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Sample records for brachial ejection time

  1. Birth brachial plexus palsy: a race against time.

    PubMed

    Patra, Sambeet; Narayana Kurup, Jayakrishnan K; Acharya, Ashwath M; Bhat, Anil K

    2016-01-01

    A 5-year-old child presented to us with weakness of the left upper limb since birth. With the given history of obstetric trauma and limb examination, a diagnosis of birth brachial plexus palsy was made. Brachial plexus exploration along with microsurgery was performed at the same time which included extrinsic neurolysis of the roots and trunks and nerve transfer for better shoulder external rotation and elbow flexion. Both the movements were severely restricted previously due to co-contractures with the shoulder internal rotators and triceps. The problem of birth brachial plexus palsy is proving to be a global health burden both in developed countries and in developing countries such as India. The lack of awareness among the general public and primary healthcare providers and inadequate orthopaedic and neurosurgeons trained to treat the condition have worsened the prognosis. This case lays stress on the delayed complications in birth brachial palsy and its effective management. PMID:27402656

  2. "Paradoxical" reduction in postexercise ejection time and increased transthoracic impedance.

    PubMed

    Nakamura, Y; Kotilainen, P; Haffty, B; Jolda, R; Bishop, R; Spodick, D

    1978-12-01

    Despite decreasing heart rate, left ventricular ejection time (LVET) transiently falls immediately following bicycle exercise. In seven normal, untrained subjects LVET decreases at 15 s postexercise corresponded (r = 0.78) with an increase in transthoracic electrical impedance (Z) consistent with decreased venous return to the thorax. Because the determinants of LVET are stroke volume (SV) and ejection rate, the deltaZ implies that decreased SV contributed to the "paradoxical" fall in LVET.

  3. Bilateral transit time assessment of upper and lower limbs as a surrogate ankle brachial index marker.

    PubMed

    Foo, Jong Yong Abdiel

    2008-01-01

    Ankle brachial index is useful in monitoring the pathogenesis of peripheral arterial occlusive diseases. Sphygmomanometer is the standard instrument widely used but frequent prolonged monitoring can be less comfortable for patients. Pulse transit time is known to be inversely correlated with blood pressure and a ratio-based pulse transit time measurement has been proposed as a surrogate ankle brachial index marker. In this study, 17 normotensive adults (9 men; aged 25.4 +/- 3.9 years) were recruited. Two postural change test activities were performed to induce changes in the stiffness of the arterial wall of the moved periphery. Results showed that only readings from the limbs that adopted a new posture registered significant blood pressure and pulse transit time changes (P < .05). Furthermore, there was significant correlation between the ankle brachial index and pulse transit time ratio measure for both test activities (R(2) > or = 0.704). The findings herein suggest that pulse transit time ratio is a surrogate and accommodating ankle brachial index marker. PMID:18480079

  4. Duration of diastole versus cycle length as correlates of left ventricular ejection time

    NASA Technical Reports Server (NTRS)

    Weisdorf, D.; Spodick, D. H.

    1976-01-01

    Studies were done on 82 normal subjects to evaluate cycle length vs duration of diastole as determinants of left ventricular ejection time. Cycle length and its reciprocal, heart rate, had the highest correlation with left ventricular ejection time. Removal of the self-correlation of left ventricular ejection time within cycle length reduces the correlation so that, of all intervals, duration of diastole had the highest correlation as a determinant of left ventricular ejection time. Cycle length and heart rate remain valuable as spuriously close but not misleading correlates for predicting or correcting left ventricular ejection time.

  5. Ejection time by ear densitogram and its derivative - Clinical and physiologic applications.

    NASA Technical Reports Server (NTRS)

    Quarry-Pigott, V.; Chirife, R.; Spodick, D. H.

    1973-01-01

    Ear densitographic ejection times (EDET) and first derivative ear densitogram ejection times (dEDET) were studied to determine whether their reliability and validity justify their substitution for ejection times derived from the far less stable carotid pulse tracing. Inter- and intra-subject comparisons were made on thirty individuals under a wide variety of disease and challenge states. Statistical analysis of the data - which had been obtained through a blinded procedure - showed an overall correlation (r) of .98 for carotid vs EDET and .99 for carotid vs dEDET. The t-test demonstrated no significant differences among ejection times derived from the three methods. Moreover, the close tracking at rest and during challenges of ejection times derived from these curves with those from the carotid indicate that either method may be substituted for standard carotid curves without sacrificing reliability or validity of the measure.

  6. Space-time evolution of ejected plasma for the triggering of gas switch

    NASA Astrophysics Data System (ADS)

    Liu, Shanhong; Liu, Xuandong; Shen, Xi; Feng, Lei; Tie, Weihao; Zhang, Qiaogen

    2016-06-01

    Ejected plasma has been widely applied to the discharge process of gas spark switches as a trigger technology, and the development process of ejected plasma has a direct and important effect on the discharge characteristics of gas switches. In this paper, both the injection characteristics and space-time evolution of ejected plasma for the triggering of gas spark switch with different stored energies, pulse polarities, and pressures are studied. The discharge characteristics and breakdown process of a gas switch ignited by ejected plasma under different working coefficients are also discussed briefly. The results show that stored energy has significant influence on the characteristics of ejected plasma. With the increase of stored energy, the propulsion mode of ejected plasma in the axial direction transforms from "plasmoid" to "plasma flow," and the distribution of the ejected plasma goes through "cloud," "core-cloud," and "branch" in sequence. The velocity of ejected plasma under negative pulse polarity is obviously higher than that under positive pulse polarity, especially at the very beginning time. The radial dimensions of ejected plasma under two kinds of pulse polarities follow the similar varying pattern over time, which increase first and then decrease, assuming an inverted "U"-shaped curve. With the increase of pressure, the velocity of ejected plasma significantly decreases and the "branch" channels droop earlier. Applying the ejected plasma to the triggering of a gas switch, the switch can be triggered reliably in a much wide working coefficient range of 10%-90%. With the increase of working coefficient, the breakdown process of the switch translates from slow working mode to fast working mode, and the delay time reduces from tens of μs to hundreds of ns.

  7. Radionuclide analysis of ejection time, peak ejection rate, and time to peak ejection rate: response to supine bicycle exercise in normal subjects and in patients with coronary heart disease

    SciTech Connect

    Slutsky, R.A.; Mancini, G.B.; Gerber, K.H.; Carey, P.H.; Ashburn, W.L.; Higgins, C.B.

    1983-05-01

    Using equilibrium radionuclide angiography, we evaluated the ejection time (ET), peak ejection rate (PER), and time to peak ejection rate (TTp) at test and during supine bicycle exercise in 39 subjects, divided into three groups: group 1 . 13 normal subjects; group 2 . 10 patients with a previous infarction (MI); and group 3 . 16 patients with coronary disease without a previous MI. Normal subjects had greater ejection fractions and PERs than the other two groups at rest or peak exercise (p less than 0.05). PER was no more useful than ejection fraction in identifying cardiac dysfunction at either rest or exercise. The time of its occurrence varied with the group studied, and was slightly but significantly later in systole in groups 2 and 3 when compared to normals (p less than 0.05), though substantial overlap between groups occurred. During exercise, absolute ET shortened in all groups, but actually increased as a function of the R-R interval. The time to peak ejection rate (normalized for the R-R interval) was greater in the noninfarct group (group 3) patients (p less than 0.05) when compared to the group 1 or group 2 individuals at peak exercise. In conclusion, equilibrium radionuclide angiography is a useful technique for the quantification and characterization of events during systole, and is capable of providing information on the timing of events during ejection. Tardokinesis, or the delay of ventricular ejection, is not seen in the response of global indices of left ventricular function to exercise stress. While global early systolic indexes may not detect regional dyssynchrony, their timing during stress may occasionally aid in discerning the presence of cardiac dysfunction.

  8. Brachial plexus

    MedlinePlus

    The brachial plexus is a group of nerves that run from the lower neck through the upper shoulder area. These ... Damage to the brachial plexus nerves can cause muscle and sensation problems that are often associated with pain in the same area. Symptoms may ...

  9. THE NATURE OF HYPERVELOCITY STARS AND THE TIME BETWEEN THEIR FORMATION AND EJECTION

    SciTech Connect

    Brown, Warren R.; Geller, Margaret J.; Kenyon, Scott J.; Cohen, Judith G. E-mail: mgeller@cfa.harvard.edu E-mail: jlc@astro.caltech.edu

    2012-07-20

    We obtain Keck HIRES spectroscopy of HVS5, one of the fastest unbound stars in the Milky Way halo. We show that HVS5 is a 3.62 {+-} 0.11 M{sub Sun} main-sequence B star at a distance of 50 {+-} 5 kpc. The difference between its age and its flight time from the Galactic center is 105 {+-} 18 (stat) {+-}30 (sys) Myr; flight times from locations elsewhere in the Galactic disk are similar. This 10{sup 8} yr 'arrival time' between formation and ejection is difficult to reconcile with any ejection scenario involving massive stars that live for only 10{sup 7} yr. For comparison, we derive arrival times of 10{sup 7} yr for two unbound runaway B stars, consistent with their disk origin where ejection results from a supernova in a binary system or dynamical interactions between massive stars in a dense star cluster. For HVS5, ejection during the first 10{sup 7} yr of its lifetime is ruled out at the 3{sigma} level. Together with the 10{sup 8} yr arrival times inferred for three other well-studied hypervelocity stars (HVSs), these results are consistent with a Galactic center origin for the HVSs. If the HVSs were indeed ejected by the central black hole, then the Galactic center was forming stars {approx_equal}200 Myr ago, and the progenitors of the HVSs took {approx_equal}100 Myr to enter the black hole's loss cone.

  10. Time dependent ablation and liquid ejection processes during the laser drilling of metals

    NASA Astrophysics Data System (ADS)

    Solana, Pablo; Kapadia, Phiroze; Dowden, John; Rodden, William S. O.; Kudesia, Sean S.; Hand, Duncan P.; Jones, Julian D. C.

    2001-05-01

    A self-consistent time dependent model for the laser drilling of metals is provided, including the analysis of ablation mechanisms, liquid ejection and heat conduction. The energy balance relation assumed to be valid at the ablation front links all the various interacting phenomena involving the absorption of laser light within the vapour. Two liquid ejection mechanisms are identified and discussed, the first of them taking place at the beginning of the process in the form of a sudden blast. The second mechanism occurs with laser beam profiles where the intensity declines with radial distance (e.g. Gaussian beams), and operates locally after the first one has vanished. In addition, experimental results are presented which quantify the ratio of material removed by liquid ejection under practical single pulse drilling conditions. This ratio is determined by the direct collection and weighing of the ejected melt on a glass slide of known mass. The dynamics of the ejection process are also investigated using a high speed digital camera capable of operating at 40,500 frames per second.

  11. Topographic pattern of the brachial plexus at the axillary fossa through real-time ultrasonography in Koreans

    PubMed Central

    Han, Jin Hye; Kim, Jong Hak; Kim, Dong Yeon; Lee, Guie Yong; Kim, Chi Hyo

    2014-01-01

    Background The ability to explore the anatomy has improved our appreciation of the brachial anatomy and the quality of regional anesthesia. Using real-time ultrasonography, we investigated the cross-sectional anatomy of the brachial plexus and of vessels at the axillary fossa in Koreans. Methods One hundred and thirty-one patients scheduled to undergo surgery in the region below the elbow were enrolled after giving their informed written consent. Using the 5-12 MHz linear probe of an ultrasound system, we examined cross-sectional images of the brachial plexus in the supine position with the arm abducted by 90°, the shoulder externally rotated, and the forearm flexed by 90° at the axillary fossa. The results of the nerve positions were expressed on a 12-section pie chart and the numbers of arteries and veins were reported. Results Applying gentle pressure to prevent vein collapse, the positions of the nerves changed easily and showed a clockwise order around the axillary artery (AA). The most frequent positions were observed in the 10-11 section (79.2%) for the median, 1-2 section (79.3%) for the ulnar, 3-5 section (78.4%) for the radial, and 8-9 section (86.9%) for the musculocutaneous nerve. We also noted anatomical variations consisting of double arteries (9.2%) and multiple axillary veins (87%). Conclusions Using real-time ultrasonography, we found that the anatomical pattern of the major nerves in Koreans was about 80% of the frequent position of individual nerves, 90.8% of the single AA, and 87% of multiple veins around the AA. PMID:25473459

  12. Brachial Plexus Injuries

    MedlinePlus

    ... Diversity Find People About NINDS NINDS Brachial Plexus Injuries Information Page Synonym(s): Erb's Palsy Table of Contents ( ... done? Clinical Trials Organizations What are Brachial Plexus Injuries? The brachial plexus is a network of nerves ...

  13. Heart rate-left ventricular ejection time relations - Variations during postural change and cardiovascular challenges

    NASA Technical Reports Server (NTRS)

    Lance, V. Q.; Spodick, D. H.

    1976-01-01

    Experiments were conducted on healthy human subjects to determine HR-LVET (Heart Rate-Left Ventricular Ejection Time) regression relations in different postures, including tilt, and during isometric exercise. The subjects were tested in the resting state in supine and sitting positions, during isometric handgrip in supine and sitting positions and during 70 deg headup tilt. The recordings included a bipolar electrocardiogram and a right external carotid pulse curve. Comparison of the HR-LVET relation for the conditions under analysis revealed differences among the respective regression equations, which can be explained by the well-established differences in stroke volume and ejection rate among these states. These differences appear to account for the fact that under conditions in which stroke volume variations should be the major determinant, slopes will be similar but intercepts will vary. Since substantial differences among intercepts are observed, caution should be exercised whenever the intercept factor is used to predict LVET for HR.

  14. User-guided automated segmentation of time-series ultrasound images for measuring vasoreactivity of the brachial artery induced by flow mediation

    NASA Astrophysics Data System (ADS)

    Sehgal, Chandra M.; Kao, Yen H.; Cary, Ted W.; Arger, Peter H.; Mohler, Emile R.

    2005-04-01

    Endothelial dysfunction in response to vasoactive stimuli is closely associated with diseases such as atherosclerosis, hypertension and congestive heart failure. The current method of using ultrasound to image the brachial artery along the longitudinal axis is insensitive for measuring the small vasodilatation that occurs in response to flow mediation. The goal of this study is to overcome this limitation by using cross-sectional imaging of the brachial artery in conjunction with the User-Guided Automated Boundary Detection (UGABD) algorithm for extracting arterial boundaries. High-resolution ultrasound imaging was performed on rigid plastic tubing, on elastic rubber tubing phantoms with steady and pulsatile flow, and on the brachial artery of a healthy volunteer undergoing reactive hyperemia. The area of cross section of time-series images was analyzed by UGABD by propagating the boundary from one frame to the next. The UGABD results were compared by linear correlation with those obtained by manual tracing. UGABD measured the cross-sectional area of the phantom tubing to within 5% of the true area. The algorithm correctly detected pulsatile vasomotion in phantoms and in the brachial artery. A comparison of area measurements made using UGABD with those made by manual tracings yielded a correlation of 0.9 and 0.8 for phantoms and arteries, respectively. The peak vasodilatation due to reactive hyperemia was two orders of magnitude greater in pixel count than that measured by longitudinal imaging. Cross-sectional imaging is more sensitive than longitudinal imaging for measuring flow-mediated dilatation of brachial artery, and thus may be more suitable for evaluating endothelial dysfunction.

  15. Brachial plexus injury in newborns

    MedlinePlus

    ... palsy; Obstetrical brachial plexus palsy; Birth-related brachial plexus palsy; Neonatal brachial plexus palsy; NBPP ... The nerves of the brachial plexus can be affected during a ... may be caused by: The infant's head and neck pulling toward the ...

  16. To determine block establishment time of supraclavicular brachial plexus block using blunt versus short bevel needle: A prospective randomized trial

    PubMed Central

    Ahuja, V; Thapa, D; Gombar, S; Dhiman, D

    2016-01-01

    Background: Unintentional intraneural injection under ultrasound guidance (USG) with fine caliber needles and lower success rate with large caliber Tuohy needles in supraclavicular brachial plexus block (SCB) have been reported. Materials and Methods: We undertook study to standardize the use of 20-gauge short versus blunt bevel needle for SCB. After approval of Institutional Ethics Committee and written informed consent, patients were randomized using computer-generated random number table to either of the two groups; blunt bevel needle group (n = 30): SCB under USG using 20-gauge Tuohy needle or short bevel needle group (n = 30): SCB under USG using 20-gauge short bevel needle. The primary outcome of the study was time to establishment of sensory and motor block of individual nerves, and secondary outcome was tolerability and any adverse effects. Results: The time to establishment of sensory and motor block in individual nerve territory was similar in both the groups. The complete sensory and motor anesthesia was achieved in 78.3% patients and complete sensory and motor anesthesia after supplementary block was achieved in 86.6% patients. Paresthesias during SCB were recorded in 15 patients. Out of these eight patients were of blunt bevel group and seven patients were of short bevel group. None of the patients experienced any neurological adverse effects. Conclusion: The establishment of sensory and motor blockade of individual nerves was similar to 20-gauge short and blunt bevel needle under ultrasound guide with no neurological adverse events. PMID:27375378

  17. Brachial plexus (image)

    MedlinePlus

    The brachial plexus is a group of nerves that originate from the neck region and branch off to give rise ... movement in the upper limb. Injuries to the brachial plexus are common and can be debilitating. If the ...

  18. Brachial Plexus Injuries

    MedlinePlus

    ... to the shoulder, arm, and hand. Brachial plexus injuries are caused by damage to those nerves. Symptoms ... sensation in the arm or hand Brachial plexus injuries can occur as a result of shoulder trauma, ...

  19. WAITING TIMES OF QUASI-HOMOLOGOUS CORONAL MASS EJECTIONS FROM SUPER ACTIVE REGIONS

    SciTech Connect

    Wang Yuming; Liu Lijuan; Shen Chenglong; Liu Rui; Ye Pinzhong; Wang, S.

    2013-02-01

    Why and how do some active regions (ARs) frequently produce coronal mass ejections (CMEs)? These are key questions for deepening our understanding of the mechanisms and processes of energy accumulation and sudden release in ARs and for improving our space weather prediction capability. Although some case studies have been performed, these questions are still far from fully answered. These issues are now being addressed statistically through an investigation of the waiting times of quasi-homologous CMEs from super ARs in solar cycle 23. It is found that the waiting times of quasi-homologous CMEs have a two-component distribution with a separation at about 18 hr. The first component is a Gaussian-like distribution with a peak at about 7 hr, which indicates a tight physical connection between these quasi-homologous CMEs. The likelihood of two or more occurrences of CMEs faster than 1200 km s{sup -1} from the same AR within 18 hr is about 20%. Furthermore, the correlation analysis among CME waiting times, CME speeds, and CME occurrence rates reveals that these quantities are independent of each other, suggesting that the perturbation by preceding CMEs rather than free energy input is the direct cause of quasi-homologous CMEs. The peak waiting time of 7 hr probably characterizes the timescale of the growth of the instabilities triggered by preceding CMEs. This study uncovers some clues from a statistical perspective for us to understand quasi-homologous CMEs as well as CME-rich ARs.

  20. Toward an Accurate Prediction of the Arrival Time of Geomagnetic-Effective Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Shi, T.; Wang, Y.; Wan, L.; Cheng, X.; Ding, M.; Zhang, J.

    2015-12-01

    Accurately predicting the arrival of coronal mass ejections (CMEs) to the Earth based on remote images is of critical significance for the study of space weather. Here we make a statistical study of 21 Earth-directed CMEs, specifically exploring the relationship between CME initial speeds and transit times. The initial speed of a CME is obtained by fitting the CME with the Graduated Cylindrical Shell model and is thus free of projection effects. We then use the drag force model to fit results of the transit time versus the initial speed. By adopting different drag regimes, i.e., the viscous, aerodynamics, and hybrid regimes, we get similar results, with a least mean estimation error of the hybrid model of 12.9 hr. CMEs with a propagation angle (the angle between the propagation direction and the Sun-Earth line) larger than their half-angular widths arrive at the Earth with an angular deviation caused by factors other than the radial solar wind drag. The drag force model cannot be reliably applied to such events. If we exclude these events in the sample, the prediction accuracy can be improved, i.e., the estimation error reduces to 6.8 hr. This work suggests that it is viable to predict the arrival time of CMEs to the Earth based on the initial parameters with fairly good accuracy. Thus, it provides a method of forecasting space weather 1-5 days following the occurrence of CMEs.

  1. Different effects of abnormal activation and myocardial disease on left ventricular ejection and filling times

    PubMed Central

    Zhou, Q; Henein, M; Coats, A; Gibson, D

    2000-01-01

    BACKGROUND—Ventricular activation is often abnormal in patients with dilated cardiomyopathy, but its specific effects on timing remain undetermined.
OBJECTIVE—To investigate the use of the ratio of the sum of left ventricular ejection and filling times to the total RR interval (Z ratio) to dissociate the effects of abnormal activation from those of cavity dilatation.
METHODS—Subjects were 20 normal individuals, 11 patients with isolated left bundle branch block (LBBB, QRS duration > 120 ms), 17 with dilated cardiomyopathy and normal activation, and 23 with dilated cardiomyopathy and LBBB. An additional 30 patients (nine with normal ventricular systolic function and 21 with dilated cardiomyopathy) were studied before and after right ventricular pacing. Left ventricular ejection and filling times were measured by pulsed wave Doppler and cavity size by M mode echocardiography.
RESULTS—Z ratio was independent of RR interval in all groups. Mean (SD) Z ratio was 82 (10)% for normal subjects, 66 (10)% for isolated LBBB (p < 0.01 v normal), 77 (7)% for dilated cardiomyopathy without LBBB (NS v normal), and 61 (7)% for dilated cardiomyopathy with LBBB (p < 0.01 v normal). In the nine patients with normal left ventricular size and QRS duration, Z ratio fell from 88 (6)% in sinus rhythm to 77 (10)% with right ventricular pacing (p = 0.26). In the 21 patients with dilated cardiomyopathy and LBBB, Z ratio rose from 59 (10)% in sinus rhythm to 74 (9)% with right ventricular DDD pacing (p < 0.001).
CONCLUSIONS—Z ratio dissociates the effects of abnormal ventricular activation and systolic disease. It also clearly differentiates right ventricular pacing from LBBB. It may thus be useful in comparing the haemodynamic effects of different pacing modes in patients with or without left ventricular disease.


Keywords: dilated cardiomyopathy; pacemaker; left bundle branch block; echocardiography. PMID:10956289

  2. Real-time Ensemble Forecasting of Coronal Mass Ejections using the WSA-ENLIL+Cone Model

    NASA Astrophysics Data System (ADS)

    Mays, M. L.; Taktakishvili, A.; Pulkkinen, A. A.; MacNeice, P. J.; Rastaetter, L.; Kuznetsova, M. M.; Odstrcil, D.

    2013-12-01

    Ensemble forecasting of coronal mass ejections (CMEs) provides significant information in that it provides an estimation of the spread or uncertainty in CME arrival time predictions due to uncertainties in determining CME input parameters. Ensemble modeling of CME propagation in the heliosphere is performed by forecasters at the Space Weather Research Center (SWRC) using the WSA-ENLIL cone model available at the Community Coordinated Modeling Center (CCMC). SWRC is an in-house research-based operations team at the CCMC which provides interplanetary space weather forecasting for NASA's robotic missions and performs real-time model validation. A distribution of n (routinely n=48) CME input parameters are generated using the CCMC Stereo CME Analysis Tool (StereoCAT) which employs geometrical triangulation techniques. These input parameters are used to perform n different simulations yielding an ensemble of solar wind parameters at various locations of interest (satellites or planets), including a probability distribution of CME shock arrival times (for hits), and geomagnetic storm strength (for Earth-directed hits). Ensemble simulations have been performed experimentally in real-time at the CCMC since January 2013. We present the results of ensemble simulations for a total of 15 CME events, 10 of which were performed in real-time. The observed CME arrival was within the range of ensemble arrival time predictions for 5 out of the 12 ensemble runs containing hits. The average arrival time prediction was computed for each of the twelve ensembles predicting hits and using the actual arrival time an average absolute error of 8.20 hours was found for all twelve ensembles, which is comparable to current forecasting errors. Some considerations for the accuracy of ensemble CME arrival time predictions include the importance of the initial distribution of CME input parameters, particularly the mean and spread. When the observed arrivals are not within the predicted range, this

  3. Transit Time of Coronal Mass Ejections under Different Ambient Solar Wind Conditions

    NASA Astrophysics Data System (ADS)

    Shanmugaraju, A.; Vršnak, Bojan

    2014-01-01

    The speed [ v( R)] of coronal mass ejections (CMEs) at various distances from the Sun is modeled (as proposed by Vršnak and Gopalswamy in J. Geophys. Res. 107, 2002, doi:10.1029/2001/JA000120) by using the equation of motion a drag= γ( v- w) and its quadratic form a drag= γ( v- w)| v- w|, where v and w are the speeds of the CME and solar wind, respectively. We assume that the parameter γ can be expressed as γ= αR β , where R is the heliocentric distance, and α and β are constants. We extend the analysis of Vršnak and Gopalswamy to obtain a more detailed insight into the dependence of the CME Sun-Earth transit time on the CME speed and the ambient solar-wind speed, for different combinations of α and β. In such a parameter-space analysis, the results obtained confirm that the CME transit time depends strongly on the state of the ambient solar wind. Specifically, we found that: i) for a particular set of values of α and β, a difference in the solar-wind speed causes larger transit-time differences at low CME speeds [ v 0], than at high v 0; ii) the difference between transit times of slow and fast CMEs is larger at low solar-wind speed [ w 0] than at high w 0; iii) transit times of fast CMEs are only slightly influenced by the solar-wind speed. The last item is especially important for space-weather forecasting, since it reduces the number of key parameters that determine the arrival time of fast CMEs, which tend to be more geo-effective than the slow ones. Finally, we compared the drag-based model results with the observational data for two CME samples, consisting of non-interacting and interacting CMEs (Manoharan et al. in J. Geophys. Res. 109, 2004). The comparison reveals that the model results are in better agreement with the observations for non-interacting events than for the interacting events. It was also found that for slow CMEs ( v 0<500 km s-1), there is a deviation between the observations and the model if slow-wind speeds (≈ 300 - 400 km

  4. Classification of Coronal Mass Ejections Based on the Analysis of Height-Time Plots

    NASA Astrophysics Data System (ADS)

    Andrews, M. D.

    2001-05-01

    The "Sheeley Diagram" has been used to argue in favor of two distinct types of Coronal Mass Ejections (CMEs) based on distinguishable structure in a plot of height versus projected velocity. A large number of manually tracked CME features were analyzed and used to create a new velocity versus altitude plot. This plot does show a distinct class of CMEs. All of the events with low initial velocity show significant acceleration. The hypothesis that these events are usually associated with the eruption of pre-existing streamer structures will be discussed. A "Sheeley Diagram" will also be presented for CME features measured in events associated with large X-ray flares. This work was preformed under contract at NRL and was supported by NASA. The LASCO telescopes are part of the SOHO mission which is a result of international cooperation between NASA and ESA.

  5. Determination of left ventricular volume, ejection fraction, and myocardial mass by real-time three-dimensional echocardiography

    NASA Technical Reports Server (NTRS)

    Qin, J. X.; Shiota, T.; Thomas, J. D.

