IL-1beta, PGE2 production after Escherichia coli lipopolysaccharide stimulation in whole blood in women with preterm low birth weight (PLBW), as compared to the control group. A case-control study of 88 postpartum women aged 17 to 39 was performed. The case group consisted of 52 women with PLBW and the control group consisted of 36 women giving birth in time. Concentration of inflammatory mediators in gingival fluid, blood serum and IL-1beta, PGE2 production in whole blood after bacterial lipopolysaccharide stimulation were determined by means of immunoenzymatic method. The levels of IL-1beta and PGE2 in gingival fluid were significantly higher in all PLBW mothers (also PLBW primiparous) than in the control group. In addition in the primiparous with PLBW group significantly higher PGE2 concentration in blood serum was found compared to the primiparous controls. There were no significant differences between women with PLBW and the controls together with a significantly higher production of IL-1beta and PGE2 in whole blood after LPS stimulation in women with periodontitis and gingivitis compared to subjects with healthy periodontium. Such findings suggest that inflammatory mediator synthesis is mainly result of specific cells exposition to bacterial products. Therefore it seems that more frequent occurrence of the phenotype of hyperactive cells that synthesise these mediators is not responsible for PLBW.

  18. Dark-matter decay as a complementary probe of multicomponent dark sectors.

    PubMed

    Dienes, Keith R; Kumar, Jason; Thomas, Brooks; Yaylali, David

    2015-02-06

    In single-component theories of dark matter, the 2→2 amplitudes for dark-matter production, annihilation, and scattering can be related to each other through various crossing symmetries. The detection techniques based on these processes are thus complementary. However, multicomponent theories exhibit an additional direction for dark-matter complementarity: the possibility of dark-matter decay from heavier to lighter components. We discuss how this new detection channel may be correlated with the others, and demonstrate that the enhanced complementarity which emerges can be an important ingredient in probing and constraining the parameter spaces of such models.

  19. Chronic Electrical Stimulation at Acupoints Reduces Body Weight and Improves Blood Glucose in Obese Rats via Autonomic Pathway.

    PubMed

    Liu, Jiemin; Jin, Haifeng; Foreman, Robert D; Lei, Yong; Xu, Xiaohong; Li, Shiying; Yin, Jieyun; Chen, Jiande D Z

    2015-07-01

    The aim of this study was to investigate effects and mechanisms of chronic electrical stimulation at acupoints (CEA) using surgically implanted electrodes on food intake, body weight, and metabolisms in diet-induced obese (DIO) rats. Thirty-six DIO rats were chronically implanted with electrodes at acupoints ST-36 (Zusanli). Three sets of parameters were tested: electrical acupuncture (EA) 1 (2-s on, 3-s off, 0.5 ms, 15 Hz, 6 mA), EA2 (same as EA1 but continuous pulses), and EA3 (same as EA2 but 10 mA). A chronic study was then performed to investigate the effects of CEA on body weight and mechanisms involving gastrointestinal hormones and autonomic functions. EA2 significantly reduced food intake without uncomfortable behaviors. CEA at EA2 reduced body weight and epididymal fat pad weight (P < 0.05). CEA reduced both postprandial blood glucose and HbA1c (P < 0.05). CEA delayed gastric emptying (P < 0.03) and increased small intestinal transit (P < 0.02). CEA increased fasting plasma level of glucagon-like peptide-1 (GLP-1) and peptide YY (P < 0.05); the increase of GLP-1 was inversely correlated with postprandial blood glucose (R (2) = 0.89, P < 0.05); and the plasma ghrelin level remained unchanged. EA increased sympathetic activity (P < 0.01) and reduced vagal activity (P < 0.01). CEA at ST-36 reduces body weight and improves blood glucose possibly attributed to multiple mechanisms involving gastrointestinal motility and hormones via the autonomic pathway.

  20. Developmental pathways of childhood dark traits.

    PubMed

    De Clercq, Barbara; Hofmans, Joeri; Vergauwe, Jasmine; De Fruyt, Filip; Sharp, Carla

    2017-10-01

    The dark triad of personality has traditionally been defined by 3 interrelated constructs, defined as Narcissism, Machiavellianism, and Psychopathy. Although the content of each of these constructs is clearly represented in childhood maladaptive trait measures, no studies have jointly addressed the prospective developmental course of this core set of maladaptive characteristics throughout childhood and adolescence. The current study uses latent growth modeling to explore how early dark traits develop over time, relying on a selected set of 6 childhood maladaptive traits that conceptually cover the adult dark triad. Across a 5-wave multi-informant design spanning 10 years of childhood, adolescence, and emerging adulthood (Nwave 1 = 717, 54.4% girls, age range T1 = 8-14.7 years, mean age = 10.73), results indicate that childhood dark traits show to some extent shared growth across time, although notable unique growth variance was also observed. Early dark traits further demonstrate significant association patterns with an adult dark triad measure across informants and are increasingly able to discriminate among more and less prototypical profiles of adult dark triad scores. Findings are discussed from a developmental psychopathology framework, underscoring that the proposed set of childhood dark traits represents a meaningful developmental precursor of the adult dark triad. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  1. ON THE BASIS PROPERTY OF THE HAAR SYSTEM IN THE SPACE \\mathscr{L}^{p(t)}(\\lbrack0,\\,1\\rbrack) AND THE PRINCIPLE OF LOCALIZATION IN THE MEAN

    NASA Astrophysics Data System (ADS)

    Sharapudinov, I. I.

    1987-02-01

    Let p=p(t) be a measurable function defined on \\lbrack0,\\,1\\rbrack. If p(t) is essentially bounded on \\lbrack0,\\,1\\rbrack, denote by \\mathscr{L}^{p(t)}(\\lbrack0,\\,1\\rbrack) the set of measurable functions f defined on \\lbrack0,\\,1\\rbrack for which \\int_0^1\\vert f(t)\\vert^{p(t)}dt<\\infty. The space \\mathscr{L}^{p(t)}(\\lbrack0,\\,1\\rbrack) with p(t)\\geqslant 1 is a normed space with norm \\displaystyle \\vert\\vert f\\vert\\vert _p=\\inf\\bigg\\{\\alpha>0:\\,\\int_0^1\\bigg\\vert\\frac{f(t)}{\\alpha}\\bigg\\vert^{p(t)}dt\\leqslant1\\bigg\\}.This paper examines the question of whether the Haar system is a basis in \\mathscr{L}^{p(t)}(\\lbrack0,\\,1\\rbrack). Conditions that are in a certain sense definitive on the function p(t) in order that the Haar system be a basis of \\mathscr{L}^{p(t)}(\\lbrack0,\\,1\\rbrack) are obtained. The concept of a localization principle in the mean is introduced, and its connection with the space \\mathscr{L}^{p(t)}(\\lbrack0,\\,1\\rbrack) is exhibited.Bibliography: 2 titles.

  2. Darkness after the K-T impact: Effects of soot

    NASA Technical Reports Server (NTRS)

    Wolbach, Wendy S.; Anders, Edward; Orth, Charles J.

    1988-01-01

    Dust from the K-T impact apparently settled from the atmosphere in less than 6 months, restoring sunlight to minimum photosynthesis levels in about 4 months. However, the discovery of a global soot component in the boundary clay makes it necessary to reconsider the problem, as soot particles not only are smaller (0.1 vs. about 0.5 micrometer) and thus settle more slowly, but also are better light absorbers (optical depth of 13 mg soot cm(-2) about 1800; and are more resistant to rainout. Still, the darkness cannot have lasted very much longer than 6 months, else no larger animals would have survived. Perhaps the soot coagulated with the rock dust and fell out with it. Evidence on this point may be sought at a relatively undisturbed K-T boundary site, such as Woodside Creek, N.Z. There the boundary clay and lowermost Tertiary strata are finely laminated and show large chemical and isotopic differences on a millimeter scale, apparently representing a detailed time sequence. Researchers studied a 3 m section across the boundary at this site, analyzing the principal forms of carbon (soot, elemental C, kerogen, and carbonate) as well as 33 elements. Correlations among the elements were sought. Apparently soot came early and coagulated with the ejecta, staying with them for the primary fallout and in the next 5 cm, but then parting company, perhaps due to size sorting.

  3. WE-G-BRD-09: Prediction of Local Control/Failure by Using Feature Histogram Selection in Follow-Up T2-Weighted MR Image in Spinal Tumors After Stereotactic Body Radiation Therapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhou, J; Harb, J; Jawad, M

    2014-06-15

    Purpose: In follow-up T2-weighted MR images of spinal tumor patients treated with stereotactic body radiation therapy (SBRT), high intensity features embedded in dark surroundings may suggest a local failure (LF). We investigated image intensity histogram in imaging features to predict LF and local control (LC). Methods: Sixty-seven spinal tumors were treated with SBRT at our institution with scheduled follow-up MR T2-weighted (TR 3200–6600ms; TE 75-132ms) imaging. The LF group included 10 tumors with 8.7 months median follow-up, while the LC group had 11 tumors with 24.1 months median follow-up. The follow-up images were fused to the planning CT. Image intensitymore » histograms of the GTV were calculated. Voxels in greater than 90% (V90), 80% (V80), and peak (Vpeak) of the histogram were grouped into sub-ROIs to determine the best feature histogram. The intensity of each sub-ROI was evaluated using the mean T2-weighted signal ratio (intensity in sub-ROI / intensity in normal vertebrae). An ROC curve in predicting LF for each sub-ROI was calculated to determine the best feature histogram parameter for LF prediction. Results: Mean T2-weighted signal ratio in the LF group was significantly higher than that in the LC group for all sub-ROIs (1.1±0.4 vs. 0.7±0.2, 1.2±0.4 vs. 0.8±0.2, 1.4±0.5 vs. 0.8±0.2, for V90, V80, and Vpeak, p=0.02, 0.02, and 0.002, respectively). The corresponding areas-under-curve (AUC) of ROC were 0.78, 0.80, and 0.87, p=0.02, 0.03, 0.004, respectively. No correlation was found between T2-weighted signal ratio in Vpeak and follow-up time (Pearson's ρ=0.15). Conclusion: Increased T2-weighted signal can be used to identify local failure while decreased signal indicates local control after spinal SBRT. By choosing the best histogram parameter (here the Vpeak), the AUC of the ROC can be substantially improved, which implies reliable prediction of LC and LF. These results are being further studied and validated with large multi

  4. Trends of T. cruzi infection based on data from blood bank screening.

    PubMed

    Zicker, F; Martelli, C M; de Andrade, A L; Almeida e Silva, S

    1990-01-01

    Between October 1988 and April 1989 a cross-sectional survey was carried out in six out of eight blood banks of Goiánia, Central Brazil. Subjects attending for first-time blood donation in the mornings of the study period (n = 1358) were interviewed and screened for T. cruzi infection as a part of a major study among blood donors. Tests to anti-T. cruzi antibodies were performed, simultaneously, by indirect hemagglutination test (IHA) and complement fixation test (CFT). A subject was considered seropositive when any one of the two tests showed a positive result. Information on age, sex, place of birth, migration and socio-economic level was recorded. Results from this survey were compared with seroprevalence rates obtained in previous studies in an attempt to analyse trend of T. cruzi infection in an endemic urban area. The overall seroprevalence of T. cruzi infection among first-time donors was found to be 3.5% (95% confidence interval 2.5%-4.5%). The seroprevalence rate increased with age up to 45 years and then decreased. Migrants from rural areas had higher seroprevalence rates than subjects from urban counties (1.8%-16.2% vs. 0%-3.6%). A four fold decrease in prevalence rates was observed when these rates were compared with those of fifteen years ago. Two possible hypotheses to explain this difference were suggested: 1. a cohort effect related with the decrease of transmission in rural areas and/or 2. a differential proportion of people of rural origin among blood donors between the two periods. The potential usefulness of blood banks as a source of epidemiological information to monitor trends of T. cruzi infection in an urban adult population was stressed.

  5. Dark cosmic rays

    DOE PAGES

    Hu, Ping-Kai; Kusenko, Alexander; Takhistov, Volodymyr

    2017-02-22

    If dark matter particles have an electric charge, as in models of millicharged dark matter, such particles should be accelerated in the same astrophysical accelerators that produce ordinary cosmic rays, and their spectra should have a predictable rigidity dependence. Depending on the charge, the resulting “dark cosmic rays” can be detected as muon-like or neutrino-like events in Super-Kamiokande, IceCube, and other detectors. We present new limits and propose several new analyses, in particular, for the Super-Kamiokande experiment, which can probe a previously unexplored portion of the millicharged dark matter parameter space. Here, most of our results are fairly general andmore » apply to a broad class of dark matter models.« less

  6. Comparison of amyloid plaque contrast generated by T2-, T2*-, and susceptibility-weighted imaging methods in transgenic mouse models of Alzheimer’s disease

    PubMed Central

    Chamberlain, Ryan; Reyes, Denise; Curran, Geoffrey L.; Marjanska, Malgorzata; Wengenack, Thomas M.; Poduslo, Joseph F.; Garwood, Michael; Jack, Clifford R.

    2009-01-01

    One of the hallmark pathologies of Alzheimer’s disease (AD) is amyloid plaque deposition. Plaques appear hypointense on T2- and T2*-weighted MR images probably due to the presence of endogenous iron, but no quantitative comparison of various imaging techniques has been reported. We estimated the T1, T2, T2*, and proton density values of cortical plaques and normal cortical tissue and analyzed the plaque contrast generated by a collection of T2-, T2*-, and susceptibility-weighted imaging (SWI) methods in ex vivo transgenic mouse specimens. The proton density and T1 values were similar for both cortical plaques and normal cortical tissue. The T2 and T2* values were similar in cortical plaques, which indicates that the iron content of cortical plaques may not be as large as previously thought. Ex vivo plaque contrast was increased compared to a previously reported spin echo sequence by summing multiple echoes and by performing SWI; however, gradient echo and susceptibility weighted imaging was found to be impractical for in vivo imaging due to susceptibility interface-related signal loss in the cortex. PMID:19253386

  7. Deleterious effects of increased body weight associated with intensive insulin therapy for type 1 diabetes: increased blood pressure and worsened lipid profile partially negate improvements in life expectancy.

    PubMed

    Palmer, Andrew J; Roze, Stéphane; Valentine, William J; Minshall, Michael E; Lammert, Morten; Nicklasson, Lars; Spinas, Giatgen A

    2004-08-01

    Weight gain is an unwanted side effect of improved glycaemic control in type 1 diabetes, associated with increased blood pressure (BP) and worsening lipid profiles. While improved glycaemic control per se should improve long-term patient outcomes, increases in BP and worsening lipid profiles may counteract these benefits. The aim of this modelling study was to assess whether the increased body weight and associated worsening of lipid profile and blood pressure would negate the improvements in glycaemic control seen with intensive therapy in patients with type 1 diabetes. A validated diabetes model projected life expectancy (LE), quality-adjusted LE (QALE) and total lifetime costs of complications in type 1 diabetes cohorts with the characteristics of patients from the Diabetes Control and Complications Trial (DCCT). The following four cohorts (A-D) were created based on increased body weight under either conventional or intensive therapy: A) conventional glycaemic control in the subgroup with lowest weight-gain quartile after 6.5 years (HbA1c increased by 11% from baseline); B) conventional control in the highest weight-gain quartile (no change in HbA1c from baseline); C) intensive control in the lowest quartile of weight gain (with 16.1% decrease in HbA1c, but no increase in weight or associated BP, and improved lipid profile); D) intensive control in the highest quartile of weight gain (with 21% decrease in HbA1c, increased systolic BP of 6 mmHg, and worsened lipid profile). Data were derived from DCCT and other published sources. Intensive control, even with weight gain, led to major improvements in LE and QALE, and reduction in costs of complications versus conventional therapy. Intensive therapy with no weight increase led to a higher LE (increased by 0.57 years) and higher QALE (increased by 0.28 years) and lower costs of complications (reduced by 523 dollars/patient), compared to intensive therapy with the highest quartile of weight gain. Concerns about

  8. CLOCK 3111 T/C SNP interacts with emotional eating behavior for weight-loss in a Mediterranean population

    USDA-ARS?s Scientific Manuscript database

    The goals of this research was (1) to analyze the role of emotional eating behavior on weight-loss progression during a 30-week weight-loss program in 1,272 individuals from a large Mediterranean population and (2) to test for interaction between CLOCK 3111 T/C SNP and emotional eating behavior on t...

  9. Finite Inflation, Holography, and Dark Matter Annihilation

    NASA Astrophysics Data System (ADS)

    Scacco, Andrew Joseph

    This thesis covers work on theoretical cosmology relating to inflation, de Sitter space, dark matter annihilation, and holography. A unifying feature of all these topics is that all of them occur in de Sitter space or focus on epochs of the Universe when the spacetime was close to de Sitter and that all of them have some connection to holography. Chapter 1 provides a pedagogical introduction to the fundamentals of cosmology, inflation, de Sitter space, dark matter annihilation and entanglement entropy. Chapter 2 covers the impact on the causal entropic principle of dark matter annihilation that we find to have the greatest relevance at late times in the future when the dark energy has driven the universe to be asymptotically de Sitter. In this chapter we estimate holographically preferred dark matter properties for a range of assumptions. Chapter 3 covers holographic bounds in models of finite inflation, specifically the Banks-Fischler bound and de Sitter equilibrium. The assumptions in each of these models are explored in detail and some interesting new connections are presented. Chapter 4 tests models of inflation with a fast-roll start that happen to satisfy the holographic bounds in Chapter 3 against cosmic microwave background data from Planck. We find a slight preference for a feature at the scale predicted by the Banks-Fischler bound though this preference is not found to be statistically significant. Chapter 5 contains a numerical computation of the holographic mutual information for an annular configuration of regions on a conformal field theory in de Sitter space using the AdS/CFT correspondence. This computation shows that the de Sitter space CFT entanglement entropy matches what would be expected from a Minkowski CFT and shows that the HRT conjecture works for this case.

  10. Acute dark chocolate and cocoa ingestion and endothelial function: a randomized controlled crossover trial.

    PubMed

    Faridi, Zubaida; Njike, Valentine Yanchou; Dutta, Suparna; Ali, Ather; Katz, David L

    2008-07-01

    Studies suggest cardioprotective benefits of dark chocolate containing cocoa. This study examines the acute effects of solid dark chocolate and liquid cocoa intake on endothelial function and blood pressure in overweight adults. Randomized, placebo-controlled, single-blind crossover trial of 45 healthy adults [mean age: 53 y; mean body mass index (in kg/m(2)): 30]. In phase 1, subjects were randomly assigned to consume a solid dark chocolate bar (containing 22 g cocoa powder) or a cocoa-free placebo bar (containing 0 g cocoa powder). In phase 2, subjects were randomly assigned to consume sugar-free cocoa (containing 22 g cocoa powder), sugared cocoa (containing 22 g cocoa powder), or a placebo (containing 0 g cocoa powder). Solid dark chocolate and liquid cocoa ingestion improved endothelial function (measured as flow-mediated dilatation) compared with placebo (dark chocolate: 4.3 +/- 3.4% compared with -1.8 +/- 3.3%; P < 0.001; sugar-free and sugared cocoa: 5.7 +/- 2.6% and 2.0 +/- 1.8% compared with -1.5 +/- 2.8%; P < 0.001). Blood pressure decreased after the ingestion of dark chocolate and sugar-free cocoa compared with placebo (dark chocolate: systolic, -3.2 +/- 5.8 mm Hg compared with 2.7 +/- 6.6 mm Hg; P < 0.001; and diastolic, -1.4 +/- 3.9 mm Hg compared with 2.7 +/- 6.4 mm Hg; P = 0.01; sugar-free cocoa: systolic, -2.1 +/- 7.0 mm Hg compared with 3.2 +/- 5.6 mm Hg; P < 0.001; and diastolic: -1.2 +/- 8.7 mm Hg compared with 2.8 +/- 5.6 mm Hg; P = 0.014). Endothelial function improved significantly more with sugar-free than with regular cocoa (5.7 +/- 2.6% compared with 2.0 +/- 1.8%; P < 0.001). The acute ingestion of both solid dark chocolate and liquid cocoa improved endothelial function and lowered blood pressure in overweight adults. Sugar content may attenuate these effects, and sugar-free preparations may augment them.

  11. Avian Blood-Vessel Formation in Space

    NASA Technical Reports Server (NTRS)

    Lelkes, Peter I.

    1999-01-01

    Based on previous studies, we hypothesized that the developmental anomalies observed in the past might be related to or caused by delayed or improper vascular development. The objective of our research is to test the hypothesis that exposure to microgravity during space flight cause delayed or improper vascular development during embryogenesis. The effects of microgravity on the time course and extent of avian blood-vessel formation are assessed using two models, one for angiogenesis and one for vasculogenesis. The methodological approach is dictated by the constraints of the tissue preservation method used in space. Thus, both in the chorioallantoic membrane (CAM) and in the adrenal, we will evaluate microscopically the vascular architecture and immunostain endothelial cells with specific antibodies (anti- vWF and QH1). The extent of ECM protein deposition will be assessed by immunohistochemistry and correlated with the degree of vascularization, using computer-based image analysis. Also, the cellular source for ECM proteins will be assessed by in situ hybridization.

  12. Red blood cell and iron metabolism during space flight

    NASA Technical Reports Server (NTRS)

    Smith, Scott M.

    2002-01-01

    Space flight anemia is a widely recognized phenomenon in astronauts. Reduction in circulating red blood cells and plasma volume results in a 10% to 15% decrement in circulatory volume. This effect appears to be a normal physiologic adaptation to weightlessness and results from the removal of newly released blood cells from the circulation. Iron availability increases, and (in the few subjects studied) iron stores increase during long-duration space flight. The consequences of these changes are not fully understood.

  13. Determining the amount of physical activity needed for long-term weight control

    NASA Technical Reports Server (NTRS)

    Wier, L. T.; Ayers, G. W.; Jackson, A. S.; Rossum, A. C.; Poston, W. S.; Foreyt, J. P.