    2000-01-01

    Reconstructed three-dimensional (3-D) echocardiography is an accurate and reproducible method of assessing left ventricular (LV) functions. However, it has limitations for clinical study due to the requirement of complex computer and echocardiographic analysis systems, electrocardiographic/respiratory gating, and prolonged imaging times. Real-time 3-D echocardiography has a major advantage of conveniently visualizing the entire cardiac anatomy in three dimensions and of potentially accurately quantifying LV volumes, ejection fractions, and myocardial mass in patients even in the presence of an LV aneurysm. Although the image quality of the current real-time 3-D echocardiographic methods is not optimal, its widespread clinical application is possible because of the convenient and fast image acquisition. We review real-time 3-D echocardiographic image acquisition and quantitative analysis for the evaluation of LV function and LV mass.

  6. Connecting speeds, directions and arrival times of 22 coronal mass ejections from the sun to 1 AU

    SciTech Connect

    Möstl, C.; Veronig, A. M.; Rollett, T.; Temmer, M.; Peinhart, V.; Amla, K.; Hall, J. R.; Liewer, P. C.; De Jong, E. M.; Colaninno, R. C.; Davies, J. A.; Harrison, R. A.; Lugaz, N.; Farrugia, C. J.; Galvin, A. B.; Liu, Y. D.; Luhmann, J. G.; Vršnak, B.

    2014-06-01

    Forecasting the in situ properties of coronal mass ejections (CMEs) from remote images is expected to strongly enhance predictions of space weather and is of general interest for studying the interaction of CMEs with planetary environments. We study the feasibility of using a single heliospheric imager (HI) instrument, imaging the solar wind density from the Sun to 1 AU, for connecting remote images to in situ observations of CMEs. We compare the predictions of speed and arrival time for 22 CMEs (in 2008-2012) to the corresponding interplanetary coronal mass ejection (ICME) parameters at in situ observatories (STEREO PLASTIC/IMPACT, Wind SWE/MFI). The list consists of front- and backsided, slow and fast CMEs (up to 2700 km s{sup –1}). We track the CMEs to 34.9 ± 7.1 deg elongation from the Sun with J maps constructed using the SATPLOT tool, resulting in prediction lead times of –26.4 ± 15.3 hr. The geometrical models we use assume different CME front shapes (fixed-Φ, harmonic mean, self-similar expansion) and constant CME speed and direction. We find no significant superiority in the predictive capability of any of the three methods. The absolute difference between predicted and observed ICME arrival times is 8.1 ± 6.3 hr (rms value of 10.9 hr). Speeds are consistent to within 284 ± 288 km s{sup –1}. Empirical corrections to the predictions enhance their performance for the arrival times to 6.1 ± 5.0 hr (rms value of 7.9 hr), and for the speeds to 53 ± 50 km s{sup –1}. These results are important for Solar Orbiter and a space weather mission positioned away from the Sun-Earth line.

  7. Characteristic Times of Gradual Solar Energetic Particle Events and Their Dependence on Associated Coronal Mass Ejection Properties

    NASA Astrophysics Data System (ADS)

    Kahler, S. W.

    2005-08-01

    We use 20 MeV proton intensities from the EPACT instrument on Wind and coronal mass ejections (CMEs) from the LASCO coronagraph on SOHO observed during 1998-2002 to statistically determine three characteristic times of gradual solar energetic particle (SEP) events as functions of solar source longitude: (1) TO, the time from associated CME launch to SEP onset at 1 AU, (2) TR, the rise time from SEP onset to the time when the SEP intensity is a factor of 2 below peak intensity, and (3) TD, the duration over which the SEP intensity is within a factor of 2 of the peak intensity. Those SEP event times are compared with associated CME speeds, accelerations, and widths to determine whether and how the SEP event times may depend on the formation and dynamics of coronal/interplanetary shocks driven by the CMEs. Solar source longitudinal variations are clearly present in the SEP times, but TR and TD are significantly correlated with CME speeds only for SEP events in the best-connected longitude range. No significant correlations between the SEP times and CME accelerations are found except for TD in one longitude range, but there is a weak correlation of TR and TD with CME widths. We also find no correlation of any SEP times with the solar wind O+7/O+6 values, suggesting no dependence on solar wind stream type. The SEP times of the small subset of events occurring in interplanetary CMEs may be slightly shorter than those of all events.

  8. Modification over time of pulse wave velocity parallel to changes in aortic BP, as well as in 24-h ambulatory brachial BP.

    PubMed

    Oliveras, A; Segura, J; Suarez, C; García-Ortiz, L; Abad-Cardiel, M; Vigil, L; Gómez-Marcos, M A; Sans Atxer, L; Martell-Claros, N; Ruilope, L M; de la Sierra, A

    2016-03-01

    Arterial stiffness as assessed by carotid-femoral pulse wave velocity (cfPWV) is a marker of preclinical organ damage and a predictor of cardiovascular outcomes, independently of blood pressure (BP). However, limited evidence exists on the association between long-term variation (Δ) on aortic BP (aoBP) and ΔcfPWV. We aimed to evaluate the relationship of ΔBP with ΔcfPWV over time, as assessed by office and 24-h ambulatory peripheral BP, and aoBP. AoBP and cfPWV were evaluated in 209 hypertensive patients with either diabetes or metabolic syndrome by applanation tonometry (Sphygmocor) at baseline(b) and at 12 months of follow-up(fu). Peripheral BP was also determined by using validated oscillometric devices (office(o)-BP) and on an outpatient basis by using a validated (Spacelabs-90207) device (24-h ambulatory BP). ΔcfPWV over time was calculated as follows: ΔcfPWV=[(cfPWVfu-cfPWVb)/cfPWVb] × 100. ΔBP over time resulted from the same formula applied to BP values obtained with the three different measurement techniques. Correlations (Spearman 'Rho') between ΔBP and ΔcfPWV were calculated. Mean age was 62 years, 39% were female and 80% had type 2 diabetes. Baseline office brachial BP (mm Hg) was 143±20/82±12. Follow-up (12 months later) office brachial BP (mm Hg) was 136±20/79±12. ΔcfPWV correlated with ΔoSBP (Rho=0.212; P=0.002), Δ24-h SBP (Rho=0.254; P<0.001), Δdaytime SBP (Rho=0.232; P=0.001), Δnighttime SBP (Rho=0.320; P<0.001) and ΔaoSBP (Rho=0.320; P<0.001). A multiple linear regression analysis included the following independent variables: ΔoSBP, Δ24-h SBP, Δdaytime SBP, Δnighttime SBP and ΔaoSBP. ΔcfPWV was independently associated with Δ24-h SBP (β-coefficient=0.195; P=0.012) and ΔaoSBP (β-coefficient= 0.185; P=0.018). We conclude that changes in both 24-h SBP and aoSBP more accurately reflect changes in arterial stiffness than do office BP measurements. PMID:26108366

  9. Material ejection

    NASA Technical Reports Server (NTRS)

    Webb, David F.; Forbes, Terry G.; Aurass, Henry; Chen, James; Martens, Piet; Rompolt, Bogdan; Rusin, Vojtech; Martin, Sara F.

    1994-01-01

    This paper reviews the major discussions and conclusions of the Flares 22 Workshop concerning the physical processes involved in mass ejecta events, with an emphasis on large-scale phenomena, especially Coronal Mass Ejections (CMEs). New insights have been gained from recent data obtained from the Solar Maximum Mission (SMM) and Yohkoh spacecraft and from several new ground-based radio and optical instruments, as well as from theoretical advances concerning the origins, driving mechanisms and long-term evolution of CMEs.

  10. Brachial plexus anesthesia: an analysis of options.

    PubMed Central

    Brown, D. L.

    1993-01-01

    There are multiple sites at which the brachial plexus block can be induced in selecting regional anesthesia for upper extremity surgical patients. The most frequently used blocks are axillary, infraclavicular, supraclavicular, and interscalene. One must understand brachial plexus anatomy to use these blocks effectively, as well as the practical clinical differences between the blocks. Axillary brachial plexus block is most effective for surgical procedures distal to the elbow. This block is induced at a distance from both the centroneuraxis and the lung; thus, complications in those areas are avoided. Infraclavicular block is often the most effective method of maintaining a continuous block of the brachial plexus, since the catheter is easily secured to the anterior chest. Supraclavicular block provides anesthesia of the entire upper extremity in the most consistent, time-efficient manner of any brachial plexus technique; however, the block needle is necessarily positioned near the lung during injection. Interscalene block is especially effective for surgical procedures involving the shoulder or upper arm because the roots of the brachial plexus are most easily blocked with this technique. The final needle tip position with this block is potentially near the centroneuraxis and arteries perfusing the brain, thus careful aspiration of the needle and incremental injection are important. In summary, when an understanding of branchial plexus anatomy is combined with proper block technique and a patient- and procedure-specific balancing of risk-benefit, our patients and colleagues will be coadvocates of our branchial plexus regional blocks. Images Figure 2 Figure 3 Figure 6 Figure 7 Figure 8 Figure 9 PMID:7825342

  11. Correlation Analyses Between the Characteristic Times of Gradual Solar Energetic Particle Events and the Properties of Associated Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Pan, Z. H.; Wang, C. B.; Wang, Yuming; Xue, X. H.

    2011-06-01

    It is generally believed that gradual solar energetic particles (SEPs) are accelerated by shocks associated with coronal mass ejections (CMEs). Using an ice-cream cone model, the radial speed and angular width of 95 CMEs associated with SEP events during 1998 - 2002 are calculated from SOHO/LASCO observations. Then, we investigate the relationships between the kinematic properties of these CMEs and the characteristic times of the intensity-time profile of their accompanied SEP events observed at 1 AU. These characteristic times of SEP are i) the onset time from the accompanying CME eruption at the Sun to the SEP arrival at 1 AU, ii) the rise time from the SEP onset to the time when the SEP intensity is one-half of peak intensity, and iii) the duration over which the SEP intensity is within a factor of two of the peak intensity. It is found that the onset time has neither significant correlation with the radial speed nor with the angular width of the accompanying CME. For events that are poorly connected to the Earth, the SEP rise time and duration have no significant correlation with the radial speed and angular width of the associated CMEs. However, for events that are magnetically well connected to the Earth, the SEP rise time and duration have significantly positive correlations with the radial speed and angular width of the associated CMEs. This indicates that a CME event with wider angular width and higher speed may more easily drive a strong and wide shock near to the Earth-connected interplanetary magnetic field lines, may trap and accelerate particles for a longer time, and may lead to longer rise time and duration of the ensuing SEP event.

  12. Posterior subscapular dissection: An improved approach to the brachial plexus for human anatomy students.

    PubMed

    Hager, Shaun; Backus, Timothy Charles; Futterman, Bennett; Solounias, Nikos; Mihlbachler, Matthew C

    2014-05-01

    Students of human anatomy are required to understand the brachial plexus, from the proximal roots extending from spinal nerves C5 through T1, to the distal-most branches that innervate the shoulder and upper limb. However, in human cadaver dissection labs, students are often instructed to dissect the brachial plexus using an antero-axillary approach that incompletely exposes the brachial plexus. This approach readily exposes the distal segments of the brachial plexus but exposure of proximal and posterior segments require extensive dissection of neck and shoulder structures. Therefore, the proximal and posterior segments of the brachial plexus, including the roots, trunks, divisions, posterior cord and proximally branching peripheral nerves often remain unobserved during study of the cadaveric shoulder and brachial plexus. Here we introduce a subscapular approach that exposes the entire brachial plexus, with minimal amount of dissection or destruction of surrounding structures. Lateral retraction of the scapula reveals the entire length of the brachial plexus in the subscapular space, exposing the brachial plexus roots and other proximal segments. Combining the subscapular approach with the traditional antero-axillary approach allows students to observe the cadaveric brachial plexus in its entirety. Exposure of the brachial dissection in the subscapular space requires little time and is easily incorporated into a preexisting anatomy lab curriculum without scheduling additional time for dissection.

  13. Predicting the Arrival Time of Coronal Mass Ejections with the Graduated Cylindrical Shell and Drag Force Model

    NASA Astrophysics Data System (ADS)

    Shi, Tong; Wang, Yikang; Wan, Linfeng; Cheng, Xin; Ding, Mingde; Zhang, Jie

    2015-06-01

    Accurately predicting the arrival of coronal mass ejections (CMEs) to the Earth based on remote images is of critical significance for the study of space weather. In this paper, we make a statistical study of 21 Earth-directed CMEs, specifically exploring the relationship between CME initial speeds and transit times. The initial speed of a CME is obtained by fitting the CME with the Graduated Cylindrical Shell model and is thus free of projection effects. We then use the drag force model to fit results of the transit time versus the initial speed. By adopting different drag regimes, i.e., the viscous, aerodynamics, and hybrid regimes, we get similar results, with a least mean estimation error of the hybrid model of 12.9 hr. CMEs with a propagation angle (the angle between the propagation direction and the Sun-Earth line) larger than their half-angular widths arrive at the Earth with an angular deviation caused by factors other than the radial solar wind drag. The drag force model cannot be reliably applied to such events. If we exclude these events in the sample, the prediction accuracy can be improved, i.e., the estimation error reduces to 6.8 hr. This work suggests that it is viable to predict the arrival time of CMEs to the Earth based on the initial parameters with fairly good accuracy. Thus, it provides a method of forecasting space weather 1-5 days following the occurrence of CMEs.

  14. Predicting the Arrival Time of Coronal Mass Ejections with the Graduated Cylindrical Shell and Drag Force Model

    NASA Astrophysics Data System (ADS)

    Shi, Tong; Wang, Yikang; Wan, Linfeng; Cheng, Xin; Ding, Mingde; Zhang, Jie

    2015-06-01

    Accurately predicting the arrival of coronal mass ejections (CMEs) to the Earth based on remote images is of critical significance for the study of space weather. In this paper, we make a statistical study of 21 Earth-directed CMEs, specifically exploring the relationship between CME initial speeds and transit times. The initial speed of a CME is obtained by fitting the CME with the Graduated Cylindrical Shell model and is thus free of projection effects. We then use the drag force model to fit results of the transit time versus the initial speed. By adopting different drag regimes, i.e., the viscous, aerodynamics, and hybrid regimes, we get similar results, with a least mean estimation error of the hybrid model of 12.9 hr. CMEs with a propagation angle (the angle between the propagation direction and the Sun–Earth line) larger than their half-angular widths arrive at the Earth with an angular deviation caused by factors other than the radial solar wind drag. The drag force model cannot be reliably applied to such events. If we exclude these events in the sample, the prediction accuracy can be improved, i.e., the estimation error reduces to 6.8 hr. This work suggests that it is viable to predict the arrival time of CMEs to the Earth based on the initial parameters with fairly good accuracy. Thus, it provides a method of forecasting space weather 1–5 days following the occurrence of CMEs.

  15. Determination of left ventricular ejection fraction by visual estimation during real-time two-dimensional echocardiography

    SciTech Connect

    Rich, S.; Sheikh, A.; Gallastegui, J.; Kondos, G.T.; Mason, T.; Lam, W.

    1982-09-01

    It has been shown that the measured reduction in the cross-sectional area of the left ventricle (LV), as viewed in the short axis, closely approximates its ejection fraction (EF). We assessed the reliability of using two-dimensional echocardiography (2DE) to visually estimate the EF during real-time viewing, without the need of digitizers, planimetry, or calculations. Twenty-five adult hospitalized patients with either suspected or known cardiac disease were evaluated prospectively. Each patient also had gated nuclear angiography during the same admission, and 14 had cardiac catheterization with left ventriculography. The EF was determined by 2DE using a visual estimate of the percent area reduction of the LV cavity in the short-axis view at the level of the papillary muscles. All 2 DE studies were read by two or more blinded reviewers, with a value for the EF to the nearest 2.5% determined by consensus. These values correlated closely to the values determined in all 25 patients with gated nuclear angiography (r . 0.927) and the 14 patients who had left ventriculography (r . 0.935). We believe that this method of visually estimating the LVEF will enable echocardiographers to easily use 2 DE for a reliable and instantaneous assessment of ventricular function, without the need of sophisticated analytical equipment.

  16. Ultrasound guided axillary brachial plexus block.

    PubMed

    Ranganath, Anil; Srinivasan, Karthikeyan Kallidaikurichi; Iohom, Gabriella

    2014-09-01

    The axillary brachial plexus block is the most widely performed upper limb block. It is relatively simple to perform and one of the safest approaches to brachial plexus block. With the advent of ultrasound technology, there is a marked improvement in the success rate of the axillary block. This review will focus on the technique of ultrasound guided axillary brachial plexus block. PMID:25110766

  17. Stable Ejection Seat

    NASA Technical Reports Server (NTRS)

    Hirsch, R. S.

    1986-01-01

    Drogue chute for ejection seat slows down seat in more stable fashion than conventional parachutes and thus improves chances for survival. Square drogue linked to seat from its corners suppresses tendency of seat to rotate in pitch and yaw. New parachute expected to reduce dynamic forces on ejected person and extend maximum possible ejection altitude by 50 percent. Used at high or low speeds.

  18. Regional ejection fraction and regional area strain for left ventricular function assessment in male patients after first-time myocardial infarction.

    PubMed

    Teo, Soo-Kng; Vos, F J A; Tan, Ru-San; Zhong, Liang; Su, Yi

    2015-04-01

    In this work, we present a method to assess left ventricle (LV) regional function from cardiac magnetic resonance (CMR) imaging based on the regional ejection fraction (REF) and regional area strain (RAS). CMR scans were performed for 30 patients after first-time myocardial infarction (MI) and nine age- and sex-matched healthy volunteers. The CMR images were processed to reconstruct three-dimensional LV geometry, and the REF and RAS in a 16-segment model were computed using our proposed methodology. The method of computing the REF was tested and shown to be robust against variation in user input. Furthermore, analysis of data was feasible in all patients and healthy volunteers without any exclusions. The REF correlated well with the RAS in a nonlinear manner (quadratic fit-R(2) = 0.88). In patients after first-time MI, the REF and RAS were significantly reduced across all 16 segments (REF: p < 0.05; RAS: p < 0.01). Moreover, the REF and RAS significantly decreased with the extent of transmural scar obtained from late gadolinium-enhanced CMR images. In addition, we show that the REF and RAS can be used to identify regions with compromised function in the patients with preserved global ejection fraction with reasonable accuracy (more than 78%). These preliminary results confirmed the validity of our approach for accurate analysis of LV regional function. Our approach potentially offers physicians new insights into the local characteristics of the myocardial mechanics after a MI.

  19. Ankle-Brachial Index, Toe-Brachial Index, and Pulse Volume Recording in Healthy Young Adults

    PubMed Central

    Masaki, Hisao; Yunoki, Yasuhiro; Tabuchi, Atushi; Morita, Ichiro; Mohri, Satoshi; Tanemoto, Kazuo

    2015-01-01

    Objective: To clarify the characteristics of ankle-brachial index (ABI), toe-brachial index (TBI), and pulse volume recording (PVR) of the ankle with brachial-ankle pulse wave velocity (baPWV) in healthy young adults. Material and Methods: We analyzed ABI, TBI, baPWV, and PVR in the ankle of healthy adults aged 20 to 25 years (median, 20 years) using an automatic oscillometric device between 2002 and 2013. The ABI, baPWV, and PVR in 1282 legs of 641 subjects (301 men and 340 women) and the TBI in 474 toes of 237 subjects (117 men and 120 women) were evaluated. Results: The measured values showed no bilateral differences. ABI and baPWV were higher in men than in women, but TBI was similar in both sexes. ABI <1.0 was observed in 18.1% of the legs in men and in 25.6% in women. TBI <0.7 was observed in 16.2% of the toes in men and 19.1% in women. For ankle PVR, the % mean arterial pressure was higher in women than in men. The upstroke time was <180 ms in most subjects. Conclusions: For young people, ABI <1.0 or TBI <0.7 may not always indicate vascular abnormalities. When evaluating circulatory indexes, age and sex should be considered. PMID:26421072

  20. The breathing hand: obstetric brachial plexopathy reinnervation from thoracic roots?

    PubMed

    Friedenberg, S M; Hermann, R C

    2004-01-01

    It has been found that in cases of obstetric brachial plexopathy, injured phrenic nerve or C3/4/5 roots may sprout into the adjacent injured upper and middle trunks of the brachial plexus. This aberrant regeneration produces co-contraction of the diaphragm and proximal upper limb muscles. This phenomenon, referred to as respiratory synkinesis or "the breathing arm", may not be limited to the upper cervical roots. We present two cases, identified through electromyographic investigations, of respiratory synkinesis selectively affecting intrinsic hand muscles, and propose that upper thoracic roots and their intercostal nerves may also produce respiratory synkinesis, resulting in a "breathing hand." This novel brand of synkinesis indicates that obstetric brachial plexus neuropathies can have quite proximal nerve injury in all trunks. The findings in our patients may not be entirely unique. The time required to develop distal muscle synkinesis and the subtle nature of our findings may suggest that with time and the assistance of EMG the breathing hand may be more common. When considering brachial plexus surgery, the significance of respiratory synkinesis should not be overlooked as its presence indicates injury at a root or proximal trunk level and may come from either nerves destined for the diaphragm or for the intercostal muscles.

  1. ESTIMATING THE ARRIVAL TIME OF EARTH-DIRECTED CORONAL MASS EJECTIONS AT IN SITU SPACECRAFT USING COR AND HI OBSERVATIONS FROM STEREO

    SciTech Connect

    Mishra, Wageesh; Srivastava, Nandita

    2013-07-20

    Predicting the arrival time and transit speed of coronal mass ejections (CMEs) near the Earth is critical to understanding the solar-terrestrial relationship. Even though STEREO observations now provide multiple views of CMEs in the heliosphere, the true speeds derived from stereoscopic reconstruction of SECCHI coronagraph data are not quite sufficient for accurate forecasting of the arrival time at Earth of a majority of CMEs. This uncertainty is due to many factors that change CME kinematics, such as the interaction of two or more CMEs or the interaction of CMEs with the pervading solar wind. In order to understand the propagation of CMEs, we have used the three-dimensional triangulation method on SECCHI coronagraph (COR2) images and geometric triangulation on the J-maps constructed from Heliospheric Imagers HI1 and HI2 data for eight Earth-directed CMEs observed during 2008-2010. Based on the reconstruction, and implementing the drag-based model for the distance where the CMEs could not be tracked unambiguously in the interplanetary (IP) medium, the arrival time of these CMEs have been estimated. These arrival times have also been compared with the actual arrival times as observed by in situ instruments. The analysis reveals the importance of heliospheric imaging for improved forecasting of the arrival time and direction of propagation of CMEs in the IP medium.

  2. [Ipsilateral brachial plexus C7 root transfer. Presentation of a case and a literature review].

    PubMed

    Vergara-Amador, Enrique; Ramírez, Alejandro

    2014-01-01

    The C7 root in brachial plexus injuries has been used since 1986, since the first description by Gu at that time. This root can be used completely or partially in ipsilateral or contralateral lesions of the brachial plexus. A review of the literature and the case report of a 21-month-old girl with stab wounds to the neck and section of the C5 root of the right brachial plexus are presented. A transfer of the anterior fibres of the ipsilateral C7 root was performed. At 9 months there was complete recovery of abduction and external rotation of the shoulder. PMID:23474130

  3. A linear relationship between crystal size and fragment binding time observed crystallographically: implications for fragment library screening using acoustic droplet ejection.

    PubMed

    Cole, Krystal; Roessler, Christian G; Mulé, Elizabeth A; Benson-Xu, Emma J; Mullen, Jeffrey D; Le, Benjamin A; Tieman, Alanna M; Birone, Claire; Brown, Maria; Hernandez, Jesus; Neff, Sherry; Williams, Daniel; Allaire, Marc; Orville, Allen M; Sweet, Robert M; Soares, Alexei S

    2014-01-01

    High throughput screening technologies such as acoustic droplet ejection (ADE) greatly increase the rate at which X-ray diffraction data can be acquired from crystals. One promising high throughput screening application of ADE is to rapidly combine protein crystals with fragment libraries. In this approach, each fragment soaks into a protein crystal either directly on data collection media or on a moving conveyor belt which then delivers the crystals to the X-ray beam. By simultaneously handling multiple crystals combined with fragment specimens, these techniques relax the automounter duty-cycle bottleneck that currently prevents optimal exploitation of third generation synchrotrons. Two factors limit the speed and scope of projects that are suitable for fragment screening using techniques such as ADE. Firstly, in applications where the high throughput screening apparatus is located inside the X-ray station (such as the conveyor belt system described above), the speed of data acquisition is limited by the time required for each fragment to soak into its protein crystal. Secondly, in applications where crystals are combined with fragments directly on data acquisition media (including both of the ADE methods described above), the maximum time that fragments have to soak into crystals is limited by evaporative dehydration of the protein crystals during the fragment soak. Here we demonstrate that both of these problems can be minimized by using small crystals, because the soak time required for a fragment hit to attain high occupancy depends approximately linearly on crystal size. PMID:24988328

  4. Torticollis associated with neonatal brachial plexus palsy.

    PubMed

    Hervey-Jumper, Shawn L; Justice, Denise; Vanaman, Monique M; Nelson, Virginia S; Yang, Lynda J-S

    2011-11-01

    We investigate the incidence of torticollis associated with neonatal brachial plexus palsy, whether the severity of brachial plexus palsy affects outcomes and the rate of recovery. We performed a retrospective review of 128 consecutive neonatal brachial plexus palsy patients evaluated at the University of Michigan from 2005-2009. Patients were followed for at least 3 months, with regular physical examinations and imaging. Forty-three percent presented concurrently with torticollis. Significant differences were evident in mean age at first brachial plexus examination, suggesting that patients with concurrent torticollis present earlier for clinical examination. Recovery from torticollis was evident in 62% of patients by 23 ± 12 weeks with conservative management. No statistically significant differences were evident between torticollis and nontorticollis groups after reviewing their severity of neonatal brachial plexus palsy (Narakas score), recovery from neonatal brachial plexus palsy (biceps function at 6 months), need for nerve repair or reconstructive procedures, or infant, maternal, or other factors associated with labor. Results suggest that although torticollis occurs with increased frequency in children with brachial plexus palsy, its presence is not related to severity and does not affect the probability of recovery from brachial plexus palsy. Conservative management for torticollis yields reasonable recovery.

  5. Liquid metal drop ejection

    NASA Technical Reports Server (NTRS)

    Khuri-Yakub, B. T.

    1993-01-01

    The aim of this project was to demonstrate the possibility of ejecting liquid metals using drop on demand printing technology. The plan was to make transducers for operation in the 100 MHz frequency range and to use these transducers to demonstrate the ability to eject drops of liquid metals such as gallium. Two transducers were made by indium bonding piezoelectric lithium niobate to quartz buffer rods. The lithium niobate plates were thinned by mechanical polishing to a thickness of 37 microns for operation at 100 MHz. Hemispherical lenses were polished in the opposite ends of the buffer rods. The lenses, which focus the sound waves in the liquid metal, had an F-number equals 1. A mechanical housing was made to hold the transducers and to allow precise control over the liquid level above the lens. We started by demonstrating the ability to eject drops of water on demand. The drops of water had a diameter of 15 microns which corresponds to the wavelength of the sound wave in the water. A videotape of this ejection was made. We then used a mixture of Gallium and Indium (used to lower the melting temperature of the Gallium) to demonstrate the ejection of liquid metal drops. This proved to be difficult because of the oxide skin which forms on the surface of the liquid. In some instances, we were able to eject metal drops, however, this was not consistent and reproducible. An experiment was set up at NASA-Lewis to stabilize the process of drop on demand liquid metal ejection. The object was to place the transducer and liquid metal in a vacuum station so that no oxide would form on the surface. We were successful in demonstrating that liquid metals could be ejected on demand and that this technology could be used for making sheet metal in space.