    2001-01-01

    OBJECTIVE: To evaluate prospectively the influence of habitual physical activity on body weight of men and women and to develop a model that defines the role of physical activity on longitudinal weight change. DESIGN AND SETTING: Occupational cohort study conducted for a mean of 5.5 y. SUBJECTS: A total of 496 (341 male and 155 female) NASA/Johnson Space Center employees who completed the 3 month education component of the employee health-related fitness program and remained involved for a minimum of 2 y. MEASUREMENTS: Body weights were measured at baseline (T1) and follow-up (T2), and habitual physical activity was obtained from the mean of multiple ratings of the 11-point (0-10) NASA Activity Scale (NAS) recorded quarterly between T1 and T2. Other measures included age, gender, VO(2 max) obtained from maximal treadmill testing, body mass index (BMI), and body fat percentage. RESULTS: Multiple regression demonstrated that mean NAS, T1 weight, aging and gender all influence long-term T2 weight. T1 age was significant for the men only. Independently, each increase in mean NAS significantly (P<0.01) reduced T2 weight in men (b=-0.91 kg; 95% CI:-1.4 to-0.42 kg) and women (b=-2.14 kg; 95% CI:-2.93 to-1.35 kg). Mean NAS had a greater effect on T2 weight as T1 weight increased, and the relationship was dose-dependent. CONCLUSIONS: Habitual physical activity is a significant source of long-term weight change. The use of self-reported activity level is helpful in predicting long-term weight changes and may be used by health care professionals when counseling patients about the value of physical activity for weight control.

  14. First results from the DarkSide-50 dark matter experiment at Laboratori Nazionali del Gran Sasso

    NASA Astrophysics Data System (ADS)

    Agnes, P.; Alexander, T.; Alton, A.; Arisaka, K.; Back, H. O.; Baldin, B.; Biery, K.; Bonfini, G.; Bossa, M.; Brigatti, A.; Brodsky, J.; Budano, F.; Cadonati, L.; Calaprice, F.; Canci, N.; Candela, A.; Cao, H.; Cariello, M.; Cavalcante, P.; Chavarria, A.; Chepurnov, A.; Cocco, A. G.; Crippa, L.; D'Angelo, D.; D'Incecco, M.; Davini, S.; De Deo, M.; Derbin, A.; Devoto, A.; Di Eusanio, F.; Di Pietro, G.; Edkins, E.; Empl, A.; Fan, A.; Fiorillo, G.; Fomenko, K.; Forster, G.; Franco, D.; Gabriele, F.; Galbiati, C.; Goretti, A.; Grandi, L.; Gromov, M.; Guan, M. Y.; Guardincerri, Y.; Hackett, B.; Herner, K.; Hungerford, E. V.; Ianni, Al.; Ianni, An.; Jollet, C.; Keeter, K.; Kendziora, C.; Kidner, S.; Kobychev, V.; Koh, G.; Korablev, D.; Korga, G.; Kurlej, A.; Li, P. X.; Loer, B.; Lombardi, P.; Love, C.; Ludhova, L.; Luitz, S.; Ma, Y. Q.; Machulin, I.; Mandarano, A.; Mari, S.; Maricic, J.; Marini, L.; Martoff, C. J.; Meregaglia, A.; Meroni, E.; Meyers, P. D.; Milincic, R.; Montanari, D.; Monte, A.; Montuschi, M.; Monzani, M. E.; Mosteiro, P.; Mount, B.; Muratova, V.; Musico, P.; Nelson, A.; Odrowski, S.; Okounkova, M.; Orsini, M.; Ortica, F.; Pagani, L.; Pallavicini, M.; Pantic, E.; Papp, L.; Parmeggiano, S.; Parsells, R.; Pelczar, K.; Pelliccia, N.; Perasso, S.; Pocar, A.; Pordes, S.; Pugachev, D.; Qian, H.; Randle, K.; Ranucci, G.; Razeto, A.; Reinhold, B.; Renshaw, A.; Romani, A.; Rossi, B.; Rossi, N.; Rountree, S. D.; Sablone, D.; Saggese, P.; Saldanha, R.; Sands, W.; Sangiorgio, S.; Segreto, E.; Semenov, D.; Shields, E.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Stanford, C.; Suvorov, Y.; Tartaglia, R.; Tatarowicz, J.; Testera, G.; Tonazzo, A.; Unzhakov, E.; Vogelaar, R. B.; Wada, M.; Walker, S.; Wang, H.; Wang, Y.; Watson, A.; Westerdale, S.; Wojcik, M.; Wright, A.; Xiang, X.; Xu, J.; Yang, C. G.; Yoo, J.; Zavatarelli, S.; Zec, A.; Zhu, C.; Zuzel, G.

    2015-04-01

    We report the first results of DarkSide-50, a direct search for dark matter operating in the underground Laboratori Nazionali del Gran Sasso (LNGS) and searching for the rare nuclear recoils possibly induced by weakly interacting massive particles (WIMPs). The dark matter detector is a Liquid Argon Time Projection Chamber with a (46.4 ± 0.7) kg active mass, operated inside a 30 t organic liquid scintillator neutron veto, which is in turn installed at the center of a 1 kt water Cherenkov veto for the residual flux of cosmic rays. We report here the null results of a dark matter search for a (1422 ± 67) kgd exposure with an atmospheric argon fill. This is the most sensitive dark matter search performed with an argon target, corresponding to a 90% CL upper limit on the WIMP-nucleon spin-independent cross section of 6.1 ×10-44 cm2 for a WIMP mass of 100 Gev /c2.

  15. Dark stars: a review.

    PubMed

    Freese, Katherine; Rindler-Daller, Tanja; Spolyar, Douglas; Valluri, Monica

    2016-06-01

    Dark stars are stellar objects made (almost entirely) of hydrogen and helium, but powered by the heat from dark matter annihilation, rather than by fusion. They are in hydrostatic and thermal equilibrium, but with an unusual power source. Weakly interacting massive particles (WIMPs), among the best candidates for dark matter, can be their own antimatter and can annihilate inside the star, thereby providing a heat source. Although dark matter constitutes only [Formula: see text]0.1% of the stellar mass, this amount is sufficient to power the star for millions to billions of years. Thus, the first phase of stellar evolution in the history of the Universe may have been dark stars. We review how dark stars come into existence, how they grow as long as dark matter fuel persists, and their stellar structure and evolution. The studies were done in two different ways, first assuming polytropic interiors and more recently using the MESA stellar evolution code; the basic results are the same. Dark stars are giant, puffy (∼10 AU) and cool (surface temperatures  ∼10 000 K) objects. We follow the evolution of dark stars from their inception at  ∼[Formula: see text] as they accrete mass from their surroundings to become supermassive stars, some even reaching masses  >[Formula: see text] and luminosities  >[Formula: see text], making them detectable with the upcoming James Webb Space Telescope. Once the dark matter runs out and the dark star dies, it may collapse to a black hole; thus dark stars may provide seeds for the supermassive black holes observed throughout the Universe and at early times. Other sites for dark star formation may exist in the Universe today in regions of high dark matter density such as the centers of galaxies. The current review briefly discusses dark stars existing today, but focuses on the early generation of dark stars.

  16. New holographic dark energy model with constant bulk viscosity in modified f(R,T) gravity theory

    NASA Astrophysics Data System (ADS)

    Srivastava, Milan; Singh, C. P.

    2018-06-01

    The aim of this paper is to study new holographic dark energy (HDE) model in modified f(R,T) gravity theory within the framework of a flat Friedmann-Robertson-Walker model with bulk viscous matter content. It is thought that the negative pressure caused by the bulk viscosity can play the role of dark energy component, and drive the accelerating expansion of the universe. This is the motive of this paper to observe such phenomena with bulk viscosity. In the specific model f(R,T)=R+λ T, where R is the Ricci scalar, T the trace of the energy-momentum tensor and λ is a constant, we find the solution for non-viscous and viscous new HDE models. We analyze new HDE model with constant bulk viscosity, ζ =ζ 0= const. to explain the present accelerated expansion of the universe. We classify all possible scenarios (deceleration, acceleration and their transition) with possible positive and negative ranges of λ over the constraint on ζ 0 to analyze the evolution of the universe. We obtain the solutions of scale factor and deceleration parameter, and discuss the evolution of the universe. We observe the future finite-time singularities of type I and III at a finite time under certain constraints on λ . We also investigate the statefinder and Om diagnostics of the viscous new HDE model to discriminate with other existing dark energy models. In late time the viscous new HDE model approaches to Λ CDM model. We also discuss the thermodynamics and entropy of the model and find that it satisfies the second law of thermodynamics.

  17. Blood CXCR3+ CD4 T Cells Are Enriched in Inducible Replication Competent HIV in Aviremic Antiretroviral Therapy-Treated Individuals

    PubMed Central

    Banga, Riddhima; Procopio, Francesco A.; Ruggiero, Alessandra; Noto, Alessandra; Ohmiti, Khalid; Cavassini, Matthias; Corpataux, Jean-Marc; Paxton, William A.; Pollakis, Georgios; Perreau, Matthieu

    2018-01-01

    We recently demonstrated that lymph nodes (LNs) PD-1+/T follicular helper (Tfh) cells from antiretroviral therapy (ART)-treated HIV-infected individuals were enriched in cells containing replication competent virus. However, the distribution of cells containing inducible replication competent virus has been only partially elucidated in blood memory CD4 T-cell populations including the Tfh cell counterpart circulating in blood (cTfh). In this context, we have investigated the distribution of (1) total HIV-infected cells and (2) cells containing replication competent and infectious virus within various blood and LN memory CD4 T-cell populations of conventional antiretroviral therapy (cART)-treated HIV-infected individuals. In the present study, we show that blood CXCR3-expressing memory CD4 T cells are enriched in cells containing inducible replication competent virus and contributed the most to the total pool of cells containing replication competent and infectious virus in blood. Interestingly, subsequent proviral sequence analysis did not indicate virus compartmentalization between blood and LN CD4 T-cell populations, suggesting dynamic interchanges between the two compartments. We then investigated whether the composition of blood HIV reservoir may reflect the polarization of LN CD4 T cells at the time of reservoir seeding and showed that LN PD-1+ CD4 T cells of viremic untreated HIV-infected individuals expressed significantly higher levels of CXCR3 as compared to CCR4 and/or CCR6, suggesting that blood CXCR3-expressing CD4 T cells may originate from LN PD-1+ CD4 T cells. Taken together, these results indicate that blood CXCR3-expressing CD4 T cells represent the major blood compartment containing inducible replication competent virus in treated aviremic HIV-infected individuals. PMID:29459864

  18. Blood CXCR3+ CD4 T Cells Are Enriched in Inducible Replication Competent HIV in Aviremic Antiretroviral Therapy-Treated Individuals.

    PubMed

    Banga, Riddhima; Procopio, Francesco A; Ruggiero, Alessandra; Noto, Alessandra; Ohmiti, Khalid; Cavassini, Matthias; Corpataux, Jean-Marc; Paxton, William A; Pollakis, Georgios; Perreau, Matthieu

    2018-01-01

    We recently demonstrated that lymph nodes (LNs) PD-1 + /T follicular helper (Tfh) cells from antiretroviral therapy (ART)-treated HIV-infected individuals were enriched in cells containing replication competent virus. However, the distribution of cells containing inducible replication competent virus has been only partially elucidated in blood memory CD4 T-cell populations including the Tfh cell counterpart circulating in blood (cTfh). In this context, we have investigated the distribution of (1) total HIV-infected cells and (2) cells containing replication competent and infectious virus within various blood and LN memory CD4 T-cell populations of conventional antiretroviral therapy (cART)-treated HIV-infected individuals. In the present study, we show that blood CXCR3-expressing memory CD4 T cells are enriched in cells containing inducible replication competent virus and contributed the most to the total pool of cells containing replication competent and infectious virus in blood. Interestingly, subsequent proviral sequence analysis did not indicate virus compartmentalization between blood and LN CD4 T-cell populations, suggesting dynamic interchanges between the two compartments. We then investigated whether the composition of blood HIV reservoir may reflect the polarization of LN CD4 T cells at the time of reservoir seeding and showed that LN PD-1 + CD4 T cells of viremic untreated HIV-infected individuals expressed significantly higher levels of CXCR3 as compared to CCR4 and/or CCR6, suggesting that blood CXCR3-expressing CD4 T cells may originate from LN PD-1 + CD4 T cells. Taken together, these results indicate that blood CXCR3-expressing CD4 T cells represent the major blood compartment containing inducible replication competent virus in treated aviremic HIV-infected individuals.

  19. Red blood cells inhibit activation-induced cell death and oxidative stress in human peripheral blood T lymphocytes.

    PubMed

    Fonseca, A M; Porto, G; Uchida, K; Arosa, F A

    2001-05-15

    Red blood cells (RBCs) are known to perform one prominent function: to carry and deliver oxygen to the tissues. Earlier studies, however, suggested a role for RBCs in potentiating T-cell proliferation in vitro. Here it is shown that the presence of RBCs in cultures of stimulated human peripheral blood lymphocytes strengthens T-cell proliferation and survival. Analysis of phosphatidylserine externalization and DNA fragmentation showed that RBCs inhibit T-cell apoptosis. This inhibition correlated with a reduction in CD71 but not CD95 expression. RBCs enhanced T-cell proliferation and survival upon activation with phytohemagglutinin and with OKT3 antibodies. Studies aimed at characterizing the cellular and molecular basis of the protection afforded to T cells by RBCs showed that (1) optimal protection required intact RBCs and red cell/T-cell contact but not monocytes; (2) RBCs markedly reduced the level of intracellular reactive oxygen species; and (3) RBCs inhibited the formation of protein-bound acrolein, a peroxidation adduct in biologic systems. Overall, these data indicate that human RBCs protect T cells from activation-induced cell death, at least in part by reducing the pro-oxidant state, and suggest a role for RBCs as conceivable modulators of T-cell homeostasis.

  20. Real-world glycemic, blood pressure, and weight control in patients with type 2 diabetes mellitus treated with canagliflozin-an electronic health-record-based study.

    PubMed

    Lefebvre, Patrick; Pilon, Dominic; Robitaille, Marie-Noëlle; Lafeuille, Marie-Hélène; Chow, Wing; Pfeifer, Michael; Duh, Mei Sheng

    2016-06-01

    Canagliflozin (CANA) has been shown to improve HbA1c, blood pressure (BP), and weight in patients with type 2 diabetes mellitus (T2DM) in clinical trials. This study describes HbA1c, BP, and weight in T2DM patients treated with CANA in a real-world setting. Adults with ≥1 diagnosis for T2DM and ≥12 months of clinical activity before the first CANA prescription (index) were identified in the IMS Health Real-World Data Electronic Medical Records - US database. Patient quality measures were described at baseline and 3, 6, 9, and 12 months post-index. Selected goals were HbA1c <7% (<53 mmol/mol), <8% (<64 mmol/mol), and >9% (>75 mmol/mol, poor control), BP <140/90 mmHg, and weight loss ≥5%. In total, 16,163 patients were identified (mean age = 58.5 years; 47.9% female; 75.8% white). At baseline, 90.4% of patients used ≥1 anti-hyperglycemic agent. Among patients with baseline HbA1c ≥7% (n = 10,478; 64.8%; mean HbA1c = 8.8%), 21.2%, 59.5%, and 17.6% had an HbA1c <7%, <8%, and >9% after 3 months, respectively; these proportions remained stable through 12 months. Among patients with baseline BP ≥140/90, 60.0% and 75.6% attained systolic BP <140 mmHg and diastolic BP <90 mmHg after 3 months, respectively; proportions remained stable through 12 months. Weight loss ≥5% was observed in 13.3% of patients at 3 months and the proportion increased to 25.8% at 12 months. This study relied on prescription data, which does not necessarily indicate that the medication was taken as prescribed. Some patients were also treated with other anti-hyperglycemics, anti-hypertensives, and weight loss medications during the follow-up, which may have contributed to the effects reported. Most patients with inadequate HbA1c and BP levels at baseline achieved respective goals after 3 months of CANA, and the proportions of responders remained stable through 12 months. Weight loss ≥5% was increasingly observed over time.

  1. Dark Soliton Solutions of Space-Time Fractional Sharma-Tasso-Olver and Potential Kadomtsev-Petviashvili Equations

    NASA Astrophysics Data System (ADS)

    Guner, Ozkan; Korkmaz, Alper; Bekir, Ahmet

    2017-02-01

    Dark soliton solutions for space-time fractional Sharma-Tasso-Olver and space-time fractional potential Kadomtsev-Petviashvili equations are determined by using the properties of modified Riemann-Liouville derivative and fractional complex transform. After reducing both equations to nonlinear ODEs with constant coefficients, the \\tanh ansatz is substituted into the resultant nonlinear ODEs. The coefficients of the solutions in the ansatz are calculated by algebraic computer computations. Two different solutions are obtained for the Sharma-Tasso-Olver equation as only one solution for the potential Kadomtsev-Petviashvili equation. The solution profiles are demonstrated in 3D plots in finite domains of time and space.

  2. T2-Weighted Liver MRI Using the MultiVane Technique at 3T: Comparison with Conventional T2-Weighted MRI

    PubMed Central

    Kang, Kyung A; Kim, EunJu; Jeong, Woo Kyoung; Choi, Dongil; Lee, Won Jae; Jung, Sin-Ho; Baek, Sun-Young

    2015-01-01

    Objective To assess the value of applying MultiVane to liver T2-weighted imaging (T2WI) compared with conventional T2WIs with emphasis on detection of focal liver lesions. Materials and Methods Seventy-eight patients (43 men and 35 women) with 86 hepatic lesions and 20 pancreatico-biliary diseases underwent MRI including T2WIs acquired using breath-hold (BH), respiratory-triggered (RT), and MultiVane technique at 3T. Two reviewers evaluated each T2WI with respect to artefacts, organ sharpness, and conspicuity of intrahepatic vessels, hilar duct, and main lesion using five-point scales, and made pairwise comparisons between T2WI sequences for these categories. Diagnostic accuracy (Az) and sensitivity for hepatic lesion detection were evaluated using alternative free-response receiver operating characteristic analysis. Results MultiVane T2WI was significantly better than BH-T2WI or RT-T2WI for organ sharpness and conspicuity of intrahepatic vessels and main lesion in both separate reviews and pairwise comparisons (p < 0.001). With regard to motion artefacts, MultiVane T2WI or BH-T2WI was better than RT-T2WI (p < 0.001). Conspicuity of hilar duct was better with BH-T2WI than with MultiVane T2WI (p = 0.030) or RT-T2WI (p < 0.001). For detection of 86 hepatic lesions, sensitivity (mean, 97.7%) of MultiVane T2WI was significantly higher than that of BH-T2WI (mean, 89.5%) (p = 0.008) or RT-T2WI (mean, 84.9%) (p = 0.001). Conclusion Applying the MultiVane technique to T2WI of the liver is a promising approach to improving image quality that results in increased detection of focal liver lesions compared with conventional T2WI. PMID:26357498

  3. A light/dark cycle in the NICU accelerates body weight gain and shortens time to discharge in preterm infants.

    PubMed

    Vásquez-Ruiz, Samuel; Maya-Barrios, José Alfonso; Torres-Narváez, Patricia; Vega-Martínez, Benito Rubén; Rojas-Granados, Adelina; Escobar, Carolina; Angeles-Castellanos, Manuel

    2014-09-01

    Bright constant light levels in the NICU may have negative effects on the growth and development of preterm infants The aim of this study is to evaluate the benefits of an alternating light/dark cycle in the NICU on weight gain and early discharge from the therapy in premature infants. A randomized interventional study was designed comparing infants in the NICU of Hospital Juarez de México, exposed from birth either to an LD environment (LD, n=19) or to the traditional continuous light (LL, n=19). The LD condition was achieved by placing individual removable helmets over the infant's heads. Body weight gain was analyzed, as the main indicator of stability and the main criteria for discharge in preterm infants born at 31.73±0.31week gestational age. Infants maintained in an LD cycle gained weight faster than infants in LL and therefore attained a shorter hospital stay, (34.37±3.12 vs 51.11±5.29days; P>0.01). Also, LD infants exhibited improved oxygen saturation and developed a daily melatonin rhythm. These findings provide a convenient alternative for establishing an LD environment for preterm healthy newborns in the NICU and confirm the beneficial effects of an alternating LD cycle for growth and weight gain and for earlier discharge time. Here we provide an easy and practical alternative to implement light/dark conditions in the NICU. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Reticular Appearance on Gadolinium-enhanced T1- and Diffusion-weighted MRI, and Low Apparent Diffusion Coefficient Values in Microcystic Meningioma Cysts.

    PubMed

    Terada, Yukinori; Toda, Hiroki; Okumura, Ryosuke; Ikeda, Naokado; Yuba, Yoshiaki; Katayama, Toshiro; Iwasaki, Koichi

    2018-03-01

    Microcystic meningioma, a rare meningioma subtype, can present diagnostic difficulty. We aimed to investigate the historadiological properties of microcystic meningioma using conventional magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) analysis. We retrospectively analyzed conventional MRI and DWI results of six microcystic meningioma cases by examining their appearance and determining their apparent diffusion coefficient (ADC) values. The ADC values of the intratumoral components were normalized with ADC values of the cerebrospinal fluid in the lateral ventricle (ADC ratios). As cystic formations are frequently associated with microcystic meningiomas, their MRI characteristics were compared with the imaging data from 11 cystic meningiomas of non-microcystic subtypes. We found that cysts in microcystic meningioma tended to have a reticular appearance on DWI, as they did on gadolinium-enhanced T1-weighted imaging. Additionally, these reticular cysts had significantly lower ADC ratios than microcystic non-reticular and non-microcystic cysts. These DWI characteristics likely reflect the histological properties of microcystic meningioma. A reticular appearance on gadolinium-enhanced T1-weighted MRI and DWI, and cyst formation with relatively low ADC values can be diagnostic markers of microcystic meningiomas.

  5. Distribution function approach to redshift space distortions. Part IV: perturbation theory applied to dark matter

    NASA Astrophysics Data System (ADS)

    Vlah, Zvonimir; Seljak, Uroš; McDonald, Patrick; Okumura, Teppei; Baldauf, Tobias

    2012-11-01

    We develop a perturbative approach to redshift space distortions (RSD) using the phase space distribution function approach and apply it to the dark matter redshift space power spectrum and its moments. RSD can be written as a sum over density weighted velocity moments correlators, with the lowest order being density, momentum density and stress energy density. We use standard and extended perturbation theory (PT) to determine their auto and cross correlators, comparing them to N-body simulations. We show which of the terms can be modeled well with the standard PT and which need additional terms that include higher order corrections which cannot be modeled in PT. Most of these additional terms are related to the small scale velocity dispersion effects, the so called finger of god (FoG) effects, which affect some, but not all, of the terms in this expansion, and which can be approximately modeled using a simple physically motivated ansatz such as the halo model. We point out that there are several velocity dispersions that enter into the detailed RSD analysis with very different amplitudes, which can be approximately predicted by the halo model. In contrast to previous models our approach systematically includes all of the terms at a given order in PT and provides a physical interpretation for the small scale dispersion values. We investigate RSD power spectrum as a function of μ, the cosine of the angle between the Fourier mode and line of sight, focusing on the lowest order powers of μ and multipole moments which dominate the observable RSD power spectrum. Overall we find considerable success in modeling many, but not all, of the terms in this expansion. This is similar to the situation in real space, but predicting power spectrum in redshift space is more difficult because of the explicit influence of small scale dispersion type effects in RSD, which extend to very large scales.

  6. Fermion dark matter in gauge-Higgs unification

    DOE PAGES

    Maru, Nobuhito; Miyaji, Takashi; Okada, Nobuchika; ...

    2017-07-11

    Here, we propose a Majorana fermion dark matter in the context of a s imple gauge-Higgs Unification (GHU) scenario based on the gauge group SU(3)×U(1)' in 5-dimensional Minkowski space with a compactification of the 5th dimension on S 1/Z 2 orbifold. The dark matter particle is identified with the lightest mode in SU(3) triplet fermions additionally introduced in the 5-dimensional bulk. We find an allowed parameter region for the dark matter mass around a half of the Standard Model Higgs boson mass, which is consistent with the observed dark matter density and the constraint from the LUX 2016 result formore » the direct dark matter search. The entire allowed region will be covered by, for example, the LUX-ZEPLIN dark matter experiment in the near future. We also show that in the presence of the bulk SU(3) triplet fermions the 125 GeV Higgs boson mas s is reproduced through the renormalization group evolution of Higgs quartic coupling with the compactification scale of around 10 8 GeV.« less

  7. Higgs exotic decays in general NMSSM with self-interacting dark matter

    NASA Astrophysics Data System (ADS)

    Wang, Wenyu; Zhang, Mengchao; Zhao, Jun

    2018-04-01

    Under current LHC and dark matter constraints, the general NMSSM can have self-interacting dark matter to explain the cosmological small structure. In this scenario, the dark matter is the light singlino-like neutralino (χ) which self-interacts through exchanging the light singlet-like scalars (h1,a1). These light scalars and neutralinos inevitably interact with the 125 GeV SM-like Higgs boson (hSM), which cause the Higgs exotic decays hSM → h1h1, a1a1, χχ. We first demonstrate the parameter space required by the explanation of the cosmological small structure and then display the Higgs exotic decays. We find that in such a parameter space the Higgs exotic decays can have branching ratios of a few percent, which should be accessible in the future e+e‑ colliders.

  8. Development of PEGylated KMnF3 nanoparticles as a T1-weighted contrast agent: chemical synthesis, in vivo brain MR imaging, and accounting for high relaxivity.

    PubMed

    Liu, Zhi-jun; Song, Xiao-xia; Tang, Qun

    2013-06-07

    Magnetic nanoparticles consisting of manganese-based T1-weighted contrast agents have rapidly achieved clinical application, however low proton relaxivity impedes further development. In this report, by analyzing nanoparticles' surface oxidation states we propose the possible reason for the low r1 relaxivity of common MnO nanoparticles and develop PEGylated fluoroperovskite KMnF3 nanoparticles as new T1-weighted contrast agents, which exhibit the highest longitudinal relaxivity (r1 = 23.15 mM(-1) s(-1)) among all the reported manganese-based T1-weighted contrast agents. We, for the first time, illustrate a typical example showing that the surface oxidation states of metal ions exposed on the nanoparticles' surfaces are able to influence not only the optical, magnetic, electronic or catalytic properties but also water proton longitudinal relaxivity when applied as an MRI contrast agent. Cytotoxicity tests demonstrate that the PEGylated KMnF3 nanoparticles are free from toxicity. Further in vivo MRI experiments distinctively depict fine anatomical features in brain imaging at a low dose of 5 mg of Mn per kg and possible removal from the kidneys due to their small size and biocompatibility.

  9. ScienceCast 88: Dark Lightning

    NASA Image and Video Library

    2013-01-07

    Researchers studying thunderstorms have made a surprising discovery: The lightning we see with our eyes has a dark competitor that discharges storm clouds and flings antimatter into space. Scientists are scrambling to understand "dark lightning."

  10. Whole Blood Activation Results in Altered T Cell and Monocyte Cytokine Production Profiles by Flow Cytometry

    NASA Technical Reports Server (NTRS)

    Crucian, Brian E.; Sams, Clarence F.

    2001-01-01

    An excellent monitor of the immune balance of peripheral circulating cells is to determine their cytokine production patterns in response to stimuli. Using flow cytometry, a positive identification of cytokine producing cells in a mixed culture may be achieved. Recently, the ability to assess cytokine production following a whole-blood activation culture has been described. In this study, whole blood activation was compared to traditional PBMC activation and the individual cytokine secretion patterns for both T cells, T cell subsets and monocytes was determined by flow cytometry. RESULTS: For T cell cytokine assessment (IFNg/IL-10 and IL-21/L-4) following PMA +ionomycin activation: (1) a Significantly greater percentages of T cells producing IFNgamma and IL-2 were observed following whole-blood culture and (2) altered T cell cytokine production kinetics were observed by varying whole blood culture times. Four-color analysiS was used to allow assessment of cytokine production by specific T cell subsets. It was found that IFNgamma production was significantly elevated in the CD3+/CD8+ T cell population as compared to the CD3+/CD8- population following five hours of whole blood activation. Conversely, IL-2 and IL-10 production were Significantly elevated in the CD3+/CD8- T cell population as compared to the CD3+/CD8+ population. Monocyte cytokine production was assessed in both culture systems following LPS activation for 24 hours. A three-color flow cytometric was used to assess two cytokines (IL-1a/IL-12 and TNFa/IL-10) in conjunction with CD14. Nearly all monocytes were stimulated to produce IL-1a, IL-12 and TNFa. equally well in both culture systems, however monocyte production of IL-10 was significantly elevated in whole blood culture as compared to PBMC culture. IL-12 producing monocytes appeared to be a distinct subpopulation of the IL-1a producing set, whereas IL-10 and TNFa producing monocytes were largely mutually exclusive. IL-10 and TNFa producing

  11. Assessment of Arterial Wall Enhancement for Differentiation of Parent Artery Disease from Small Artery Disease: Comparison between Histogram Analysis and Visual Analysis on 3-Dimensional Contrast-Enhanced T1-Weighted Turbo Spin Echo MR Images at 3T.

    PubMed

    Jang, Jinhee; Kim, Tae-Won; Hwang, Eo-Jin; Choi, Hyun Seok; Koo, Jaseong; Shin, Yong Sam; Jung, So-Lyung; Ahn, Kook-Jin; Kim, Bum-Soo

    2017-01-01

    The purpose of this study was to compare the histogram analysis and visual scores in 3T MRI assessment of middle cerebral arterial wall enhancement in patients with acute stroke, for the differentiation of parent artery disease (PAD) from small artery disease (SAD). Among the 82 consecutive patients in a tertiary hospital for one year, 25 patients with acute infarcts in middle cerebral artery (MCA) territory were included in this study including 15 patients with PAD and 10 patients with SAD. Three-dimensional contrast-enhanced T1-weighted turbo spin echo MR images with black-blood preparation at 3T were analyzed both qualitatively and quantitatively. The degree of MCA stenosis, and visual and histogram assessments on MCA wall enhancement were evaluated. A statistical analysis was performed to compare diagnostic accuracy between qualitative and quantitative metrics. The degree of stenosis, visual enhancement score, geometric mean (GM), and the 90th percentile (90P) value from the histogram analysis were significantly higher in PAD than in SAD ( p = 0.006 for stenosis, < 0.001 for others). The receiver operating characteristic curve area of GM and 90P were 1 (95% confidence interval [CI], 0.86-1.00). A histogram analysis of a relevant arterial wall enhancement allows differentiation between PAD and SAD in patients with acute stroke within the MCA territory.

  12. T1ρ MRI Quantification of Arthroscopically-Confirmed Cartilage Degeneration

    PubMed Central

    Witschey, Walter RT; Borthakur, Arijitt; Fenty, Matt; Kneeland, J Bruce; Lonner, Jess H; McArdle, Erin L.; Sochor, Matt; Reddy, Ravinder

    2010-01-01

    9 asymptomatic subjects and 6 patients underwent T1ρ MRI to determine whether Outerbridge grade 1 or 2 cartilage degeneration observed during arthroscopy could be detected noninvasively. MRI was performed 2–3 months post-arthroscopy using sagittal T1-weighted and axial and coronal T1ρ MRI from which spatial T1ρ relaxation maps were calculated from segmented T1-weighted images. Median T1ρ relaxation times of patients with arthroscopically documented cartilage degeneration and asymptomatic subjects were significantly different (p < 0.001) and median T1ρ exceeded asymptomatic articular cartilage median T1ρ by 2.5 to 9.2 ms. In 8 observations of mild cartilage degeneration at arthroscopy (Outerbridge grades 1 and 2), mean compartment T1ρ was elevated in 5, but in all observations, large foci of increased T1ρ were observed. It was determined that T1ρ could detect some, but not all, Outerbridge grade 1 and 2 cartilage degeneration but that a larger patient population is needed to determine the sensitivity to these changes. PMID:20432308

  13. The acute hormonal response to free weight and machine weight resistance exercise.

    PubMed

    Shaner, Aaron A; Vingren, Jakob L; Hatfield, Disa L; Budnar, Ronald G; Duplanty, Anthony A; Hill, David W

    2014-04-01

    Resistance exercise can acutely increase the concentrations of circulating neuroendocrine factors, but the effect of mode on this response is not established. The purpose of this study was to examine the effect of resistance exercise selection on the acute hormonal response using similar lower-body multijoint movement free weight and machine weight exercises. Ten resistance trained men (25 ± 3 years, 179 ± 7 cm, 84.2 ± 10.5 kg) completed 6 sets of 10 repetitions of squat or leg press at the same relative intensity separated by 1 week. Blood samples were collected before (PRE), immediately after (IP), and 15 (P15) and 30 minutes (P30) after exercise, and analyzed for testosterone (T), growth hormone (GH), and cortisol (C) concentrations. Exercise increased (p ≤ 0.05) T and GH at IP, but the concentrations at IP were greater for the squat (T: 31.4 ± 10.3 nmol·L(-1); GH: 9.5 ± 7.3 μg·L(-1)) than for the leg press (T: 26.9 ± 7.8 nmol·L(-1); GH: 2.8 ± 3.2 μg·L(-1)). At P15 and P30, GH was greater for the squat (P15: 12.3 ± 8.9 μg·L(-1); P30: 12.0 ± 8.9 μg·L(-1)) than for the leg press (P15: 4.8 ± 3.4 μg·L(-1); P30: 5.4 ± 4.1 μg·L(-1)). C was increased after exercise and was greater for the squat than for the leg press. Although total work (external load and body mass moved) was greater for the squat than for the leg press, rating of perceived exertion did not differ between the modes. Free weight exercises seem to induce greater hormonal responses to resistance exercise than machine weight exercises using similar lower-body multijoint movements and primary movers.

  14. First results from the DarkSide-50 dark matter experiment at Laboratori Nazionali del Gran Sasso

    DOE PAGES

    Agnes, P.

    2015-03-11

    We report the first results of DarkSide-50, a direct search for dark matter operating in the underground Laboratori Nazionali del Gran Sasso (LNGS) and searching for the rare nuclear recoils possibly induced by weakly interacting massive particles (WIMPs). The dark matter detector is a Liquid Argon Time Projection Chamber with a (46.4 ± 0.7) kg active mass, operated inside a 30 t organic liquid scintillator neutron veto, which is in turn installed at the center of a 1 kt water Cherenkov veto for the residual flux of cosmic rays. We report here the null results of a dark matter searchmore » for a (1422 ± 67) kg d exposure with an atmospheric argon fill. As a result, this is the most sensitive dark matter search performed with an argon target, corresponding to a 90% CL upper limit on the WIMP-nucleon spin-independent cross section of 6.1×10 -44 cm 2 for a WIMP mass of 100 Gev/c 2.« less

  15. Low-molecular-weight polysaccharides from Agaricus blazei Murrill modulate the Th1 response in cancer immunity.

    PubMed

    Jiang, Liyan; Yu, Zhipu; Lin, Yu; Cui, Liran; Yao, Shujuan; Lv, Liyan; Liu, Jicheng

    2018-03-01

    To assess the effect of low-molecular-weight polysaccharides from Agaricus blazei Murrill (ABP-AW1) as an immunoadjuvant therapy for type 1 T-helper (Th1) responses in tumorigenesis, C57BL/6 mice were inoculated subcutaneously with ovalbumin (E.G7-OVA). After 3, 10 and 17 days, the mice were immunized with PBS, OVA alone, or OVA and ABP-AW1, at low (50 µg), intermediate (100 µg) or high (200 µg) doses. Tumor growth was examined and compared among the groups, as were the following parameters: Splenocyte viability/proliferation, peripheral blood CD4 + /CD8 + T cell ratio, serum OVA-specific IgG1 and IgG2b, secretion of interleukin (IL)-2 and interferon (IFN)-γ, and IFN-γ production on a single cell level from cultured splenocytes. Tumor growth in mice treated with OVA and ABP-AW1 (100 or 200 µg) was significantly slower, compared with in the other groups at the same time-points. OVA with 100 or 200 µg ABP-AW1 was associated with a higher number of total splenocytes, a higher ratio of peripheral blood CD4 + /CD8 + T-lymphocytes, higher serum levels of OVA-specific Th1-type antibody IgG2b and greater secretion of the Th1 cytokines IL-1 and IFN-γ from splenocytes. ABP-AW1 is a promising immunoadjuvant therapy candidate, due to its ability to boost the Th1 immune response when co-administered with a cancer vaccine intended to inhibit cancer progression.

  16. Low-molecular-weight polysaccharides from Agaricus blazei Murrill modulate the Th1 response in cancer immunity

    PubMed Central

    Jiang, Liyan; Yu, Zhipu; Lin, Yu; Cui, Liran; Yao, Shujuan; Lv, Liyan; Liu, Jicheng

    2018-01-01

    To assess the effect of low-molecular-weight polysaccharides from Agaricus blazei Murrill (ABP-AW1) as an immunoadjuvant therapy for type 1 T-helper (Th1) responses in tumorigenesis, C57BL/6 mice were inoculated subcutaneously with ovalbumin (E.G7-OVA). After 3, 10 and 17 days, the mice were immunized with PBS, OVA alone, or OVA and ABP-AW1, at low (50 µg), intermediate (100 µg) or high (200 µg) doses. Tumor growth was examined and compared among the groups, as were the following parameters: Splenocyte viability/proliferation, peripheral blood CD4+/CD8+ T cell ratio, serum OVA-specific IgG1 and IgG2b, secretion of interleukin (IL)-2 and interferon (IFN)-γ, and IFN-γ production on a single cell level from cultured splenocytes. Tumor growth in mice treated with OVA and ABP-AW1 (100 or 200 µg) was significantly slower, compared with in the other groups at the same time-points. OVA with 100 or 200 µg ABP-AW1 was associated with a higher number of total splenocytes, a higher ratio of peripheral blood CD4+/CD8+ T-lymphocytes, higher serum levels of OVA-specific Th1-type antibody IgG2b and greater secretion of the Th1 cytokines IL-1 and IFN-γ from splenocytes. ABP-AW1 is a promising immunoadjuvant therapy candidate, due to its ability to boost the Th1 immune response when co-administered with a cancer vaccine intended to inhibit cancer progression. PMID:29467867

  17. Increased blood levels of persistent organic pollutants (POP) in obese individuals after weight loss-A review.

    PubMed

    Jansen, Aina; Lyche, Jan L; Polder, Anuschka; Aaseth, Jan; Skaug, Marit Aralt

    2017-01-01

    Lipophilic persistent organic pollutants (POP) are stored in adipose tissue. Following rapid weight loss such as when induced by bariatric surgery, an increased release of potential harmful lipophilic compounds into the blood circulation may occur. Weight reduction is recommended for overweight and obese individuals in order to decrease risk of weight-related health problems. However, in cases of significant weight reduction POP become mobilized chemicals and consequently may adversely affect health, including endocrine disruption. The objective of the present investigation was to estimate quantitatively the level of mobilization of POP following weight loss over time. According to literature search criteria, 17 studies were identified with 2061 participants. Data from 5 of the studies with 270 participants were used to assess the change in blood levels of POP in percent per kilogram weight loss. Weight loss in the included studies varied from 4.4 to 64.8 kg. In all studies, the majority of POP concentrations in blood were found to rise following weight reduction. Blood concentrations following weight reduction were elevated by 2-4% per kilogram weight loss for most POP examined. The increased POP levels were still elevated 12 mo after intervention. Most research in this field, including animal studies, is carried out on a single compound or group of selected compounds, not taking the "cocktail effect" into consideration. This does not reflect the true range of POP to which humans are actually exposed. Few chronic investigations have been published and, in particular, few studies were available that compared the increase in POP concentrations with clinical consequences as individuals lost weight. These limitations call for caution in interpreting results. The benefits of losing weight still far outweigh the potential adverse health risks. However, further studies are recommended to determine the clinical significance of increased blood levels of POPs following

  18. A pediatric brain structure atlas from T1-weighted MR images

    NASA Astrophysics Data System (ADS)

    Shan, Zuyao Y.; Parra, Carlos; Ji, Qing; Ogg, Robert J.; Zhang, Yong; Laningham, Fred H.; Reddick, Wilburn E.

    2006-03-01

    In this paper, we have developed a digital atlas of the pediatric human brain. Human brain atlases, used to visualize spatially complex structures of the brain, are indispensable tools in model-based segmentation and quantitative analysis of brain structures. However, adult brain atlases do not adequately represent the normal maturational patterns of the pediatric brain, and the use of an adult model in pediatric studies may introduce substantial bias. Therefore, we proposed to develop a digital atlas of the pediatric human brain in this study. The atlas was constructed from T1 weighted MR data set of a 9 year old, right-handed girl. Furthermore, we extracted and simplified boundary surfaces of 25 manually defined brain structures (cortical and subcortical) based on surface curvature. Higher curvature surfaces were simplified with more reference points; lower curvature surfaces, with fewer. We constructed a 3D triangular mesh model for each structure by triangulation of the structure's reference points. Kappa statistics (cortical, 0.97; subcortical, 0.91) indicated substantial similarities between the mesh-defined and the original volumes. Our brain atlas and structural mesh models (www.stjude.org/BrainAtlas) can be used to plan treatment, to conduct knowledge and modeldriven segmentation, and to analyze the shapes of brain structures in pediatric patients.

  19. Coronary heart disease risk factors in men with light and dark skin in Puerto Rico.

    PubMed Central

    Costas, R; Garcia-Palmieri, M R; Sorlie, P; Hertzmark, E

    1981-01-01

    The association of skin color with coronary heart disease risk factors was studied in 4,000 urban Puerto Rican men. Skin color on the inner upper arm was classified according to the von Luschan color tiles. Using this grading, men were separated into two groups of light or dark skin color. The dark group had a lower socioeconomic status (SES) based on income, education, and occupation. Dark men had slightly higher mean systolic blood pressures (SBP) and lower mean serum cholesterol levels than the light, but the relative weights and cigarette smoking habits of both groups were similar. After controlling for the differences in SES, skin color showed a small but statistically significant association with SBP. Whether this association with skin color represents genetic or environmental influences on SBP could not be determined from this study. PMID:7235099

  20. Improved black-blood imaging using DANTE-SPACE for simultaneous carotid and intracranial vessel wall evaluation

    PubMed Central

    Xie, Yibin; Yang, Qi; Xie, Guoxi; Pang, Jianing; Fan, Zhaoyang; Li, Debiao

    2015-01-01

    Purpose The purpose of this work is to develop a 3D black-blood imaging method for simultaneously evaluating carotid and intracranial arterial vessel wall with high spatial resolution and excellent blood suppression with and without contrast enhancement. Methods DANTE preparation module was incorporated into SPACE sequence to improve blood signal suppression. Simulations and phantom studies were performed to quantify image contrast variations induced by DANTE. DANTE-SPACE, SPACE and 2D TSE were compared for apparent SNR, CNR and morphometric measurements in fourteen healthy subjects. Preliminary clinical validation was performed in six symptomatic patients. Results Apparent residual luminal blood was observed in 5 (pre-CE) and 9 (post-CE) subjects with SPACE, and only 2 (post-CE) subjects with DANTE-SPACE. DANTE-SPACE showed 31% (pre-CE) and 100% (post-CE) improvement in wall-to-blood CNR over SPACE. Vessel wall area measured from SPACE was significantly larger than that from DANTE-SPACE due to possible residual blood signal contamination. In patients DANTE-SPACE showed the potential to detect vessel wall dissection and identify plaque components. Conclusion DANTE-SPACE significantly improved arterial and venous blood suppression compared with SPACE. Simultaneous high-resolution carotid and intracranial vessel wall imaging to potentially identify plaque components was feasible with scan time under 6 minutes. PMID:26152900

  1. Dark matter component decaying after recombination: Sensitivity to baryon acoustic oscillation and redshift space distortion probes

    NASA Astrophysics Data System (ADS)

    Chudaykin, A.; Gorbunov, D.; Tkachev, I.

    2018-04-01

    It has been recently suggested [1] that a subdominant fraction of dark matter decaying after recombination may alleviate tension between high-redshift (CMB anisotropy) and low-redshift (Hubble constant, cluster counts) measurements. In this report, we continue our previous study [2] of the decaying dark matter (DDM) model adding all available recent baryon acoustic oscillation (BAO) and redshift space distortions (RSD) measurements. We find that the BAO/RSD measurements generically prefer the standard Λ CDM and combined with other cosmological measurements impose an upper limit on the DDM fraction at the level of ˜5 %, strengthening by a factor of 1.5 limits obtained in [2] mostly from CMB data. However, the numbers vary from one analysis to other based on the same Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12 (DR12) galaxy sample. Overall, the model with a few percent DDM fraction provides a better fit to the combined cosmological data as compared to the Λ CDM : the cluster counting and direct measurements of the Hubble parameter are responsible for that. The improvement can be as large as 1.5 σ and grows to 3.3 σ when the CMB lensing power amplitude AL is introduced as a free fitting parameter.