  6. ARRIVAL TIME CALCULATION FOR INTERPLANETARY CORONAL MASS EJECTIONS WITH CIRCULAR FRONTS AND APPLICATION TO STEREO OBSERVATIONS OF THE 2009 FEBRUARY 13 ERUPTION

    SciTech Connect

    Moestl, C.; Rollett, T.; Temmer, M.; Veronig, A. M.; Biernat, H. K.; Lugaz, N.; Farrugia, C. J.; Galvin, A. B.; Davies, J. A.; Harrison, R. A.; Crothers, S.; Luhmann, J. G.; Zhang, T. L.; Baumjohann, W.

    2011-11-01

    One of the goals of the NASA Solar TErestrial RElations Observatory (STEREO) mission is to study the feasibility of forecasting the direction, arrival time, and internal structure of solar coronal mass ejections (CMEs) from a vantage point outside the Sun-Earth line. Through a case study, we discuss the arrival time calculation of interplanetary CMEs (ICMEs) in the ecliptic plane using data from STEREO/SECCHI at large elongations from the Sun in combination with different geometric assumptions about the ICME front shape [fixed-{Phi} (FP): a point and harmonic mean (HM): a circle]. These forecasting techniques use single-spacecraft imaging data and are based on the assumption of constant velocity and direction. We show that for the slow (350 km s{sup -1}) ICME on 2009 February 13-18, observed at quadrature by the two STEREO spacecraft, the results for the arrival time given by the HM approximation are more accurate by 12 hr than those for FP in comparison to in situ observations of solar wind plasma and magnetic field parameters by STEREO/IMPACT/PLASTIC, and by 6 hr for the arrival time at Venus Express (MAG). We propose that the improvement is directly related to the ICME front shape being more accurately described by HM for an ICME with a low inclination of its symmetry axis to the ecliptic. In this case, the ICME has to be tracked to >30{sup 0} elongation to obtain arrival time errors < {+-} 5 hr. A newly derived formula for calculating arrival times with the HM method is also useful for a triangulation technique assuming the same geometry.

  7. Direct night-time ejection of particle-phase reduced biogenic sulfur compounds from the ocean to the atmosphere.

    PubMed

    Gaston, Cassandra J; Furutani, Hiroshi; Guazzotti, Sergio A; Coffee, Keith R; Jung, Jinyoung; Uematsu, Mitsuo; Prather, Kimberly A

    2015-04-21

    The influence of oceanic biological activity on sea spray aerosol composition, clouds, and climate remains poorly understood. The emission of organic material and gaseous dimethyl sulfide (DMS) from the ocean represents well-documented biogenic processes that influence particle chemistry in marine environments. However, the direct emission of particle-phase biogenic sulfur from the ocean remains largely unexplored. Here we present measurements of ocean-derived particles containing reduced sulfur, detected as elemental sulfur ions (e.g., (32)S(+), (64)S2(+)), in seven different marine environments using real-time, single particle mass spectrometry; these particles have not been detected outside of the marine environment. These reduced sulfur compounds were associated with primary marine particle types and wind speeds typically between 5 and 10 m/s suggesting that these particles themselves are a primary emission. In studies with measurements of seawater properties, chlorophyll-a and atmospheric DMS concentrations were typically elevated in these same locations suggesting a biogenic source for these sulfur-containing particles. Interestingly, these sulfur-containing particles only appeared at night, likely due to rapid photochemical destruction during the daytime, and comprised up to ∼67% of the aerosol number fraction, particularly in the supermicrometer size range. These sulfur-containing particles were detected along the California coast, across the Pacific Ocean, and in the southern Indian Ocean suggesting that these particles represent a globally significant biogenic contribution to the marine aerosol burden.

  8. Stereoscopic study of the kinematic evolution of a coronal mass ejection and its driven shock from the sun to the earth and the prediction of their arrival times

    SciTech Connect

    Hess, Phillip; Zhang, Jie

    2014-09-01

    We present a detailed study of the complete evolution of a coronal mass ejection (CME). We have tracked the evolution of both the ejecta and its shock, and further fit the evolution of the fronts to a simple but physics-based analytical model. This study focuses on the CME initiated on the Sun on 2012 July 12 and arriving at the Earth on 2012 July 14. Shock and ejecta fronts were observed by white light images, as well as in situ by the Advanced Composition Explorer satellite. We find that the propagation of the two fronts is not completely dependent upon one another, but can each be modeled in the heliosphere with a drag model that assumes the dominant force of affecting CME evolution to be the aerodynamic drag force of the ambient solar wind. Results indicate that the CME ejecta front undergoes a more rapid deceleration than the shock front within 50 R {sub ☉} and therefore the propagation of the two fronts is not completely coupled in the heliosphere. Using the graduated cylindrical shell model, as well as data from time-elongation stack plots and in situ signatures, we show that the drag model can accurately describe the behavior of each front, but is more effective with the ejecta. We also show that without the in situ data, based on measurements out to 80 R {sub ☉} combined with the general values for drag model parameters, the arrival of both the shock and ejecta can be predicted within four hours of arrival.

  9. Stereoscopic Study of the Kinematic Evolution of a Coronal Mass Ejection and Its Driven Shock from the Sun to the Earth and the Prediction of Their Arrival Times

    NASA Astrophysics Data System (ADS)

    Hess, Phillip; Zhang, Jie

    2014-09-01

    We present a detailed study of the complete evolution of a coronal mass ejection (CME). We have tracked the evolution of both the ejecta and its shock, and further fit the evolution of the fronts to a simple but physics-based analytical model. This study focuses on the CME initiated on the Sun on 2012 July 12 and arriving at the Earth on 2012 July 14. Shock and ejecta fronts were observed by white light images, as well as in situ by the Advanced Composition Explorer satellite. We find that the propagation of the two fronts is not completely dependent upon one another, but can each be modeled in the heliosphere with a drag model that assumes the dominant force of affecting CME evolution to be the aerodynamic drag force of the ambient solar wind. Results indicate that the CME ejecta front undergoes a more rapid deceleration than the shock front within 50 R ☉ and therefore the propagation of the two fronts is not completely coupled in the heliosphere. Using the graduated cylindrical shell model, as well as data from time-elongation stack plots and in situ signatures, we show that the drag model can accurately describe the behavior of each front, but is more effective with the ejecta. We also show that without the in situ data, based on measurements out to 80 R ☉ combined with the general values for drag model parameters, the arrival of both the shock and ejecta can be predicted within four hours of arrival.

  10. Stereoscopic Study of the Kinematic Evolution of a Coronal Mass Ejection and Its Driven Shock from the Sun to the Earth and the Prediction of Their Arrival Times

    NASA Astrophysics Data System (ADS)

    Hess, Phillip; Zhang, Jie

    2014-09-01

    We present a detailed study of the complete evolution of a coronal mass ejection (CME). We have tracked the evolution of both the ejecta and its shock, and further fit the evolution of the fronts to a simple but physics-based analytical model. This study focuses on the CME initiated on the Sun on 2012 July 12 and arriving at the Earth on 2012 July 14. Shock and ejecta fronts were observed by white light images, as well as in situ by the Advanced Composition Explorer satellite. We find that the propagation of the two fronts is not completely dependent upon one another, but can each be modeled in the heliosphere with a drag model that assumes the dominant force of affecting CME evolution to be the aerodynamic drag force of the ambient solar wind. Results indicate that the CME ejecta front undergoes a more rapid deceleration than the shock front within 50 R ⊙ and therefore the propagation of the two fronts is not completely coupled in the heliosphere. Using the graduated cylindrical shell model, as well as data from time-elongation stack plots and in situ signatures, we show that the drag model can accurately describe the behavior of each front, but is more effective with the ejecta. We also show that without the in situ data, based on measurements out to 80 R ⊙ combined with the general values for drag model parameters, the arrival of both the shock and ejecta can be predicted within four hours of arrival.

  11. Dynamics of polymer ejection from capsid

    NASA Astrophysics Data System (ADS)

    Linna, R. P.; Moisio, J. E.; Suhonen, P. M.; Kaski, K.

    2014-05-01

    Polymer ejection from a capsid through a nanoscale pore is an important biological process with relevance to modern biotechnology. Here, we study generic capsid ejection using Langevin dynamics. We show that even when the ejection takes place within the drift-dominated region there is a very high probability for the ejection process not to be completed. Introducing a small aligning force at the pore entrance enhances ejection dramatically. Such a pore asymmetry is a candidate for a mechanism by which viral ejection is completed. By detailed high-resolution simulations we show that such capsid ejection is an out-of-equilibrium process that shares many common features with the much studied driven polymer translocation through a pore in a wall or a membrane. We find that the ejection times scale with polymer length, τ ˜Nα. We show that for the pore without the asymmetry the previous predictions corroborated by Monte Carlo simulations do not hold. For the pore with the asymmetry the scaling exponent varies with the initial monomer density (monomers per capsid volume) ρ inside the capsid. For very low densities ρ ≤0.002 the polymer is only weakly confined by the capsid, and we measure α =1.33, which is close to α =1.4 obtained for polymer translocation. At intermediate densities the scaling exponents α =1.25 and 1.21 for ρ =0.01 and 0.02, respectively. These scalings are in accord with a crude derivation for the lower limit α =1.2. For the asymmetrical pore precise scaling breaks down, when the density exceeds the value for complete confinement by the capsid, ρ ⪆0.25. The high-resolution data show that the capsid ejection for both pores, analogously to polymer translocation, can be characterized as a multiplicative stochastic process that is dominated by small-scale transitions.

  12. A Flying Ejection Seat

    NASA Technical Reports Server (NTRS)

    Hollrock, R. H.; Barzda, J. J.

    1972-01-01

    To increase aircrewmen's chances for safe rescue in combat zones, the armed forces are investigating advanced escape and rescue concepts that will provide independent flight after ejection and thus reduce the risk of capture. One of the candidate concepts is discussed; namely, a stowable autogyro that serves as the crewman's seat during normal operations and automatically converts to a flight vehicle after ejection. Discussed are (1) the mechanism subsystems that the concept embodies to meet the weight and cockpit-packaging constraints and (2) tests that demonstrated the technical feasibility of the stowage, deployment, and flight operation of the rotor lift system.

  13. Composition of Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Zurbuchen, T. H.; Weberg, M.; von Steiger, R.; Mewaldt, R. A.; Lepri, S. T.; Antiochos, S. K.

    2016-07-01

    We analyze the physical origin of plasmas that are ejected from the solar corona. To address this issue, we perform a comprehensive analysis of the elemental composition of interplanetary coronal mass ejections (ICMEs) using recently released elemental composition data for Fe, Mg, Si, S, C, N, Ne, and He as compared to O and H. We find that ICMEs exhibit a systematic abundance increase of elements with first ionization potential (FIP) < 10 eV, as well as a significant increase of Ne as compared to quasi-stationary solar wind. ICME plasmas have a stronger FIP effect than slow wind, which indicates either that an FIP process is active during the ICME ejection or that a different type of solar plasma is injected into ICMEs. The observed FIP fractionation is largest during times when the Fe ionic charge states are elevated above Q Fe > 12.0. For ICMEs with elevated charge states, the FIP effect is enhanced by 70% over that of the slow wind. We argue that the compositionally hot parts of ICMEs are active region loops that do not normally have access to the heliosphere through the processes that give rise to solar wind. We also discuss the implications of this result for solar energetic particles accelerated during solar eruptions and for the origin of the slow wind itself.

  14. Heliocentric Distance of Coronal Mass Ejections at the Time of Energetic Particle Release: Revisiting the Ground Level Enhancement Events of Solar Cycle 23

    NASA Technical Reports Server (NTRS)

    Gopalswamy, Natchimuthuk

    2011-01-01

    Using the kinematics of coronal mass ejections (CMEs), onset time of soft X-ray flares, and the finite size of the pre-eruption CME structure, we derive the heliocentric distane at which the energetic particles during the ground level enhancement (GLE) events of Solar Cycle 23. We find that the GLE particles are released when the CMEs reach an average heliocentric distance of approx.3.25 solar radii (Rs). From this we infer that the shocks accelerating the particles are located at similar heights. Type II radio burst observations indicate that the CMEs are at much lower distances (average approx.1.4 Rs) when the CME-driven shock first forms. The shock seems to travel approx.1.8 Rs over a period of approox.30 min on the average before releasing the GLE particles. In deriving these results, we made three assumptions that have observational support: (i) the CME lift off occurs from an initial distance of about 1.25 Rs; (ii) the flare onset and CME onset are one and the same because these are two different manifestations of the same eruption; and (iii) the CME has positive acceleration from the onset to the first appearance in the coronagraphic field of view (2.5 to 6 Rs). Observations of coronal cavities in eclipse pictures and in coronagraphic images justify the assumption (i). The close relationship between the flare reconnection magnetic flux and the azimuthal flux of interplanetary magnetic clouds justify assumption (ii) consistent with the standard model (CSHKP) of solar eruption. Coronagraphic observations made close to the solar surface indicate a large positive acceleration of CMEs to a heliocentric distance of approx.3 Rs before they start slowing down due to the drag force. The inferred acceleration (approx.1.5 km/s/s) is consistent with reported values in the literature.

  15. Neurinomas of the brachial plexus: case report.

    PubMed

    Forte, A; Gallinaro, L S; Bertagni, A; Montesano, G; Prece, V; Illuminati, G

    1999-01-01

    Neurinomas, also referred to as neurilemmomas and schwannomas, are rare benign tumours of the peripheral nerves, a low proportion of which arise from the brachial plexus. Authors report a case of an ancient schwannoma arising from the brachial plexus. The tumour, usually asymptomatic, may cause sensory radicular symptoms, or rarely motor deficits in the involved arm. Enucleation of the tumour from the nerve without damage to any of the fascicles is the correct treatment.

  16. Neurinomas of the brachial plexus: case report.

    PubMed

    Forte, A; Gallinaro, L S; Bertagni, A; Montesano, G; Prece, V; Illuminati, G

    1999-01-01

    Neurinomas, also referred to as neurilemmomas and schwannomas, are rare benign tumours of the peripheral nerves, a low proportion of which arise from the brachial plexus. Authors report a case of an ancient schwannoma arising from the brachial plexus. The tumour, usually asymptomatic, may cause sensory radicular symptoms, or rarely motor deficits in the involved arm. Enucleation of the tumour from the nerve without damage to any of the fascicles is the correct treatment. PMID:10710825

  17. Coronal mass ejections

    SciTech Connect

    Steinolfson, R.S.

    1990-01-01

    Coronal mass ejections (CMEs) are now recognized as an important component of the large-scale evolution of the solar corona. Some representative observations of CMEs are reviewed with emphasis on more recent results. Recent observations and theory are examined as they relate to the following aspects of CMEs: (1) the role of waves in determining the white-light signature; and (2) the mechanism by which the CME is driven (or launched) into the corona.

  18. Comparision of nerve stimulator and ultrasonography as the techniques applied for brachial plexus anesthesia

    PubMed Central

    2011-01-01

    Background Brachial plexus block is useful for upper extremity surgery, and many techniques are available. The aim of our study was to compare the efficacy of axillary brachial plexus block using an ultrasound technique to the peripheral nerve stimulation technique. Methods 60 patients scheduled for surgery of the forearm or hand were randomly allocated into two groups (n = 30 per group). For Group 1; US, and for Group 2 PNS was applied. The quality and the onset of the sensorial and motor blockade were assessed. The sensorial blockade, motor blockade time and quality of blockade were compared among the cases. Results The time needed to perform the axillary brachial plexus block averaged is similar in both groups (p > 0.05). Although not significant statistically, it was observed that the sensory block had formed earlier in Group 1 (p > 0.05). But the degree of motor blockade was intenser in Group 1 than in Group 2 (p < 0.05). Conclusions Ultrasound offers a new possibility for identifiying the nerves of the brachial plexus for regional anesthesia. The ultrasound-guided axillary brachial plexus block is a safe method with faster onset time and better quality of motor blockade compared to peripheral nerve stimulation technique. PMID:21255404

  19. Polymer ejection from strong spherical confinement

    NASA Astrophysics Data System (ADS)

    Piili, J.; Linna, R. P.

    2015-12-01

    We examine the ejection of an initially strongly confined flexible polymer from a spherical capsid through a nanoscale pore. We use molecular dynamics for unprecedentedly high initial monomer densities. We show that the time for an individual monomer to eject grows exponentially with the number of ejected monomers. By measurements of the force at the pore we show this dependence to be a consequence of the excess free energy of the polymer due to confinement growing exponentially with the number of monomers initially inside the capsid. This growth relates closely to the divergence of mixing energy in the Flory-Huggins theory at large concentration. We show that the pressure inside the capsid driving the ejection dominates the process that is characterized by the ejection time growing linearly with the lengths of different polymers. Waiting time profiles would indicate that the superlinear dependence obtained for polymers amenable to computer simulations results from a finite-size effect due to the final retraction of polymers' tails from capsids.

  20. Action as ejection.

    PubMed

    Franco, Daisy

    2006-01-01

    The systematic analysis of acting-out episodes can be used in assessing analytic progress. Variables to be considered are the nature of the wish, the type of defense, and the degree of concreteness (versus symbolization) of the mental processes used in attempting actualization (as distinct from the resort to action). Two acting-out episodes of a borderline patient who acted out as a character trait, both occurring outside the analytic setting, are presented as illustrations. In the first one, occurring relatively early in the analysis, when split-off negative and positive self-images had to be rigidly maintained, ejection of the negative self-image was actualized via the regressive use of a symbolic equation and the mechanism of displacement, obliterating the distinction between an internal feeling and an external thing that here was literally thrown out. The later episode, occurring after the split was healed and within the context of a frustrating heterosexual involvement, contained an acted-out allusion to identification and competition with the mother. As in a dream, via associations, an unconscious wish for oedipal victory was revealed. Whereas in the first episode the goal of ejection was central, with splitting and denial the underlying defenses, it was absent from the second, in which an attempt was made to actualize a repressed infantile wish and made greater use of symbolization. It is concluded that acting-out episodes at different periods of the analysis, when systematically analyzed, can serve in assessing a patient's progress.

  1. High pressure melt ejection

    SciTech Connect

    Tarbell, W.W.; Brockmann, J.E.; Pilch, M.

    1983-01-01

    Recent probabilistic risk assessments have identified the potential for reactor pressure vessel failure while the reactor coolant system is at elevated pressure. The analyses postulate that the blowdown of steam and hydrogen into the reactor cavity will cause the core material to be swept from the cavity region into the containment building. The High Pressure Melt Streaming (HIPS) program is an experimental study of the high pressure ejection of molten material and subsequent interactions within a concrete cavity. The program focuses on using prototypic system conditions and scaled models of reactor geometries to accurately simulate the ex-vessel processes during high-pressure accident sequences. Scaling analyses of the experiment show that the criteria established for core debris removal from the cavity are met or exceeded. Tests are performed at two scales, representing 1/10th and 1/20th linear reproductions of the Zion reactor plant. Results of the 1/20th scale tests are presented.

  2. What has changed in brachial plexus surgery?

    PubMed Central

    de Rezende, Marcelo Rosa; Silva, Gustavo Bersani; de Paula, Emygdio José Leomil; Junior, Rames Mattar; de Camargo, Olavo Pires

    2013-01-01

    Brachial plexus injuries, in all their severity and complexity, have been extensively studied. Although brachial plexus injuries are associated with serious and often definitive sequelae, many concepts have changed since the 1950s, when this pathological condition began to be treated more aggressively. Looking back over the last 20 years, it can be seen that the entire approach, from diagnosis to treatment, has changed significantly. Some concepts have become better established, while others have been introduced; thus, it can be said that currently, something can always be offered in terms of functional recovery, regardless of the degree of injury. Advances in microsurgical techniques have enabled improved results after neurolysis and have made it possible to perform neurotization, which has undoubtedly become the greatest differential in treating brachial plexus injuries. Improvements in imaging devices and electrical studies have allowed quick decisions that are reflected in better surgical outcomes. In this review, we intend to show the many developments in brachial plexus surgery that have significantly changed the results and have provided hope to the victims of this serious injury. PMID:23644864

  3. [Percutaneous brachial access: a few simple considerations].

    PubMed

    Marcy, P Y; Ianessi, A; Ben Taarit, I

    2009-01-01

    This letter is with regards to the recently published article by Vidal et al. in the Journal Français de Radiologie Médicale. A clarification of US and venographic techniques of brachial venous catheterization and related complications are presented. The main indications for PICC line and subcutaneous port placement are described.

  4. What has changed in brachial plexus surgery?

    PubMed

    Rezende, Marcelo Rosa de; Silva, Gustavo Bersani; Paula, Emygdio José Leomil de; Mattar Junior, Rames; Camargo, Olavo Pires de

    2013-01-01

    Brachial plexus injuries, in all their severity and complexity, have been extensively studied. Although brachial plexus injuries are associated with serious and often definitive sequelae, many concepts have changed since the 1950s, when this pathological condition began to be treated more aggressively. Looking back over the last 20 years, it can be seen that the entire approach, from diagnosis to treatment, has changed significantly. Some concepts have become better established, while others have been introduced; thus, it can be said that currently, something can always be offered in terms of functional recovery, regardless of the degree of injury. Advances in microsurgical techniques have enabled improved results after neurolysis and have made it possible to perform neurotization, which has undoubtedly become the greatest differential in treating brachial plexus injuries. Improvements in imaging devices and electrical studies have allowed quick decisions that are reflected in better surgical outcomes. In this review, we intend to show the many developments in brachial plexus surgery that have significantly changed the results and have provided hope to the victims of this serious injury.

  5. DRAMATIC INFRARED VARIABILITY OF WISE J1810-3305: CATCHING EARLY-TIME DUST EJECTION DURING THE THERMAL PULSE OF AN ASYMPTOTIC GIANT BRANCH STAR?

    SciTech Connect

    Gandhi, Poshak; Yamamura, Issei; Takita, Satoshi

    2012-05-20

    We present the discovery of a source with broadband infrared photometric characteristics similar to Sakurai's object. WISE J180956.27-330500.2 (hereafter J1810-3305) shows very red WISE colors, but a very blue 2MASS [K] versus WISE [W1 (3.4 {mu}m)] color. It was not visible during the IRAS era, but now has a 12 {mu}m flux well above the IRAS point-source catalog detection limit. There are also indications of variability in historical optical photographic plates as well as in multi-epoch AKARI mid-infrared measurements. The broadband infrared spectral energy distribution (SED) shape, post-IRAS brightening, and multiwavelength variability are all characteristics also shared by Sakurai's object-a post-asymptotic giant branch (post-AGB) star which underwent a late thermal pulse and recently ejected massive envelopes of dust that are currently expanding and cooling. Optical progenitor colors suggest that J1810-3305 may have been of late spectral class. Its dramatic infrared brightening and the detection of a late-type optical counterpart are consistent with a scenario in which we have caught an extremely massive dust ejection event (in 1998 or shortly before) during the thermal pulse of an AGB star, thus providing a unique opportunity to observe stellar evolution in this phase. J1810-3305 is the only source in the entire WISE preliminary data release with similar infrared SED and variability, emphasizing the rarity of such sources. Confirmation of its nature is of great importance.

  6. Different associations between beta-blockers and other antihypertensive medication combinations with brachial blood pressure and aortic waveform parameters

    PubMed Central

    Sluyter, John D.; Hughes, Alun D.; Lowe, Andrew; Parker, Kim H.; Camargo, Carlos A.; Hametner, Bernhard; Wassertheurer, Siegfried; Scragg, Robert K.R.

    2016-01-01

    Background Comparing the relationships of antihypertensive medications with brachial blood pressure (BP) and aortic waveform parameters may help clinicians to predict the effect on the latter in brachial BP-based antihypertensive therapy. We aimed to make such comparisons with new waveform measures and a wider range of antihypertensive regimens than examined previously. Methods Cross-sectional analysis of 2933 adults (61% male; aged 50–84 years): 1637 on antihypertensive treatment and 1296 untreated hypertensives. Sixteen medicine regimens of up to 4 combinations of drugs from 6 antihypertensive classes were analysed. Aortic systolic BP, augmentation index (AIx), excess pressure integral (EPI), backward pressure amplitude (Pb), reflection index (RI) and pulse wave velocity (PWV) were calculated from aortic pressure waveforms derived from suprasystolic brachial measurement. Results Forest plots of single-drug class comparisons across regimens with the same number of drugs (for between 1- and 3-drug regimens) revealed that AIx, Pb, RI and/or loge(EPI) were higher (maximum difference = 5.6%, 2.2 mm Hg, 0.0192 and 0.13 loge(mm Hg · s), respectively) with the use of a beta-blocker compared with vasodilators and diuretics, despite no brachial systolic and diastolic BP differences. These differences were reduced (by 34–57%) or eliminated after adjustment for heart rate, and similar effects occurred when controlling for systolic ejection period or diastolic duration. Conclusions Beta-blocker effects on brachial BP may overestimate effects on aortic waveform parameters. Compared to other antihypertensives, beta-blockers have weaker associations with wave reflection measures and EPI; this is predominantly due to influences on heart rate. PMID:27340919

  7. Shoulder pain and isolated brachial plexopathy.

    PubMed

    Kishan, Amar U; Syed, Sana; Fiorito-Torres, Franchesca; Thakore-James, Manisha

    2012-06-28

    Pancoast syndrome, classically considered as a constellation of (1) pain along the C8-T2 dermatomes, (2) weakness and atrophy of the hand and (3) Horner's syndrome, often presents a diagnostic challenge. In fact, it may manifest as a singular orthopaedic complaint, prompting a futile barrage of tests and referrals. The authors present the case of an elderly man who initially presented with severe shoulder pain. Due to progressive pain and weakness, he was referred to rheumatology and was treated with corticosteroid injections for a presumed musculoskeletal lesion. Ultimately, he manifested gross muscular atrophy and worsening pain, prompting a referral to neurology. An electromyogram (EMG) suggested a lower brachial plexopathy, and a follow-up brachial plexus MRI identified a large Pancoast tumour. Unfortunately, his disease was rapidly progressive, and he passed away within 2 months. While the MRI remains the gold standard for diagnosing Pancoast syndrome, an EMG can facilitate diagnosis in difficult cases such as this one.

  8. Complex anatomic variation in the brachial region.

    PubMed

    Troupis, Th; Michalinos, A; Protogerou, V; Mazarakis, A; Skandalakis, P

    2015-01-01

    Authors describe a case of a complex anatomic variation discovered during dissection of the humeral region. On the right side, brachial artery followed a superficial course. Musculocutaneous nerve did not pierce coracobrachialis muscle but instead passed below the muscle before continuing in the forearm. On the left side, a communication between musculocutaneous and median nerve was dissected. Those variations are analytically presented with a brief review on their anatomic and clinical implications. Considerations on their embryological origin are attempted.

  9. Ejection Fraction Heart Failure Measurement

    MedlinePlus

    ... 70. You can have a normal ejection fraction reading and still have heart failure (called HFpEF or ... to be made. Here we delve into the importance of shared decision making. HF Resources For Life ...

  10. Coronal ejectives in Ahtna Athabaskan

    NASA Astrophysics Data System (ADS)

    Tuttle, Siri

    2005-04-01

    Ahtna, a non-tonal Alaskan language, is one of few Athabaskan languages that has retained word-final ejectives. The loss of stem-final glottal stops and ejectives in the other languages is correlated with tonogenesis. Hargus (2004) finds voice quality distinctions (creakiness, variability, and increased energy in higher harmonics) preceding stem-final glottal consonants in Witsuwiten, another nontonal Northern language. The present study considers the acoustics of stem-initial and stem-final [t'] and [ts'] in Central and Lower Ahtna. Stem-initial ejectives are canonically shaped, with defined silent period following oral release. In stem-final position, as predicted by Kari (1990), variable non-ejective realizations are found in both word-final and intervocalic (suffixed) position. These realizations are accompanied by variable voice quality effects in preceding vowels, more frequent and pronounced than those found variably in vowels following stem-initial ejectives. Stem-final [t'] is frequently pronounced as glottal stop, and final [ts'] as ['s] where <,> stands for glottal stop. Strikingly, non-ejective realizations of stem-finals are found in suffixed and non-suffixed pairs with the same stem, suggesting that stem-final effects generalize to all tokens of stems. These findings support Leers (1979) picture of spirantization and suprasegmentalization in Athabaskan tonogenesis, as glottal effects gravitate to nucleus position.

  11. Valproic acid protects neurons and promotes neuronal regeneration after brachial plexus avulsion

    PubMed Central

    Li, Qiang; Wu, Dianxiu; Li, Rui; Zhu, Xiaojuan; Cui, Shusen

    2013-01-01

    Valproic acid has been shown to exert neuroprotective effects and promote neurite outgrowth in several peripheral nerve injury models. However, whether valproic acid can exert its beneficial effect on neurons after brachial plexus avulsion injury is currently unknown. In this study, brachial plexus root avulsion models, established in Wistar rats, were administered daily with valproic acid dissolved in drinking water (300 mg/kg) or normal water. On days 1, 2, 3, 7, 14 and 28 after avulsion injury, tissues of the C5–T1 spinal cord segments of the avulsion injured side were harvested to investigate the expression of Bcl-2, c-Jun and growth associated protein 43 by real-time PCR and western blot assay. Results showed that valproic acid significantly increased the expression of Bcl-2 and growth associated protein 43, and reduced the c-Jun expression after brachial plexus avulsion. Our findings indicate that valproic acid can protect neurons in the spinal cord and enhance neuronal regeneration following brachial plexus root avulsion. PMID:25206605

  12. Magnetohydrodynamic simulations of the ejection of a magnetic flux rope

    NASA Astrophysics Data System (ADS)

    Pagano, P.; Mackay, D. H.; Poedts, S.

    2013-06-01

    Context. Coronal mass ejections (CME's) are one of the most violent phenomena found on the Sun. One model to explain their occurrence is the flux rope ejection model. In this model, magnetic flux ropes form slowly over time periods of days to weeks. They then lose equilibrium and are ejected from the solar corona over a few hours. The contrasting time scales of formation and ejection pose a serious problem for numerical simulations. Aims: We simulate the whole life span of a flux rope from slow formation to rapid ejection and investigate whether magnetic flux ropes formed from a continuous magnetic field distribution, during a quasi-static evolution, can erupt to produce a CME. Methods: To model the full life span of magnetic flux ropes we couple two models. The global non-linear force-free field (GNLFFF) evolution model is used to follow the quasi-static formation of a flux rope. The MHD code ARMVAC is used to simulate the production of a CME through the loss of equilibrium and ejection of this flux rope. Results: We show that the two distinct models may be successfully coupled and that the flux rope is ejected out of our simulation box, where the outer boundary is placed at 2.5 R⊙. The plasma expelled during the flux rope ejection travels outward at a speed of 100 km s-1, which is consistent with the observed speed of CMEs in the low corona. Conclusions: Our work shows that flux ropes formed in the GNLFFF can lead to the ejection of a mass loaded magnetic flux rope in full MHD simulations. Coupling the two distinct models opens up a new avenue of research to investigate phenomena where different phases of their evolution occur on drastically different time scales. Movies are available in electronic form at http://www.aanda.org

  13. The Accretion Flow–Discrete Ejection Connection in GRS 1915+105

    NASA Astrophysics Data System (ADS)

    Punsly, Brian; Rodriguez, Jérôme; Trushkin, Sergei A.

    2016-07-01

    The microquasar GRS 1915+105 is known for its spectacular discrete ejections. They occur unexpectedly, thus their inception has escaped direct observation. It has been shown that the X-ray flux increases in the hours leading up to a major ejection. In this article, we consider the serendipitous interferometric monitoring of a modest version of a discrete ejection described in Reid et al. that would have otherwise escaped detection in daily radio light curves. The observation begins ˜1 hr after the onset of the ejection, providing unprecedented accuracy on the estimate of the ejection time. The astrometric measurements allow us to determine the time of ejection as {{MJD}} {56436.274}-0.013+0.016, i.e., within a precision of 41 minutes (95% confidence). Just like larger flares, we find that the X-ray luminosity increases in last 2–4 hr preceding ejection. Our finite temporal resolution indicates that this elevated X-ray flux persists within {21.8}-19.1+22.6 minutes of the ejection with 95% confidence, the highest temporal precision of the X-ray–superluminal ejection connection to date. This observation provides direct evidence that the physics that launches major flares occurs on smaller scales as well (lower radio flux and shorter ejection episodes). The observation of a X-ray spike prior to a discrete ejection, although of very modest amplitude, suggests that the process linking accretion behavior to ejection is general from the smallest scales to high luminosity major superluminal flares.

  14. Supraclavicular Brachial Plexus Block for Arteriovenous Hemodialysis Access Procedures.

    PubMed

    Hull, Jeffrey; Heath, Jean; Bishop, Wendy

    2016-05-01

    Ultrasound-guided supraclavicular brachial plexus block using 1% and 2% lidocaine in 21 procedures is reported. Average procedure time was 5.1 minutes (± 1.2 min; range, 2-8 min). Average time of onset and duration were 4.8 minutes (± 3.7 min; range, 0-10 min) and 77.9 minutes (± 26.7 min; range, 44-133 min), respectively, for sensory block and 8.4 minutes (± 5.7 min; range, 3-23 min) and 99 minutes (± 40.5 min; range, 45-171 min), respectively, for motor block. The pain scale assessment averaged 0.4 (± 1.1; range, 0-4). There were no complications. PMID:27106648

  15. Combined Spinal Cord Stimulation and Peripheral Nerve Stimulation for Brachial Plexopathy: A Case Report.

    PubMed

    Choi, Ji Hye; Choi, Shu Chung; Kim, Dong Kyu; Sung, Choon Ho; Chon, Jin Young; Hong, Sung Jin; Lee, Ji Young; Moon, Ho Sik

    2016-03-01

    Brachial plexopathy usually results from an iatrogenic brachial plexus injury and can sometimes cause severe chronic pain and disability. There are a number of possible treatments for this condition, including medication, physical therapy, nerve blocks, and neuromodulation, but they are not always successful. Recently, combined spinal cord stimulation (SCS) and peripheral nerve stimulation (PNS) have been tried for various chronic pain diseases because of their different mechanisms of action.Here, we describe the case of a 54-year-old man who was diagnosed with brachial plexopathy 8 years ago. He underwent video-assisted thoracoscopic surgery to remove a superior mediastinal mass. However, his brachial plexus was damaged during the surgery. Although he had received various treatments, the pain did not improve. For the management of intractable severe pain, he underwent SCS 2 years ago, which initially reduced his pain from numeric rating scale (NRS) 10/10 to NRS 4 - 5/10, but the pain then gradually increased, reaching NRS 8/10, 6 months ago. At that time, he was refractory to other treatments, and we therefore applied PNS in combination with SCS. The PNS electrode was positioned on the radial nerve under ultrasound guidance. After combined PNS and SCS, his background pain disappeared, although a breakthrough pain (NRS 3 - 4/10) was caused intermittently by light touch. Furthermore, the patient's need for analgesics decreased, and he was satisfied with the outcome of this combined treatment. We concluded that combined SCS and PNS is a very useful treatment modality, which can stimulate the target nerve both directly and indirectly, and hence, relieve pain from brachial plexopathy. PMID:27008302

  16. MHD shocks in coronal mass ejections

    NASA Technical Reports Server (NTRS)

    Steinolfson, R. S.

    1991-01-01

    The primary objective of this research program is the study of the magnetohydrodynamic (MHD) shocks and nonlinear simple waves produced as a result of the interaction of ejected lower coronal plasma with the ambient corona. The types of shocks and nonlinear simple waves produced for representative coronal conditions and disturbance velocities were determined. The wave system and the interactions between the ejecta and ambient corona were studied using both analytic theory and numerical solutions of the time-dependent, nonlinear MHD equations. Observations from the SMM coronagraph/polarimeter provided both guidance and motivation and are used extensively in evaluating the results. As a natural consequence of the comparisons with the data, the simulations assisted in better understanding the physical interactions in coronal mass ejections (CME's).

  17. Evidence linking coronal mass ejections with interplanetary magnetic clouds

    NASA Technical Reports Server (NTRS)

    Wilson, R. M.; Hildner, E.

    1983-01-01

    Using proxy data for the occurrence of those mass ejections from the solar corona which are directed earthward, we investigate the association between the post-1970 interplanetary magnetic clouds of Klein and Burlaga and coronal mass ejections. The evidence linking magnetic clouds following shocks with coronal mass ejections is striking; six of nine clouds observed at Earth were preceded an appropriate time earlier by meter-wave type II radio bursts indicative of coronal shock waves and coronal mass ejections occurring near central meridian. During the selected periods when no clouds were detected near Earth, the only type II bursts reported were associated with solar activity near the limbs. Where the proxy solar data to be sought are not so clearly suggested, that is, for clouds preceding interaction regions and clouds within cold magnetic enhancements, the evidence linking the clouds and coronal mass ejections is not as clear; proxy data usually suggest many candidate mass-ejection events for each cloud. Overall, the data are consistent with and support the hypothesis suggested by Klein and Burlaga that magnetic clouds observed with spacecraft at 1 AU are manifestations of solar coronal mass ejection transients.

  18. A multipurpose satellite ejection system

    NASA Technical Reports Server (NTRS)

    Moore, Michael B.

    1987-01-01

    A design is presented for a pneumatic ejection system capable of ejecting a spin stabilized satellite from the cargo bay of space vehicles. This system was orginally designed for use on the Spacelab 6 shuttle mission, but is now being considered for use with expendable rockets for launching satellites. The ejection system was designed to launch a 150 lb satellite at an initial ejection velocity of 32 ft/sec with a spin rate of 30 rev/min. The ejection system consists of a pneumatic cylinder, satellite retaining mechanism, and bearing assembly to allow the satellite to rotate during the spin up phase. As the cylinder is pressurized rapidly causing movement of the actuation piston, the mechanism automatically releases the spinning satellite by retracting a pneumatic locking pin and three spring loaded holddown pins. When the piston reaches the end of its stroke, it encounters a crushable aluminum honeycomb shock absorber which decelerates the piston and retaining mechanism. The assembly is designed for multiple uses except for the crushable shock absorber and pyrotechnic valves. The advantage of the design is discussed and patent no. and date given.

  19. Lightning strike-induced brachial plexopathy.

    PubMed

    Bhargava, Amita N; Kasundra, Gaurav M; Khichar, Subhakaran; Bhushan, Bharat S K

    2014-10-01

    We describe a patient who presented with a history of lightning strike injury. Following the injury, he sustained acute right upper limb weakness with pain. Clinically, the lesion was located to the upper and middle trunk of the right brachial plexus, and the same confirmed with electrophysiological studies. Nerve damage due to lightning injuries is considered very rare, and a plexus damage has been described infrequently, if ever. Thus, the proposed hypothesis that lightning rarely causes neuropathy, as against high-voltage electric current, due to its shorter duration of exposure not causing severe burns which lead to nerve damage, needs to be reconsidered. PMID:25288846

  20. Central Adaptation following Brachial Plexus Injury.

    PubMed

    Simon, Neil G; Franz, Colin K; Gupta, Nalin; Alden, Tord; Kliot, Michel

    2016-01-01

    Brachial plexus trauma (BPT) often affects young patients and may result in lasting functional deficits. Standard care following BPT involves monitoring for clinical and electrophysiological evidence of muscle reinnervation, with surgical treatment decisions based on the presence or absence of spontaneous recovery. Data are emerging to suggest that central and peripheral adaptation may play a role in recovery following BPT. The present review highlights adaptive and maladaptive mechanisms of central and peripheral nervous system changes following BPT that may contribute to functional outcomes. Rehabilitation and other treatment strategies that harness or modulate these intrinsic adaptive mechanisms may improve functional outcomes following BPT. PMID:26409073

  1. Lightning strike-induced brachial plexopathy.

    PubMed

    Bhargava, Amita N; Kasundra, Gaurav M; Khichar, Subhakaran; Bhushan, Bharat S K

    2014-10-01

    We describe a patient who presented with a history of lightning strike injury. Following the injury, he sustained acute right upper limb weakness with pain. Clinically, the lesion was located to the upper and middle trunk of the right brachial plexus, and the same confirmed with electrophysiological studies. Nerve damage due to lightning injuries is considered very rare, and a plexus damage has been described infrequently, if ever. Thus, the proposed hypothesis that lightning rarely causes neuropathy, as against high-voltage electric current, due to its shorter duration of exposure not causing severe burns which lead to nerve damage, needs to be reconsidered.

  2. Idiopathic brachial plexus neuritis after laparoscopic treatment of endometriosis: a complication that may mimic position-related brachial plexus injury.

    PubMed

    Minas, Vasileios; Aust, Thomas

    2013-01-01

    We report the case of a 37-year-old woman who developed idiopathic brachial plexus neuritis, also referred to as Parsonage-Turner syndrome, after laparoscopic excision of endometriosis. The differential diagnosis between this non-position-related neuritis and brachial plexus injury is discussed. The aim of this report was to raise awareness on this distressing postoperative complication. PMID:24183278

  3. The Solar Mass Ejection Imager

    NASA Technical Reports Server (NTRS)

    Jackson, B. V.; Buffington, A.; Hick, P. L.; Kahler, S. W.; Altrock, R. C.; Gold, R. E.; Webb, D. F.

    1995-01-01

    We are designing a Solar Mass Ejection Imager (SMEI) capable of observing the Thomson-scattered signal from transient density features in the heliosphere from a spacecraft situated near AU. The imager is designed to trace these features, which include coronal mass ejections. corotating structures and shock waves, to elongations greater than 90 deg from the Sun. The instrument may be regarded as a progeny of the heliospheric imaging capability shown possible by the zodiacal-light photometers of the HELIOS spacecraft. The instrument we are designing would make more effective use of in-situ solar wind data from spacecraft in the vicinity of the imager by extending these observations to the surrounding environment. The observations from the instrument should allow deconvolution of these structures from the perspective views obtained as they pass the spacecraft. An imager at Earth could allow up to three days warning of the arrival of a mass ejection from the Sun .

  4. Lateral approach for supraclavicular brachial plexus block

    PubMed Central

    Sahu, DK; Sahu, Anjana

    2010-01-01

    A lateral approach described by Volker Hempel and Dr. Dilip Kotharihas been further studied, evaluated and described in detail in the present study. The aim of this study was to evaluate lateral approach of supraclavicular brachial plexus block, mainly in terms of successes rate and complication rate. The study was conducted in secondary level hospital and tertiary level hospital from 2004 to 2008. It was a prospective nonrandomized open-level study. Eighty-two patients of both sexes, aged between 18 and 65 years with ASA Grade I and II scheduled to undergo elective major surgery of the upper limb below the midarm, were selected for this new lateral approach of brachial plexus block. The onset and duration of sensory and motor block, any complications and need for supplement anaesthesia were observed. Success and complication rate were calculated in percentage. Average onset and duration of sensory and motor block was calculated as mean ± SD and percentage. Out of 82 patients, 75 (92%) have got successful block with no significant complication in any case. PMID:20885867

  5. Shoulder pain and isolated brachial plexopathy

    PubMed Central

    Kishan, Amar U; Syed, Sana; Fiorito-Torres, Franchesca; Thakore-James, Manisha

    2012-01-01

    Pancoast syndrome, classically considered as a constellation of (1) pain along the C8–T2 dermatomes, (2) weakness and atrophy of the hand and (3) Horner's syndrome, often presents a diagnostic challenge. In fact, it may manifest as a singular orthopaedic complaint, prompting a futile barrage of tests and referrals. The authors present the case of an elderly man who initially presented with severe shoulder pain. Due to progressive pain and weakness, he was referred to rheumatology and was treated with corticosteroid injections for a presumed musculoskeletal lesion. Ultimately, he manifested gross muscular atrophy and worsening pain, prompting a referral to neurology. An electromyogram (EMG) suggested a lower brachial plexopathy, and a follow-up brachial plexus MRI identified a large Pancoast tumour. Unfortunately, his disease was rapidly progressive, and he passed away within 2 months. While the MRI remains the gold standard for diagnosing Pancoast syndrome, an EMG can facilitate diagnosis in difficult cases such as this one. PMID:22744250

  6. Dose–Volume Modeling of Brachial Plexus-Associated Neuropathy After Radiation Therapy for Head-and-Neck Cancer: Findings From a Prospective Screening Protocol

    SciTech Connect

    Chen, Allen M.; Wang, Pin-Chieh; Daly, Megan E.; Cui, Jing; Hall, William H.; Vijayakumar, Srinivasan; Phillips, Theodore L.; Farwell, D. Gregory; Purdy, James A.

    2014-03-15

    Purpose: Data from a prospective screening protocol administered for patients previously irradiated for head-and-neck cancer was analyzed to identify dosimetric predictors of brachial plexus-associated neuropathy. Methods and Materials: Three hundred fifty-two patients who had previously completed radiation therapy for squamous cell carcinoma of the head and neck were prospectively screened from August 2007 to April 2013 using a standardized self-administered instrument for symptoms of neuropathy thought to be related to brachial plexus injury. All patients were disease-free at the time of screening. The median time from radiation therapy was 40 months (range, 6-111 months). A total of 177 patients (50%) underwent neck dissection. Two hundred twenty-one patients (63%) received concurrent chemotherapy. Results: Fifty-one patients (14%) reported brachial plexus-related neuropathic symptoms with the most common being ipsilateral pain (50%), numbness/tingling (40%), and motor weakness and/or muscle atrophy (25%). The 3- and 5-year estimates of freedom from brachial plexus-associated neuropathy were 86% and 81%, respectively. Clinical/pathological N3 disease (P<.001) and maximum radiation dose to the ipsilateral brachial plexus (P=.01) were significantly associated with neuropathic symptoms. Cox regression analysis revealed significant dose–volume effects for brachial plexus-associated neuropathy. The volume of the ipsilateral brachial plexus receiving >70 Gy (V70) predicted for symptoms, with the incidence increasing with V70 >10% (P<.001). A correlation was also observed for the volume receiving >74 Gy (V74) among patients treated without neck dissection, with a cutoff of 4% predictive of symptoms (P=.038). Conclusions: Dose–volume guidelines were developed for radiation planning that may limit brachial plexus-related neuropathies.

  7. Gas Ejection from Spiral Galaxy Disks

    NASA Astrophysics Data System (ADS)

    Durelle, Jeremy

    We present the results of three proposed mechanisms for ejection of gas from a spiral arm into the halo. The mechanisms were modelled using magnetohydrodynamics (MHD) as a theoretical template. Each mechanism was run through simulations using a Fortran code: ZEUS-3D, an MHD equation solver. The first mechanism modelled the gas dynamics with a modified Hartmann flow which describes the fluid flow between two parallel plates. We initialized the problem based on observation of lagging halos; that is, that the rotational velocity falls to a zero at some height above the plane of the disk. When adopting a density profile which takes into account the various warm and cold H I and HII molecular clouds, the system evolves very strangely and does not reproduce the steady velocity gradient observed in edge-on galaxies. This density profile, adopted from Martos and Cox (1998), was used in the remaining models. However, when treating a system with a uniform density profile, a stable simulation can result. Next we considered supernova (SN) blasts as a possible mechanism for gas ejection. While a single SN was shown to be insufficient to promote vertical gas structures from the disk, multiple SN explosions proved to be enough to promote gas ejection from the disk. In these simulations, gas ejected to a height of 0.5 kpc at a velocity of 130 km s--1 from 500 supernovae, extending to an approximate maximum height of 1 kpc at a velocity of 6.7 x 103 km s--1 from 1500 supernovae after 0.15 Myr, the approximate time of propagation of a supernova shock wave. Finally, we simulated gas flowing into the spiral arm at such a speed to promote a jump in the disk gas, termed a hydraulic jump. The height of the jump was found to be slightly less than a kiloparsec with a flow velocity of 41 km s--1 into the halo after 167 Myr. The latter models proved to be effective mechanisms through which gas is ejected from the disk whereas the Hartmann flow (or toy model) mechanism remains unclear as the

  8. [Measurement ofthe ankle-brachial pressure index (ABPI)].

    PubMed

    Kulisić, Sandra Marinović

    2012-10-01

    Measurement of the ankle-brachial pressure index, also known as ankle-brachial index or ankle-arm index is a ratio of the ankle blood pressure and brachial blood pressure. It is easy to perform and allows for diagnosis and further definition of the severity of peripheral arterial disease with sensitivity 90% and specificity 98%. The test is not appropriate for mild arterial changes as in case of comorbidity. Its further objectives are to identify patients at an higher risk of cardiovascular events. PMID:23193828

  9. Brachial plexus injuries in neonates: an osteopathic approach.

    PubMed

    Mason, David C; Ciervo, Carman A

    2009-02-01

    Neonates and infants with brachial plexus injuries are typically treated using splinting, range-of-motion exercise, and, in more severe cases, nerve reconstruction. However, myofascial release--a common osteopathic manipulative treatment technique that has been used to manage thoracic outlet syndrome in adults--may provide effective, noninvasive management of brachial plexus injuries in neonates and infants. While emphasizing the importance of good communication with parents of affected patients, the authors review brachial plexus anatomy, describe diagnostic examinations, and outline a comprehensive treatment strategy. PMID:19269939

  10. A new Doppler method of assessing left ventricular ejection force in chronic congestive heart failure.

    PubMed

    Isaaz, K; Ethevenot, G; Admant, P; Brembilla, B; Pernot, C

    1989-07-01

    A noninvasive method using Doppler echocardiography was developed to determine the force exerted by the left ventricle in accelerating the blood into the aorta. The value of this new Doppler ejection index in the assessment of left ventricular (LV) performance was tested in 36 patients with chronic congestive heart disease undergoing cardiac catheterization and in 11 age-matched normal control subjects. The 36 patients were subgrouped into 3 groups based on angiographic ejection fraction (LV ejection fraction greater than 60, 41 to 60 and less than or equal to 40%). According to Newton's second law of motion (force = mass X acceleration), the LV ejection force was derived from the product of the mass of blood ejected during the acceleration time with the mean acceleration undergone during that time. In patients with LV ejection fraction less than or equal to 40%, LV ejection force, peak aortic velocity and mean acceleration were severely depressed when compared with the other groups (p less than 0.001). In patients with LV ejection fraction of 41 to 60%, LV ejection force was significantly reduced (22 +/- 3 kdynes) when compared with normal subjects (29 +/- 5 kdynes, p = 0.002) and with patients with LV ejection fraction greater than 60% (29 +/- 7 kdynes, p = 0.009); peak velocity and mean acceleration did not differ between these 3 groups. The LV ejection force showed a good linear correlation with LV ejection fraction (r = 0.86) and a better power fit (r = 0.91). Peak aortic blood velocity and mean acceleration showed less good linear correlations with LV ejection fraction (r = 0.73 and r = 0.66, respectively). The mass of blood ejected during the acceleration time also showed a weak linear correlation with LV ejection fraction (r = 0.64). An LV ejection force less than 20 kdynes was associated with a depressed LV performance (LV ejection fraction less than 50%) with 91% sensitivity and 90% specificity. Thus, these findings suggest that LV ejection force is a new

  11. Brachial Plexopathy in Apical Non-Small Cell Lung Cancer Treated With Definitive Radiation: Dosimetric Analysis and Clinical Implications

    SciTech Connect

    Eblan, Michael J.; Corradetti, Michael N.; Lukens, J. Nicholas; Xanthopoulos, Eric; Mitra, Nandita; Christodouleas, John P.; Grover, Surbhi; Fernandes, Annemarie T.; Langer, Corey J.; Evans, Tracey L.; Stevenson, James; Rengan, Ramesh; Apisarnthanarax, Smith

    2013-01-01

    Purpose: Data are limited on the clinical significance of brachial plexopathy in patients with apical non-small cell lung cancers (NSCLC) treated with definitive radiation therapy. We report the rates of radiation-induced brachial plexopathy (RIBP) and tumor-related brachial plexopathy (TRBP) and associated dosimetric parameters in apical NSCLC patients. Methods and Materials: Charts of NSCLC patients with primary upper lobe or superiorly located nodal disease who received {>=}50 Gy of definitive conventionally fractionated radiation or chemoradiation were retrospectively reviewed for evidence of brachial plexopathy and categorized as RIBP, TRBP, or trauma-related. Dosimetric data were gathered on ipsilateral brachial plexuses (IBP) contoured according to Radiation Therapy Oncology Group atlas guidelines. Results: Eighty patients were identified with a median follow-up and survival time of 17.2 and 17.7 months, respectively. The median prescribed dose was 66.6 Gy (range, 50.4-84.0), and 71% of patients received concurrent chemotherapy. RIBP occurred in 5 patients with an estimated 3-year rate of 12% when accounting for competing risk of death. Seven patients developed TRBP (estimated 3-year rate of 13%), comprising 24% of patients who developed locoregional failures. Grade 3 brachial plexopathy was more common in patients who experienced TRBP than RIBP (57% vs 20%). No patient who received {<=}78 Gy to the IBP developed RIBP. On multivariable competing risk analysis, IBP V76 receiving {>=}1 cc, and primary tumor failure had the highest hazard ratios for developing RIBP and TRBP, respectively. Conclusions: RIBP is a relatively uncommon complication in patients with apical NSCLC tumors receiving definitive doses of radiation, while patients who develop primary tumor failures are at high risk for developing morbid TRBP. These findings suggest that the importance of primary tumor control with adequate doses of radiation outweigh the risk of RIBP in this population of

  12. Vertebral fracture after aircraft ejection during Operation Desert Storm.

    PubMed

    Osborne, R G; Cook, A A

    1997-04-01

    During Operation Desert Storm, 21 United States and 2 Italian military personnel were held in Iraq as prisoners of war. Of these, 18 had ejected from fixed-wing, ejection seat-equipped, combat aircraft prior to their capture. Of the 18, 6 (33%) had sustained vertebral fractures; 4 of these were compression fractures. This fracture rate is comparable to that of previously studied groups. Fractures were noted to be at several different vertebral sites and after ejecting from a variety of aircraft. Apart from contusions and abrasions, vertebral fractures were the most common injuries discovered in this repatriated population. None of the vertebral fractures produced recognizable neurological disability. The development of vertebral fractures was neither associated with the use of any particular ejection system or aircraft nor did the development of vertebral fractures appear dependent on the age, height or length of service of the affected personnel. Ejected aircrew with low altitude mission profiles seemed more predisposed to vertebral fracture than those at high altitudes, but with a small sample population, this relationship was not statistically significant (p > 0.25). Reliable data were unavailable on aircrew positioning and preparation time for ejection. PMID:9096832

  13. Safety belt use, ejection and entrapment.

    PubMed

    O'Day, J; Scott, R E

    1984-01-01

    One in every five occupants thrown from a car receives fatal injuries. A motorist who uses a safety belt, in all probability, will not be thrown from the car during a crash. The rate of fatal injury for ejected occupants was found to be 40 times the rate for occupants not thrown from their cars, as determined from national accident sampling data. These data refute the popular notion that "being thrown clear" has survival benefit. In addition, there was no evidence that wearing a safety belt increased fatality risk from vehicle fire or submersion. PMID:6519997

  14. Drop Ejection From an Oscillating Rod

    NASA Technical Reports Server (NTRS)

    Wilkes, E. D.; Basaran, O. A.