  2. SAR Reduction in 7T C-Spine Imaging Using a “Dark Modes” Transmit Array Strategy

    PubMed Central

    Eryaman, Yigitcan; Guerin, Bastien; Keil, Boris; Mareyam, Azma; Herraiz, Joaquin L.; Kosior, Robert K.; Martin, Adrian; Torrado-Carvajal, Angel; Malpica, Norberto; Hernandez-Tamames, Juan A.; Schiavi, Emanuele; Adalsteinsson, Elfar; Wald, Lawrence L.

    2016-01-01

    Purpose Local specific absorption rate (SAR) limits many applications of parallel transmit (pTx) in ultra high-field imaging. In this Note, we introduce the use of an array element, which is intentionally inefficient at generating spin excitation (a “dark mode”) to attempt a partial cancellation of the electric field from those elements that do generate excitation. We show that adding dipole elements oriented orthogonal to their conventional orientation to a linear array of conventional loop elements can lower the local SAR hotspot in a C-spine array at 7 T. Methods We model electromagnetic fields in a head/torso model to calculate SAR and excitation B1+ patterns generated by conventional loop arrays and loop arrays with added electric dipole elements. We utilize the dark modes that are generated by the intentional and inefficient orientation of dipole elements in order to reduce peak 10g local SAR while maintaining excitation fidelity. Results For B1+ shimming in the spine, the addition of dipole elements did not significantly alter the B1+ spatial pattern but reduced local SAR by 36%. Conclusion The dipole elements provide a sufficiently complimentary B1+ and electric field pattern to the loop array that can be exploited by the radiofrequency shimming algorithm to reduce local SAR. PMID:24753012

  3. Gravitational collapse of dark energy field configurations and supermassive black hole formation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jhalani, V.; Kharkwal, H.; Singh, A., E-mail: anupamsingh.iitk@gmail.com

    Dark energy is the dominant component of the total energy density of our Universe. The primary interaction of dark energy with the rest of the Universe is gravitational. It is therefore important to understand the gravitational dynamics of dark energy. Since dark energy is a low-energy phenomenon from the perspective of particle physics and field theory, a fundamental approach based on fields in curved space should be sufficient to understand the current dynamics of dark energy. Here, we take a field theory approach to dark energy. We discuss the evolution equations for a generic dark energy field in curved space-timemore » and then discuss the gravitational collapse for dark energy field configurations. We describe the 3 + 1 BSSN formalism to study the gravitational collapse of fields for any general potential for the fields and apply this formalism to models of dark energy motivated by particle physics considerations. We solve the resulting equations for the time evolution of field configurations and the dynamics of space-time. Our results show that gravitational collapse of dark energy field configurations occurs and must be considered in any complete picture of our Universe. We also demonstrate the black hole formation as a result of the gravitational collapse of the dark energy field configurations. The black holes produced by the collapse of dark energy fields are in the supermassive black hole category with the masses of these black holes being comparable to the masses of black holes at the centers of galaxies.« less

  4. T2-Weighted Dixon Turbo Spin Echo for Accelerated Simultaneous Grading of Whole-Body Skeletal Muscle Fat Infiltration and Edema in Patients With Neuromuscular Diseases.

    PubMed

    Schlaeger, Sarah; Klupp, Elisabeth; Weidlich, Dominik; Cervantes, Barbara; Foreman, Sarah C; Deschauer, Marcus; Schoser, Benedikt; Katemann, Christoph; Kooijman, Hendrik; Rummeny, Ernst J; Zimmer, Claus; Kirschke, Jan S; Karampinos, Dimitrios C

    2018-04-02

    The assessment of fatty infiltration and edema in the musculature of patients with neuromuscular diseases (NMDs) typically requires the separate performance of T1-weighted and fat-suppressed T2-weighted sequences. T2-weighted Dixon turbo spin echo (TSE) enables the generation of T2-weighted fat- and water-separated images, which can be used to assess both pathologies simultaneously. The present study examines the diagnostic performance of T2-weighted Dixon TSE compared with the standard sequences in 10 patients with NMDs and 10 healthy subjects. Whole-body magnetic resonance imaging was performed including T1-weighted Dixon fast field echo, T2-weighted short-tau inversion recovery, and T2-weighted Dixon TSE. Fatty infiltration and intramuscular edema were rated by 2 radiologists using visual semiquantitative rating scales. To assess intermethod and interrater agreement, weighted Cohen's κ coefficients were calculated. The ratings of fatty infiltration showed high intermethod and high interrater agreement (T1-weighted Dixon fast field echo vs T2-weighted Dixon TSE fat image). The evaluation of edematous changes showed high intermethod and good interrater agreement (T2-weighted short-tau inversion recovery vs T2-weighted Dixon TSE water image). T2-weighted Dixon TSE imaging is an alternative for accelerated simultaneous grading of whole-body skeletal muscle fat infiltration and edema in patients with NMDs.

  5. Optical response of highly reflective film used in the water Cherenkov muon veto of the XENON1T dark matter experiment

    NASA Astrophysics Data System (ADS)

    Geis, Ch.; Grignon, C.; Oberlack, U.; Ramírez García, D.; Weitzel, Q.

    2017-06-01

    The XENON1T experiment is the most recent stage of the XENON Dark Matter Search, aiming for the direct detection of dark matter candidates, such as the Weakly Interacting Massive Particles (WIMPs). The projected sensitivity for the spin-independent WIMP-nucleon elastic scattering cross-section is σ ≈ 2 × 10-47 cm2 for a WIMP mass of mχ = 50 GeV/c2. To reach its projected sensitivity, the background has to be reduced by two orders of magnitude compared to its predecessor XENON100. This requires a water Cherenkov muon veto surrounding the XENON1T TPC, both to shield external backgrounds and to tag muon-induced energetic neutrons through detection of a passing muon or the secondary shower induced by a muon interacting in the surrounding rock. The muon veto is instrumented with 84 8'' PMTs with high quantum efficiency (QE) in the Cherenkov regime and the walls of the watertank are clad with the highly reflective DF2000MA foil by 3M. Here, we present a study of the reflective properties of this foil, as well as the measurement of its wavelength shifting (WLS) properties. Furthermore, we present the impact of reflectance and WLS on the detection efficiency of the muon veto, through the use of a Monte Carlo simulation carried out with the Geant4 toolkit. The measurements yield a specular reflectance of ≈100% for wavelengths larger than 400 nm, while ≈90% of the incoming light below 370 nm is absorbed by the foil. Approximately 3-7.5% of the light hitting the foil within the wavelength range 250 nm <= λ <= 390 nm is used for the WLS process. The intensity of the emission spectrum of the WLS light is slightly dependent on the absorbed wavelength and shows the shape of a rotational-vibrational fluorescence spectrum, peaking at around λ ≈ 420 nm. Adjusting the reflectance values to the measured ones in the Monte Carlo simulation originally used for the muon veto design, the veto detection efficiency remains unchanged. Including the wavelength shifting in the

  6. Environmental Lead (Pb) Exposure Versus Fatty Acid Content in Blood and Milk of the Mother and in the Blood of Newborn Children.

    PubMed

    Baranowska-Bosiacka, Irena; Kosińska, Ida; Jamioł, Dominika; Gutowska, Izabela; Prokopowicz, Adam; Rębacz-Maron, Ewa; Goschorska, Marta; Olszowski, Tomasz; Chlubek, Dariusz

    2016-04-01

    Significant progress in understanding the effects of the neurotoxic action of lead (Pb) in young organisms had led to reduction of "safe" level in the blood (Pb-B) to 5 μg/dL in children and pregnant women. Prolonged exposure to relatively low levels of Pb, generally asymptomatic and subclinical (i.e., microintoxication), is currently the dominant form of environmental poisoning, and its negative effects on health may appear after many years, e.g., secondary contamination from Pb bone deposits released in pregnancy. Therefore, the aim of this study was to investigate the effect of environmental exposure (urban areas) of mothers to Pb, on its levels in their milk and blood and in the blood of newborns. Moreover, the aim was to determine the fatty acid profile in the mothers' blood and milk and in the blood of newborns. We also wanted to find if infant birth weight depends on Pb blood levels, as well as on Pb and fatty acid levels in the blood and milk of the mothers. Finally, we examined if the mothers' weight and body mass index (BMI) before pregnancy influenced the concentration of Pb and fatty acid profile in the blood and milk of mothers and in the blood of their children. Analysis of fatty acids elaidic (C18:1, 9t), oleic (C18:1, 9c), vaccenic (C18:1, 11t), cis-vaccenic (C18:1, 11c), linoleic (C18:2, cis), γ-linolenic (C18:3, n-6), α-linolenic (C18:3, n-3), arachidonic (C20:4, n-6), eicosapentaenoic (C20:5, n-3), and docosahexaenoic (C22:6, n-3) was conducted by gas chromatography. The concentration of Pb in the whole blood and milk were determined by atomic absorption spectrometry with graphite furnace atomization and Zeeman correction. Our study established a significant and strong correlation between the content of Pb in the blood of the mother and the child. This supports the assumption that the transport of Pb through the placenta is neither regulated nor selective. Environmental maternal exposure to lead resulting in Pb-B levels considered safe for

  7. Directly Detecting MeV-Scale Dark Matter Via Solar Reflection.

    PubMed

    An, Haipeng; Pospelov, Maxim; Pradler, Josef; Ritz, Adam

    2018-04-06

    If dark matter (DM) particles are lighter than a few   MeV/c^{2} and can scatter off electrons, their interaction within the solar interior results in a considerable hardening of the spectrum of galactic dark matter received on Earth. For a large range of the mass versus cross section parameter space, {m_{e},σ_{e}}, the "reflected" component of the DM flux is far more energetic than the end point of the ambient galactic DM energy distribution, making it detectable with existing DM detectors sensitive to an energy deposition of 10-10^{3}  eV. After numerically simulating the small reflected component of the DM flux, we calculate its subsequent signal due to scattering on detector electrons, deriving new constraints on σ_{e} in the MeV and sub-MeV range using existing data from the XENON10/100, LUX, PandaX-II, and XENON1T experiments, as well as making projections for future low threshold direct detection experiments.

  8. Directly Detecting MeV-Scale Dark Matter Via Solar Reflection

    NASA Astrophysics Data System (ADS)

    An, Haipeng; Pospelov, Maxim; Pradler, Josef; Ritz, Adam

    2018-04-01

    If dark matter (DM) particles are lighter than a few MeV /c2 and can scatter off electrons, their interaction within the solar interior results in a considerable hardening of the spectrum of galactic dark matter received on Earth. For a large range of the mass versus cross section parameter space, {me,σe}, the "reflected" component of the DM flux is far more energetic than the end point of the ambient galactic DM energy distribution, making it detectable with existing DM detectors sensitive to an energy deposition of 10 -103 eV . After numerically simulating the small reflected component of the DM flux, we calculate its subsequent signal due to scattering on detector electrons, deriving new constraints on σe in the MeV and sub-MeV range using existing data from the XENON10/100, LUX, PandaX-II, and XENON1T experiments, as well as making projections for future low threshold direct detection experiments.

  9. Node 1 and PMA-1 are moved for weight and center of gravity determination

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Node 1, the first U.S. element for the International Space Station, and Pressurized Mating Adapter-1 (PMA-1) continue with prelaunch preparation activities at KSC's Space Station Processing Facility. Node 1 is a connecting passageway to the living and working areas of the space station. The node and PMA-1 are being moved to an element rotation stand, or test stand, where they will undergo an interim weight and center of gravity determination. The final determination is planned to be performed prior to transporting Node 1 to the launch pad. Node 1 is scheduled to fly on STS-88.

  10. [Effect of physical activity and t-786C polymorphism in blood pressure and blood flow in the elderly].

    PubMed

    Zago, Anderson Saranz; Kokubun, Eduardo; Fenty-Stewart, Nicola; Park, Joon-Young; Attipoe, Selasi; Hagberg, James; Brown, Michael

    2010-10-01

    the T-786C polymorphism of the gene for endothelial nitric oxide synthase (eNOS) and superoxide anion production may reduce production and bioavailability of nitric oxide, affecting the degree of vasodilation. This effect can be reversed by exercise. to investigate the influence of aerobic training and T-786C polymorphism in the concentrations of nitric oxide metabolites (NOx) in blood flow (BF) and blood pressure (BP). thirty-two elderly pre-hypertensive women (59 ± 6 years old) were divided into two groups according to the T-786C polymorphism (TT and TC + CC). We analyzed the concentrations of NOx (plasma) and blood flow by venous occlusion plethysmography at rest, 1, 2 and 3 minutes post-occlusion (BF-0, BF-1 BF-2 BF-3, respectively). Evaluations were performed before and after 6 months of a program of aerobic exercise. In the pre-training evaluations, NOx levels were lower in TC + CC group than in TT group. The TT group showed correlations between NOx and BF-0 (r = 0.6) and diastolic blood pressure (DBP) and BF-0 (r = -0.7), but no correlation was found in TC + CC group. In the post-training evaluations, there were correlations between NOx and BF-0 (r = 0.6) and the changes in NOx and DBP (r = -0.6) in TT group. There were also correlations between DBP and BF-1 (r = -0.8), DBP, and BF-2 (r = -0.6), DBP, and BF-3 (r = -0.6), in the changes between NOx and BF-1 (r = 0.8) and changes in NOx and DBP (r = -0.7) in TC + CC group. it was concluded that 6 months of aerobic exercise can increase the relationship between NO, BP and BF in elderly of allele C carriers.

  11. A highly stable l-alanine-based mono(aquated) Mn(ii) complex as a T1-weighted MRI contrast agent.

    PubMed

    Khannam, Mahmuda; Weyhermüller, Thomas; Goswami, Upashi; Mukherjee, Chandan

    2017-08-08

    The synthesized lithium (S)-6,6'-(1-carboxyethylazanediyl)bis(methylene)dipicolinate (Li 3 cbda) is a new chiral, alanine-based ligand bearing two picolinate functionalities. The trianionic form of the ligand [(cbda) 3- ] constitutes a seven-coordinate, water-soluble, pentagonal bipyramidal Mn(ii) complex (1). The structural analysis reveals the presence of a water coordinating site in the complex. The complex is thermodynamically very stable, and the stability is not affected by the presence of physiological anions (HCO 3 - , PO 4 3- , and F - ). The pH of the medium exerts a small effect on the stability of the complex. The r 1 relaxivity of 3.02 mM -1 s -1 is exhibited by the complex at 1.41 T, pH ∼7.4, and 25 °C. Phantom images obtained via a clinical MRI BRIVO MR355 system established concentration-dependent signal enhancement by the complex. The cytotoxicity test confirmed complex 1 as a biocompatible potential T 1 -weighted MRI contrast agent.

  12. In vitro evaluation of BacT/Alert FA blood culture bottles and T2Candida assay for the detection of Candida in the presence of antifungals.

    PubMed

    Beyda, Nicholas D; Amadio, Jonathan; Rodriguez, Jose R; Malinowski, Karen; Garey, Kevin W; Wanger, Audrey; Ostrosky-Zeichner, Luis

    2018-06-13

    The T2Candida assay is a novel, non-culture based assay for the diagnosis of candidemia directly from whole blood. The impact of antifungals on the performance of the T2Candida assay and blood culture bottles have not been well described. In this study, the performance of the T2Candida assay was compared to that of blood culture in detecting Candida spp. in spiked blood cultures with or without the presence of antifungals. Clinical bloodstream isolates of Candida spp. were inoculated into human whole blood at low (1 - 5 cells/mL) and high (10-50 cells/mL) concentrations with or without presence of caspofungin and fluconazole. Time to detection (TTD) was assessed for prepared samples using BacTAlert FA aerobic blood culture bottles or the T2Candida assay. In the absence of antifungals, T2Candida assay sensitivity was comparable to that of blood culture at both the low and high inoculum (95% vs. 97.5% and 100% vs. 100%, respectively) and had an average TTD that was significantly faster (5.1 hrs vs 27.2 - 30 hrs, respectively). Neither caspofungin nor fluconazole was observed to impact the sensitivity or TTD of the T2Candida assay, while fluconazole reduced overall blood culture sensitivity by 7.5% - 12.5% (at low and high inoculum, respectively) and significantly prolonged the TTD of C. albicans, C. tropicalis , and C. parapsilosis by 14.8 - 67 hrs. Neither caspofungin nor fluconazole impacted the performance of the T2Candida assay in-vitro and may be useful for the diagnosis of candidemia in patients receiving antifungal therapy. Copyright © 2018 American Society for Microbiology.

  13. The Phase-space Density Distribution of Dark Matter Halos

    NASA Astrophysics Data System (ADS)

    Williams, Liliya L. R.; Austin, Crystal; Barnes, Eric; Babul, Arif; Dalcanton, Julianne

    2004-12-01

    High resolution N-body simulations have all but converged on a common empirical form for the shape of the density profiles of halos, but the full understanding of the underlying physics of halo formation has eluded them so far. We investigate the formation and structure of dark matter halos using analytical and semi-analytical techniques. Our halos are formed via an extended secondary infall model (ESIM); they contain secondary perturbations and hence random tangential and ra- dial motions which affect the halo’s evolution at it undergoes shell-crossing and virialization. Even though the density profiles of NFW and ESIM halos are different their phase-space density distributions are the same: ρ σ3 ∝ r α , with α 1 875 over 3 decades in radius. We use two approaches to try to explain this “universal” slope: (1) The Jeans equation analysis yields many insights, however, does not answer why α 1 875. (2) The secondary infall model of the 1960’s £ ¤ and 1970’s, augmented by “thermal motions” of particles does predict that halos should have α 1 875. However, this relies on assumptions of spherical symmetry and slow accretion. While £ ¤ for ESIM halos these assumptions are justified, they most certainly break down for simulated halos which forms hierarchically. We speculate that our argument may apply to an “on-average” formation scenario of halos within merger-driven numerical simulations, and thereby explain why α 1 875 for NFW halos. Thus, ρ σ3 ∝ r 1 875 may be a generic feature of violent relaxation.

  14. Can dark matter be a scalar field?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jesus, J.F.; Malatrasi, J.L.G.; Pereira, S.H.

    2016-08-01

    In this paper we study a real scalar field as a possible candidate to explain the dark matter in the universe. In the context of a free scalar field with quadratic potential, we have used Union 2.1 SN Ia observational data jointly with a Planck prior over the dark matter density parameter to set a lower limit on the dark matter mass as m ≥0.12 H {sub 0}{sup -1} eV ( c = h-bar =1). For the recent value of the Hubble constant indicated by the Hubble Space Telescope, namely H {sub 0}=73±1.8 km s{sup -1}Mpc{sup -1}, this leads tomore » m ≥1.56×10{sup -33} eV at 99.7% c.l. Such value is much smaller than m ∼ 10{sup -22} eV previously estimated for some models. Nevertheless, it is still in agreement with them once we have not found evidences for a upper limit on the scalar field dark matter mass from SN Ia analysis. In practice, it confirms free real scalar field as a viable candidate for dark matter in agreement with previous studies in the context of density perturbations, which include scalar field self interaction.« less

  15. Benefits of commercial weight-loss programs on blood pressure and lipids: a systematic review.

    PubMed

    Mehta, Ambereen K; Doshi, Ruchi S; Chaudhry, Zoobia W; Jacobs, David K; Vakil, Rachit M; Lee, Clare J; Bleich, Sara N; Clark, Jeanne M; Gudzune, Kimberly A

    2016-09-01

    Our objective was to compare the effect of commercial weight-loss programs on blood pressure and lipids to control/education or counseling among individuals with overweight/obesity. We conducted a systematic review by searching MEDLINE and Cochrane Database of Systematic Reviews from inception to November 2014 and references identified by the programs. We included randomized, controlled trials ≥12weeks in duration. Two reviewers extracted information on study design, interventions, and mean change in systolic blood pressure (SBP), diastolic blood pressure (DBP), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), triglycerides, and total cholesterol and assessed risk of bias. We included 27 trials. Participants' blood pressure and lipids were normal at baseline in most trials. At 12months, Weight Watchers showed little change in blood pressure or lipid outcomes as compared to control/education (2 trials). At 12months, Atkins' participants had higher HDL-c and lower triglycerides than counseling (4 trials). Other programs had inconsistent effects or lacked long-term studies. Risk of bias was high for most trials of all programs. In conclusion, limited data exist regarding most commercial weight-loss programs' long-term effects on blood pressure and lipids. Clinicians should be aware that Weight Watchers has limited data that demonstrate CVD risk factor benefits relative to control/education. Atkins may be a reasonable option for patients with dyslipidemia. Additional well-designed, long-term trials are needed to confirm these conclusions and evaluate other commercial programs. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. T2-weighted MRI of the upper abdomen: comparison of four fat-suppressed T2-weighted sequences including PROPELLER (BLADE) technique.

    PubMed

    Bayramoglu, Sibel; Kilickesmez, Ozgür; Cimilli, Tan; Kayhan, Arda; Yirik, Gülseren; Islim, Filiz; Alibek, Sedat

    2010-03-01

    The aim of this study was to compare four different fat-suppressed T2-weighted sequences with different techniques with regard to image quality and lesion detection in upper abdominal magnetic resonance imaging (MRI) scans. Thirty-two consecutive patients referred for upper abdominal MRI for the evaluation of various suspected pathologies were included in this study. Different T2-weighted sequences (free-breathing navigator-triggered turbo spin-echo [TSE], free-breathing navigator-triggered TSE with restore pulse (RP), breath-hold TSE with RP, and free-breathing navigator-triggered TSE with RP using the periodically rotated overlapping parallel lines with enhanced reconstruction technique [using BLADE, a Siemens implementation of this technique]) were used on all patients. All images were assessed independently by two radiologists. Assessments of motion artifacts; the edge sharpness of the liver, pancreas, and intrahepatic vessels; depictions of the intrahepatic vessels; and overall image quality were performed qualitatively. Quantitative analysis was performed by calculation of the signal-to-noise ratios for liver tissue and gallbladder as well as contrast-to-noise ratios of liver to spleen. Liver and gallbladder signal-to-noise ratios as well as liver to spleen contrast-to-noise ratios were significantly higher (P < .05) for the BLADE technique compared to all other sequences. In qualitative analysis, the severity of motion artifacts was significantly lower with T2-weighted free-breathing navigator-triggered BLADE sequences compared to other sequences (P < .01). The edge sharpness of the liver, pancreas, and intrahepatic vessels; depictions of the intrahepatic vessels; and overall image quality were significantly better with the BLADE sequence (P < .05). The T2-weighted free-breathing navigator-triggered TSE sequence with the BLADE technique is a promising approach for reducing motion artifacts and improving image quality in upper abdominal MRI scans.