    1999-01-01

    The dynamics of a drop of a Newtonian liquid that is pendant from or sessile on a solid rod that is forced to undergo time-periodic oscillations along its axis is studied theoretically. The free boundary problem governing the time evolution of the shape of the drop and the flow field inside it is solved by a method of lines using a finite element algorithm incorporating an adaptive mesh. When the forcing amplitude is small, the drop approaches a limit cycle at large times and undergoes steady oscillations thereafter. However, drop breakup is the consequence if the forcing amplitude exceeds a critical value. Over a wide range of amplitudes above this critical value, drop ejection from the rod occurs during the second oscillation period from the commencement of rod motion. Remarkably, the shape of the interface at breakup and the volume of the primary drop formed are insensitive to changes in forcing amplitude. The interface shape at times close to and at breakup is a multi-valued function of distance measured along the rod axis and hence cannot be described by recently popularized one-dimensional approximations. The computations show that drop ejection occurs without the formation of a long neck. Therefore, this method of drop formation holds promise of preventing formation of undesirable satellite droplets.

  15. Electrodiagnosis in traumatic brachial plexus injury.

    PubMed

    Mansukhani, K A

    2013-01-01

    Electrodiagnosis (EDX) is a useful test to accurately localize the site, determine the extent, identify the predominant pathophysiology, and objectively quantify the severity of brachial plexopathies. It can also be used to examine muscles not easily assessed clinically and recognize minimal defects. Post-operatively and on follow up studies, it is important for early detection of re-innervation. It can be used intra-operatively to assess conduction across a neuroma, which would help the surgeon to decide further course of action. Localization of the site of the lesion can be very challenging as there may be multiple sites of involvement and hence the electroneuromyographic evaluation must be adequate. The unaffected limb also needs to be examined for comparison. The final impression must be co-related with the type and severity of injury.

  16. Comparison of the Supraclavicular, Infraclavicular and Axillary Approaches for Ultrasound-Guided Brachial Plexus Block for Surgical Anesthesia

    PubMed Central

    Stav, Anatoli; Reytman, Leonid; Stav, Michael-Yohay; Portnoy, Isaak; Kantarovsky, Alexander; Galili, Offer; Luboshitz, Shmuel; Sevi, Roger; Sternberg, Ahud

    2016-01-01

    Objective We hypothesized that ultrasound (US)-guided technique of the supra- and infraclavicular and axillary approaches of brachial plexus block (BPB) will produce a high quality of surgical anesthesia for operations below the shoulder independently of the approach and body mass index (BMI). Intercostobrachial and medial brachial cutaneous nerves will be blocked separately because they are not a part of the brachial plexus. Methods This is a prospective randomized observer-blinded study. The three approaches of the US-guided BPB without neurostimulation were compared for quality, performance time, and correlation between performance time and BMI. Intercostobrachial and medial brachial cutaneous nerve blocks were used in all patients. Results A total of 101 patients were randomized into three groups: SCL (supraclavicular), ICL (infraclavicular), and AX (axillary). Seven patients were excluded due to various factors. All three groups were similar in demographic data, M:F proportion, preoperative diagnosis and type of surgery, anesthesiologists who performed the block, and surgical staff that performed the surgical intervention. The time between the end of the block performance and the start of the operation was also similar. The quality of the surgical anesthesia and discomfort during the operation were identical following comparison between groups. No direct positive correlation was observed between BMI and the block performance time. The time for the axillary block was slightly longer than the time for the supra- and infraclavicular approaches, but it had no practical clinical significance. Transient Horner syndrome was observed in three patients in the SCL group. No other adverse effects or complications were observed. Conclusions All three approaches can be used for US-guided BPB with similar quality of surgical anesthesia for operations of below the shoulder. A block of the intercostobrachial and medial brachial cutaneous nerves is recommended. Obesity is not

  17. What triggers coronal mass ejections ?

    NASA Astrophysics Data System (ADS)

    Aulanier, Guillaume

    Coronal mass ejections (CMEs) are large clouds of highly magnetized plasma. They are ac-celerated from the solar atmosphere into interplanetary space by the Lorentz force, which is associated to their strong current-carrying magnetic fields. Both theory and observations lead to the inevitable conclusion that the launch of a CME must result from the sudden release of free magnetic energy, which has slowly been accumulated in the corona for a long time before the eruption. Since the incomplete, but seminal, loss-of-equilibrium model was proposed by van Tend and Kuperus (1978), a large variety of analytical and numerical storage-and-release MHD models has been put forward in the past 20 years or so. All these models rely on the slow increase of currents and/or the slow decrease of the restraining magnetic tension preceding the eruption. But they all put the emphazis on different physical mechanisms to achieve this preeruptive evolution, and to suddenly trigger and later drive a CME. Nevertheless, all these models actually share many common features, which all describe many individual observed aspects of solar eruptions. It is therefore not always clear which of all the suggested mecha-nisms do really account for the triggering of observed CMEs in general. Also, these mechanisms should arguably not be as numerous as the models themselves, owing to the common occurence of CMEs. In order to shed some light on this challenging, but unripe, topic, I will attempt to rediscuss the applicability of the models to the Sun, and to rethink the most sensitive ones in a common frame, so as to find their common denominator. I will elaborate on the idea that many of the proposed triggering mechanisms may actually only be considered as different ways to apply a "last push", which puts the system beyond its eruptive threshold. I will argue that, in most cases, the eruptive threshold is determined by the vertical gradient of the magnetic field in the low-β corona, just like the usual

  18. [Myxoid/round cell liposarcoma of the brachial plexus].

    PubMed

    Giner, Javier; Isla, Alberto; Hernández, Borja; Nistal, Manuel

    2014-01-01

    Myxoid/round cell liposarcoma is a soft tissue sarcoma that is extremely rare in the brachial plexus. We report a case of a myxoid/round cell liposarcoma originating in the brachial plexus that was surgically resected and evolved well, with no deficit or recurrence after 2 years of follow-up. To date, there has been no other case of this sarcoma in the literature. PMID:25126709

  19. Limb preference in children with obstetric brachial plexus palsy.

    PubMed

    Yang, Lynda J-S; Anand, Praveen; Birch, Rolfe

    2005-07-01

    Brachial plexus palsy affects children differently than adults. In children with obstetric brachial plexus palsy, motor development must depend on nervous system adaptation. Previous studies report sensory plasticity in these children. This noninvasive study provides support for neural plasticity (the general ability of the brain to reorganize neural pathways based on new experiences) in children with obstetric brachial plexus palsy by considering upper limb preference. As in the general population, we expect that 90% of children would prefer their right upper limb. However, only 17% of children affected by right obstetric brachial plexus palsy prefer the right upper limb for overall movement; children with left obstetric brachial plexus palsy did not significantly differ from the general population in upper limb preference. This study also provides the first evidence of a significant correlation between actual task performance and select obstetric brachial plexus palsy outcome measurement systems, thereby justifying the routine use of these outcome measurement systems as a reflection of the practical utility of the affected limb to the patient. PMID:15876521

  20. Ejecting Phage DNA against Cellular Turgor Pressure

    PubMed Central

    Marion, Sanjin; Šiber, Antonio

    2014-01-01

    We examine in vivo ejection of noncondensed DNA from tailed bacteriophages into bacteria. The ejection is dominantly governed by the physical conditions in the bacteria. The confinement of the DNA in the virus capsid only slightly helps the ejection, becoming completely irrelevant during its last stages. A simple calculation based on the premise of condensed DNA in the cell enables us to estimate the maximal bacterial turgor pressure against which the ejection can still be fully realized. The calculated pressure (∼5 atm) shows that the ejection of DNA into Gram-negative bacteria could proceed spontaneously, i.e., without the need to invoke active mechanisms. PMID:25418173

  1. Ejecting phage DNA against cellular turgor pressure.

    PubMed

    Marion, Sanjin; Siber, Antonio

    2014-10-21

    We examine in vivo ejection of noncondensed DNA from tailed bacteriophages into bacteria. The ejection is dominantly governed by the physical conditions in the bacteria. The confinement of the DNA in the virus capsid only slightly helps the ejection, becoming completely irrelevant during its last stages. A simple calculation based on the premise of condensed DNA in the cell enables us to estimate the maximal bacterial turgor pressure against which the ejection can still be fully realized. The calculated pressure (~5 atm) shows that the ejection of DNA into Gram-negative bacteria could proceed spontaneously, i.e., without the need to invoke active mechanisms.

  2. Phrenic Nerve Transfer for Reconstruction of Elbow Extension in Severe Brachial Plexus Injuries.

    PubMed

    Flores, Leandro P; Socolovsky, Mariano

    2016-09-01

    Background Restoring elbow extension is an important objective to pursue when repairing the brachial plexus in patients with a flail arm. Based upon the good results obtained using the phrenic nerve to restore elbow flexion and shoulder stability, we hypothesized that this nerve could also be employed to reconstruct elbow extension in patients with severe brachial plexus injuries. Methods A retrospective study of 10 patients in which the phrenic nerve targeted the radial nerve (7 patients) or the branch to the long head of the triceps (3 patients) as a surgical strategy for reconstruction of the brachial plexus. Results The mean postoperative follow-up time was 34 months. At final follow-up, elbow extension graded as M4 was measured in three patients, Medical Research Council MRC M3 in five patients, and M2 in one patient, while one patient experienced no measurable recovery (M0). No patient complained or demonstrated any signs of respiratory insufficiency postoperatively. Conclusions The phrenic nerve is a reliable donor for reanimation of elbow extension in such cases, and the branch to the long head of the triceps should be considered as a better target for the nerve transfer. PMID:27144951

  3. Does retraction of the sternum during median sternotomy result in brachial plexus injuries?

    PubMed

    Healey, Scott; O'Neill, Bridie; Bilal, Haris; Waterworth, Paul

    2013-07-01

    A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'does retraction of the sternum during median sternotomy result in brachial plexus injuries or peripheral neuropathies?' Altogether 58 papers were found using the reported search, of which 12 represented the best evidence to answer the question. The authors, date, journal and country of publication, patient group studied, study type, relevant outcomes and results of these papers were tabulated. Caudal placement of the retractor or relieving the pressure superiorly by removing the upper blades of a retractor (P = 0.02) and use of a caudally placed symmetrical retractor has been shown to reduce neuropathy. Positioning of the patient with 'hands up' positioning showed significant reduction in the incidence of brachial plexus injuries. Furthermore, how wide the retractor is opened and use of an asymmetrical retractor for internal mammary artery (IMA) harvesting are also important factors in quantifying risk of postoperative neuropathy. Wider sternal retraction and longer bypass time did increase the risk of developing postoperative neuropathy. Three asymmetrical retractors were looked at that demonstrates the Delacroix-Chevalier to be the safest (P < 0.05). We conclude that median sternotomy risks brachial plexus injury and where possible the sternum should be opened as small a distance as possible with symmetrical retractor and using a caudally placed retractor.

  4. Phrenic Nerve Transfer for Reconstruction of Elbow Extension in Severe Brachial Plexus Injuries.

    PubMed

    Flores, Leandro P; Socolovsky, Mariano

    2016-09-01

    Background Restoring elbow extension is an important objective to pursue when repairing the brachial plexus in patients with a flail arm. Based upon the good results obtained using the phrenic nerve to restore elbow flexion and shoulder stability, we hypothesized that this nerve could also be employed to reconstruct elbow extension in patients with severe brachial plexus injuries. Methods A retrospective study of 10 patients in which the phrenic nerve targeted the radial nerve (7 patients) or the branch to the long head of the triceps (3 patients) as a surgical strategy for reconstruction of the brachial plexus. Results The mean postoperative follow-up time was 34 months. At final follow-up, elbow extension graded as M4 was measured in three patients, Medical Research Council MRC M3 in five patients, and M2 in one patient, while one patient experienced no measurable recovery (M0). No patient complained or demonstrated any signs of respiratory insufficiency postoperatively. Conclusions The phrenic nerve is a reliable donor for reanimation of elbow extension in such cases, and the branch to the long head of the triceps should be considered as a better target for the nerve transfer.

  5. Analysis of melt ejection during long pulsed laser drilling

    NASA Astrophysics Data System (ADS)

    Ting-Zhong, Zhang; Zhi-Chao, Jia; Hai-Chao, Cui; De-Hua, Zhu; Xiao-Wu, Ni; Jian, Lu

    2016-05-01

    In pulsed laser drilling, melt ejection greatly influences the keyhole shape and its quality as well, but its mechanism has not been well understood. In this paper, numerical simulation and experimental investigations based on 304 stainless steel and aluminum targets are performed to study the effects of material parameters on melt ejection. The numerical method is employed to predict the temperatures, velocity fields in the solid, liquid, and vapour front, and melt pool dynamics of targets as well. The experimental methods include the shadow-graphic technique, weight method, and optical microscope imaging, which are applied to real-time observations of melt ejection phenomena, measurements of collected melt and changes of target mass, observations of surface morphology and the cross-section of the keyhole, respectively. Numerical and experimental results show that the metallic material with high thermal diffusivity like aluminum is prone to have a thick liquid zone and a large quantity of melt ejection. Additionally, to the best of our knowledge, the liquid zone is used to illustrate the relations between melt ejection and material thermal diffusivity for the first time. The research result in this paper is useful for manufacturing optimization and quality control in laser-material interaction. Project supported by the Natural Science Foundation of Jiangsu Province, China (Grant No. KYLX_0341) and the National Natural Science Foundation of China (Grant No. 61405147).

  6. Analysis of melt ejection during long pulsed laser drilling

    NASA Astrophysics Data System (ADS)

    Ting-Zhong, Zhang; Zhi-Chao, Jia; Hai-Chao, Cui; De-Hua, Zhu; Xiao-Wu, Ni; Jian, Lu

    2016-05-01

    In pulsed laser drilling, melt ejection greatly influences the keyhole shape and its quality as well, but its mechanism has not been well understood. In this paper, numerical simulation and experimental investigations based on 304 stainless steel and aluminum targets are performed to study the effects of material parameters on melt ejection. The numerical method is employed to predict the temperatures, velocity fields in the solid, liquid, and vapour front, and melt pool dynamics of targets as well. The experimental methods include the shadow-graphic technique, weight method, and optical microscope imaging, which are applied to real-time observations of melt ejection phenomena, measurements of collected melt and changes of target mass, observations of surface morphology and the cross-section of the keyhole, respectively. Numerical and experimental results show that the metallic material with high thermal diffusivity like aluminum is prone to have a thick liquid zone and a large quantity of melt ejection. Additionally, to the best of our knowledge, the liquid zone is used to illustrate the relations between melt ejection and material thermal diffusivity for the first time. The research result in this paper is useful for manufacturing optimization and quality control in laser-material interaction. Project supported by the Natural Science Foundation of Jiangsu Province, China (Grant No. KYLX_0341) and the National Natural Science Foundation of China (Grant No. 61405147).

  7. MEMEX: Mechanisms of Energetic Mass Ejection Explorer

    NASA Astrophysics Data System (ADS)

    Moore, T. E.; Chappell, C. R.; Clemmons, J. H.; Cully, C. M.; Donovan, E.; Earle, G. D.; Heelis, R. A.; Kistler, L. M.; Kepko, L.; Khazanov, G. V.; Knudsen, D. J.; Lessard, M.; McFadden, J. P.; Nicolls, M. J.; Pollock, C. J.; Pfaff, R. F.; Rankin, R.; Rowland, D. E.; Semeter, J. L.; Thayer, J. P.; Winglee, R.

    2013-12-01

    MEMEX is designed to find out how gravitationally-trapped volatile matter is being lost from atmospheres by energetic processes, depleting them of key constituents, as has occurred most dramatically at Mars. This process is exemplified in geospace by the dissipation of solar energy to produce ionospheric outflows that feed back on dynamics of the solar wind interaction with Earth's magnetosphere. Kinetic and electromagnetic energy flow from the Sun into the coupled (auroral) ionosphere, where resultant electron, ion, and gas heating give rise to upwelling, ionization, and mass ejection. Proposed mechanisms involve wave-particle heating interactions, upward ambipolar electric fields, or ponderomotive forces. A large number of free energy sources have been identified, but empirical guidance remains weak concerning their relative importance. Moreover, it is unclear if the waves interact with particles primarily in a cyclotron resonant mode, or in a lower hybrid exchange of electron (parallel) and ion (perpendicular) energy, or in a bulk ponderomotive mode. MEMEX will answer the questions raised by these issues: Where do the waves that produce mass ejection grow? How do they propagate and transport energy? How can wave amplitudes, heating, and escape rates be derived from solar wind conditions? Is the heating a cyclotron resonant process or a bulk ponderomotive forcing process? To obtain answers, MEMEX will for the first time simultaneously observe the magnetospheric and atmospheric boundary conditions applied to the topside or exobase layer, and the response of ions and electrons to the ensuing battle between electrodynamic forcing and collisional damping.

  8. Fractionation of hydrogen and deuterium on Venus due to collisional ejection

    NASA Technical Reports Server (NTRS)

    Gurwell, Mark A.; Yung, Yuk L.

    1993-01-01

    The collisional ejection process for hydrogen on Venus is reanalyzed. Improved values for the efficiency of H and D escape as a function of the ionospheric temperature are reported. It is proposed that the reduction of the hydrogen flux for collisional ejection be reduced from 8 to 3.5 x 10 exp 6/sq cm/s, and a revised D/H fractional factor of 0.47 due to collisional ejection is suggested. The resulting deuterium flux is 3.1 x 10 exp 4/sq cm/s, roughly six times the flux due to charge exchange, making collisional ejection the dominant escape mechanism for deuterium on Venus.

  9. Brachial Plexus-Associated Neuropathy After High-Dose Radiation Therapy for Head-and-Neck Cancer

    SciTech Connect

    Chen, Allen M.; Hall, William H.; Li, Judy; Beckett, Laurel; Farwell, D. Gregory; Lau, Derick H.; Purdy, James A.

    2012-09-01

    Purpose: To identify clinical and treatment-related predictors of brachial plexus-associated neuropathies after radiation therapy for head-and-neck cancer. Methods and Materials: Three hundred thirty patients who had previously completed radiation therapy for head-and-neck cancer were prospectively screened using a standardized instrument for symptoms of neuropathy thought to be related to brachial plexus injury. All patients were disease-free at the time of screening. The median time from completion of radiation therapy was 56 months (range, 6-135 months). One-hundred fifty-five patients (47%) were treated by definitive radiation therapy, and 175 (53%) were treated postoperatively. Radiation doses ranged from 50 to 74 Gy (median, 66 Gy). Intensity-modulated radiation therapy was used in 62% of cases, and 133 patients (40%) received concurrent chemotherapy. Results: Forty patients (12%) reported neuropathic symptoms, with the most common being ipsilateral pain (50%), numbness/tingling (40%), motor weakness, and/or muscle atrophy (25%). When patients with <5 years of follow-up were excluded, the rate of positive symptoms increased to 22%. On univariate analysis, the following factors were significantly associated with brachial plexus symptoms: prior neck dissection (p = 0.01), concurrent chemotherapy (p = 0.01), and radiation maximum dose (p < 0.001). Cox regression analysis confirmed that both neck dissection (p < 0.001) and radiation maximum dose (p < 0.001) were independently predictive of symptoms. Conclusion: The incidence of brachial plexus-associated neuropathies after radiation therapy for head-and-neck cancer may be underreported. In view of the dose-response relationship identified, limiting radiation dose to the brachial plexus should be considered when possible.

  10. Morphology of brachial plexus and axillary artery in bonobo (Pan paniscus).

    PubMed

    Kikuchi, Y; Oishi, M; Shimizu, D

    2011-02-01

    A left brachial plexus and axillary artery of bonobo (Pan paniscus) were examined, and the interrelation between the brachial plexus and the axillary artery was discussed. This is the first report of the brachial plexus and the axillary artery of bonobo. The bonobo brachial plexus formed very similar pattern to that of other ape species and human. On the other hand, the branches of the bonobo axillary artery had uncommon architecture in comparison with human case. The axillary artery did not penetrate the brachial plexus and passes through all way along anterior to the brachial plexus. Only 4.9% of human forelimbs have this pattern. Moreover, the brachial artery runs through superficially anterior to branches of the brachial plexus.

  11. Kinematics of Earth Impacting Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Colaninno, R. C.; Vourlidas, A.

    2012-12-01

    With the data from the STEREO mission, we are able to continuously monitor Coronal Mass Ejections (CMEs) as they progress from the Sun to Earth. However, even with continuous monitoring with remote sensing observations, we are still unable to accurately predict the arrival or terrestrial impact of a CME. In this study, we analyze nine CMEs from the Sun to Earth as observed in both the remote sensing and in situ data sets. In this study, we track nine CMEs from the Sun to 70% - 98% of the distance to Earth with the remote sensing data. We use the Graduate Cyclical Shell (GCS) model to estimate the position of each CME as it is observed in the inner heliosphere. From the derived kinematics, we compare the predicted arrival times and impact velocities with the in situ data. We consider different method for fitting the kinematics and the modeled geometry of the CME to improve the predicted arrival time.

  12. Numerical simulation of fluid ejection from a spinning cylinder

    NASA Astrophysics Data System (ADS)

    Fedele, P. D.

    1985-02-01

    A computer code, based on a convective flux approximation on a finite difference Eulerian grid, was to model the rate of fluid ejection from the opened end of an azimuthally rotating cylinder. The computer code, SOLA-VOF/CSL is described in a previous support. A constantly rotating cylinder, with an 80% fluid fill, is set in equilibrium solid body rotation and one end is instantaneously removed, allowing the centrifugal force to drive the fluid from the opened end. Fluid parameters have been chosen to model the behavior of water and glycerin at 25 C. The ratio of the volume ejection rate to the volume rotation shows similarity when expressed as a function of the cylinder rotation time. The fluid viscosity is observed to have negligible effect on the ejection rate for the spin rates of interest. This behavior is shown to be consistent with a dimensional analysis of the flows considered.

  13. Factors Affecting Ejection Risk in Rollover Crashes

    PubMed Central

    Funk, James R.; Cormier, Joseph M.; Bain, Charles E.; Wirth, Jeffrey L.; Bonugli, Enrique B.; Watson, Richard A.

    2012-01-01

    Ejection greatly increases the risk of injury and fatality in a rollover crash. The purpose of this study was to determine the crash, vehicle, and occupant characteristics that affect the risk of ejection in rollovers. Information from real world rollover crashes occurring from 2000 – 2010 was obtained from the National Automotive Sampling System (NASS) in order to analyze the effect of the following parameters on ejection risk: seatbelt use, rollover severity, vehicle type, seating position, roof crush, side curtain airbag deployment, glazing type, and occupant age, gender, and size. Seatbelt use was found to reduce the risk of partial ejection and virtually eliminate the risk of complete ejection. For belted occupants, the risk of partial ejection risk was significantly increased in rollover crashes involving more roof inversions, light trucks and vans (LTVs), and larger occupants. For unbelted occupants, the risk of complete ejection was significantly increased in rollover crashes involving more roof inversions, LTVs, far side occupants, and higher levels of roof crush. Roof crush was not a significant predictor of ejection after normalizing for rollover severity. Curtain airbag deployment was associated with reduced rates of partial and complete ejection, but the effect was not statistically significant, perhaps due to the small sample size (n = 89 raw cases with curtain deployments). A much greater proportion of occupants who were ejected in spite of curtain airbag deployment passed through the sunroof and other portals as opposed to the adjacent side window compared to occupants who were ejected in rollovers without a curtain airbag deployment. The primary factors that reduce ejection risk in rollover crashes are, in generally decreasing order of importance: seatbelt use, fewer roof inversions, passenger car body type, curtain airbag deployment, near side seating position, and small occupant size. PMID:23169130

  14. Factors affecting ejection risk in rollover crashes.

    PubMed

    Funk, James R; Cormier, Joseph M; Bain, Charles E; Wirth, Jeffrey L; Bonugli, Enrique B; Watson, Richard A

    2012-01-01

    Ejection greatly increases the risk of injury and fatality in a rollover crash. The purpose of this study was to determine the crash, vehicle, and occupant characteristics that affect the risk of ejection in rollovers. Information from real world rollover crashes occurring from 2000 - 2010 was obtained from the National Automotive Sampling System (NASS) in order to analyze the effect of the following parameters on ejection risk: seatbelt use, rollover severity, vehicle type, seating position, roof crush, side curtain airbag deployment, glazing type, and occupant age, gender, and size. Seatbelt use was found to reduce the risk of partial ejection and virtually eliminate the risk of complete ejection. For belted occupants, the risk of partial ejection risk was significantly increased in rollover crashes involving more roof inversions, light trucks and vans (LTVs), and larger occupants. For unbelted occupants, the risk of complete ejection was significantly increased in rollover crashes involving more roof inversions, LTVs, far side occupants, and higher levels of roof crush. Roof crush was not a significant predictor of ejection after normalizing for rollover severity. Curtain airbag deployment was associated with reduced rates of partial and complete ejection, but the effect was not statistically significant, perhaps due to the small sample size (n = 89 raw cases with curtain deployments). A much greater proportion of occupants who were ejected in spite of curtain airbag deployment passed through the sunroof and other portals as opposed to the adjacent side window compared to occupants who were ejected in rollovers without a curtain airbag deployment. The primary factors that reduce ejection risk in rollover crashes are, in generally decreasing order of importance: seatbelt use, fewer roof inversions, passenger car body type, curtain airbag deployment, near side seating position, and small occupant size. PMID:23169130

  15. Merging galaxies and black hole ejections

    NASA Technical Reports Server (NTRS)

    Valtonen, M. J.

    1990-01-01

    In mergers of galaxies their central black holes are accumulated together. Researchers show that few black hole systems arise which decay through black hole collisions and black hole ejections. The ejection statistics are calculated and compared with two observed systems where ejections have been previously suggested: double radio sources and high redshift quasars near low redshift galaxies. In both cases certain aspects of the associations are explained by the merger hypothesis.

  16. Electronic circuit detects left ventricular ejection events in cardiovascular system

    NASA Technical Reports Server (NTRS)

    Gebben, V. D.; Webb, J. A., Jr.

    1972-01-01

    Electronic circuit processes arterial blood pressure waveform to produce discrete signals that coincide with beginning and end of left ventricular ejection. Output signals provide timing signals for computers that monitor cardiovascular systems. Circuit operates reliably for heart rates between 50 and 200 beats per minute.