  17. Research opportunities in loss of red blood cell mass in space flight

    NASA Technical Reports Server (NTRS)

    Talbot, J. M.; Fisher, K. D.

    1985-01-01

    Decreases of red blood cell mass and plasma volume have been observed consistently following manned space flights. Losses of red cell mass by United States astronauts have averaged 10 to 15% (range: 2 to 21%). Based on postflight estimates of total hemoglobin, Soviet cosmonauts engaged in space missions lasting from 1 to 7 months have exhibited somewhat greater losses. Restoration of red cell mass requires from 4 to 6 weeks following return to Earth, regardless of the duration of space flight.

  18. Modification of a Kowa RC-2 fundus camera for self-photography without the use of mydriatics. [for blood vessel monitoring during space flight

    NASA Technical Reports Server (NTRS)

    Philpott, D. E.; Harrison, G.; Turnbill, C.; Bailey, P. F.

    1979-01-01

    Research on retinal circulation during space flight required the development of a simple technique to provide self monitoring of blood vessel changes in the fundus without the use of mydriatics. A Kowa RC-2 fundus camera was modified for self-photography by the use of a bite plate for positioning and cross hairs for focusing the subject's retina relative to the film plane. Dilation of the pupils without the use of mydriatics was accomplished by dark-adaption of the subject. Pictures were obtained without pupil constriction by the use of a high speed strobe light. This method also has applications for clinical medicine.

  19. Diagnostic examination performance by using microvascular leakage, cerebral blood volume, and blood flow derived from 3-T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in the differentiation of glioblastoma multiforme and brain metastasis.

    PubMed

    Server, Andrés; Orheim, Tone E Døli; Graff, Bjørn A; Josefsen, Roger; Kumar, Theresa; Nakstad, Per H

    2011-05-01

    Conventional magnetic resonance (MR) imaging has limited capacity to differentiate between glioblastoma multiforme (GBM) and metastasis. The purposes of this study were: (1) to compare microvascular leakage (MVL), cerebral blood volume (CBV), and blood flow (CBF) in the distinction of metastasis from GBM using dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging (DSC-MRI), and (2) to estimate the diagnostic accuracy of perfusion and permeability MR imaging. A prospective study of 61 patients (40 GBMs and 21 metastases) was performed at 3 T using DSC-MRI. Normalized rCBV and rCBF from tumoral (rCBVt, rCBFt), peri-enhancing region (rCBVe, rCBFe), and by dividing the value in the tumor by the value in the peri-enhancing region (rCBVt/e, rCBFt/e), as well as MVL were calculated. Hemodynamic and histopathologic variables were analyzed statistically and Spearman/Pearson correlations. Receiver operating characteristic curve analysis was performed for each of the variables. The rCBVe, rCBFe, and MVL were significantly greater in GBMs compared with those of metastases. The optimal cutoff value for differentiating GBM from metastasis was 0.80 which implies a sensitivity of 95%, a specificity of 92%, a positive predictive value of 86%, and a negative predictive value of 97% for rCBVe ratio. We found a modest correlation between rCBVt and rCBFt ratios. MVL measurements in GBMs are significantly higher than those in metastases. Statistically, both rCBVe, rCBVt/e and rCBFe, rCBFt/e were useful in differentiating between GBMs and metastases, supporting the hypothesis that perfusion MR imaging can detect infiltration of tumor cells in the peri-enhancing region.

  20. Working the Dark Edges

    ERIC Educational Resources Information Center

    Weston, Anthony

    2014-01-01

    Environmentalism's wider and wilder possibilities today appear as regions of seeming darkness that bracket or frame acceptable environmental thinking. One of these barely-mentionable darknesses is outer space--the cosmos. Another is the inner and chthonic powers of the land and natural beings generally. This essay aims to bring these two kinds of…

  1. Atherosclerosis imaging using 3D black blood TSE SPACE vs 2D TSE

    PubMed Central

    Wong, Stephanie K; Mobolaji-Iawal, Motunrayo; Arama, Leron; Cambe, Joy; Biso, Sylvia; Alie, Nadia; Fayad, Zahi A; Mani, Venkatesh

    2014-01-01

    AIM: To compare 3D Black Blood turbo spin echo (TSE) sampling perfection with application-optimized contrast using different flip angle evolution (SPACE) vs 2D TSE in evaluating atherosclerotic plaques in multiple vascular territories. METHODS: The carotid, aortic, and femoral arterial walls of 16 patients at risk for cardiovascular or atherosclerotic disease were studied using both 3D black blood magnetic resonance imaging SPACE and conventional 2D multi-contrast TSE sequences using a consolidated imaging approach in the same imaging session. Qualitative and quantitative analyses were performed on the images. Agreement of morphometric measurements between the two imaging sequences was assessed using a two-sample t-test, calculation of the intra-class correlation coefficient and by the method of linear regression and Bland-Altman analyses. RESULTS: No statistically significant qualitative differences were found between the 3D SPACE and 2D TSE techniques for images of the carotids and aorta. For images of the femoral arteries, however, there were statistically significant differences in all four qualitative scores between the two techniques. Using the current approach, 3D SPACE is suboptimal for femoral imaging. However, this may be due to coils not being optimized for femoral imaging. Quantitatively, in our study, higher mean total vessel area measurements for the 3D SPACE technique across all three vascular beds were observed. No significant differences in lumen area for both the right and left carotids were observed between the two techniques. Overall, a significant-correlation existed between measures obtained between the two approaches. CONCLUSION: Qualitative and quantitative measurements between 3D SPACE and 2D TSE techniques are comparable. 3D-SPACE may be a feasible approach in the evaluation of cardiovascular patients. PMID:24876923

  2. Study of electroweak vacuum stability from extended Higgs portal of dark matter and neutrinos

    NASA Astrophysics Data System (ADS)

    Ghosh, Purusottam; Saha, Abhijit Kumar; Sil, Arunansu

    2018-04-01

    We investigate the electroweak vacuum stability in an extended version of the Standard Model that incorporates two additional singlet scalar fields and three right-handed neutrinos. One of these extra scalars plays the role of dark matter, while the other scalar not only helps make the electroweak vacuum stable but also opens up the low-mass window of the scalar singlet dark matter (<500 GeV ). We consider the effect of large neutrino Yukawa coupling on the running of Higgs quartic coupling. We have analyzed the constraints on the model and identified the range of parameter space that is consistent with the neutrino mass, appropriate relic density, and direct search limits from the latest XENON 1T preliminary result as well as realized the stability of the electroweak vacuum up to the Planck scale.

  3. Diffusion-Weighted Magnetic Resonance Imaging of Cholesteatoma Using PROPELLER at 1.5T: A Single-Centre Retrospective Study.

    PubMed

    Clarke, Sharon E; Mistry, Dipan; AlThubaiti, Talal; Khan, M Naeem; Morris, David; Bance, Manohar

    2017-05-01

    The purpose of this study was to evaluate the sensitivity, specificity, and positive and negative predictive values of the diffusion-weighted periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) technique in the detection of cholesteatoma at our institution with surgical confirmation in all cases. A retrospective review of 21 consecutive patients who underwent diffusion-weighted PROPELLER magnetic resonance imaging (MRI) on a 1.5T MRI scanner prior to primary or revision/second-look surgery for suspected cholesteatoma from 2009-2012 was performed. Diffusion-weighted PROPELLER had a sensitivity of 75%, specificity of 60%, positive predictive value of 86%, and negative predictive value of 43%. In the 15 patients for whom the presence or absence of cholesteatoma was correctly predicted, there were 2 cases where the reported locations of diffusion restriction did not correspond to the location of the cholesteatoma observed at surgery. On the basis of our retrospective study, we conclude that diffusion-weighted PROPELLER MRI is not sufficiently accurate to replace second look surgery at our institution. Copyright © 2016 Canadian Association of Radiologists. Published by Elsevier Inc. All rights reserved.

  4. Searching for dark absorption with direct detection experiments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bloch, Itay M.; Essig, Rouven; Tobioka, Kohsaku

    We consider the absorption by bound electrons of dark matter in the form of dark photons and axion-like particles, as well as of dark photons from the Sun, in current and next-generation direct detection experiments. Experiments sensitive to electron recoils can detect such particles with masses between a few eV to more than 10 keV. For dark photon dark matter, we update a previous bound based on XENON10 data and derive new bounds based on data from XENON100 and CDMSlite. We find these experiments to disfavor previously allowed parameter space. Moreover, we derive sensitivity projections for SuperCDMS at SNOLAB formore » silicon and germanium targets, as well as for various possible experiments with scintillating targets (cesium iodide, sodium iodide, and gallium arsenide). The projected sensitivity can probe large new regions of parameter space. For axion-like particles, the same current direction detection data improves on previously known direct-detection constraints but does not bound new parameter space beyond known stellar cooling bounds. However, projected sensitivities of the upcoming SuperCDMS SNOLAB using germanium can go beyond these and even probe parameter space consistent with possible hints from the white dwarf luminosity function. We find similar results for dark photons from the sun. For all cases, direct-detection experiments can have unprecedented sensitivity to dark-sector particles.« less

  5. Searching for dark absorption with direct detection experiments

    DOE PAGES

    Bloch, Itay M.; Essig, Rouven; Tobioka, Kohsaku; ...

    2017-06-16

    We consider the absorption by bound electrons of dark matter in the form of dark photons and axion-like particles, as well as of dark photons from the Sun, in current and next-generation direct detection experiments. Experiments sensitive to electron recoils can detect such particles with masses between a few eV to more than 10 keV. For dark photon dark matter, we update a previous bound based on XENON10 data and derive new bounds based on data from XENON100 and CDMSlite. We find these experiments to disfavor previously allowed parameter space. Moreover, we derive sensitivity projections for SuperCDMS at SNOLAB formore » silicon and germanium targets, as well as for various possible experiments with scintillating targets (cesium iodide, sodium iodide, and gallium arsenide). The projected sensitivity can probe large new regions of parameter space. For axion-like particles, the same current direction detection data improves on previously known direct-detection constraints but does not bound new parameter space beyond known stellar cooling bounds. However, projected sensitivities of the upcoming SuperCDMS SNOLAB using germanium can go beyond these and even probe parameter space consistent with possible hints from the white dwarf luminosity function. We find similar results for dark photons from the sun. For all cases, direct-detection experiments can have unprecedented sensitivity to dark-sector particles.« less

  6. Constraining Dark Matter Interactions with Pseudoscalar and Scalar Mediators Using Collider Searches for Multijets plus Missing Transverse Energy.

    PubMed

    Buchmueller, Oliver; Malik, Sarah A; McCabe, Christopher; Penning, Bjoern

    2015-10-30

    The monojet search, looking for events involving missing transverse energy (E_{T}) plus one or two jets, is the most prominent collider dark matter search. We show that multijet searches, which look for E_{T} plus two or more jets, are significantly more sensitive than the monojet search for pseudoscalar- and scalar-mediated interactions. We demonstrate this in the context of a simplified model with a pseudoscalar interaction that explains the excess in GeV energy gamma rays observed by the Fermi Large Area Telescope. We show that multijet searches already constrain a pseudoscalar interpretation of the excess in much of the parameter space where the mass of the mediator M_{A} is more than twice the dark matter mass m_{DM}. With the forthcoming run of the Large Hadron Collider at higher energies, the remaining regions of the parameter space where M_{A}>2m_{DM} will be fully explored. Furthermore, we highlight the importance of complementing the monojet final state with multijet final states to maximize the sensitivity of the search for the production of dark matter at colliders.

  7. Diagnostic Quality of 3D T2-SPACE Compared with T2-FSE in the Evaluation of Cervical Spine MRI Anatomy.

    PubMed

    Chokshi, F H; Sadigh, G; Carpenter, W; Allen, J W

    2017-04-01

    Spinal anatomy has been variably investigated using 3D MRI. We aimed to compare the diagnostic quality of T2 sampling perfection with application-optimized contrasts by using flip angle evolution (SPACE) with T2-FSE sequences for visualization of cervical spine anatomy. We predicted that T2-SPACE will be equivalent or superior to T2-FSE for visibility of anatomic structures. Adult patients undergoing cervical spine MR imaging with both T2-SPACE and T2-FSE sequences for radiculopathy or myelopathy between September 2014 and February 2015 were included. Two blinded subspecialty-trained radiologists independently assessed the visibility of 12 anatomic structures by using a 5-point scale and assessed CSF pulsation artifact by using a 4-point scale. Sagittal images and 6 axial levels from C2-T1 on T2-FSE were reviewed; 2 weeks later and after randomization, T2-SPACE was evaluated. Diagnostic quality for each structure and CSF pulsation artifact visibility on both sequences were compared by using a paired t test. Interobserver agreement was calculated (κ). Forty-five patients were included (mean age, 57 years; 40% male). The average visibility scores for intervertebral disc signal, neural foramina, ligamentum flavum, ventral rootlets, and dorsal rootlets were higher for T2-SPACE compared with T2-FSE for both reviewers ( P < .001). Average scores for remaining structures were either not statistically different or the superiority of one sequence was discordant between reviewers. T2-SPACE showed less degree of CSF flow artifact ( P < .001). Interobserver variability ranged between -0.02-0.20 for T2-SPACE and -0.02-0.30 for T2-FSE (slight to fair agreement). T2-SPACE may be equivalent or superior to T2-FSE for the evaluation of cervical spine anatomic structures, and T2-SPACE shows a lower degree of CSF pulsation artifact. © 2017 by American Journal of Neuroradiology.

  8. Discrete pre-processing step effects in registration-based pipelines, a preliminary volumetric study on T1-weighted images.

    PubMed

    Muncy, Nathan M; Hedges-Muncy, Ariana M; Kirwan, C Brock

    2017-01-01

    Pre-processing MRI scans prior to performing volumetric analyses is common practice in MRI studies. As pre-processing steps adjust the voxel intensities, the space in which the scan exists, and the amount of data in the scan, it is possible that the steps have an effect on the volumetric output. To date, studies have compared between and not within pipelines, and so the impact of each step is unknown. This study aims to quantify the effects of pre-processing steps on volumetric measures in T1-weighted scans within a single pipeline. It was our hypothesis that pre-processing steps would significantly impact ROI volume estimations. One hundred fifteen participants from the OASIS dataset were used, where each participant contributed three scans. All scans were then pre-processed using a step-wise pipeline. Bilateral hippocampus, putamen, and middle temporal gyrus volume estimations were assessed following each successive step, and all data were processed by the same pipeline 5 times. Repeated-measures analyses tested for a main effects of pipeline step, scan-rescan (for MRI scanner consistency) and repeated pipeline runs (for algorithmic consistency). A main effect of pipeline step was detected, and interestingly an interaction between pipeline step and ROI exists. No effect for either scan-rescan or repeated pipeline run was detected. We then supply a correction for noise in the data resulting from pre-processing.

  9. Discrete pre-processing step effects in registration-based pipelines, a preliminary volumetric study on T1-weighted images

    PubMed Central

    2017-01-01

    Pre-processing MRI scans prior to performing volumetric analyses is common practice in MRI studies. As pre-processing steps adjust the voxel intensities, the space in which the scan exists, and the amount of data in the scan, it is possible that the steps have an effect on the volumetric output. To date, studies have compared between and not within pipelines, and so the impact of each step is unknown. This study aims to quantify the effects of pre-processing steps on volumetric measures in T1-weighted scans within a single pipeline. It was our hypothesis that pre-processing steps would significantly impact ROI volume estimations. One hundred fifteen participants from the OASIS dataset were used, where each participant contributed three scans. All scans were then pre-processed using a step-wise pipeline. Bilateral hippocampus, putamen, and middle temporal gyrus volume estimations were assessed following each successive step, and all data were processed by the same pipeline 5 times. Repeated-measures analyses tested for a main effects of pipeline step, scan-rescan (for MRI scanner consistency) and repeated pipeline runs (for algorithmic consistency). A main effect of pipeline step was detected, and interestingly an interaction between pipeline step and ROI exists. No effect for either scan-rescan or repeated pipeline run was detected. We then supply a correction for noise in the data resulting from pre-processing. PMID:29023597

  10. Interleukin-1β (IL-1β) increases pain behavior and the blood glucose level: possible involvement of glucocorticoid system.

    PubMed

    Sim, Yun-Beom; Park, Soo-Hyun; Kang, Yu-Jung; Jung, Jun-Sub; Ryu, Ohk-Hyun; Choi, Moon-Gi; Choi, Seong-Soo; Suh, Hong-Won

    2013-10-01

    The possible involvement of glucocorticoid system in interleukin-1β (IL-1β)-induced nociception and the blood glucose level was studied in ICR mice. In the first experiment, mice were treated intrathecally (i.t.) with IL-1β (100 pg). Corticotrophin releasing hormone (CRH) mRNA (hypothalamus) and c-Fos mRNA (pituitary gland, spinal cord, and the adrenal gland) levels were measured at 30, 60 and 120 min after IL-1β administration. We found that i.t. injection with IL-1β increased CRH mRNA level in the hypothalamus. The IL-1β administered i.t. elevated c-Fos mRNA levels in the spinal cord, pituitary and adrenal glands. Furthermore, i.t. administration of IL-1β significantly increased the plasma corticosterone level up to 60 min. In addition, the adrenalectomy caused the reductions of the blood glucose level and pain behavior induced by IL-1β injected i.t. in normal and D-glucose-fed groups. Furthermore, intraperitoneal (i.p.) pretreatment with RU486 (100mg/kg) attenuated the blood glucose level and pain behavior induced by IL-1β administered i.t. in normal and D-glucose-fed groups. Our results suggest that IL-1β administered i.t. increases the blood glucose level and pain behavior via an activation of the glucocorticoid system. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. [Effects of dietary habits modifications on selected metabolic parameters during weight loss in obese persons].

    PubMed

    Ostrowska, Lucyna; Stefańska, Ewa; Jastrzebska, Marta; Adamska, Edyta; Wujek, Anita; Waszczeniuk, Magdalena

    2012-01-01

    Obesity is a serious social problem, one of the most important health issues of the modern world, especially in industrialized countries. Due to the prevalence obesity is a social disease, chronic and also a risk factor for many diseases such as hypertension, type 2 diabetes mellitus, coronary heart disease, gall stones or cancers. The aim of the study was to examine and evaluation whether the systematic one-year modifications of dietary habits affect the changes in body weight and some metabolic parameters in obese patients. 30 women and 30 men who declared intentions to decrease body weight were examined. The mean age of women was 48 +/- 12.5 years (range 31-72 years), men 51 +/- 13.2 years (range 23-70 years). The questionnaire survey concerning the subject matter was designed in the Department of Dietetics and Clinical Nutrition, Medical University of Bialystok. At the initial and final visit the frequency of some products consumption were assessed and concentrations of some biochemical parameters in the peripheral blood were measured. Women after one-year dietotherapy significantly reduced the incidence of eating: pasta, fruit and vegetable juices, potatoes, ripening cheese, sugar, meat, bacon and lard, butter and cream, and increased incidence of eating dark bread, groats, rice, vegetables and fruit, cottage cheese, fish and vegetable oils. Men significantly reduced the incidence of eating: pasta, potatoes, ripening cheese, sweet beverages, bacon and lard, margarine, and increased the incidence of eating dark bread, groats, rice, vegetables, cottage cheese and fish. After one year the average body weight decrease was 2.8 +/- 7.1 kg in women and 1.4 +/- 3.2 kg in men. The average reduction in waist circumference was 3.6 +/- 6.5 cm in women and 3.6 +/- 4,8 cm in men. HDL cholesterol levels increased significantly in women and not significantly in men. LDL cholesterol and triglyceride levels decreased significantly in both groups. In women systolic blood

  12. Protective effects of flavanol-rich dark chocolate on endothelial function and wave reflection during acute hyperglycemia.

    PubMed

    Grassi, Davide; Desideri, Giovambattista; Necozione, Stefano; Ruggieri, Fabrizio; Blumberg, Jeffrey B; Stornello, Michele; Ferri, Claudio

    2012-09-01

    Nitric oxide plays a pivotal role in regulating vascular tone. Different studies show endothelial function is impaired during hyperglycemia. Dark chocolate increases flow-mediated dilation in healthy and hypertensive subjects with and without glucose intolerance; however, the effect of pretreatment with dark chocolate on endothelial function and other vascular responses to hyperglycemia has not been examined. Therefore, we aimed to investigate the effects of flavanol-rich dark chocolate administration on (1) flow-mediated dilation and wave reflections; (2) blood pressure, endothelin-1 and oxidative stress, before and after oral glucose tolerance test (OGTT). Twelve healthy volunteers (5 males, 28.2±2.7 years) randomly received either 100 g/d dark chocolate or flavanol-free white chocolate for 3 days. After 7 days washout period, volunteers were switched to the other treatment. Flow-mediated dilation, stiffness index, reflection index, peak-to-peak time, blood pressure, endothelin-1 and 8-iso-PGF(2α) were evaluated after each treatment phase and OGTT. Compared with white chocolate, dark chocolate ingestion improved flow-mediated dilation (P=0.03), wave reflections, endothelin-1 and 8-iso-PGF(2α) (P<0.05). After white chocolate ingestion, flow-mediated dilation was reduced after OGTT from 7.88±0.68 to 6.07±0.76 (P=0.027), 6.74±0.51 (P=0.046) at 1 and 2 h after the glucose load, respectively. Similarly, after white chocolate but not after dark chocolate, wave reflections, blood pressure, and endothelin-1 and 8-iso-PGF(2α) increased after OGTT. OGTT causes acute, transient impairment of endothelial function and oxidative stress, which is attenuated by flavanol-rich dark chocolate. These results suggest cocoa flavanols may contribute to vascular health by reducing the postprandial impairment of arterial function associated with the pathogenesis of atherosclerosis.

  13. Effects of 100-μT extremely low frequency electromagnetic fields exposure on hematograms and blood chemistry in rats

    PubMed Central

    Lai, Jinsheng; Zhang, Yemao; Zhang, Jiangong; Liu, Xingfa; Ruan, Guoran; Chaugai, Sandip; Tang, Jiarong; Wang, Hong; Chen, Chen; Wang, Dao Wen

    2016-01-01

    The aim of this study was to test whether extremely low frequency electromagnetic fields (ELF EMFs) affect health or not. Here, we constructed a 100-μT/50 Hz electromagnetic field atmosphere. A total of 128 rats were randomly assigned into two groups: the ELF EMF group and the sham group. The ELF EMF group was exposed to 100-μT/50-Hz ELF EMF for 20 h per day for three months; at the same time the other group was exposed to a sham device without ELF EMF. During the three months, the weight was recorded every 2 weeks, and the water intake and food intake of the animals were recorded weekly. The hematologic parameters were detected before and after the exposure, whereas blood chemistry analysis was performed every 4 weeks. The general condition of the exposed rats was not affected by ELF EMF. Compared with the sham group, the hematograms were not significantly altered in the ELF EMF group. Similarly, the blood chemistry (including lipid profile, blood glucose, liver function and renal function of rats) from the ELF EMF group showed no difference compared with rats from the control group during the three months exposure. The present study indicated that short-term exposure of 100-μT/50-Hz ELF EMF may not affect hematograms and blood chemistry in rats. PMID:26404558

  14. 46 CFR 32.56-25 - Category A machinery spaces: Windows and port lights-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Category A machinery spaces: Windows and port lights-T... Laying Date On or After January 1, 1975 § 32.56-25 Category A machinery spaces: Windows and port lights—T..., boundaries of category A machinery spaces and boundaries of cargo pumprooms must not be pierced for windows...

  15. T1- and T2*-dominant extravasation correction in DSC-MRI: Part I—theoretical considerations and implications for assessment of tumor hemodynamic properties

    PubMed Central

    Bjornerud, Atle; Sorensen, A Gregory; Mouridsen, Kim; Emblem, Kyrre E

    2011-01-01

    We present a novel contrast agent (CA) extravasation-correction method based on analysis of the tissue residue function for assessment of multiple hemodynamic parameters. The method enables semiquantitative determination of the transfer constant and can be used to distinguish between T1- and T2*-dominant extravasation effects, while being insensitive to variations in tissue mean transit time (MTT). Results in 101 patients with confirmed glioma suggest that leakage-corrected absolute cerebral blood volume (CBV) values obtained with the proposed method provide improved overall survival prediction compared with normalized CBV values combined with an established leakage-correction method. Using a standard gradient-echo echo-planar imaging sequence, ∼60% and 10% of tumors with detectable CA extravasation mainly exhibited T1- and T2*-dominant leakage effects, respectively. The remaining 30% of leaky tumors had mixed T1- and T2*-dominant effects. Using an MTT-sensitive correction method, our results show that CBV is underestimated when tumor MTT is significantly longer than MTT in the reference tissue. Furthermore, results from our simulations suggest that the relative contribution of T1- versus T2*-dominant extravasation effects is strongly dependent on the effective transverse relaxivity in the extravascular space and may thus be a potential marker for cellular integrity and tissue structure. PMID:21505483

  16. T2-weighted images are superior to other MR image types for the determination of diffuse intrinsic pontine glioma intratumoral heterogeneity.

    PubMed

    Harward, Stephen; Harrison Farber, S; Malinzak, Michael; Becher, Oren; Thompson, Eric M

    2018-03-01

    Diffuse intrinsic pontine glioma (DIPG) remains the main cause of death in children with brain tumors. Given the inefficacy of numerous peripherally delivered agents to treat DIPG, convection enhanced delivery (CED) of therapeutic agents is a promising treatment modality. The purpose of this study was to determine which MR imaging type provides the best discrimination of intratumoral heterogeneity to guide future stereotactic implantation of CED catheters into the most cellular tumor regions. Patients ages 18 years or younger with a diagnosis of DIPG from 2000 to 2015 were included. Radiographic heterogeneity index (HI) of the tumor was calculated by measuring the standard deviation of signal intensity of the tumor (SD Tumor ) normalized to the genu of the corpus callosum (SD Corpus Callosum ). Four MR image types (T2-weighted, contrast-enhanced T1-weighted, FLAIR, and ADC) were analyzed at several time points both before and after radiotherapy and chemotherapy. HI values across these MR image types were compared and correlated with patient survival. MR images from 18 patients with DIPG were evaluated. The mean survival ± standard deviation was 13.8 ± 13.7 months. T2-weighted images had the highest HI (mean ± SD, 5.1 ± 2.5) followed by contrast-enhanced T1-weighted images (3.7 ± 1.5), FLAIR images (3.0 ± 1.1), and ADC maps (1.6 ± 0.4). ANOVA demonstrated that HI values were significantly higher for T2-weighted images than FLAIR (p < 0.01) and ADC (p < 0.0001). Following radiotherapy, T2-weighted and contrast-enhanced T1-weighted image HI values increased, while FLAIR and ADC HI values decreased. Univariate and multivariate analyses did not reveal a relationship between HI values and patient survival (p > 0.05). For children with DIPG, T2-weighted MRI demonstrates the greatest signal intensity variance suggesting tumor heterogeneity. Within this heterogeneity, T2-weighted signal hypointensity is known to correlate with

  17. High-cocoa polyphenol-rich chocolate improves blood pressure in patients with diabetes and hypertension.

    PubMed

    Rostami, Ali; Khalili, Mohammad; Haghighat, Neda; Eghtesadi, Shahryar; Shidfar, Farzad; Heidari, Iraj; Ebrahimpour-Koujan, Soraiya; Eghtesadi, Maryam

    2015-01-01

    The aim was to examine the effects of high-cocoa polyphenol-rich chocolate on lipid profiles, weight, blood pressure, glycemic control, and inflammation in individuals with Type 2 diabetes and hypertension. Sixty individuals [32 in dark chocolate group (DCG) and 28 in white chocolate group (WCG)] with Type 2 diabetes on stable medication were enrolled in a randomized, placebo-controlled double-blind study. Subjects were randomized to consume 25 g DCG or WCG for 8 weeks. Changes in weight, blood pressure, glycemic control, lipid profile, and high sensitive C-reactive protein (hsCRP) were measured at the beginning and end of the intervention. This clinical trial was registered at the Iranian registry of clinical trials. In DCC group, compared with baseline, serum levels of Apo A-1 (P = 0.045) was increased and fasting blood sugar (FBS) (P = 0.027), hemoglobin A1c (HbA1c) (P = 0.025), Apo B (P = 0.012) and Log of hsCRP (P = 0.043) levels were decreased at the end of study. No changes were seen within the WCG in studied parameters. High polyphenol chocolate consumption compared to white chocolate resulted in significant decrease in of systolic (-5.93 ± 6.25 vs. -1.07 ± 7.97 mmHg, P = 0.004) and diastolic blood pressure (-6.4 ± 6.25 vs. 0.17 ± 7.9 mmHg, P = 0.002), FBS (-7.84 ± 19.15 vs. 4.00 ± 20.58 mg/dl, P = 0.019) over the course of 8 weeks of daily chocolate consumption neither weight nor body mass index and TG levels altered from baseline. High polyphenol chocolate is effective in improving TG levels in hypertensive patients with diabetes and decreasing blood pressure and FBS without affecting weight, inflammatory markers, insulin resistance or glycemic control.

  18. The 17 MeV anomaly in beryllium decays and U(1) portal to dark matter

    NASA Astrophysics Data System (ADS)

    Chen, Chian-Shu; Lin, Guey-Lin; Lin, Yen-Hsun; Xu, Fanrong

    2017-11-01

    The experiment of Krasznahorkay et al. observed the transition of a 8Be excited state to its ground state and accompanied by an emission of an e+e‑ pair with 17 MeV invariant mass. This 6.8σ anomaly can be fitted by a new light gauge boson. We consider the new particle as a U(1) gauge boson, Z‧, which plays as a portal linking dark sector and visible sector. In particular, we study the new U(1) gauge symmetry as a hidden or nonhidden group separately. The generic hidden U(1) model, referred to as dark Z model, is excluded by imposing various experimental constraints. On the other hand, a nonhidden Z‧ is allowed due to the additional interactions between Z‧ and Standard Model fermions. We also study the implication of the dark matter direct search on such a scenario. We found that the search for the DM-nucleon scattering cannot probe the parameter space that is allowed by 8Be-anomaly for the range of DM mass above 500 MeV. However, the DM-electron scattering for DM between 20 MeV and 50 MeV can test the underlying U(1) portal model using the future Si and Ge detectors with the 5e‑ threshold charges.

  19. Distributions of heavy metals in maternal and cord blood and the association with infant birth weight in China.

    PubMed

    Hu, Xiaobin; Zheng, Tongzhang; Cheng, Yibin; Holford, Theodore; Lin, Shaobin; Leaderer, Brian; Qiu, Jie; Bassig, Bryan A; Shi, Kunchong; Zhang, Yawei; Niu, Jianjun; Zhu, Yong; Li, Yonghong; Guo, Huan; Chen, Qiong; Zhang, Jianqing; Xu, Shunqing; Jin, Yinlong

    2015-01-01

    To measure serum levels of heavy metals in Chinese pregnant women and their newborns, and to evaluate the association of these metals with infant birth weight. We measured serum concentrations of lead (Pb), thallium (Tl), cadmium (Cd), selenium (Se), arsenic (As), nickle (Ni), vanadium (V), cobalt (Co), and mercury (Hg) in 81 mother-infant pairs using an inductively coupled plasma mass spectrometry method. Multiple linear regression analyses were used to evaluate the associations of these heavy metals with infant birth weight. Se, Pb, As, and Cd showed the highest detection rates (98.8%) in both the maternal and cord blood, followed by Tl, which was detected in 79.0% and 71.6% of the maternal and cord blood samples, respectively. Pb had the highest concentrations in both the maternal and cord blood samples of all toxic metals detected, with concentrations of 23.1 ng/g and 22.0 ng/g, respectively. No significant associations were observed between any heavy metals and birth weight. However, Tl in the maternal and cord blood was most notably inversely associated with birth weight. Se intake was low in Chinese women and their newborns, whereas Pb had the highest concentrations in both the maternal and cord blood samples of all toxic metals detected. Tl was a unique pollution source in this population, and Tl levels were shown to have the largest effect on decreasing infant birth weight in this pilot study. Further research incorporating larger sample sizes is needed to investigate the effects of prenatal exposure to heavy metals--especially Tl and Pb--on birth outcome in Chinese infants.

  20. 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.

    PubMed

    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

  1. Water-dispersible magnetic carbon nanotubes as T2-weighted MRI contrast agents.

    PubMed

    Liu, Yue; Hughes, Timothy C; Muir, Benjamin W; Waddington, Lynne J; Gengenbach, Thomas R; Easton, Christopher D; Hinton, Tracey M; Moffat, Bradford A; Hao, Xiaojuan; Qiu, Jieshan

    2014-01-01

    An efficient MRI T2-weighted contrast agent incorporating a potential liver targeting functionality was synthesized via the combination of superparamagnetic iron oxide (SPIO) nanoparticles with multiwalled carbon nanotubes (MWCNTs). Poly(diallyldimethylammonium chloride) (PDDA) was coated on the surface of acid treated MWCNTs via electrostatic interactions and SPIO nanoparticles modified with a potential targeting agent, lactose-glycine adduct (Lac-Gly), were subsequently immobilized on the surface of the PDDA-MWCNTs. A narrow magnetic hysteresis loop indicated that the product displayed superparamagnetism at room temperature which was further confirmed by ZFC (zero field cooling)/FC (field cooling) curves measured by SQUID. The multifunctional MWCNT-based magnetic nanocomposites showed low cytotoxicity in vitro to HEK293 and Huh7 cell lines. Enhanced T2 relaxivities were observed for the hybrid material (186 mM(-1) s(-1)) in comparison with the pure magnetic nanoparticles (92 mM(-1) s(-1)) due to the capacity of the MWCNTs to "carry" more nanoparticles as clusters. More importantly, after administration of the composite material to an in vivo liver cancer model in mice, a significant increase in tumor to liver contrast ratio (277%) was observed in T2 weighted magnetic resonance images. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  2. Topographical Variation of Human Femoral Articular Cartilage Thickness, T1rho and T2 Relaxation Times Is Related to Local Loading during Walking.

    PubMed

    Van Rossom, Sam; Wesseling, Mariska; Van Assche, Dieter; Jonkers, Ilse

    2018-01-01

    Objective Early detection of degenerative changes in the cartilage matrix composition is essential for evaluating early interventions that slow down osteoarthritis (OA) initiation. T1rho and T2 relaxation times were found to be effective for detecting early changes in proteoglycan and collagen content. To use these magnetic resonance imaging (MRI) methods, it is important to document the topographical variation in cartilage thickness, T1rho and T2 relaxation times in a healthy population. As OA is partially mechanically driven, the relation between these MRI-based parameters and localized mechanical loading during walking was investigated. Design MR images were acquired in 14 healthy adults and cartilage thickness and T1rho and T2 relaxation times were determined. Experimental gait data was collected and processed using musculoskeletal modeling to identify weight-bearing zones and estimate the contact force impulse during gait. Variation of the cartilage properties (i.e., thickness, T1rho, and T2) over the femoral cartilage was analyzed and compared between the weight-bearing and non-weight-bearing zone of the medial and lateral condyle as well as the trochlea. Results Medial condyle cartilage thickness was correlated to the contact force impulse ( r = 0.78). Lower T1rho, indicating increased proteoglycan content, was found in the medial weight-bearing zone. T2 was higher in all weight-bearing zones compared with the non-weight-bearing zones, indicating lower relative collagen content. Conclusions The current results suggest that medial condyle cartilage is adapted as a long-term protective response to localized loading during a frequently performed task and that the weight-bearing zone of the medial condyle has superior weight bearing capacities compared with the non-weight-bearing zones.

  3. Recovery from welding-fume-exposure-induced MRI T1 signal intensities after cessation of welding-fume exposure in brains of cynomolgus monkeys.

    PubMed

    Han, Jeong Hee; Chung, Yong Hyun; Park, Jung Duck; Kim, Choong Yong; Yang, Seoung Oh; Khang, Hyun Soo; Cheong, Hae Kwan; Lee, Jong Seong; Ha, Chang Soo; Song, Chang-Woo; Kwon, Il Hoon; Sung, Jae Hyuck; Heo, Jeong Doo; Kim, Na-Young; Huang, Mingai; Cho, Myung Haing; Yu, Il Je

    2008-09-01

    The shortening of the MRI T1 relaxation time, indicative of a high signal intensity in a T1-weighted MRI, is known as a useful biomarker for Mn exposure after short-term welding-fume exposure. A previous monkey experimental study found that the T1 relaxation times decreased time-dependently after exposure, and a visually detectable high signal intensity appeared after 150 days of exposure. The nadir for the shortening of the T1 relaxation time was also previously found to correspond well with the blood Mn concentration in welders, suggesting a correlation between a prolonged high blood Mn concentration and shortened T1 relaxation time. Accordingly, to clarify the clearance of the brain Mn concentration after the cessation of welding-fume exposure, cynomolgus monkeys were assigned to 3 groups-unexposed, low dose (31 mg/m(3) total suspended particulate (TSP), 0.9 mg Mn/m(3)), and high dose (62 mg/m(3) TSP, 1.95 mg Mn/m(3))-and exposed to manual metal-arc stainless steel (MMA-SS) welding fumes for 2 h per day for 8 mo in an inhalation chamber system equipped with an automatic fume generator. After reaching the peak MRI T1 signal intensity (shortest T1 relaxation time), the monkeys were allowed to recover by ceasing the welding-fume exposure. Within 2 mo, the MRI T1 signal intensities for the exposed monkeys returned to nearly the same level as those for the unexposed monkeys, indicating the potential for recovery from a high MRI T1 signal intensity induced by welding-fume exposure, even after prolonged exposure. Clearance of the Mn tissue concentration was also demonstrated in the globus pallidus, plus other tissues from the brain, liver, spleen, and blood. In contrast, there was no clearance of the lung concentrations of Mn, indicating that a soluble form of Mn was transported to the blood and brain. Therefore, the solubility of Mn in welding fumes would appear to be an important determinant as regards the retention of blood Mn levels and brain tissue Mn

  4. Fine-structure constant constraints on dark energy. II. Extending the parameter space

    NASA Astrophysics Data System (ADS)

    Martins, C. J. A. P.; Pinho, A. M. M.; Carreira, P.; Gusart, A.; López, J.; Rocha, C. I. S. A.

    2016-01-01

    Astrophysical tests of the stability of fundamental couplings, such as the fine-structure constant α , are a powerful probe of new physics. Recently these measurements, combined with local atomic clock tests and Type Ia supernova and Hubble parameter data, were used to constrain the simplest class of dynamical dark energy models where the same degree of freedom is assumed to provide both the dark energy and (through a dimensionless coupling, ζ , to the electromagnetic sector) the α variation. One caveat of these analyses was that it was based on fiducial models where the dark energy equation of state was described by a single parameter (effectively its present day value, w0). Here we relax this assumption and study broader dark energy model classes, including the Chevallier-Polarski-Linder and early dark energy parametrizations. Even in these extended cases we find that the current data constrains the coupling ζ at the 1 0-6 level and w0 to a few percent (marginalizing over other parameters), thus confirming the robustness of earlier analyses. On the other hand, the additional parameters are typically not well constrained. We also highlight the implications of our results for constraints on violations of the weak equivalence principle and improvements to be expected from forthcoming measurements with high-resolution ultrastable spectrographs.

  5. Composite iron oxide-Prussian blue nanoparticles for magnetically guided T1-weighted magnetic resonance imaging and photothermal therapy of tumors.

    PubMed

    Kale, Shraddha S; Burga, Rachel A; Sweeney, Elizabeth E; Zun, Zungho; Sze, Raymond W; Tuesca, Anthony; Subramony, J Anand; Fernandes, Rohan

    2017-01-01

    Theranostic nanoparticles offer the potential for mixing and matching disparate diagnostic and therapeutic functionalities within a single nanoparticle for the personalized treatment of diseases. In this article, we present composite iron oxide-gadolinium-containing Prussian blue nanoparticles (Fe 3 O 4 @GdPB) as a novel theranostic agent for T 1 -weighted magnetic resonance imaging (MRI) and photothermal therapy (PTT) of tumors. These particles combine the well-described properties and safety profiles of the constituent Fe 3 O 4 nanoparticles and gadolinium-containing Prussian blue nanoparticles. The Fe 3 O 4 @GdPB nanoparticles function both as effective MRI contrast agents and PTT agents as determined by characterizing studies performed in vitro and retain their properties in the presence of cells. Importantly, the Fe 3 O 4 @GdPB nanoparticles function as effective MRI contrast agents in vivo by increasing signal:noise ratios in T 1 -weighted scans of tumors and as effective PTT agents in vivo by decreasing tumor growth rates and increasing survival in an animal model of neuroblastoma. These findings demonstrate the potential of the Fe 3 O 4 @GdPB nanoparticles to function as effective theranostic agents.

  6. Composite iron oxide–Prussian blue nanoparticles for magnetically guided T1-weighted magnetic resonance imaging and photothermal therapy of tumors

    PubMed Central

    Kale, Shraddha S; Burga, Rachel A; Sweeney, Elizabeth E; Zun, Zungho; Sze, Raymond W; Tuesca, Anthony; Subramony, J Anand; Fernandes, Rohan

    2017-01-01

    Theranostic nanoparticles offer the potential for mixing and matching disparate diagnostic and therapeutic functionalities within a single nanoparticle for the personalized treatment of diseases. In this article, we present composite iron oxide-gadolinium-containing Prussian blue nanoparticles (Fe3O4@GdPB) as a novel theranostic agent for T1-weighted magnetic resonance imaging (MRI) and photothermal therapy (PTT) of tumors. These particles combine the well-described properties and safety profiles of the constituent Fe3O4 nanoparticles and gadolinium-containing Prussian blue nanoparticles. The Fe3O4@GdPB nanoparticles function both as effective MRI contrast agents and PTT agents as determined by characterizing studies performed in vitro and retain their properties in the presence of cells. Importantly, the Fe3O4@GdPB nanoparticles function as effective MRI contrast agents in vivo by increasing signal:noise ratios in T1-weighted scans of tumors and as effective PTT agents in vivo by decreasing tumor growth rates and increasing survival in an animal model of neuroblastoma. These findings demonstrate the potential of the Fe3O4@GdPB nanoparticles to function as effective theranostic agents. PMID:28919744

  7. Statistical analyses of Higgs- and Z -portal dark matter models

    NASA Astrophysics Data System (ADS)

    Ellis, John; Fowlie, Andrew; Marzola, Luca; Raidal, Martti

    2018-06-01

    We perform frequentist and Bayesian statistical analyses of Higgs- and Z -portal models of dark matter particles with spin 0, 1 /2 , and 1. Our analyses incorporate data from direct detection and indirect detection experiments, as well as LHC searches for monojet and monophoton events, and we also analyze the potential impacts of future direct detection experiments. We find acceptable regions of the parameter spaces for Higgs-portal models with real scalar, neutral vector, Majorana, or Dirac fermion dark matter particles, and Z -portal models with Majorana or Dirac fermion dark matter particles. In many of these cases, there are interesting prospects for discovering dark matter particles in Higgs or Z decays, as well as dark matter particles weighing ≳100 GeV . Negative results from planned direct detection experiments would still allow acceptable regions for Higgs- and Z -portal models with Majorana or Dirac fermion dark matter particles.

  8. Is Self-Interacting Dark Matter Undergoing Dark Fusion?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    McDermott, Samuel D.

    2017-11-02

    We suggest that two-to-two dark matter fusion may be the relaxation process that resolves the small-scale structure problems of the cold collisionless dark matter paradigm. In order for the fusion cross section to scale correctly across many decades of astrophysical masses from dwarf galaxies to galaxy clusters, we require the fractional binding energy released to be greater than v^n ~ [10^{-(2-3)}]^n, where n=1,2 depends on local dark sector chemistry. The size of the dark-sector interaction cross sections must be sigma ~ 0.1-1 barn, moderately larger than for Standard Model deuteron fusion, indicating a dark nuclear scale Lambda ~ O(100 MeV).more » Dark fusion firmly predicts constant sigma v below the characteristic velocities of galaxy clusters. Observations of the inner structure of galaxy groups with velocity dispersion of several hundred kilometer per second, of which a handful have been identified, could differentiate dark fusion from a dark photon model.« less

  9. Is Self-Interacting Dark Matter Undergoing Dark Fusion?

    NASA Astrophysics Data System (ADS)

    McDermott, Samuel D.

    2018-06-01

    We suggest that two-to-two dark matter fusion may be the relaxation process that resolves the small-scale structure problems of the cold collisionless dark matter paradigm. In order for the fusion cross section to scale correctly across many decades of astrophysical masses from dwarf galaxies to galaxy clusters, we require the fractional binding energy released to be greater than vn˜(10-(2 -3 ))n , where n =1 , 2 depends on local dark sector chemistry. The size of the dark-sector interaction cross sections must be σ˜0.1 - 1 barn, moderately larger than for standard model deuteron fusion, indicating a dark nuclear scale Λ ˜O (100 MeV ) . Dark fusion firmly predicts constant σ v below the characteristic velocities of galaxy clusters. Observations of the inner structure of galaxy groups with velocity dispersion of several hundred kilometers per second, of which a handful have been identified, could differentiate dark fusion from a dark photon model.