  17. Mass ejections. [during solar flares

    NASA Technical Reports Server (NTRS)

    Rust, D. M.; Hildner, E.; Hansen, R. T.; Dryer, M.; Mcclymont, A. N.; Mckenna-Lawlor, S. M. P.; Mclean, D. J.; Schmahl, E. J.; Steinolfson, R. S.; Tandberg-Hanssen, E.

    1980-01-01

    Observations and model simulations of solar mass ejection phenomena are examined in an investigation of flare processes. Consideration is given to Skylab and other observations of flare-associated sprays, eruptive prominences, surges and coronal transients, and to MHD, gas dynamic and magnetic loop models developed to account for them. Magnetic forces are found to confine spray material, which originates in preexisting active-region filaments, within steadily expanding loops, while surges follow unmoving, preexisting magnetic field lines. Simulations of effects of a sudden pressure pulse at the bottom of the corona are found to exhibit many characteristics of coronal transients associated with flares, and impulsive heating low in the chromosphere is found to be able to account for surges. The importance of the magnetic field as the ultimate source of energy which drives eruptive phenomena as well as flares is pointed out.

  18. Electroacupuncture attenuates neuropathic pain after brachial plexus injury.

    PubMed

    Zhang, Shenyu; Tang, Hailiang; Zhou, Junming; Gu, Yudong

    2014-07-15

    Electroacupuncture has traditionally been used to treat pain, but its effect on pain following brachial plexus injury is still unknown. In this study, rat models of an avulsion injury to the left brachial plexus root (associated with upper-limb chronic neuropathic pain) were given electroacupuncture stimulation at bilateral Quchi (LI11), Hegu (LI04), Zusanli (ST36) and Yanglingquan (GB34). After electroacupuncture therapy, chronic neuropathic pain in the rats' upper limbs was significantly attenuated. Immunofluorescence staining showed that the expression of β-endorphins in the arcuate nucleus was significantly increased after therapy. Thus, experimental findings indicate that electroacupuncture can attenuate neuropathic pain after brachial plexus injury through upregulating β-endorphin expression. PMID:25221593

  19. Brachial Artery Access for Percutaneous Renal Artery Interventions

    SciTech Connect

    Kaukanen, Erkki T.; Manninen, Hannu I.; Matsi, Pekka J.; Soeder, Heini K.

    1997-09-15

    Purpose: To evaluate the suitability of transbrachial access for endovascular renal artery interventions. Methods: During 37 consecutive endovascular renal artery interventions, the transbrachial approach was used on nine patients (mean age 63 years; range 41-76 years) for 11 renal artery procedures on native kidneys and one percutaneous transluminal angioplasty (PTA) on a transplanted kidney. The reason for using transbrachial access was a steep aorta-renal angle in five, and severe aorta-iliac atherosclerosis in the remaining patients. In addition to the intervention catheter in the left brachial artery, an additional nonselective catheter for controlling the procedure was inserted transfemorally (six patients) or via the contralateral brachial artery. Results: Eleven interventions (six PTAs, five stents) were successfully completed. The one failure resulted from impenetrable subclavian artery stenosis. The only major complication was a brachial artery pseudoaneurysm requiring surgical treatment. Conclusion: Transbrachial access is an effective and relatively safe technique for renal artery interventions when transfemoral access is not possible.

  20. MAGNETOHYDRODYNAMIC SIMULATIONS OF INTERPLANETARY CORONAL MASS EJECTIONS

    SciTech Connect

    Lionello, Roberto; Downs, Cooper; Linker, Jon A.; Török, Tibor; Riley, Pete; Mikić, Zoran E-mail: cdowns@predsci.com E-mail: tibor@predsci.com E-mail: mikic@predsci.com

    2013-11-01

    We describe a new MHD model for the propagation of interplanetary coronal mass ejections (ICMEs) in the solar wind. Accurately following the propagation of ICMEs is important for determining space weather conditions. Our model solves the MHD equations in spherical coordinates from a lower boundary above the critical point to Earth and beyond. On this spherical surface, we prescribe the magnetic field, velocity, density, and temperature calculated typically directly from a coronal MHD model as time-dependent boundary conditions. However, any model that can provide such quantities either in the inertial or rotating frame of the Sun is suitable. We present two validations of the technique employed in our new model and a more realistic simulation of the propagation of an ICME from the Sun to Earth.

  1. Permanent upper trunk plexopathy after interscalene brachial plexus block.

    PubMed

    Avellanet, Merce; Sala-Blanch, Xavier; Rodrigo, Lidia; Gonzalez-Viejo, Miguel A

    2016-02-01

    Interscalene brachial plexus block (IBPB) has been widely used in shoulder surgical procedures. The incidence of postoperative neural injury has been estimated to be as high as 3 %. We report a long-term neurologic deficit after a nerve stimulator assisted brachial plexus block. A 55 year-old male, with right shoulder impingement syndrome was scheduled for elective surgery. The patient was given an oral dose of 10 mg of diazepam prior to the nerve stimulator assisted brachial plexus block. The patient immediately complained, as soon as the needle was placed in the interscalene area, of a sharp pain in his right arm and he was sedated further. Twenty-four hours later, the patient complained of severe shoulder and arm pain that required an increased dose of analgesics. Severe peri-scapular atrophy developed over the following days. Electromyography studies revealed an upper trunk plexus injury with severe denervation of the supraspinatus, infraspinatus and deltoid muscles together with a moderate denervation of the biceps brachii muscle. Chest X-rays showed a diaphragmatic palsy which was not present post operatively. Pulmonary function tests were also affected. Phrenic nerve paralysis was still present 18 months after the block as was dysfunction of the brachial plexus resulting in an inability to perform flexion, abduction and external rotation of the right shoulder. Severe brachial plexopathy was probably due to a local anesthetic having been administrated through the perineurium and into the nerve fascicles. Severe brachial plexopathy is an uncommon but catastrophic complication of IBPB. We propose a clinical algorithm using ultrasound guidance during nerve blocks as a safer technique of regional anesthesia. PMID:25744163

  2. Magnetic Reconnection in Interplanetary Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Fermo, R. L.; Opher, M.; Drake, J. F.

    2014-12-01

    Magnetic reconnection is a ubiquitous phenomenon in many varied space and astrophysical plasmas, and as such plays an important role in the dynamics of interplanetary coronal mass ejections (ICMEs). It is widely regarded that reconnection is instrumental in the formation and ejection of the initial CME flux rope, but reconnection also continues to affect the dynamics as it propagates through the interplanetary medium. For example, reconnection on the leading edge of the ICME, by which it interacts with the interplanetary medium, leads to flux erosion. However, recent in situ observations by Gosling et al. found signatures of reconnection exhausts in the interior. In light of this data, we consider the stability properties of systems with this flux rope geometry with regard to their minimum energy Taylor state. Variations from this state will result in the magnetic field relaxing back towards the minimum energy state, subject to the constraints that the toroidal flux and magnetic helicity remain invariant. In reversed field pinches, this relaxation is mediated by reconnection in the interior of the system, as has been shown theoretically and experimentally. By treating the ICME flux rope in a similar fashion, we show analytically that the the elongation of the flux tube cross section in the latitudinal direction will result in a departure from the Taylor state. The resulting relaxation of the magnetic field causes reconnection to commence in the interior of the ICME, in agreement with the observations of Gosling et al. We present MHD simulations in which reconnection initiates at a number of rational surfaces, and ultimately produces a stochastic magnetic field. If the time scales for this process are shorter than the propagation time to 1 AU, this result explains why many ICME flux ropes no longer exhibit the smooth, helical flux structure characteristic of a magnetic cloud.

  3. Electrodiagnosis of brachial plexopathies and proximal upper extremity neuropathies.

    PubMed

    Simmons, Zachary

    2013-02-01

    This article describes the normal anatomy of the brachial plexus and its major terminal branches, as well as the major causes and clinical presentations of lesions of these structures. An approach to electrodiagnosis of brachial plexopathies and proximal upper extremity neuropathies is provided, with an emphasis on those nerve conduction studies and portions of the needle examination, which permit localization of lesions to specific trunks, cords, and terminal branches. The importance of specific sensory nerve conduction studies for differentiating plexopathies from radiculopathies and mononeuropathies is emphasized.

  4. Acute presentation of brachial plexus schwannoma secondary to infarction.

    PubMed

    Sidani, Charif; Saraf-Lavi, Efrat; Lyapichev, Kirill A; Nadji, Mehrdad; Levi, Allan D

    2015-06-01

    Schwannomas of the brachial plexus are rare and typically present as slowly growing masses. We describe a case of a 37-year-old female who presented with acute onset of severe left upper extremity pain. Magnetic resonance imaging (MRI) showed a 2.3 × 2.1 cm peripherally enhancing centrally cystic lesion in the left axilla, along the cords of the left brachial plexus, with significant surrounding edema and enhancement. The mass was surgically removed. Pathology was consistent with a schwannoma with infarction. The pain completely resolved immediately after surgery.

  5. Pediatric Stinger Syndrome: Acute Brachial Plexopathy After Minor Trauma

    PubMed Central

    Quong, Whitney L.; Hynes, Sally L.

    2015-01-01

    Summary: The “stinger” or “burner” is a form of transient brachial plexopathy termed for its characteristic knife-like pain extending from the neck to the fingertips. Muscle weakness and paresthesia are oftentimes associated symptoms and are similarly temporary. Commonly observed in athletes of contact sports, the stinger results from high force trauma causing either traction/direct compression to the brachial plexus or extension/compression of the cervical nerve roots. We describe a pediatric case of a stinger in a 14-year-old boy, which was caused by a relatively low force trauma accident. Our management strategy and recommendations are discussed. PMID:26893985

  6. Magnetized Accretion-Ejection Structures

    NASA Astrophysics Data System (ADS)

    Ferreira, Jonathan

    1994-09-01

    For both active galactic nuclei (AGN) and young stellar objects (YSO), the common belief is growing that there is an interdependency between accretion of mass onto a central object and the highly collimated jets. This thesis deals with the investigation of the physical mechanism that leads to the formation of jets from a magnetized accretion disk. This has been done by solving the set of magnetohydrodynamical (MHD) equations in the case of an isothermal disk, using a self-similar approach. All the dynamical terms are included, so that the main results are independant of the modelling and thus, completely general. Indeed, a different temperature vertical profile only slightly modifies the parameters required for stationarity. A resistive thin accretion disk is thread by open magnetic field lines, sheared by its differential rotation. The field lines brake the disk and extract both angular momentum and mechanical energy from it. Because of the large magnetic "lever arm" acting on the disk, the magnetic braking is always dominant and the viscous torque is negligible. An equipartition magnetic field is enough, without significantly perturbing the Keplerian rotation. Thus, jets carry away all the angular momentum of the underlying accretion disk. Steady state accretion is achieved in the disk due to an anomalous magnetic diffusivity that allows the matter to slip across the field lines. This anomalous transport coefficient should arise from the saturation of a strong magnetic instability triggered in the disk. Ambipolar diffusion, which could have been used without losing the generality of the present results, remains however smaller than this anomalous diffusivity in the inner parts of a circumstellar disk. It has been found that steady state ejection can be achieved only if the magnetic torque changes its sign at the disk surface. From this point on, the field lines accelerate azimuthaly the matter transfering it both angular momentum and energy. This requires a

  7. A smart pinless ejection mechanism using dual-resonance excitation Langevin piezoelectric transducers

    NASA Astrophysics Data System (ADS)

    Wang, Yu-Jen; Fu, Kuo-Chieh; Wang, Chun-Chieh

    2016-01-01

    This study investigated a smart pinless ejection mechanism comprising two dual-resonance excitation Langevin piezoelectric transducers (DRELPTs) for keeping the injection parts intact and protecting their top and bottom surfaces from scarring during plastic injection molding. The dimensions of each DRELPT were determined using longitudinal vibration models, and an optimization method was used to set the frequency ratio of the first to the second longitudinal mode to 1:2. This concept enables the driving of DRELPT in its two longitudinal modes consistent with the ejection direction in resonant-type smooth impact drive mechanisms. During the ejection process, DRELPT provides an ejection force, which is applied on the sidewalls of the injection parts to protect their top and bottom surfaces from scarring. Considering individual differences in the resonance frequencies of DRELPTs, a resonance frequency tracking circuit based on a phase-locked loop was designed to keep DRELPT actuating in resonance. The ejection velocity of the injection part was estimated using the kinetic models derived from the dynamic behavior of the mold cavity and injection parameters. A characteristic number S was defined to evaluate the average velocity of the injection part during ejection. Proof-of-concept experimental results of the pinless ejection mechanism are presented. The ejection time, that is, the time from triggering the composite wave to the full departure of the injection part from the mold cavity, was 72 ms.

  8. Axillary brachial plexus block--an underused technique in the accident and emergency department.

    PubMed Central

    Mackay, C A; Bowden, D F

    1997-01-01

    OBJECTIVE: To compare axillary brachial plexus block and Bier's block as methods of providing upper limb anaesthesia. METHODS: Axillary brachial plexus or Bier's blocks were performed on all patients requiring upper limb anaesthesia in a three month period. For Bier's block, a single cuff tourniquet and 3 mg/kg 0.5% prilocaine were used. For axillary plexus block, 40 ml 1% lignocaine with adrenaline (1:200,000) were used, given by perivascular or transarterial technique. Prospective analysis was made of time to complete limb anaesthesia, type of procedure performed, and duration of limb anaesthesia. Patient perception of analgesia and satisfaction with the method of anaesthesia was assessed using a 10 point visual analogue scale. RESULTS: 75 patients underwent procedures requiring upper limb anaesthesia; 39 received axillary plexus block and 36 Bier's block. 72% of Bier's blocks and 77% of axillary plexus provided complete anaesthesia without the need for supplemental analgesia. The median time to onset of anaesthesia was 10 min for Bier's block and 32.5 min for axillary block (P < 0.001). The median duration of anaesthesia was 15 min for Bier's block and 240 min for axillary block (P < 0.001). Mean scores for analgesia were 9.7 for axillary blocks and 8.8 for Bier's block (P < 0.001). 87% of the axillary block group were completely satisfied with the method of anaesthesia, compared with 56% of the Bier's block group. CONCLUSIONS: Brachial plexus blocks are an alternative form of providing upper limb anaesthesia in the accident and emergency department. They are relatively simple to perform, well tolerated by patients, and have the advantage of providing prolonged analgesia without the need for additional medication. Images Figure 1 Figure 2 Figure 3 PMID:9248910

  9. Models for coronal mass ejections

    NASA Astrophysics Data System (ADS)

    Jacobs, Carla; Poedts, Stefaan

    2011-06-01

    Coronal mass ejections (CMEs) play a key role in space weather. The mathematical modelling of these violent solar phenomena can contribute to a better understanding of their origin and evolution and as such improve space weather predictions. We review the state-of-the-art in CME simulations, including a brief overview of current models for the background solar wind as it has been shown that the background solar wind affects the onset and initial evolution of CMEs quite substantially. We mainly focus on the attempt to retrieve the initiation and propagation of CMEs in the framework of computational magnetofluid dynamics (CMFD). Advanced numerical techniques and large computer resources are indispensable when attempting to reconstruct an event from Sun to Earth. Especially the simulations developed in dedicated event studies yield very realistic results, comparable with the observations. However, there are still a lot of free parameters in these models and ad hoc source terms are often added to the equations, mimicking the physics that is not really understood yet in detail.

  10. Initiation of Coronal Mass Ejections

    NASA Technical Reports Server (NTRS)

    Moore, Ronald L.; Sterling, Alphonse C.

    2005-01-01

    This paper is a synopsis of the initiation of the strong-field magnetic explosions that produce large, fast coronal mass ejections. Cartoons based on observations are used to describe the inferred basic physical processes and sequences that trigger and drive the explosion. The magnetic field that explodes is a sheared-core bipole that may or may not be embedded in surrounding strong magnetic field, and may or may not contain a flux rope before it starts to explode. We describe three different mechanisms that singly or in combination trigger the explosion: (1) runaway internal tether-cutting reconnection, (2) runaway external tether-cutting reconnection, and (3) ideal MHD instability or loss or equilibrium. For most eruptions, high-resolution, high-cadence magnetograms and chromospheric and coronal movies (such as from TRACE and/or Solar-B) of the pre-eruption region and of the onset of the eruption and flare are needed to tell which one or which combination of these mechanisms is the trigger. Whatever the trigger, it leads to the production of an erupting flux rope. Using a simple model flux rope, we demonstrate that the explosion can be driven by the magnetic pressure of the expanding flux rope, provided the shape of the expansion is "fat" enough.

  11. Axillary Brachial Plexus Blockade for the Reflex Sympathetic Dystrophy Syndrome.

    ERIC Educational Resources Information Center

    Ribbers, G. M.; Geurts, A. C. H.; Rijken, R. A. J.; Kerkkamp, H. E. M.

    1997-01-01

    Reflex sympathetic dystrophy syndrome (RSD) is a neurogenic pain syndrome characterized by pain, vasomotor and dystrophic changes, and often motor impairments. This study evaluated the effectiveness of brachial plexus blockade with local anaesthetic drugs as a treatment for this condition. Three patients responded well; three did not. (DB)

  12. Constraints on the original ejection velocity fields of asteroid families

    NASA Astrophysics Data System (ADS)

    Carruba, V.; Nesvorný, D.

    2016-04-01

    Asteroid families form as a result of large-scale collisions among main belt asteroids. The orbital distribution of fragments after a family-forming impact could inform us about their ejection velocities. Unfortunately, however, orbits dynamically evolve by a number of effects, including the Yarkovsky drift, chaotic diffusion, and gravitational encounters with massive asteroids, such that it is difficult to infer the ejection velocities eons after each family's formation. Here, we analyse the inclination distribution of asteroid families, because proper inclination can remain constant over long time intervals, and could help us to understand the distribution of the component of the ejection velocity that is perpendicular to the orbital plane (vW). From modelling the initial break up, we find that the distribution of vW of the fragments, which manage to escape the parent body's gravity, should be more peaked than a Gaussian distribution (i.e. be leptokurtic) even if the initial distribution was Gaussian. We surveyed known asteroid families for signs of a peaked distribution of vW using a statistical measure of the distribution peakedness or flatness known as kurtosis. We identified eight families whose vW distribution is significantly leptokurtic. These cases (e.g. the Koronis family) are located in dynamically quiet regions of the main belt, where, presumably, the initial distribution of vW was not modified by subsequent orbital evolution. We suggest that, in these cases, the inclination distribution can be used to obtain interesting information about the original ejection velocity field.

  13. Post-Exercise Ankle-Brachial Pressure Index Demonstrates Altered Endothelial Function in the Elderly

    PubMed Central

    Sato, Shinji; Masami, Kozue; Otsuki, Shingo; Tanaka, Shiro; Nakayama, Noriko; Makita, Shigeru; Koshiyama, Hiroyuki; Nohara, Ryuji

    2011-01-01

    Background: The ankle-brachial pressure index (ABI), the ratio of the systolic blood pressure of the ankle to the systolic brachial pressure, is commonly measured at rest, but ABI values post-exercise enhance the sensitivity of the test and can be used to identify atherosclerotic vascular damage. However, it has not been established whether or not enhanced post-exercise ABI is also associated with endothelial dysfunction. We hypothesized that a decrease in post-exercise ABI is related to impaired endothelial function. Purpose: To investigate alterations in post-exercise ABI values and endothelial dysfunction in the elderly. Methods: The study population comprised 35 men and women aged 51–77 years (mean age: 66 years). Patients with peripheral arterial disease or a history of heart failure were excluded. The ABI was estimated at rest and immediately after exercise. The exercise protocol comprised 2.5 min of active pedal flexion exercises at a speed of 60 times/min. Endothelial function was assessed by measuring flow-mediated vasodilation (FMD) in the brachial artery using ultrasound imaging. Results: No correlation was found between FMD and the ABI at rest. However, a weak correlation was found between FMD and post-exercise ABI (r = 0.46, P = 0.06). A strong correlation was observed between FMD and a decrease in post-exercise ABI compared to baseline readings (r = −0.52, P = 0.01). Multiple linear regression analysis was used to generate a prediction equation for FMD using the percentage decrease in post-exercise ABI. Significant correlations were observed between the ultrasound imaging-measured FMD and the predicted FMD (R2 = 0.27, P = 0.001). Conclusions: Post-exercise ABI appears to be a simple surrogate marker for endothelial function in the elderly, although larger studies are required for validation. PMID:23885186

  14. Young Star Probably Ejected From Triple System

    NASA Astrophysics Data System (ADS)

    2003-01-01

    Astronomers analyzing nearly 20 years of data from the National Science Foundation's Very Large Array radio telescope have discovered that a small star in a multiple-star system in the constellation Taurus probably has been ejected from the system after a close encounter with one of the system's more-massive components, presumed to be a compact double star. This is the first time any such event has been observed. Path of Small Star, 1983-2001 "Our analysis shows a drastic change in the orbit of this young star after it made a close approach to another object in the system," said Luis Rodriguez of the Institute of Astronomy of the National Autonomous University of Mexico (UNAM). "The young star was accelerated to a large velocity by the close approach, and certainly now is in a very different, more remote orbit, and may even completely escape its companions," said Laurent Loinard, leader of the research team that also included Monica Rodriguez in addition to Luis Rodriguez. The UNAM astronomers presented their findings at the American Astronomical Society's meeting in Seattle, WA. The discovery of this chaotic event will be important for advancing our understanding of classical dynamic astronomy and of how stars evolve, including possibly providing an explanation for the production of the mysterious "brown dwarfs," the astronomers said. The scientists analyzed VLA observations of T Tauri, a multiple system of young stars some 450 light-years from Earth. The observations were made from 1983 to 2001. The T Tauri system includes a "Northern" star, the famous star that gives its name to the class of young visible stars, and a "Southern" system of stars, all orbiting each other. The VLA data were used to track the orbit of the smaller Southern star around the larger Southern object, presumed to be a pair of stars orbiting each other closely. The astronomers' plot of the smaller star's orbit shows that it followed an apparently elliptical orbit around its twin companions

  15. Therapeutic application of electrical stimulation and constraint induced movement therapy in perinatal brachial plexus injury: A case report.

    PubMed

    Berggren, Jamie; Baker, Lucinda L

    2015-01-01

    Infants and children with perinatal brachial plexus injury (PBPI) have motion limitations in the shoulder, elbow, forearm and hand that are dependent on the level of injury and degree of recovery. The injury and subsequent recovery period occur during critical periods of central and spinal neural development placing infants and children at-risk for developmental disregard and disuse of the affected arm and hand. A case report outlines the therapy and surgical interventions provided in the first 2 years of life for a child with global PBPI and a positive Horner's sign. Electrical stimulation and constraint induced movement therapy provided sequentially were effective therapy interventions. Neurosurgery to repair the brachial plexus was performed at an optimal time period.(2) The Assisting Hand Assessment,(12) Modified Mallet(13) and Active Movement Scale(14) are effective outcome measures in PBPI and served as valuable guides for therapy intervention. Oxford Level of Evidence: 3b; Individual Case Control Study.

  16. Aug. 31, 2012 Coronal Mass Ejection

    NASA Video Gallery

    This two part movie shows an Aug. 31 coronal mass ejection (CME) from the sun , the same event that caused depletion and refilling of the radiation belts just after the Relativistic Electron-Proton...

  17. Heart failure with preserved ejection fraction

    PubMed Central

    Gladden, James D.; Linke, Wolfgang A.

    2014-01-01

    As part of this series devoted to heart failure (HF), we review the epidemiology, diagnosis, pathophysiology, and treatment of HF with preserved ejection fraction (HFpEF). Gaps in knowledge and needed future research are discussed. PMID:24663384

  18. Sept. 28, 2012 Coronal Mass Ejection

    NASA Video Gallery

    This Sept. 28 coronal mass ejection (CME) from the sun, captured by NASA’s Solar Dynamics Observatory (SDO), is the event which caused the near total annihilation of the new radiation belt and sl...

  19. Novel description of the 24-hour circadian rhythms of brachial versus central aortic blood pressure and the impact of blood pressure treatment in a randomized controlled clinical trial: The Ambulatory Central Aortic Pressure (AmCAP) Study.

    PubMed

    Williams, Bryan; Lacy, Peter S; Baschiera, Fabio; Brunel, Patrick; Düsing, Rainer

    2013-06-01

    Elevated brachial blood pressure (BP) is associated with increased cardiovascular risk and predicts morbidity and mortality in humans. Recently, 24-hour ambulatory BP monitoring and assessment of central aortic BP have been introduced to improve BP phenotyping. The Ambulatory Central Aortic Pressure (AmCAP) study combines these approaches and describes, for the first time, the diurnal patterns of simultaneously measured 24-hour ambulatory brachial and central pressures in a prespecified substudy embedded within a clinical trial of BP lowering in patients with hypertension. Twenty-four-hour ambulatory brachial and central pressure measurements were acquired using a tonometer mounted into the articulating strap of a wristwatch-like device (BPro) in 171 participants with hypertension recruited into the ASSERTIVE (AliSkiren Study of profound antihypERtensive efficacy in hyperTensIVE patients) trial. Participants were randomly assigned to BP lowering with either aliskiren 300 mg QD or telmisartan 80 mg QD for 12 weeks. Ambulatory brachial and central BP was measured in all participants both at baseline and at study end. Brachial and central BP both demonstrated typical diurnal patterns with lower pressures at night. However, night time was associated with smaller reductions in central relative to brachial pressure and decreased pulse pressure amplification (P<0.0001 for both). These effects were not modulated after BP lowering and were maintained after adjustment for day and night-time BP and heart rate (P=0.02). This study demonstrates that brachial and central pressure show different diurnal patterns, which are not modulated by BP-lowering therapy, with relatively higher night-time central pressures. These novel data indicate that night-time central BP may provide prognostic importance and warrants further investigation. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00865020. PMID:23630950

  20. Pulse Ejection Presentation System Synchronized with Breathing

    NASA Astrophysics Data System (ADS)

    Kadowaki, Ami; Sato, Junta; Ohtsu, Kaori; Bannai, Yuichi; Okada, Kenichi

    Trials on transmission of olfactory information together with audio/visual information are currently being conducted in the field of multimedia. However, continuous emission of scents in high concentration creates problems of human adaptation and remnant odors in air. To overcome such problems we developed an olfactory display in conjunction with Canon Inc. This display has high emission control in the ink-jet so that it can provide stable pulse emission of scents. Humans catch a scent when they breathe in and inhale smell molecules in air. Therefore, it is important that the timing of scent presentation is synchronized with human breathing. We also developed a breath sensor which detects human inspiration. In this study, we combined the olfactory display with the breath sensor to make a pulse ejection presentation system synchronized the breath. The experimental evaluation showed that the system had more than 90 percent of detection rate. Another evaluation was held at KEIO TECHNO-MALL 2007. From questionnaire results of the participants, we found that the system made the user feel continuous sense of smell avoiding adaptation. It is expected that our system enables olfactory information to be synchronized with audio/visual information in arbitrary duration at any time.