  10. Correlation between thyroidal and peripheral blood total T cells, CD8+ T cells, and CD8+ T- regulatory cells and T-cell reactivity to calsequestrin and collagen XIII in patients with Graves' ophthalmopathy.

    PubMed

    Al-Ansari, Farah; Lahooti, Hooshang; Stokes, Leanne; Edirimanne, Senarath; Wall, Jack

    2018-05-22

    Purpose/aim of the study: Graves' ophthalmopathy (GO) is closely related to the thyroid autoimmune disorder Graves' disease. Previous studies have suggested roles for thyroidal CD8 +  T cells and autoimmunity against calsequestrin-1 (CASQ)-1 in the link between thyroidal and orbital autoimmune reactions in GO. A role for autoimmunity against CollXIII has also been suggested. In this study, we aimed to investigate correlations between some thyroidal and peripheral blood T-cell subsets and thyroidal T-cell reactivity against CASQ1 and CollXIII in patients with GO. Fresh thyroid tissues were processed by enzyme digestion and density gradient to isolate mononuclear cells (MNCs). Peripheral blood MNCs were also isolated using density gradient. Flow-cytometric analysis was used to identify the various T-cell subsets. T -cell reactivity to CASQ1 and CollXIII was measured by a 5-day culture of the MNCs and BrdU uptake method. We found a positive correlation between thyroidal CD8 +  T cells and CD8 +  T-regulatory (T-reg) cells in patients with GO. Thyroidal T cells from two out of the three patients with GO tested (66.7%) showed a positive response to CASQ1, while thyroidal T cells from none of the six Graves' Disease patients without ophthalmopathy (GD) tested showed a positive response to this antigen. Thyroidal T cells from these patient groups however, showed no significant differences in their response to CollXIII. Our observations provide further evidence for a possible role of thyroidal CD8 +  T cells, CD8 +  T-reg cells and the autoantigen CASQ1 in the link between thyroidal and orbital autoimmune reactions of GO.

  11. Improved black-blood imaging using DANTE-SPACE for simultaneous carotid and intracranial vessel wall evaluation.

    PubMed

    Xie, Yibin; Yang, Qi; Xie, Guoxi; Pang, Jianing; Fan, Zhaoyang; Li, Debiao

    2016-06-01

    The purpose of this study was to develop a three-dimensional black blood imaging method for simultaneously evaluating the carotid and intracranial arterial vessel walls with high spatial resolution and excellent blood suppression with and without contrast enhancement. The delay alternating with nutation for tailored excitation (DANTE) preparation module was incorporated into three-dimensional variable flip angle turbo spin echo (SPACE) sequence to improve blood signal suppression. Simulations and phantom studies were performed to quantify image contrast variations induced by DANTE. DANTE-SPACE, SPACE, and two-dimensional turbo spin echo were compared for apparent signal-to-noise ratio, contrast-to-noise ratio, and morphometric measurements in 14 healthy subjects. Preliminary clinical validation was performed in six symptomatic patients. Apparent residual luminal blood was observed in five (pre-contrast) and nine (post-contrast) subjects with SPACE and only two (post-contrast) subjects with DANTE-SPACE. DANTE-SPACE showed 31% (pre-contrast) and 100% (post-contrast) improvement in wall-to-blood contrast-to-noise ratio over SPACE. Vessel wall area measured from SPACE was significantly larger than that from DANTE-SPACE due to possible residual blood signal contamination. DANTE-SPACE showed the potential to detect vessel wall dissection and identify plaque components in patients. DANTE-SPACE significantly improved arterial and venous blood suppression compared with SPACE. Simultaneous high-resolution carotid and intracranial vessel wall imaging to potentially identify plaque components was feasible with a scan time under 6 min. Magn Reson Med 75:2286-2294, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  12. Relationship between phenotype, carcass characteristics and the incidence of dark cutting in heifers.

    PubMed

    Mahmood, S; Basarab, J A; Dixon, W T; Bruce, H L

    2016-11-01

    Previous research has suggested that cattle predisposed to dark cutting can be identified from live animal or carcass characteristics. This hypothesis was tested using production and phenotype data from an existing data set collected from heifers (n=467) on study at three farms. Carcasses in the data set graded Canada AAA (n=136), AA (n=296), A (n=14), and B4 (dark cutting, n=21). Farm was identified as significant (P=0.0268) by CATMOD analysis and slaughter weight and carcass weight accounted for the variation in dark cutting frequency across the farms. Analysis of variance indicated that dark cutting heifers had reduced weight at weaning (P<0.0001) and at slaughter (P<0.0001), and produced reduced weight carcasses (P<0.0001). Results of logistic regression indicated that the probability of dark cutting was decreased in heifers slaughtered at live weight greater than 550kg and in carcasses weighing greater than 325kg. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Saturation-inversion-recovery: A method for T1 measurement

    NASA Astrophysics Data System (ADS)

    Wang, Hongzhi; Zhao, Ming; Ackerman, Jerome L.; Song, Yiqiao

    2017-01-01

    Spin-lattice relaxation (T1) has always been measured by inversion-recovery (IR), saturation-recovery (SR), or related methods. These existing methods share a common behavior in that the function describing T1 sensitivity is the exponential, e.g., exp(- τ /T1), where τ is the recovery time. In this paper, we describe a saturation-inversion-recovery (SIR) sequence for T1 measurement with considerably sharper T1-dependence than those of the IR and SR sequences, and demonstrate it experimentally. The SIR method could be useful in improving the contrast between regions of differing T1 in T1-weighted MRI.

  14. Effects of meal preparation training on body weight, glycemia, and blood pressure: results of a phase 2 trial in type 2 diabetes.

    PubMed

    Dasgupta, Kaberi; Hajna, Samantha; Joseph, Lawrence; Da Costa, Deborah; Christopoulos, Stavroula; Gougeon, Rejeanne

    2012-10-17

    Modest reductions in weight and small increases in step- related activity (e.g., walking) can improve glycemic and blood pressure control in type 2 diabetes mellitus (DM2). We examined changes in these parameters following training in time- efficient preparation of balanced, low- energy meals combined with pedometer- based step count monitoring. Seventy- two adults with DM2 were enrolled in a 24- week program (i.e., 15 three- hour group sessions). They prepared meals under a chef's supervision, and discussed eating behaviours/nutrition with a registered dietitian. They maintained a record of pedometer- assessed step counts. We evaluated changes from baseline to 24 weeks in terms of weight, step counts, hemoglobin A1c (HbA1c, glycemic control), blood pressure, and eating control ability (Weight Efficacy Lifestyle WEL Questionnaire). 53 participants (73.6%) completed assessments. There were improvements in eating control (11.2 point WEL score change, 95% CI 4.7 to 17.8), step counts (mean change 869 steps/day, 95% CI 198 to 1,540), weight (mean change -2.2%; 95% CI -3.6 to -0.8), and HbA1c (mean change -0.3% HbA1c, 95% CI -0.6 to -0.1), as well as suggestion of systolic blood pressure reduction (mean change -3.5 mm Hg, 95% CI -7.8 to 0.9). Findings were not attributable to medication changes. In linear regression models (adjusted for age, sex, ethnicity, insulin use, season), a -2.5% weight change was associated with a -0.3% HbA1c change (95% CI -0.4 to -0.2) and a -3.5% systolic blood pressure change (95% CI -5.5 to -1.4). In this 'proof of concept' study, persistence with the program led to improvements in eating and physical activity habits, glycemia reductions, and suggestion of blood pressure lowering effects. The strategy thus merits further study and development to expand the range of options for vascular risk reduction in DM2.

  15. Collider Signal II:. Missing ET Signatures and Dark Matter Connection

    NASA Astrophysics Data System (ADS)

    Baer, Howard

    2010-08-01

    These lectures give an overview of aspects of missing ET signatures from new physics at the LHC, along with their important connection to dark matter physics. Mostly, I will concentrate on supersymmetric (SUSY) sources of ɆT, but will also mention Little Higgs models with T-parity (LHT) and universal extra dimensions (UED) models with KK-parity. Lecture 1 covers SUSY basics, model building and spectra computation. Lecture 2 addresses sparticle production and decay mechanisms at hadron colliders and event generation. Lecture 3 covers SUSY signatures at LHC, along with LHT and UED signatures for comparison. In Lecture 4, I address the dark matter connection, and how direct and indirect dark matter searches, along with LHC collider searches, may allow us to both discover and characterize dark matter in the next several years. Finally, the interesting scenario of Yukawa-unified SUSY is examined; this case works best if the dark matter turns out to be a mixture of axion/axino states, rather than neutralinos.

  16. T-cell immunity and cytokine production in cosmonauts after long-duration space flights

    NASA Astrophysics Data System (ADS)

    Morukov, B.; Rykova, M.; Antropova, E.; Berendeeva, T.; Ponomaryov, S.; Larina, I.

    2011-04-01

    Long-duration spaceflight effects on T-cell immunity and cytokine production were studied in 12 Russian cosmonauts flown onto the International Space Station. Specific assays were performed before launch and after landing and included analysis of peripheral leukocyte distribution, analysis of T-cell phenotype, expression of activation markers, apoptosis, proliferation of T cells in response to a mitogen, concentrations of cytokines in supernatants of cell cultures. Statistically significant increase was observed in leukocytes', lymphocytes', monocytes' and granulocytes' total number, increase in percentage and absolutely number of CD3 +CD4 +-cells, CD4 +CD45RA +-cells and CD4 +CD45RA +/CD4 +CD45RО + ratio, CD4 +CD25 +Bright regulatory cells ( p<0,05) in peripheral blood after landing. T-lymphocytes' capacity to present CD69 and CD25 on its own surfaces was increased for the majority of crewmembers. Analysis of T-cell response to PHA-stimulation in vitro revealed there were some trends toward reduced proliferation of stimulated T-lymphocytes. There was an apparent post flight decrease in secreted IFN-g for the majority of crewmembers and in most instances there was elevation in secreted IL-10. It revealed depression of IFN-g/IL-10 ratio after flight. Correlation analysis according to Spearman's rank correlation test established significant positive correlations ( p<0.05) between cytokine production and T-cell activation (CD25+, CD38+) and negative correlation ( p<0.05) between cytokine production and number of bulk memory CD4+T-cells (CD45RO+). Thus, these results suggest that T-cell dysfunction can be conditioned by cytokine dysbalance and could lead to development of disease after long-duration space flights.

  17. Collisional dark matter and the origin of massive black holes

    PubMed

    Ostriker

    2000-06-05

    If the cosmological dark matter is primarily in the form of an elementary particle which has mass m(p) and cross section for self-interaction sigma, then seed black holes (formed in stellar collapse) will grow in a Hubble time t(H) due to accretion of the dark matter to a mass, M(H) = sqrt[IC(9)(A)t(H)(sigma/G(3)m(p)c(2))] = 7.1x10(6)(sigma/m(p))(1/2)V(9/2)(c)t(1/2)(H,15) solar masses. Here I is a numerical factor, C(A) the galactic velocity dispersion, and V(c) its rotation velocity. For the same values of ( sigma/m(p)) that are attractive with respect to other cosmological desiderata, this produces massive black holes in the (10(6)-10(9))M( middle dot in circle) range observed, with the same dependence on a V(c) seen, and with a time dependence consistent with observations. Other astrophysical consequences of collisional dark matter and tests of the idea are noted.

  18. Phase sensitive reconstruction of T1-weighted inversion recovery in the evaluation of the cervical cord lesions in multiple Sclerosis; is it similarly eligible in 1.5 T magnet fields?

    PubMed

    Shayganfar, A; Sarrami, A H; Fathi, S; Shaygannejad, V; Shamsian, S

    2018-04-22

    In primary studies with 3 T Magnets, phase sensitive reconstruction of T1-weighted inversion recovery (PSIR) have showed ability to depict the cervical multiple sclerosis (MS) lesions some of which may not be detected by short tau inversion recovery (STIR). Regarding to more availability of 1.5 T MRI, this study was designed to evaluate the eligibility of PSIR in 1.5 T for detection of spinal cord MS lesions. In a study between September 2016 till March 2017 the patients with proven diagnosis of MS enrolled to the study. The standard protocol (sagittal STIR and T2W FSE and axial T2W FSE) as well as sagittal PSIR sequences were performed using a 1.5 T magnet. The images were studied and the lesions were localized and recorded as sharp or faint on each sequence. Of 25 patients (22 females and 3 males, with mean age of 33.5 ± 9.8 years and mean disease duration of 5.4 ± 3.9 years) 69 lesions in STIR, 53 lesions in T2W FSE, 47 lesions in Magnitude reconstruction of PSIR (Magnitude), and 30 lesions in phase sensitive (real) reconstruction PSIR were detected. A Wilcoxon signed-rank test showed STIR has a statistically significant higher detection rate of the plaques rather than other three sequences. (STIR and T2W FSE, Z = -4.000, p < 0.0001, STIR and Magnitude, Z = -4.690, p < 0.0001, STIR and PSIR, Z = -6.245, p = 0.002) Also, STIR had a statistically significant superiority in the boundary definition of the plaques rather than other three sequences. This study shows that in the setting of a 1.5 T magnet field, STIR significantly has a superiority over both of the PSIR reconstructions (i.e. real and magnitude) for the detection as well as the boundary definition of the cervical cord lesions of MS. These results have a good relevance to clinical practice by using MRI scanners and sequences routinely available, however, it is discrepant with other reports performed by 3 T Magnet fields. Copyright © 2018 Elsevier B.V. All rights

  19. A medical device-grade T1 and ECV phantom for global T1 mapping quality assurance-the T1 Mapping and ECV Standardization in cardiovascular magnetic resonance (T1MES) program.

    PubMed

    Captur, Gabriella; Gatehouse, Peter; Keenan, Kathryn E; Heslinga, Friso G; Bruehl, Ruediger; Prothmann, Marcel; Graves, Martin J; Eames, Richard J; Torlasco, Camilla; Benedetti, Giulia; Donovan, Jacqueline; Ittermann, Bernd; Boubertakh, Redha; Bathgate, Andrew; Royet, Celine; Pang, Wenjie; Nezafat, Reza; Salerno, Michael; Kellman, Peter; Moon, James C

    2016-09-22

    T 1 mapping and extracellular volume (ECV) have the potential to guide patient care and serve as surrogate end-points in clinical trials, but measurements differ between cardiovascular magnetic resonance (CMR) scanners and pulse sequences. To help deliver T 1 mapping to global clinical care, we developed a phantom-based quality assurance (QA) system for verification of measurement stability over time at individual sites, with further aims of generalization of results across sites, vendor systems, software versions and imaging sequences. We thus created T1MES: The T1 Mapping and ECV Standardization Program. A design collaboration consisting of a specialist MRI small-medium enterprise, clinicians, physicists and national metrology institutes was formed. A phantom was designed covering clinically relevant ranges of T 1 and T 2 in blood and myocardium, pre and post-contrast, for 1.5 T and 3 T. Reproducible mass manufacture was established. The device received regulatory clearance by the Food and Drug Administration (FDA) and Conformité Européene (CE) marking. The T1MES phantom is an agarose gel-based phantom using nickel chloride as the paramagnetic relaxation modifier. It was reproducibly specified and mass-produced with a rigorously repeatable process. Each phantom contains nine differently-doped agarose gel tubes embedded in a gel/beads matrix. Phantoms were free of air bubbles and susceptibility artifacts at both field strengths and T 1 maps were free from off-resonance artifacts. The incorporation of high-density polyethylene beads in the main gel fill was effective at flattening the B 1 field. T 1 and T 2 values measured in T1MES showed coefficients of variation of 1 % or less between repeat scans indicating good short-term reproducibility. Temperature dependency experiments confirmed that over the range 15-30 °C the short-T 1 tubes were more stable with temperature than the long-T 1 tubes. A batch of 69 phantoms was mass-produced with random sampling of

  20. Ultra-high-field (9.4 T) MRI Analysis of Contrast Agent Transport Across the Blood-Perilymph Barrier and Intrastrial Fluid-Blood Barrier in the Mouse Inner Ear.

    PubMed

    Counter, S Allen; Nikkhou-Aski, Sahar; Damberg, Peter; Berglin, Cecilia Engmér; Laurell, Göran

    2017-08-01

    Effective paramagnetic contrast agent for the penetration of the perilymphatic spaces of the scala tympani, scala vestibuli, and scala media of the mouse inner ear can be determined using intravenous injection of various gadolinium (Gd) complexes and ultra-high-field magnetic resonance imaging (MRI) at 9.4 Tesla. A number of contrast agents have been explored in experimental high-field MRI to determine the most effective Gd complex for ideal signal-to-noise ratio and maximal visualization of the in vivo mammalian inner ear in analyzing the temporal and spatial parameters involved in drug penetration of the blood-perilymph barrier and intrastrial fluid-blood barrier in the mouse model using MRI. Gadoteric acid (Dotarem), Gadobutrol (Gadovist), Gadodiamide (Omniscan), Gadopent acid (Magnevist), and Mangafodipir (Teslascan) were administered intravenously using the tail vein of 60 Balb/C mice. High-resolution T1 images of drug penetration were acquired with a horizontal 9.4 T Agilent magnet after intravenously injection. Signal intensity was used as a metric of temporal and spatial parameters of drug delivery and penetration of the perilymphatic and endolymphatic spaces. ANOVA analysis of the area under the curve of intensity enhancement in perilymph revealed a significant difference (p < 0.05) in the scalae uptake using different contrast agents (F (3,25) = 3.54, p = 0.029). The Gadoteric acid complex Dotarem was found to be the most effective Gd compound in terms of rapid, morphological enhancement for analysis of the temporal, and spatial distribution in the perilymphatic space of the inner ear. Gadoteric acid (Dotarem) demonstrated efficacy as a contrast agent for enhanced visualization of the perilymphatic spaces of the inner ear labyrinthine in the mouse, including the scala tympani and scala vestibuli of the cochlea, and the semicircular canals of the vestibular apparatus. These findings may inform the clinical application of Gd compounds in

  1. T1-T2 dual-modal MRI of brain gliomas using PEGylated Gd-doped iron oxide nanoparticles.

    PubMed

    Xiao, Ning; Gu, Wei; Wang, Hao; Deng, Yunlong; Shi, Xin; Ye, Ling

    2014-03-01

    To overcome the negative contrast limitations of iron oxide-based contrast agents and to improve the biocompatibility of Gd-chelate contrast agents, PEGylated Gd-doped iron oxide (PEG-GdIO) NPs as a T1-T2 dual-modal contrast agent were synthesized by the polyol method. The transverse relaxivity (r2) and longitudinal relaxivity (r1) of PEG-GdIO were determined to be 66.9 and 65.9 mM(-1) s(-1), respectively. The high r1 value and low r2/r1 ratio make PEG-GdIO NPs suitable as a T1-T2 dual-modal contrast agent. The in vivo MRI demonstrated a brighter contrast enhancement in T1-weighted image and a simultaneous darken effect in T2-weighted MR image compared to the pre-contrast image in the region of glioma. Furthermore, the biocompatibility of PEG-GdIO NPs was confirmed by the in vitro MTT cytotoxicity and in vivo histological analyses (H&E). Therefore, PEG-GdIO NPs hold great potential in T1-T2 dual-modal imaging for the diagnosis of brain glioma. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Optimization of T2-weighted imaging for shoulder magnetic resonance arthrography by synthetic magnetic resonance imaging.

    PubMed

    Lee, Seung Hyun; Lee, Young Han; Hahn, Seok; Yang, Jaemoon; Song, Ho-Taek; Suh, Jin-Suck

    2017-01-01

    Background Synthetic magnetic resonance imaging (MRI) allows reformatting of various synthetic images by adjustment of scanning parameters such as repetition time (TR) and echo time (TE). Optimized MR images can be reformatted from T1, T2, and proton density (PD) values to achieve maximum tissue contrast between joint fluid and adjacent soft tissue. Purpose To demonstrate the method for optimization of TR and TE by synthetic MRI and to validate the optimized images by comparison with conventional shoulder MR arthrography (MRA) images. Material and Methods Thirty-seven shoulder MRA images acquired by synthetic MRI were retrospectively evaluated for PD, T1, and T2 values at the joint fluid and glenoid labrum. Differences in signal intensity between the fluid and labrum were observed between TR of 500-6000 ms and TE of 80-300 ms in T2-weighted (T2W) images. Conventional T2W and synthetic images were analyzed for diagnostic agreement of supraspinatus tendon abnormalities (kappa statistics) and image quality scores (one-way analysis of variance with post-hoc analysis). Results Optimized mean values of TR and TE were 2724.7 ± 1634.7 and 80.1 ± 0.4, respectively. Diagnostic agreement for supraspinatus tendon abnormalities between conventional and synthetic MR images was excellent (κ = 0.882). The mean image quality score of the joint space in optimized synthetic images was significantly higher compared with those in conventional and synthetic images (2.861 ± 0.351 vs. 2.556 ± 0.607 vs. 2.750 ± 0.439; P < 0.05). Conclusion Synthetic MRI with optimized TR and TE for shoulder MRA enables optimization of soft-tissue contrast.