  1. Solar origins of coronal mass ejections

    NASA Technical Reports Server (NTRS)

    Kahler, Stephen

    1987-01-01

    The large scale properties of coronal mass ejections (CMEs), such as morphology, leading edge speed, and angular width and position, have been cataloged for many events observed with coronagraphs on the Skylab, P-78, and SMM spacecraft. While considerable study has been devoted to the characteristics of the SMEs, their solar origins are still only poorly understood. Recent observational work has involved statistical associations of CMEs with flares and filament eruptions, and some evidence exists that the flare and eruptive-filament associated CMEs define two classes of events, with the former being generally more energetic. Nevertheless, it is found that eruptive-filament CMEs can at times be very energetic, giving rise to interplanetary shocks and energetic particle events. The size of the impulsive phase in a flare-associated CME seems to play no significant role in the size or speed of the CME, but the angular sizes of CMEs may correlate with the scale sizes of the 1-8 angstrom x-ray flares. At the present time, He 10830 angstrom observations should be useful in studying the late development of double-ribbon flares and transient coronal holes to yield insights into the CME aftermath. The recently available white-light synoptic maps may also prove fruitful in defining the coronal conditions giving rise to CMEs.

  2. Low speed vehicle passenger ejection restraint effectiveness.

    PubMed

    Seluga, Kristopher J; Ojalvo, Irving U; Obert, Richard M

    2005-07-01

    Current golf carts and LSV's (Low Speed Vehicles) produce a significant number of passenger ejections during sharp turns. These LSV's do not typically possess seatbelts, but do provide outboard bench seat hip restraints that also serve as handholds. However, many current restraint designs appear incapable of preventing passenger ejections due to their low height and inefficient handhold position. Alternative handhold and hip restraint designs may improve passenger safety. Accordingly, this paper examines minimum size requirements for hip restraints to prevent passenger ejection during sharp turns and evaluates the effectiveness of a handhold mounted at the center of the bench seat. In this study, a simulation of a turning cart supplies the dynamic input to a biomechanical model of an adult male seated in a golf cart. Various restraint combinations are considered, both with and without the central handhold, to determine the likelihood of passenger ejection. It is shown that only the largest restraint geometries prevent passenger ejection. Adequate hip restraints should be much larger than current designs and a central handhold should be provided. In this way, golf cart and LSV manufacturers could reduce passenger ejections and improve fleet safety by incorporating recommendations provided herein. PMID:15893288

  3. Supraclavicular Brachial Plexus Block With or Without Dexamethasone as an Adjuvant to 0.5% Levobupivacaine: A Comparative Study

    PubMed Central

    Bhupal, Jatinder Paul Singh; Kumar, Parmod; Gandhi, Gurjit Singh

    2016-01-01

    Introduction Brachial plexus block is an excellent method for attaining optimal operating conditions by producing complete muscular relaxation, maintaining stable intraoperative haemodynamics and the associated sympathetic block. In addition, they provide extended postoperative analgesia with minimal side effects. Different adjuvants have been described in literature to hasten the onset and prolong the duration of block. The present study was conducted to study the effect of adding dexamethasone to levobupivacaine in supraclavicular brachial plexus block. Aim To observe the effect of dexamethasone on onset and duration of anaesthesia, when used as an adjuvant to levobupivacaine in supraclavicular brachial plexus block. Materials and Methods A total of 60 patients in the age group of 18-65 years belonging to ASA physical status I or II were included in the study. They are randomly allocated in two groups and each group included 30 patients. In group 1, patients received 30ml of 0.5% isobaric levobupivacaine with 2ml of isotonic sodium chloride. In group 2 patients received 8mg (2ml) dexamethasone in addition to 30ml of 0.5% isobaric levobupivacaine. Results The results showed that the onset of sensory and motor block were faster in group 2(p<0.05). The duration of sensory and motor block were significantly longer in group 2 (p<0.05). VAS score at 12 hours were significantly lower in group 2 (p<0.05). None of the patients had bradycardia, hypotension or any other side effects. Conclusion Dexamethasone added to levobupivacaine for supraclavicular brachial plexus block reduces the time to onset of sensory and motor blockage and prolongs the duration of analgesia. PMID:27504384

  4. Brachial plexus birth palsy: Management during the first year of life.

    PubMed

    Abid, A

    2016-02-01

    Brachial plexus birth palsy (BPBP) is defined as an injury to any nerve root of the brachial plexus during difficult delivery. BPBP is relatively rare; its incidence has remained constant over the last few decades, mostly due to unpredictable risk factors, such as shoulder dystocia. Both diagnosis and assessment of spontaneous recovery is based on clinical examination. Electromyography is difficult to interpret in the newborn and is therefore not meaningful. MRI of the cervical spine requires sedation or general anesthesia. Searching for a pre-ganglion tear prior to surgery is indicted. Prognosis depends on the level of the injury (pre- or post-ganglion), size and severity of the post-ganglion tears, speed of recovery, and quality of initial management. Although spontaneous recovery is frequent, some children suffer various degrees of sequelae, up to complete loss of function of the affected upper limb. Recent publications have improved general knowledge and indications for surgery. However, some aspects, such as indication and timing of nerve repair continue to be debated. PMID:26774906

  5. Particle Heating Resulting from Coronal Mass Ejection

    NASA Astrophysics Data System (ADS)

    Paul, Suman; Sundar De, Syam; Guha, Gautam

    2016-07-01

    Coronal Mass Ejection (CME) is a continuous phenomena occurring from the entire solar coronal zone responsible for the outflow of solar masses, viz., protons, electrons, neutrons and solar wind in the form of plasma. These perturb the Earth's atmosphere via magnetopause. Very high temperature plasma generator in the solar atmosphere produces huge magnetic dipoles with intense magnetic field. It traps the energetic charged particles released from the solar corona. These particles gyrate along the magnetic field lines and are gradually elongated outwards from the Sun. Due to this, the field lines get detached at some critical limit thereby enhancing the magnetic reconnection with the interplanetary magnetic field releasing huge energy in the form of X-rays and γ-rays. This perturbs the Earth's atmosphere. In this work, the situation has been investigated by momentum balance equation, energy balance equation along with the equations of continuity and states. From the analyses, the dispersive nature of the thermospheric medium is studied. Variation of normalized electron temperature with dimensionless time has been critically contemplated. The altitude dependent electric field in the medium is also investigated.

  6. Dynamic simulation of coronal mass ejections

    NASA Technical Reports Server (NTRS)

    Steinolfson, R. S.; Wu, S. T.

    1980-01-01

    A model is developed for the formation and propagation through the lower corona of the loop-like coronal transients in which mass is ejected from near the solar surface to the outer corona. It is assumed that the initial state for the transient is a coronal streamer. The initial state for the streamer is a polytropic, hydrodynamic solution to the steady-state radial equation of motion coupled with a force-free dipole magnetic field. The numerical solution of the complete time-dependent equations then gradually approaches a stationary coronal streamer configuration. The streamer configuration becomes the initial state for the coronal transient. The streamer and transient simulations are performed completely independent of each other. The transient is created by a sudden increase in the pressure at the base of the closed-field region in the streamer configuration. Both coronal streamers and coronal transients are calculated for values of the plasma beta (the ratio of thermal to magnetic pressure) varying from 0.1 to 100.

  7. EIT Observations of Coronal Mass Ejections

    NASA Technical Reports Server (NTRS)

    Gurman, J. B.; Fisher, Richard B. (Technical Monitor)

    2000-01-01

    Before the Solar and Heliospheric Observatory (SOHO), we had only the sketchiest of clues as to the nature and topology of coronal mass ejections (CMEs) below 1.1 - 1.2 solar radii. Occasionally, dimmings (or 'transient coronal holes') were observed in time series of soft X-ray images, but they were far less frequent than CME's. Simply by imaging the Sun frequently and continually at temperatures of 0.9 - 2.5 MK we have stumbled upon a zoo of CME phenomena in this previously obscured volume of the corona: (1) waves, (2) dimmings, and (3) a great variety of ejecta. In the three and a half years since our first observations of coronal waves associated with CME's, combined Large Angle Spectroscopic Coronagraph (LASCO) and extreme ultra-violet imaging telescope (EIT) synoptic observations have become a standard prediction tool for space weather forecasters, but our progress in actually understanding the CME phenomenon in the low corona has been somewhat slower. I will summarize the observations of waves, hot (> 0.9 MK) and cool ejecta, and some of the interpretations advanced to date. I will try to identify those phenomena, analysis of which could most benefit from the spectroscopic information available from ultraviolet coronograph spectrometer (UVCS) observations.

  8. Recent advances in the management of brachial plexus injuries

    PubMed Central

    Bhandari, Prem Singh; Maurya, Sanjay

    2014-01-01

    Management of brachial plexus injury is a demanding field of hand and upper extremity surgery. With currently available microsurgical techniques, functional gains are rewarding in upper plexus injuries. However, treatment options in the management of flail and anaesthetic limb are still evolving. Last three decades have witnessed significant developments in the management of these injuries, which include a better understanding of the anatomy, advances in the diagnostic modalities, incorporation of intra-operative nerve stimulation techniques, more liberal use of nerve grafts in bridging nerve gaps, and the addition of new nerve transfers, which selectively neurotise the target muscles close to the motor end plates. Newer research works on the use of nerve allografts and immune modulators (FK 506) are under evaluation in further improving the results in nerve reconstruction. Direct reimplantation of avulsed spinal nerve roots into the spinal cord is another area of research in brachial plexus reconstruction. PMID:25190913

  9. Une cause rare de plexopathie brachiale: une metastase d'un cancer du sein

    PubMed Central

    Maâroufi, Mustapha; Kamaoui, Imane; Boubbou, Meriem; Sqalli, Nadia; Tizniti, Siham

    2014-01-01

    Nous rapportons le cas d'une patiente de 50 ans ayant une histoire de cancer du sein et qui accuse une symptomatologie d'atteinte du plexus brachial. L'IRM montre une masse qui envahie le plexus brachial compatible avec une métastase. L'IRM est très utile pour le diagnostic et l'orientation thérapeutique des plexopathies brachiales chez les femmes présentant un cancer du sein PMID:25360196

  10. Effects of the driving mechanism in MHD simulations of coronal mass ejections

    NASA Technical Reports Server (NTRS)

    Linker, J. A.; Van Hoven, G.; Schnack, D. D.

    1990-01-01

    Results of time-dependent MHD simulations of mass ejections in the solar coronal are presented. Previous authors have shown that results from simulations using a thermal driving mechanism are consistent with the observations only if an elaborate model of the initial corona is used. The first simulation effort, using a simple model of a plasmoid as the driving mechanism and a simple model of the initial corona, produces results that are also consistent with many observational features, suggesting that the nature of the driving mechanism plays an important role in determining the subsequent evolution of mass ejections. First simulations are based on the assumption that mass ejections are driven by magnetic forces.

  11. Magnetic resonance imaging of traumatic and non-traumatic brachial plexopathies

    PubMed Central

    Fan, Yiru Lorna; Othman, Mohamad Isham Bin; Dubey, Niraj; Peh, Wilfred CG

    2016-01-01

    Adult-onset brachial plexopathy can be classified into traumatic and non-traumatic aetiologies. Traumatic brachial plexopathies can affect the pre- or postganglionic segments of the plexus. Non-traumatic brachial plexopathies may be due to neoplasia, radiotherapy, thoracic outlet syndrome and idiopathic neuralgic amyotrophy. Conventional magnetic resonance imaging (MRI) is useful to localise the area of injury or disease, and identify the likely cause. This review discusses some of the common causes of adult-onset brachial plexopathy and their imaging features on MRI. We also present a series of cases to illustrate some of these causes and their MRI findings. PMID:27779278

  12. Delayed rupture of a pseudoaneurysm in the brachial artery of a burn reconstruction patient

    PubMed Central

    2013-01-01

    A brachial artery pseudoaneurysm is a rare but serious condition that can be limb threatening. A number of reports have found that it may be the result of damage to the blood vessels around the brachial artery, either directly or indirectly, due to trauma or systemic diseases. We present our experience of delayed pseudoaneurysm rupture of the brachial artery in a rehabilitation patient with burns of the upper extremity who underwent fasciotomy and musculocutaneous flap coverage. We also provide a review of the brachial artery pseudoaneurysm. PMID:23758847

  13. Novel Axillary Approach for Brachial Plexus in Robotic Surgery: A Cadaveric Experiment

    PubMed Central

    Tetik, Cihangir; Uzun, Metin

    2014-01-01

    Brachial plexus surgery using the da Vinci surgical robot is a new procedure. Although the supraclavicular approach is a well known described and used procedure for robotic surgery, axillary approach was unknown for brachial plexus surgery. A cadaveric study was planned to evaluate the robotic axillary approach for brachial plexus surgery. Our results showed that robotic surgery is a very useful method and should be used routinely for brachial plexus surgery and particularly for thoracic outlet syndrome. However, we emphasize that new instruments should be designed and further studies are needed to evaluate in vivo results. PMID:25140251

  14. Post-operative brachial plexus neuropraxia: A less recognised complication of combined plastic and laparoscopic surgeries

    PubMed Central

    Thomas, Jimmy

    2014-01-01

    This presentation is to increase awareness of the potential for brachial plexus injury during prolonged combined plastic surgery procedures. A case of brachial plexus neuropraxia in a 26-year-old obese patient following a prolonged combined plastic surgery procedure was encountered. Nerve palsy due to faulty positioning on the operating table is commonly seen over the elbow and popliteal fossa. However, injury to the brachial plexus has been a recently reported phenomenon due to the increasing number of laparoscopic and robotic procedures. Brachial plexus injury needs to be recognised as a potential complication of prolonged combined plastic surgery. Preventive measures are discussed. PMID:25593443

  15. Primary non-Hodgkin's lymphoma of brachial plexus.

    PubMed

    Suzuki, M; Watanabe, T; Mogi, G

    1999-07-01

    We report the case of a 65-year-old man with non-Hodgkin's lymphoma (NHL) not only in the brachial plexus but also in the central nervous system and parotid gland. He was referred to our hospital for evaluation of a right parotid mass. He also presented with bilateral facial palsy and paralysis of the left superior limb. Computed tomography scan and magnetic resonance imaging revealed mass lesions in the right parapharyngeal space, the deep lobe of the right parotid gland. and the left brachial plexus. A gallium-67 citrate scan demonstrated abnormal uptake in the left brachial plexus. These symptoms and lesions improved during steroid therapy. However, the symptoms worsened again after steroid therapy was discontinued. We performed a right parotidectomy to confirm the diagnosis. Histopathological study revealed NHL. He was treated with combination chemotherapy, and most of the lesions and symptoms, except bilateral facial palsy, improved. Despite follow-up treatment, a brain metastasis occured, and he died 16 months after the onset of symptoms. PMID:10419043

  16. Bipolar Ejection of Matter from Hot Stars

    NASA Technical Reports Server (NTRS)

    Pismis, P.

    1985-01-01

    A general program on the internal velocities in H II regions was carried out within the past decade by the use of photographic Fabry-Perot interferometry, in the H (alpha) line and lately also in the N IIlambda 6584 line. Among the score of objects studied three H II regions and one planetary nebula possess pronounced symmetry around their ionizing stars. Velocity data combined with morphological properties suggest strongly that the nebulae were formed essentially by matter ejected from the central star and that ejection occurred preferentially from diametrially opposite regions on the star, that is, in a bi-polar fashion. The nebulae are discussed individually and a model for the ejection mechanism is presented.

  17. Coronal mass ejections and coronal structures

    NASA Technical Reports Server (NTRS)

    Hildner, E.; Bassi, J.; Bougeret, J. L.; Duncan, R. A.; Gary, D. E.; Gergely, T. E.; Harrison, R. A.; Howard, R. A.; Illing, R. M. E.; Jackson, B. V.

    1986-01-01

    Research on coronal mass ejections (CMF) took a variety of forms, both observational and theoretical. On the observational side there were: case studies of individual events, in which it was attempted to provide the most complete descriptions possible, using correlative observations in diverse wavelengths; statistical studies of the properties CMEs and their associated activity; observations which may tell us about the initiation of mass ejections; interplanetary observations of associated shocks and energetic particles even observations of CMEs traversing interplanetary space; and the beautiful synoptic charts which show to what degree mass ejections affect the background corona and how rapidly (if at all) the corona recovers its pre-disturbance form. These efforts are described in capsule form with an emphasis on presenting pictures, graphs, and tables so that the reader can form a personal appreciation of the work and its results.

  18. Visualization of the air ejected from the temporary cavity in brain and tissue simulants during gunshot wounding.

    PubMed

    Lazarjan, M S; Geoghegan, P H; Taylor, M C; Jermy, M C

    2015-01-01

    One hypothesis for the physical mechanism responsible for backspatter during cranial gunshot wounding is that air is ejected by the collapse of the temporary cavity formed around the bullet path. Using bovine and ovine heads and simulant materials, evidence of this ejection was sought by measuring the velocity of the air that was drawn in and ejected from the cavity in front of the wound channel after bullet impact. A laminar flow of fog-laden air was arranged in front of the wound channel and two high speed cameras recording at 30,000 frames/second captured the air motion. All samples were shot with standard 9 mm × 19 mm FMJ ammunition. Different concentrations of ballistic gelatine were used to characterize the effect of elasticity of the material on the velocity of the air. Fresh bovine and ovine heads were shot with the same experimental set up to investigate if there was induction of air into, and ejection of air from the entrance wounds. The results show, for the first time, that the temporary cavity does eject air in gelatine. The velocity of in-drawn air for 3, 5 and 10% concentration of gelatine was 81, 76 and 65 m/s respectively and the velocity of ejected air for 5 and 10% concentration of gelatine were 43 and 72 m/s respectively. The results show that when the concentration of gelatine is increased, the velocity of the air drawn into the cavity decreases and the velocity of the ejected air increases. However, no ejection was observed in 3% gelatine, ovine or bovine heads. Although ejection of air was not observed, ejection of brain from the wound channel was seen. Using the velocity of the ejected brain, the minimum intracranial pressure required to eject the brain tissue was estimated to be 712 kPa and 468 kPa for the sheep and bovine heads respectively.

  19. Visualization of the air ejected from the temporary cavity in brain and tissue simulants during gunshot wounding.

    PubMed

    Lazarjan, M S; Geoghegan, P H; Taylor, M C; Jermy, M C

    2015-01-01

    One hypothesis for the physical mechanism responsible for backspatter during cranial gunshot wounding is that air is ejected by the collapse of the temporary cavity formed around the bullet path. Using bovine and ovine heads and simulant materials, evidence of this ejection was sought by measuring the velocity of the air that was drawn in and ejected from the cavity in front of the wound channel after bullet impact. A laminar flow of fog-laden air was arranged in front of the wound channel and two high speed cameras recording at 30,000 frames/second captured the air motion. All samples were shot with standard 9 mm × 19 mm FMJ ammunition. Different concentrations of ballistic gelatine were used to characterize the effect of elasticity of the material on the velocity of the air. Fresh bovine and ovine heads were shot with the same experimental set up to investigate if there was induction of air into, and ejection of air from the entrance wounds. The results show, for the first time, that the temporary cavity does eject air in gelatine. The velocity of in-drawn air for 3, 5 and 10% concentration of gelatine was 81, 76 and 65 m/s respectively and the velocity of ejected air for 5 and 10% concentration of gelatine were 43 and 72 m/s respectively. The results show that when the concentration of gelatine is increased, the velocity of the air drawn into the cavity decreases and the velocity of the ejected air increases. However, no ejection was observed in 3% gelatine, ovine or bovine heads. Although ejection of air was not observed, ejection of brain from the wound channel was seen. Using the velocity of the ejected brain, the minimum intracranial pressure required to eject the brain tissue was estimated to be 712 kPa and 468 kPa for the sheep and bovine heads respectively. PMID:25485950

  20. IR Variability During a Shell Ejection of Eta Carinae

    NASA Astrophysics Data System (ADS)

    Smith, Nathan

    2006-02-01

    Every 5.5 years, η Carinae experiences a dramatic ``spectroscopic event'' when high-excitation lines in its UV, optical, and IR spectrum disappear, and its hard X-ray and radio continuum flux crash. This periodicity has been attributed to a very eccentric binary system with a shell ejection occurring at periastron. Mid-IR images and spectra with T-ReCS are needed to measure changes in the current bolometric luminosity and to trace dust formation episodes. This will provide a direct estimate of the mass ejected. Near-IR emission lines trace related changes in the post-event wind and ionization changes in the circumstellar environment needed to test specific models for the cause of η Car's variability as it recovers from its recent ``event''. High resolution near-IR spectra with GNIRS will continue the important work of HST/STIS, investigating changes in the direct and reflected spectrum of the stellar wind, and ionization changes in the nebula. The complex kinematic structure of η Car's ejecta also holds important clues to its mass ejection history, and is essential for interpreting other data. Phoenix can provide a unique kinematic map of the complex density and time-variable ionization structure of η Car's nebula, which is our best example of the pre-explosion environment of very massive stars.

  1. Effects of Slag Ejection on Solid Rocket Motor Performance

    NASA Technical Reports Server (NTRS)

    Whitesides, R. Harold; Purinton, David C.; Hengel, John E.; Skelley, Stephen E.

    1995-01-01

    In past firings of the Reusable Solid Rocket Motor (RSRM) both static test and flight motors have shown small pressure perturbations occurring primarily between 65 and 80 seconds. A joint NASA/Thiokol team investigation concluded that the cause of the pressure perturbations was the periodic ingestion and ejection of molten aluminum oxide slag from the cavity around the submerged nozzle nose which tends to trap and collect individual aluminum oxide droplets from the approach flow. The conclusions of the team were supported by numerous data and observations from special tests including high speed photographic films, real time radiography, plume calorimeters, accelerometers, strain gauges, nozzle TVC system force gauges, and motor pressure and thrust data. A simplistic slag ballistics model was formulated to relate a given pressure perturbation to a required slag quantity. Also, a cold flow model using air and water was developed to provide data on the relationship between the slag flow rate and the chamber pressure increase. Both the motor and the cold flow model exhibited low frequency oscillations in conjunction with periods of slag ejection. Motor and model frequencies were related to scaling parameters. The data indicate that there is a periodicity to the slag entrainment and ejection phenomena which is possibly related to organized oscillations from instabilities in the dividing streamline shear layer which impinges on the underneath surface of the nozzle.

  2. Dynamical ejections of massive stars from young star clusters under diverse initial conditions

    NASA Astrophysics Data System (ADS)

    Oh, Seungkyung; Kroupa, Pavel

    2016-05-01

    We study the effects that initial conditions of star clusters and their massive star population have on dynamical ejections of massive stars from star clusters up to an age of 3 Myr. We use a large set of direct N-body calculations for moderately massive star clusters (Mecl ≈ 103.5 M⊙). We vary the initial conditions of the calculations, such as the initial half-mass radius of the clusters, initial binary populations for massive stars and initial mass segregation. We find that the initial density is the most influential parameter for the ejection fraction of the massive systems. The clusters with an initial half-mass radius rh(0) of 0.1 (0.3) pc can eject up to 50% (30)% of their O-star systems on average, while initially larger (rh(0) = 0.8 pc) clusters, that is, lower density clusters, eject hardly any OB stars (at most ≈ 4.5%). When the binaries are composed of two stars of similar mass, the ejections are most effective. Most of the models show that the average ejection fraction decreases with decreasing stellar mass. For clusters that are efficient at ejecting O stars, the mass function of the ejected stars is top-heavy compared to the given initial mass function (IMF), while the mass function of stars that remain in the cluster becomes slightly steeper (top-light) than the IMF. The top-light mass functions of stars in 3 Myr old clusters in our N-body models agree well with the mean mass function of young intermediate-mass clusters in M 31, as reported previously. This implies that the IMF of the observed young clusters is the canonical IMF. We show that the multiplicity fraction of the ejected massive stars can be as high as ≈ 60%, that massive high-order multiple systems can be dynamically ejected, and that high-order multiples become common especially in the cluster. We also discuss binary populations of the ejected massive systems. Clusters that are initially not mass-segregated begin ejecting massive stars after a time delay that is caused by mass

  3. Projection effects in coronal mass ejections

    NASA Astrophysics Data System (ADS)

    Vršnak, B.; Sudar, D.; Ruždjak, D.; Žic, T.

    2007-07-01

    Context: Basic observational parameters of a coronal mass ejection (CME) are its speed and angular width. Measurements of the CME speed and angular width are severely influenced by projection effects. Aims: The goal of this paper is to investigate a statistical relationship between the plane-of-sky speeds of CMEs and the direction of their propagation, hopefully providing an estimate of the true speeds of CMEs. Methods: We analyze the correlation between the plane-of-sky velocity and the position of the CME source region, employing several non-halo CME samples. The samples are formed applying various restrictions to avoid crosstalk of relevant parameters. For example, we select only CMEs observed to radial distances larger than 10 solar radii; we omit CMEs showing a considerable acceleration in the considered distance range and treat CMEs of different angular widths separately. Finally, we combine these restriction criteria, up to the limits beyond which the statistical significance of the results becomes ambiguous. Results: A distinct anti-correlation is found between the angular width of CMEs and their source-region position, clearly showing an increasing trend towards the disc center. Similarly, all of the considered subsamples show a correlation between the CME projected speed and the distance of the source region from the disc center. On average, velocities of non-halo limb-CMEs are 1.5-2 times higher than in the case of non-halo CMEs launched from regions located close to the disc center. Conclusions: Unfortunately, the established empirical relationships provide only a rough estimate of the velocity correction as a function of the source-region location. To a certain degree, the results can be explained in terms of CME cone models, but only after taking crosstalk of various parameters and observational artifacts into account.

  4. Correlation between ultrasound imaging, cross-sectional anatomy, and histology of the brachial plexus: a review.

    PubMed

    van Geffen, Geert J; Moayeri, Nizar; Bruhn, Jörgen; Scheffer, Gert J; Chan, Vincent W; Groen, Gerbrand J

    2009-01-01

    The anatomy of the brachial plexus is complex. To facilitate the understanding of the ultrasound appearance of the brachial plexus, we present a review of important anatomic considerations. A detailed correlation of reconstructed, cross-sectional gross anatomy and histology with ultrasound sonoanatomy is provided.

  5. Percutaneous Extraluminal (Subintimal) Recanalization of a Brachial Artery Occlusion Following Cardiac Catheterization

    SciTech Connect

    Bolia, Amman; Nasim, Akhtar; Bell, Peter R.F.

    1996-05-15

    A 47-year-old woman presented with disabling right arm claudication 10 weeks after Sones cardiac catheterization via a brachial artery cut-down. A technique of extraluminal recanalization of the brachial artery occlusion, used to treat this patient, is described.