  3. Rapid Weight Loss and the Body Fluid Balance and Hemoglobin Mass of Elite Amateur Boxers

    PubMed Central

    Reljic, Dejan; Hässler, Eike; Jost, Joachim; Friedmann-Bette, Birgit

    2013-01-01

    Context Dehydration is assumed to be a major adverse effect associated with rapid loss of body mass for competing in a lower weight class in combat sports. However, the effects of such weight cutting on body fluid balance in a real-life setting are unknown. Objective To examine the effects of 5% or greater loss of body mass within a few days before competition on body water, blood volume, and plasma volume in elite amateur boxers. Design Case-control study. Setting Sports medicine laboratory. Patients or Other Participants Seventeen male boxers (age = 19.2 ± 2.9 years, height = 175.1 ± 7.0 cm, mass = 65.6 ± 9.2 kg) were assigned to the weight-loss group (WLG; n = 10) or the control group (CON; n = 7). Intervention(s) The WLG reduced body mass by restricting fluid and food and inducing excessive sweat loss by adhering to individual methods. The CON participated in their usual precompetition training. Main Outcome Measure(s) During an ordinary training period (t-1), 2 days before competition (t-2), and 1 week after competition (t-3), we performed bioelectrical impedance measurements; calculated total body water, intracellular water, and extracellular water; and estimated total hemoglobin mass (tHbmass), blood volume, and plasma volume by the CO-rebreathing method. Results In the WLG, the loss of body mass (5.6% ± 1.7%) led to decreases in total body water (6.0% ± 0.9%), extracellular water (12.4% ± 7.6%), tHbmass (5.3% ± 3.8%), blood volume (7.6% ± 2.1%; P < .001), and plasma volume (8.6% ± 3.9%). The intracellular water did not change (P > .05). At t-3, total body water, extracellular water, and plasma volume had returned to near baseline values, but tHbmass and blood volume still were less than baseline values (P < .05). In CON, we found no changes (P > .05). Conclusions In a real-life setting, the loss of approximately 6% body mass within 5 days induced hypohydration, which became evident by the decreases in body water and plasma volume. The reduction in

  4. T-Lymphocytes Traffic into the Brain across the Blood-CSF Barrier: Evidence Using a Reconstituted Choroid Plexus Epithelium

    PubMed Central

    Strazielle, Nathalie; Creidy, Rita; Malcus, Christophe; Boucraut, José; Ghersi-Egea, Jean-François

    2016-01-01

    An emerging concept of normal brain immune surveillance proposes that recently and moderately activated central memory T lymphocytes enter the central nervous system (CNS) directly into the cerebrospinal fluid (CSF) via the choroid plexus. Within the CSF space, T cells inspect the CNS environment for cognate antigens. This gate of entry into the CNS could also prevail at the initial stage of neuroinflammatory processes. To actually demonstrate T cell migration across the choroidal epithelium forming the blood-CSF barrier, an in vitro model of the rat blood-CSF barrier was established in an “inverse” configuration that enables cell transmigration studies in the basolateral to apical, i.e. blood/stroma to CSF direction. Structural barrier features were evaluated by immunocytochemical analysis of tight junction proteins, functional barrier properties were assessed by measuring the monolayer permeability to sucrose and the active efflux transport of organic anions. The migratory behaviour of activated T cells across the choroidal epithelium was analysed in the presence and absence of chemokines. The migration pathway was examined by confocal microscopy. The inverse rat BCSFB model reproduces the continuous distribution of tight junction proteins at cell margins, the restricted paracellular permeability, and polarized active transport mechanisms, which all contribute to the barrier phenotype in vivo. Using this model, we present experimental evidence of T cell migration across the choroidal epithelium. Cell migration appears to occur via a paracellular route without disrupting the restrictive barrier properties of the epithelial interface. Apical chemokine addition strongly stimulates T cell migration across the choroidal epithelium. The present data provide evidence for the controlled migration of T cells across the blood-CSF barrier into brain. They further indicate that this recruitment route is sensitive to CSF-borne chemokines, extending the relevance of this

  5. T-Lymphocytes Traffic into the Brain across the Blood-CSF Barrier: Evidence Using a Reconstituted Choroid Plexus Epithelium.

    PubMed

    Strazielle, Nathalie; Creidy, Rita; Malcus, Christophe; Boucraut, José; Ghersi-Egea, Jean-François

    2016-01-01

    An emerging concept of normal brain immune surveillance proposes that recently and moderately activated central memory T lymphocytes enter the central nervous system (CNS) directly into the cerebrospinal fluid (CSF) via the choroid plexus. Within the CSF space, T cells inspect the CNS environment for cognate antigens. This gate of entry into the CNS could also prevail at the initial stage of neuroinflammatory processes. To actually demonstrate T cell migration across the choroidal epithelium forming the blood-CSF barrier, an in vitro model of the rat blood-CSF barrier was established in an "inverse" configuration that enables cell transmigration studies in the basolateral to apical, i.e. blood/stroma to CSF direction. Structural barrier features were evaluated by immunocytochemical analysis of tight junction proteins, functional barrier properties were assessed by measuring the monolayer permeability to sucrose and the active efflux transport of organic anions. The migratory behaviour of activated T cells across the choroidal epithelium was analysed in the presence and absence of chemokines. The migration pathway was examined by confocal microscopy. The inverse rat BCSFB model reproduces the continuous distribution of tight junction proteins at cell margins, the restricted paracellular permeability, and polarized active transport mechanisms, which all contribute to the barrier phenotype in vivo. Using this model, we present experimental evidence of T cell migration across the choroidal epithelium. Cell migration appears to occur via a paracellular route without disrupting the restrictive barrier properties of the epithelial interface. Apical chemokine addition strongly stimulates T cell migration across the choroidal epithelium. The present data provide evidence for the controlled migration of T cells across the blood-CSF barrier into brain. They further indicate that this recruitment route is sensitive to CSF-borne chemokines, extending the relevance of this

  6. T cell subsets in cord blood are influenced by maternal allergy and associated with atopic dermatitis.

    PubMed

    Fu, Yujing; Lou, Hongfei; Wang, Chengshuo; Lou, Wei; Wang, Yang; Zheng, Tao; Zhang, Luo

    2013-03-01

    This study aimed to investigate the influence of maternal allergy on cord blood regulatory and effector T cells and to evaluate their role as a predictor of atopic dermatitis (AD) during the first 2 yr of life. Seventy mother-infant pairs were recruited in this prospective birth cohort study (21 allergic and 49 non-allergic mothers). Cord blood samples were collected and assayed for the percentage of regulatory T cells (Treg), interferon-γ (IFN-γ), and interleukin-4 (IL-4) producing T cells (Th1 and Th2, respectively) using flow cytometry. Experiments were undertaken to assess the function of cord blood CD4(+) CD25(+) CD127(-) Treg cells by cell proliferation and cytokine responses. Their offspring at the age of 2 yr old were evaluated by dermatologists to determine whether they had AD. During the first 2 yr of life, 15.7% of the children developed a physician-diagnosed AD. A significantly increased percentage of Th2 cell was observed in cord blood of newborns with maternal allergy. Treg/Th2 ratio significantly decreased among the offspring of allergic mothers. Treg cell-associated suppression of Th2 response was attenuated in Der p1-stimulated CD4(+) CD25(-) T cells from the offspring of allergic mothers. Children with reduced Th1/Th2 (p = 0.001, OR = 0.37) and Treg/Th2 (p = 0.001, OR = 0.47) ratio in cord blood had a higher risk of developing AD. Maternal allergic status is associated with increased percentage of IL-4(+) CD4(+) T cells and a reduced Treg/Th2 ratio in cord blood at their children's birth, which may predispose to an increased risk for developing AD. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  7. Constraints on the coupling between dark energy and dark matter from CMB data

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Murgia, R.; Gariazzo, S.; Fornengo, N., E-mail: riccardo.murgia@sissa.it, E-mail: gariazzo@to.infn.it, E-mail: fornengo@to.infn.it

    2016-04-01

    We investigate a phenomenological non-gravitational coupling between dark energy and dark matter, where the interaction in the dark sector is parameterized as an energy transfer either from dark matter to dark energy or the opposite. The models are constrained by a whole host of updated cosmological data: cosmic microwave background temperature anisotropies and polarization, high-redshift supernovae, baryon acoustic oscillations, redshift space distortions and gravitational lensing. Both models are found to be compatible with all cosmological observables, but in the case where dark matter decays into dark energy, the tension with the independent determinations of H{sub 0} and σ{sub 8}, alreadymore » present for standard cosmology, increases: this model in fact predicts lower H{sub 0} and higher σ{sub 8}, mostly as a consequence of the higher amount of dark matter at early times, leading to a stronger clustering during the evolution. Instead, when dark matter is fed by dark energy, the reconstructed values of H{sub 0} and σ{sub 8} nicely agree with their local determinations, with a full reconciliation between high- and low-redshift observations. A non-zero coupling between dark energy and dark matter, with an energy flow from the former to the latter, appears therefore to be in better agreement with cosmological data.« less

  8. Effects of handling intensity and live weight on blood acid-base status in finishing pigs.

    PubMed

    Hamilton, D N; Ellis, M; Bertol, T M; Miller, K D

    2004-08-01

    The objective of this study was to determine the effect of live weight on the plasma acid-base response of pigs subjected to various handling intensities. Eighty pigs (equal numbers of barrows and gilts) were used in a completely randomized block design with a 2 x 2 x 2 factorial arrangement of the following treatments: 1) live weight (light [104 kg] vs. heavy [128 kg]), 2) handling intensity (low vs. high), and 3) gender (barrows vs. gilts). Before the handling test, pigs were weighed, venous blood samples were taken to establish baseline levels, and rectal temperature was measured. Pigs were allowed to rest for 2 h before being subjected to the handling treatments, which consisted of moving the pigs through a course (12.2 m long x 0.91 m wide), for a total of eight laps. Animals on the high-intensity treatment were moved rapidly through the course and subjected to a total of 16 single shocks (two shocks per lap) with an electric livestock goad, whereas pigs on the low-intensity treatment were moved at their own pace using a moving panel and a paddle. Rectal temperature and a venous blood sample were taken immediately after handling and at 2 h after handling. Blood plasma was assayed for pH, partial pressure of carbon dioxide (PCO2), partial pressure of oxygen (PO2), saturated oxygen (SO2), total carbon dioxide (TCO2), bicarbonate (HCO3), base excess, and lactate. Live weight had no effect on the baseline measurements. After handling, light pigs had higher (P < 0.05) blood SO2 (65.6 vs. 57.2+/-2.80%) and showed a greater (P < 0.05) increase in PO2 from baseline to post-handling than heavy pigs (15.6 vs. 8.3+/-2.63 mmHg). Post-handling, pigs on the high- compared with the low-intensity handling treatment had greater (P < 0.001) lactate (19.1 vs. 4.9+/-0.56 mmol/L) and PO2 (51.6 vs. 36.5+/-2.44 mmHg) with lower (P < 0.001) TCO2 (18.6 vs. 34.7+/-0.64 mmol/L), pH (7.02 vs. 7.36+/-0.015), HCO3 (16.7 vs. 33.0+/-0.62 mmol/L), and base excess (-14.2 vs. 7.5+/-0.75) values

  9. Effect of low refocusing angle in T1-weighted spin echo and fast spin echo MRI on low-contrast detectability: a comparative phantom study at 1.5 and 3 Tesla.

    PubMed

    Sarkar, Subhendra N; Mangosing, Jason L; Sarkar, Pooja R

    2013-01-01

    MRI tissue contrast is not well preserved at high field. In this work, we used a phantom with known, intrinsic contrast (3.6%) for model tissue pairs to test the effects of low angle refocusing pulses and magnetization transfer from adjacent slices on intrinsic contrast at 1.5 and 3 Tesla. Only T1-weighted spin echo sequences were tested since for such sequences the contrast loss, tissue heating, and image quality degradation at high fields seem to present significant diagnostic and quality issues. We hypothesized that the sources of contrast loss could be attributed to low refocusing angles that do not fulfill the Hahn spin echo conditions or to magnetization transfer effects from adjacent slices in multislice imaging. At 1.5 T the measured contrast was 3.6% for 180° refocusing pulses and 2% for 120° pulses, while at 3 T, it was 4% for 180° and only 1% for 120° refocusing pulses. There was no significant difference between single slice and multislice imaging suggesting little or no role played by magnetization transfer in the phantom chosen. Hence, one may conclude that low angle refocusing pulses not fulfilling the Hahn spin echo conditions are primarily responsible for significant deterioration of T1-weighted spin echo image contrast in high-field MRI.

  10. Z-portal dark matter

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Arcadi, Giorgio; Institute for Theoretical Physics, Georg-August University Göttingen, Friedrich-Hund-Platz 1, Göttingen, D-37077; Mambrini, Yann

    2015-03-11

    We propose to generalize the extensions of the Standard Model where the Z boson serves as a mediator between the Standard Model sector and the dark sector χ. We show that, like in the Higgs portal case, the combined constraints from the recent direct searches restrict severely the nature of the coupling of the dark matter to the Z boson and set a limit m{sub χ}≳200 GeV (except in a very narrow region around the Z-pole region). Using complementarity between spin dependent, spin independent and FERMI limits, we predict the nature of this coupling, more specifically the axial/vectorial ratio thatmore » respects a thermal dark matter coupled through a Z-portal while not being excluded by the current observations. We also show that the next generation of experiments of the type LZ or XENON1T will test Z-portal scenario for dark matter mass up to 2 TeV. The condition of a thermal dark matter naturally predicts the spin-dependent scattering cross section on the neutron to be σ{sub χn}{sup SD}≃10{sup −40} cm{sup 2}, which then becomes a clear prediction of the model and a signature testable in the near future experiments.« less

  11. Chiral Dark Sector

    NASA Astrophysics Data System (ADS)

    Co, Raymond T.; Harigaya, Keisuke; Nomura, Yasunori

    2017-03-01

    We present a simple and natural dark sector model in which dark matter particles arise as composite states of hidden strong dynamics and their stability is ensured by accidental symmetries. The model has only a few free parameters. In particular, the gauge symmetry of the model forbids the masses of dark quarks, and the confinement scale of the dynamics provides the unique mass scale of the model. The gauge group contains an Abelian symmetry U (1 )D , which couples the dark and standard model sectors through kinetic mixing. This model, despite its simple structure, has rich and distinctive phenomenology. In the case where the dark pion becomes massive due to U (1 )D quantum corrections, direct and indirect detection experiments can probe thermal relic dark matter which is generically a mixture of the dark pion and the dark baryon, and the Large Hadron Collider can discover the U (1 )D gauge boson. Alternatively, if the dark pion stays light due to a specific U (1 )D charge assignment of the dark quarks, then the dark pion constitutes dark radiation. The signal of this radiation is highly correlated with that of dark baryons in dark matter direct detection.

  12. Chiral Dark Sector.

    PubMed

    Co, Raymond T; Harigaya, Keisuke; Nomura, Yasunori

    2017-03-10

    We present a simple and natural dark sector model in which dark matter particles arise as composite states of hidden strong dynamics and their stability is ensured by accidental symmetries. The model has only a few free parameters. In particular, the gauge symmetry of the model forbids the masses of dark quarks, and the confinement scale of the dynamics provides the unique mass scale of the model. The gauge group contains an Abelian symmetry U(1)_{D}, which couples the dark and standard model sectors through kinetic mixing. This model, despite its simple structure, has rich and distinctive phenomenology. In the case where the dark pion becomes massive due to U(1)_{D} quantum corrections, direct and indirect detection experiments can probe thermal relic dark matter which is generically a mixture of the dark pion and the dark baryon, and the Large Hadron Collider can discover the U(1)_{D} gauge boson. Alternatively, if the dark pion stays light due to a specific U(1)_{D} charge assignment of the dark quarks, then the dark pion constitutes dark radiation. The signal of this radiation is highly correlated with that of dark baryons in dark matter direct detection.

  13. Constraining Secluded Dark Matter models with the public data from the 79-string IceCube search for dark matter in the Sun

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ardid, M.; Felis, I.; Martínez-Mora, J.A.

    The 79-string IceCube search for dark matter in the Sun public data is used to test Secluded Dark Matter models. No significant excess over background is observed and constraints on the parameters of the models are derived. Moreover, the search is also used to constrain the dark photon model in the region of the parameter space with dark photon masses between 0.22 and ∼ 1 GeV and a kinetic mixing parameter ε ∼ 10{sup −9}, which remains unconstrained. These are the first constraints of dark photons from neutrino telescopes. It is expected that neutrino telescopes will be efficient tools tomore » test dark photons by means of different searches in the Sun, Earth and Galactic Center, which could complement constraints from direct detection, accelerators, astrophysics and indirect detection with other messengers, such as gamma rays or antiparticles.« less

  14. Effects of different sources of fructans on body weight, blood metabolites and fecal bacteria in normal and obese non-diabetic and diabetic rats.

    PubMed

    Rendón-Huerta, Juan A; Juárez-Flores, Bertha; Pinos-Rodríguez, Juan M; Aguirre-Rivera, J Rogelio; Delgado-Portales, Rosa E

    2012-03-01

    Fructans contribute significantly to dietary fiber with beneficial effects on gastrointestinal physiology in healthy individuals and offer a promising approach to treating some diseases. Two experiments (Experiment 1 = rats with normal weight; Experiment 2 = obese rats) were developed to compare the effects of three fructan sources (Cichorium intybus L. Asteraceae, Helianthus tuberosus L. Asteraceae and Agave angustifolia ssp. tequilana Haw, Agavaceae) on body weight change, blood metabolites and fecal bacteria in non-diabetic (ND) and diabetic (D) rats. In Experiment 1 total body weight gain and daily feed intake in D and ND rats decreased (P < 0.05) with supplements of fructan. Only in D rats, blood glucose concentrations, fecal Clostrodium spp. counts, and liver steatosis decreased, while blood HDL concentrations and fecal Lactobacillus spp. and Bifidobacterium spp. counts increased due to fructans. In Experiment 2, total body weight gain and feed intake in ND and D rats were also decreased by fructans. In ND rats, fructan decreased blood glucose concentrations. In D rats, fructans from A. angustifolia ssp. tequilana decreased blood cholesterol and LDL and liver steatosis. For both ND and D rats, fecal Lactobacillus spp. and Bifidobacterium spp. counts were higher (P < 0.05) with fructan supplements.

  15. Implications of Neutrino Oscillations on the Dark-Matter World

    NASA Astrophysics Data System (ADS)

    Hwang, W.-Y. Pauchy

    2014-01-01

    According to my own belief that "The God wouldn't create a world that is so boring that a particle knows only the very feeble weak interaction.", maybe we underestimate the roles of neutrinos. We note that right-handed neutrinos play no roles, or don't exist, in the minimal Standard Model. We discuss the language to write down an extended Standard Model - using renormalizable quantum field theory as the language; to start with a certain set of basic units under a certain gauge group; in fact, to use the three right-handed neutrinos to initiate the family gauge group SUf (3). Specifically we use the left-handed and right-handed spinors to form the basic units together with SUc (3) × SUL (2) × U (1) × SUf (3) as the gauge group. The dark-matter SUf (3) world couples with the lepton world, but not with the quark world. Amazingly enough, the space of the Standard-Model Higgs Φ (1 , 2), the family Higgs triplet Φ(3, 1), and the neutral part of the mixed family Higgs Φ0 (3 , 2) undergoes the spontaneous symmetry breaking, i.e. the Standard-Model Higgs mechanism and the "project-out" family Higgs mechanism, to give rise to the weak bosons W± and Z0, one Standard-Model Higgs, the eight massive family gauge bosons, and the remaining four massive neutral family Higgs particles, and nothing more. Thus, the roles of neutrinos in this extended Standard Model are extremely interesting in connection with the dark-matter world.

  16. Cosmological perturbations in the (1 + 3 + 6)-dimensional space-times

    NASA Astrophysics Data System (ADS)

    Tomita, K.

    2014-12-01

    Cosmological perturbations in the (1+3+6)-dimensional space-times including photon gas without viscous processes are studied on the basis of Abbott et al.'s formalism [R. B. Abbott, B. Bednarz, and S. D. Ellis, Phys. Rev. D 33, 2147 (1986)]. Space-times consist of outer space (the 3-dimensional expanding section) and inner space (the 6-dimensional section). The inner space expands initially and later contracts. Abbott et al. derived only power-type solutions, which appear at the final stage of the space-times, in the small wave-number limit. In this paper, we derive not only small wave-number solutions, but also large wave-number solutions. It is found that the latter solutions depend on the two wave-numbers k_r and k_R (which are defined in the outer and inner spaces, respectively), and that the k_r-dependent and k_R-dependent parts dominate the total perturbations when (k_r/r(t))/(k_R/R(t)) ≫ 1 or ≪ 1, respectively, where r(t) and R(t) are the scale-factors in the outer and inner spaces. By comparing the behaviors of these perturbations, moreover, changes in the spectrum of perturbations in the outer space with time are discussed.

  17. Freeze-In dark matter with displaced signatures at colliders

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Co, Raymond T.; D’Eramo, Francesco; Hall, Lawrence J.

    2015-12-11

    Dark matter, X, may be generated by new physics at the TeV scale during an early matter-dominated (MD) era that ends at temperature T{sub R}≪ TeV. Compared to the conventional radiation-dominated (RD) results, yields from both Freeze-Out and Freeze-In processes are greatly suppressed by dilution from entropy production, making Freeze-Out less plausible while allowing successful Freeze-In with a much larger coupling strength. Freeze-In is typically dominated by the decay of a particle B of the thermal bath, B→X. For a large fraction of the relevant cosmological parameter space, the decay rate required to produce the observed dark matter abundance leadsmore » to displaced signals at LHC and future colliders, for any m{sub X} in the range keV« less

  18. The Z1 truss is moved to check weight and balance

    NASA Technical Reports Server (NTRS)

    2000-01-01

    In the Space Station Processing Facility, workers watch as the Integrated Truss Structure Z1, an element of the International Space Station, is moved to another stand to check its weight and balance. The Z1 truss is the first of 10 trusses that will become the backbone of the Space Station, eventually stretching the length of a football field. Along with its companion payload, the third Pressurized Mating Adapter, the Z1 is scheduled to be launched aboard Space Shuttle Discovery Oct. 5 at 9:38 p.m. EDT. The launch will be the 100th in the Shuttle program.

  19. The Z1 truss is moved to check weight and balance

    NASA Technical Reports Server (NTRS)

    2000-01-01

    In the Space Station Processing Facility, the Integrated Truss Structure Z1, an element of the International Space Station, is moved to another stand to check its weight and balance. The Z1 truss is the first of 10 trusses that will become the backbone of the Space Station, eventually stretching the length of a football field. Along with its companion payload, the third Pressurized Mating Adapter, the Z1 is scheduled to be launched aboard Space Shuttle Discovery Oct. 5 at 9:38 p.m. EDT. The launch will be the 100th in the Shuttle program.

  20. The Z1 truss is moved to check weight and balance

    NASA Technical Reports Server (NTRS)

    2000-01-01

    In the Space Station Processing Facility, the Integrated Truss Structure Z1, an element of the International Space Station, is lifted for moving to another stand to check its weight and balance. The Z1 truss is the first of 10 trusses that will become the backbone of the Space Station, eventually stretching the length of a football field. Along with its companion payload, the third Pressurized Mating Adapter, the Z1 is scheduled to be launched aboard Space Shuttle Discovery Oct. 5 at 9:38 p.m. EDT. The launch will be the 100th in the Shuttle program.