  6. Penile erectile dysfunction after brachial plexus root avulsion injury in rats

    PubMed Central

    Fu, Guo; Qin, Bengang; Jiang, Li; Huang, Xijun; Lu, Qinsen; Zhang, Dechun; Liu, Xiaolin; Zhu, Jiakai; Zheng, Jianwen; Li, Xuejia; Gu, Liqiang

    2014-01-01

    Our previous studies have demonstrated that some male patients suffering from brachial plexus injury, particularly brachial plexus root avulsion, show erectile dysfunction to varying degrees. However, the underlying mechanism remains poorly understood. In this study, we evaluated the erectile function after establishing brachial plexus root avulsion models with or without spinal cord injury in rats. After these models were established, we administered apomorphine (via a subcutaneous injection in the neck) to observe changes in erectile function. Rats subjected to simple brachial plexus root avulsion or those subjected to brachial plexus root avulsion combined with spinal cord injury had significantly fewer erections than those subjected to the sham operation. Expression of neuronal nitric oxide synthase did not change in brachial plexus root avulsion rats. However, neuronal nitric oxide synthase expression was significantly decreased in brachial plexus root avulsion + spinal cord injury rats. These findings suggest that a decrease in neuronal nitric oxide synthase expression in the penis may play a role in erectile dysfunction caused by the combination of brachial plexus root avulsion and spinal cord injury. PMID:25422647

  7. Anatomical Variations of Brachial Artery - Its Morphology, Embryogenesis and Clinical Implications

    PubMed Central

    KS, Siddaraju; Venumadhav, Nelluri; Sharma, Ashish; Kumar, Neeraj

    2014-01-01

    Background: Accurate knowledge of variation pattern of the major arteries of upper limb is of considerable practical importance in the conduct of reparative surgery in the arm, forearm and hand however brachial artery and its terminal branches variations are less common. Aim: Accordingly the present study was designed to evaluate the anatomical variations of the brachial artery and its morphology, embryogenesis and clinical implications. Materials and Methods: In an anatomical study 140 upper limb specimens of 70 cadavers (35 males and 35 females) were used and anatomical variations of the brachial artery have been documented. Results: Accessory brachial artery was noted in eight female cadavers (11.43%). Out of eight cadavers in three cadavers (4.29%) an unusual bilateral accessory brachial artery arising from the axillary artery and it is continuing in the forearm as superficial accessory ulnar artery was noted. Rare unusual variant unilateral accessory brachial artery and its reunion with the main brachial artery in the cubital fossa and its variable course in relation to the musculocutaneous nerve and median nerve were also noted in five cadavers (7.14%). Conclusion: As per our knowledge such anatomical variations of brachial artery and its terminal branches with their relation to the surrounding structures are not reported in the modern medical literature. An awareness of such a presence is valuable for the surgeons and radiologists in evaluation of angiographic images, vascular and re-constructive surgery or appropriate treatment for compressive neuropathies. PMID:25653931

  8. Evidence of elevated X-ray absorption before and during major flare ejections in GRS 1915+105

    SciTech Connect

    Punsly, Brian; Rodriguez, Jérôme

    2014-03-10

    We present time-resolved X-ray spectroscopy of the microquasar GRS 1915+105 with the MAXI observatory in order to study the accretion state just before and during the ejections associated with its major flares. Radio monitoring with the RATAN-600 radio telescope from 4.8-11.2 GHz has revealed two large, steep-spectrum major flares in the first eight months of 2013. Since the RATAN has received one measurement per day, we cannot determine the jet-forming time without more information. Fortunately, this is possible since a distinct X-ray light curve signature that occurs preceding and during major ejections has been determined in an earlier study. The X-ray luminosity spikes to very high levels in the hours before ejection, then becomes variable (with a nearly equal X-ray luminosity when averaged over the duration of the ejection) during a brief 3-8 hr ejection process. By comparing this X-ray behavior with MAXI light curves, we can estimate the beginning and end of the ejection episode of the strong 2013 flares to within ∼3 hr. Using this estimate in conjunction with time-resolved spectroscopy from the data in the MAXI archives allows us to deduce that the X-ray absorbing hydrogen column density increases significantly in the hours preceding the ejections and remains elevated during the ejections responsible for the major flares. This finding is consistent with an outflowing wind or enhanced accretion at high latitudes.

  9. How much dust does Enceladus eject?

    NASA Astrophysics Data System (ADS)

    Kempf, Sascha; Srama, Ralf; Postberg, Frank; Schmidt, Juergen

    2016-07-01

    There is an ongoing argument how much dust per second the ice volcanoes on Saturn's ice moon eject. By adjusting their plume model to the dust flux measured by the Cassini dust detector during the close Enceladus flyby in 2005, Schmidt et al. (2008) obtained a total dust production rate in the plumes of about

  10. How much dust does Enceladus eject?

    NASA Astrophysics Data System (ADS)

    Kempf, Sascha; Southworth, Benjamin; Schmidt, Juergen; Srama, Ralf; Postberg, Frank

    2016-04-01

    There is an ongoing argument how much dust per second the ice volcanoes on Saturn's ice moon eject. By adjusting their plume model to the dust flux measured by the Cassini dust detector during the close Enceladus flyby in 2005, Schmidt et al. (2008) obtained a total dust production rate in the plumes of about

  11. Do centrioles generate a polar ejection force?

    PubMed

    Wells, Jonathan

    2005-01-01

    A microtubule-dependent polar ejection force that pushes chromosomes away from spindle poles during prometaphase is observed in animal cells but not in the cells of higher plants. Elongating microtubules and kinesin-like motor molecules have been proposed as possible causes, but neither accounts for all the data. In the hypothesis proposed here a polar ejection force is generated by centrioles, which are found in animals but not in higher plants. Centrioles consist of nine microtubule triplets arranged like the blades of a tiny turbine. Instead of viewing centrioles through the spectacles of molecular reductionism and neo-Darwinism, this hypothesis assumes that they are holistically designed to be turbines. Orthogonally oriented centriolar turbines could generate oscillations in spindle microtubules that resemble the motion produced by a laboratory vortexer. The result would be a microtubule-mediated ejection force tending to move chromosomes away from the spindle axis and the poles. A rise in intracellular calcium at the onset of anaphase could regulate the polar ejection force by shutting down the centriolar turbines, but defective regulation could result in an excessive force that contributes to the chromosomal instability characteristic of most cancer cells.

  12. Forces during Bacteriophage DNA Packaging and Ejection

    PubMed Central

    Purohit, Prashant K.; Inamdar, Mandar M.; Grayson, Paul D.; Squires, Todd M.; Kondev, Jané; Phillips, Rob

    2005-01-01

    The conjunction of insights from structural biology, solution biochemistry, genetics, and single-molecule biophysics has provided a renewed impetus for the construction of quantitative models of biological processes. One area that has been a beneficiary of these experimental techniques is the study of viruses. In this article we describe how the insights obtained from such experiments can be utilized to construct physical models of processes in the viral life cycle. We focus on dsDNA bacteriophages and show that the bending elasticity of DNA and its electrostatics in solution can be combined to determine the forces experienced during packaging and ejection of the viral genome. Furthermore, we quantitatively analyze the effect of fluid viscosity and capsid expansion on the forces experienced during packaging. Finally, we present a model for DNA ejection from bacteriophages based on the hypothesis that the energy stored in the tightly packed genome within the capsid leads to its forceful ejection. The predictions of our model can be tested through experiments in vitro where DNA ejection is inhibited by the application of external osmotic pressure. PMID:15556983

  13. Do centrioles generate a polar ejection force?

    PubMed

    Wells, Jonathan

    2005-01-01

    A microtubule-dependent polar ejection force that pushes chromosomes away from spindle poles during prometaphase is observed in animal cells but not in the cells of higher plants. Elongating microtubules and kinesin-like motor molecules have been proposed as possible causes, but neither accounts for all the data. In the hypothesis proposed here a polar ejection force is generated by centrioles, which are found in animals but not in higher plants. Centrioles consist of nine microtubule triplets arranged like the blades of a tiny turbine. Instead of viewing centrioles through the spectacles of molecular reductionism and neo-Darwinism, this hypothesis assumes that they are holistically designed to be turbines. Orthogonally oriented centriolar turbines could generate oscillations in spindle microtubules that resemble the motion produced by a laboratory vortexer. The result would be a microtubule-mediated ejection force tending to move chromosomes away from the spindle axis and the poles. A rise in intracellular calcium at the onset of anaphase could regulate the polar ejection force by shutting down the centriolar turbines, but defective regulation could result in an excessive force that contributes to the chromosomal instability characteristic of most cancer cells. PMID:15889341

  14. Dexmedetomidine as an adjuvant to levobupivacaine in supraclavicular brachial plexus block: A novel anesthetic approach

    PubMed Central

    Singh, Arvinder Pal; Mahindra, Malika; Gupta, Ruchi; Bajwa, Sukhminder Jit Singh

    2016-01-01

    Aims and Objectives: Supplementation of dexmedetomidine produces a dose-dependent sedation, anxiolysis and analgesia without respiratory depression. This study was conducted to evaluate the possible effect of dexmedetomidine as an adjuvant to levobupivacaine for supraclavicular brachial plexus block in upper limb surgery. Settings and Design: Tertiary care institute, Department of Anaesthesiology and Intensive Care, a placebo-controlled study. Materials and Methods: After obtaining Ethical Committee approval, a randomized, double-blind, placebo-controlled study was conducted on sixty American Society of Anesthesiologists physical status I and II patients in the age group of 18–60 years, divided randomly into two groups, Group I received 30 ml of 0.5% levobupivacaine with 1 ml of isotonic sodium chloride solution and Group II received 30 ml of 0.5% levobupivacaine and 1 ml (100 mcg) of dexmedetomidine for supraclavicular brachial plexus block. The onset and duration of sensory and motor blockade, duration of analgesia (DOA) and any adverse effects were noted. At the end of the study, data were compiled and analyzed using appropriate statistical tests. The value of P < 0.05 was considered significant. Results: Demographic profile was comparable in both the groups. The time to onset of sensory and motor block was 10.54 ± 2.333 min and 12.21 ± 2.529 min in Group I while it was 3.24 ± 0.951 min and 2.83 ± 1.197 min in Group II, respectively. The duration of sensory and motor block was 7.79 ± 2.007 h and 9.18 ± 1.701 h in Group I, and it was 16.31 ± 2.606 h and 17.52 ± 2.098 h in Group II, respectively. The DOA was 678.68 ± 20.492 min in Group I and 1273.79 ± 83.139 min in Group II. On statistical comparison, these values were highly significant (P < 0.001). Side effects such as nausea, vomiting, hypoxemia, pruritis, or urinary retention were not observed in either of the groups. Conclusion: Dexmedetomidine shortens the onset time for sensory and motor block

  15. Outcome following spinal accessory to suprascapular (spinoscapular) nerve transfer in infants with brachial plexus birth injuries.

    PubMed

    Ruchelsman, David E; Ramos, Lorna E; Alfonso, Israel; Price, Andrew E; Grossman, Agatha; Grossman, John A I

    2010-06-01

    The purpose of this study is to evaluate the value of distal spinal accessory nerve (SAN) transfer to the suprascapular nerve (SSN) in children with brachial plexus birth injuries in order to better define the application and outcome of this transfer in these infants. Over a 3-year period, 34 infants with brachial plexus injuries underwent transfer of the SAN to the SSN as part of the primary surgical reconstruction. Twenty-five patients (direct repair, n = 20; interposition graft, n = 5) achieved a minimum follow-up of 24 months. Fourteen children underwent plexus reconstruction with SAN-to-SSN transfer at less than 9 months of age, and 11 underwent surgical reconstruction at the age of 9 months or older. Mean age at the time of nerve transfer was 11.6 months (range, 5-30 months). At latest follow-up, active shoulder external rotation was measured in the arm abducted position and confirmed by review of videos. The Gilbert and Miami shoulder classification scores were utilized to report shoulder-specific functional outcomes. The effects of patient age at the time of nerve transfer and the use of interpositional nerve graft were analyzed. Overall mean active external rotation measured 69.6°; mean Gilbert score was 4.1 and the mean Miami score was 7.1, corresponding to overall good shoulder functional outcomes. Similar clinical and shoulder-specific functional outcomes were obtained in patients undergoing early (<9 months of age, n = 14) and late (>9 months of age, n = 11) SAN-to-SSN transfer and primary plexus reconstruction. Nine patients (27%) were lost to follow-up and are not included in the analysis. Optimum results were achieved following direct transfer (n = 20). Results following the use of an interpositional graft (n = 5) were rated satisfactory. No patient required a secondary shoulder procedure during the study period. There were no postoperative complications. Distal SAN-to-SSN (spinoscapular) nerve transfer is a reliable

  16. High resolution neurography of the brachial plexus by 3 Tesla magnetic resonance imaging.

    PubMed

    Cejas, C; Rollán, C; Michelin, G; Nogués, M

    2016-01-01

    The study of the structures that make up the brachial plexus has benefited particularly from the high resolution images provided by 3T magnetic resonance scanners. The brachial plexus can have mononeuropathies or polyneuropathies. The mononeuropathies include traumatic injuries and trapping, such as occurs in thoracic outlet syndrome due to cervical ribs, prominent transverse apophyses, or tumors. The polyneuropathies include inflammatory processes, in particular chronic inflammatory demyelinating polyneuropathy, Parsonage-Turner syndrome, granulomatous diseases, and radiation neuropathy. Vascular processes affecting the brachial plexus include diabetic polyneuropathy and the vasculitides. This article reviews the anatomy of the brachial plexus and describes the technique for magnetic resonance neurography and the most common pathologic conditions that can affect the brachial plexus. PMID:26860655

  17. High resolution neurography of the brachial plexus by 3 Tesla magnetic resonance imaging.

    PubMed

    Cejas, C; Rollán, C; Michelin, G; Nogués, M

    2016-01-01

    The study of the structures that make up the brachial plexus has benefited particularly from the high resolution images provided by 3T magnetic resonance scanners. The brachial plexus can have mononeuropathies or polyneuropathies. The mononeuropathies include traumatic injuries and trapping, such as occurs in thoracic outlet syndrome due to cervical ribs, prominent transverse apophyses, or tumors. The polyneuropathies include inflammatory processes, in particular chronic inflammatory demyelinating polyneuropathy, Parsonage-Turner syndrome, granulomatous diseases, and radiation neuropathy. Vascular processes affecting the brachial plexus include diabetic polyneuropathy and the vasculitides. This article reviews the anatomy of the brachial plexus and describes the technique for magnetic resonance neurography and the most common pathologic conditions that can affect the brachial plexus.

  18. Boston Children's Hospital approach to brachial plexus birth palsy.

    PubMed

    Vuillermin, Carley; Bauer, Andrea S

    2016-07-01

    The treatment of infants with brachial plexus birth palsy (BPBP) continues to be a focus at Boston Children's Hospital. Over the last 15 years, there have been many developments in the treatment of infants with BPBP. Some of the greatest changes have emerged through technical advances such as the advent of distal nerve transfers to allow targeted reinnervation as well as through research to understand the pathoanatomical changes that lead to glenohumeral dysplasia and how this dysplasia can be remodeled. This review will discuss our current practice of evaluation of the infant with BPBP, techniques for microsurgical reconstruction, and prevention and treatment of secondary glenohumeral dysplasia. PMID:27137763

  19. Obesity in children with brachial plexus birth palsy.

    PubMed

    Singh, Avreeta K; Mills, Janith; Bauer, Andrea S; Ezaki, Marybeth

    2015-11-01

    Fetal macrosomia is associated with a 14-fold increased risk of brachial plexus birth palsy (BPBP), and is a predictor of childhood obesity. The purpose of this study was to identify the relationships between BPBP, fetal macrosomia, and childhood obesity. We retrospectively reviewed 214 children with BPBP. The average age was 8 years and 53% had a Narakas 1 grade BPBP. Overall, 49% of children were normal weight, 22% overweight, and 29% obese. Of the children with a history of fetal macrosomia, 41% were obese; a statistically significant difference. Overall quality of life scores, however, were not correlated with obesity. PMID:26163865

  20. Obesity in children with brachial plexus birth palsy.

    PubMed

    Singh, Avreeta K; Mills, Janith; Bauer, Andrea S; Ezaki, Marybeth

    2015-11-01

    Fetal macrosomia is associated with a 14-fold increased risk of brachial plexus birth palsy (BPBP), and is a predictor of childhood obesity. The purpose of this study was to identify the relationships between BPBP, fetal macrosomia, and childhood obesity. We retrospectively reviewed 214 children with BPBP. The average age was 8 years and 53% had a Narakas 1 grade BPBP. Overall, 49% of children were normal weight, 22% overweight, and 29% obese. Of the children with a history of fetal macrosomia, 41% were obese; a statistically significant difference. Overall quality of life scores, however, were not correlated with obesity.

  1. Ejection associated injuries within the German Air Force from 1981-1997.

    PubMed

    Werner, U

    1999-12-01

    From 1981-1997 there were 86 ejections from 56 aircraft within the German Air Force. Of these, 24 accidents were associated with the F-104 Starfighter, 14 with the PA 200 Tornado, 12 from the F-4 Phantom, 5 from the Alpha Jet and 1 from a MiG 29 Fulcrum. One case involved a front seat pilot, who had already sustained fatal injuries from midair collision, being command ejected by the rear seat pilot. The remaining 85 ejections are the basis of this study. One weapons system officer died from hypothermia after landing in the sea and another from bleeding into the medulla oblongata after flailing; all other participants survived. This is an overall success rate of 97.6%. Of all 85 participants, 12 (14%) were uninjured, 41 (48.2%) were slightly injured, and 30 (35.3%) were severely injured. Typical injuries were those of the spine and lower limbs. The most common severe injury was a vertebral fracture caused by ejection acceleration. This is followed by lower limb injuries received during the parachute landing fall. At the time of ejection, all uninjured crews were flying below 3500 ft altitude and below 260 kn airspeed. Of all ejections from each aircraft type, the percentage of vertebral fractures is highest with the F-4 Phantom (31.8%), followed by the F-104 (16.6%) and the PA 200 Tornado with only 14.8%. The PA 200 is equipped with the most modern type of ejection seat of these aircraft. A conclusion of the gained data is that more modern ejection seat types provide lower injury severity but not fewer total injury numbers, and that the medical data taken during accident investigation should be taken more accurately and in a more standarized fashion to be comparable. PMID:10596782

  2. Electrostatic Droplet Ejection Using Planar Needle Inkjet Head

    NASA Astrophysics Data System (ADS)

    Hakiai, Kazunori; Ishida, Yuji; Baba, Akiyoshi; Asano, Tanemasa

    2005-07-01

    For the purpose of investigating the electrostatic droplet ejection event, a planar needle inkjet head with a projected cone-shaped needle (3-D head) was prepared to observe the phenomenon of droplet ejection. As the initial approach to developing a liquid ejection monitoring method, electric current was also measured. The ejection was found to take place as a series of single events that are composed of fine droplet ejections forming the Taylor cone and the subsequent swing back of the liquid front owing to the relationship between surface tension and electrostatic force. The critical factors for ejecting fine droplets in the case of using the inkjet head having a protruding needle were back pressure from the reservoir and the wetting control of the structures. The fast Fourier transform of electric current revealed the appearance of periodic signals during ejection, which may be used in developing a technique of sensing droplet ejection.

  3. From SOHO to STEREO: Understanding Propagation of Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Gopalswamy, N.

    2011-12-01

    Direct comparison between coronal mass ejections (CMEs) from near the Sun and their solar wind counterparts became possible roughly a decade after the discovery of CMEs (Lindsay et al. 1999). This comparison revealed that fast CMEs decelerate and slow CMEs accelerate due to the interaction with the solar wind. Gopalswamy et al. (2000) quantified this interaction as an interplanetary acceleration which is useful in predicting the arrival time and speed of CMEs at 1 AU. The interplanetary acceleration is essentially due to the aerodynamic drag between the CME and the solar wind because the propelling force and the solar gravity are effective only near the Sun. Combined remote-sensing and in situ observations from SOHO and Wind/ACE have helped us estimate the influence of the solar wind on the propagation of CMEs. However, these measurements have severe limitations because the remote-sensed and in-situ observations correspond to different portions of the CME. Furthermore, the true speeds of Earth-directed CMEs cannot be measured accurately from a spacecraft located along the Sun-Earth line. There have been attempts to model the CME as a cone and get the space speed of the CME, which did improve the travel time predictions. Instruments on board the Solar Terrestrial Relations Observatory (STEREO) mission were able to provide observations of Earth-arriving CMEs without projection effects, while the same CMEs were observed at Sun-Earth L1 by Wind and ACE spacecraft. The quadrature between STEREO and L1 spacecraft presented an ideal situation to study the interplanetary evolution of CMEs and test earlier model results. The quadrature observations did improve the CME travel time predictions, but additional factors such as the unusually slow solar wind, CME cannibalism, and coronal-hole deflection need to be considered to reconcile the difference between observed and predicted travel times. This point is illustrated using the 2011 February 15 CME. References Gopalswamy, N

  4. Ejection of atoms by laser produced optical breakdown plasma

    SciTech Connect

    Wang, M.R.; Meng, H.C.

    1981-06-01

    High-power CO/sub 2/ laser radiation has been used to study the optical breakdown plasma on various solid targets (NaCl, KBr, ZnSe, and Ge). The breakdown threshold for irreversible changes of the optical characteristics was determined as well as the evaporation threshold of Na atoms from NaCl samples by CO/sub 2/ laser irradiation; the latter value was about 2.8 x 10/sup 7/ W/cm/sup 2/. The time profiles of the ejected Na atoms and the propagation of the atoms in front of the sample was measured with the laser fluorescence method.

  5. Ultrasound-guided Continuous Axillary Brachial Plexus Block Using a Nerve Stimulating Catheter: EpiStim® Catheter

    PubMed Central

    Lee, Mi Kyoung; Kim, Jung Eun; Kim, Se Hee; Yeo, Gwi Eun

    2015-01-01

    Brachial plexus block (BPB) under ultrasound guidance has come to be widely used. However, nerve injury has been reported following ultrasound-guided BPB. We hypothesized that BPB under ultrasound guidance in conjunction with real-time electrical nerve stimulation would help us prevent nerve injury and do more successful procedure. Here, we report the successful induction and maintenance of ultrasound-guided BPB and the achievement of good peri- and postoperative pain control using a conductive catheter, the EpiStim®. PMID:26495085

  6. Use of contralateral spinal accessory nerve for ipsilateral suprascapular neurotization in global brachial plexus injury: a new technique.

    PubMed

    Bhandari, Prem Singh; Deb, Prabal

    2016-01-01

    Nerve transfer between the spinal accessory nerve (SAN) and the suprascapular nerve (SSN) is a standard technique in shoulder reanimation. In cases of global brachial plexus injury, donor nerves are few and at times severely traumatized owing to extensive traction forces. This precludes the application of standard nerve transfer techniques. The authors offer the use of the contralateral SAN as an additional option in the reinnervation of an injured SSN in such circumstances. To the best of their knowledge, this is the first successful attempt of this technique to be reported in the literature.

  7. Light vehicle occupant ejections--a comprehensive investigation.

    PubMed

    Malliaris, A C; DeBlois, J H; Digges, K H

    1996-01-01

    Occupant ejections, about 1.5% of all crash-involved occupant events, are relatively infrequent but very harmful events in highway crashes of light vehicles, including cars, pickup trucks, vans, and multipurpose vehicles (utility vehicles, jeeps, etc.). The disparity between frequency of harm to ejectees and ejection frequency is at least one order of magnitude. Partial ejections, although less frequent, have an incidence that is comparable to that of complete ejections, except for restrained occupants, where complete ejections are very infrequent. Notwithstanding the high effectiveness of safety belts in preventing ejections, and the multifold growth of safety belt use in the last 10 years, there is no detectable reduction in the ejection rate in the same period. Ejections per se and not other pre-ejection occupant impacts are responsible for the bulk of the harm to ejectees. Furthermore, ejected occupants sustain harm much larger than that which would have occurred, had these occupants not been ejected. "Closed glazing" is the leading ejection path. "Doors" and "windshield" are distant seconds. All glazing except the windshield fail overwhelmingly by disintegration. Latch failure is the primary mode of failure in opening doors. Hinges and other modes of failure are relatively minor concerns. The sources of data in this investigation are: the National Accident Sampling System for the years 1988 to 1991, and the Fatal Accident Reporting System for 1982 to 1992. PMID:8924175

  8. Injury mechanisms in supraclavicular stretch injuries of the brachial plexus.

    PubMed

    Soldado, Francisco; Ghizoni, Marcos F; Bertelli, Jayme

    2016-02-01

    The aim of this study was to describe the mechanisms involved in stretch injuries of the brachial plexus. One hundred and fifty consecutive patients with supraclavicular brachial plexus injuries (BPI) were asked about the mechanism of injury during the actual injury event, particularly about the type of trauma to their shoulder, shoulder girdle and head. Fifty-seven of the patients provided enough information about their accident to allow for analysis of the shoulder trauma. The injury mechanism for all patients having upper root or total palsy (n=46) was described as a direct vertical impact to the shoulder. In 44 of these patients, the trauma followed a motorcycle accident and, in most of them, the patient hit a fixed vertical structure before falling to the ground. The injury mechanism for the lower root palsy cases (n=11) was variable. The most frequent mechanism was forceful anterior shoulder compression by a car seat belt. We found that injury mechanisms differed significantly from the ones commonly discussed in published studies. PMID:27117025

  9. Rare case of a liposarcoma in the brachial plexus.

    PubMed

    Kosutic, D; Gajanan, K

    2016-09-01

    Introduction A liposarcoma is a rare cancer of connective tissues that resemble fat cells under light microscopy. Case History A 73-year old female patient presented to our tertiary cancer centre with an eight-year history of a large, slow-growing painless mass in the right axilla. Magnetic resonance imaging showed a lipomatous, well-circumscribed mass of dimension 30 × 16 × 10cm extending towards the right clavicle and causing deformation to the right chest wall and right breast. Surgery revealed a large tumour that had stretched all three cords of the brachial plexus. Histopathology was consistent with a diagnosis of a low-grade liposarcoma. After a period of neuropraxia, the patient returned to normal activities 4 months after surgery. Conclusions Although extremely rare, low-grade liposarcomas of the brachial plexus should be considered in the differential diagnosis of a slow-growing axillary mass. Referral to a tertiary sarcoma centre is essential for an appropriate diagnosis, adequate treatment, and long-term follow-up. PMID:27241607

  10. The Impact of Pediatric Brachial Plexus Injury on Families

    PubMed Central

    Allgier, Allison; Overton, Myra; Welge, Jeffrey; Mehlman, Charles T.

    2015-01-01

    Purpose To determine the impact on families of children with brachial plexus injuries in order to best meet their clinical and social needs. Methods Our cross-sectional study included families with children between the ages of 1 and 18 with birth or non-neonatal brachial plexus injuries (BPI). The consenting parent or guardian completed a demographic questionnaire and the validated Impact on Family Scale during a single assessment. Total scores can range from 0-100, with the higher the score indicating a higher impact on the family. Factor analysis and item-total correlations were used to examine structure, individual items, and dimensions of family impact. Results One hundred two caregivers participated. Overall, families perceived various dimensions of impact on having a child with a BPI. Total family impact was 43. The 2 individual items correlating most strongly with the overall total score were from the financial dimension of the Impact on Family Scale. The strongest demographic relationship was traveling nationally for care and treatment of the BPI. Severity of injury was marginally correlated with impact on the family. Parent-child agreement about the severity of the illness was relatively high. Conclusion Caretakers of children with a BPI perceived impact on their families in the form of personal strain, family/social factors, financial stress, and mastery. A multidisciplinary clinical care team should address the various realms of impact on family throughout the course of treatment. Level of Evidence II Prognostic PMID:25936738

  11. Pilot ejection, parachute, and helicopter crash injuries.

    PubMed

    McBratney, Colleen M; Rush, Stephen; Kharod, Chetan U

    2014-01-01

    USAF Pararescuemen (PJs) respond to downed aircrew as a fundamental mission for personnel recovery (PR), one of the Air Force's core functions. In addition to responding to these in Military settings, the PJs from the 212 Rescue Squadron routinely respond to small plane crashes in remote regions of Alaska. While there is a paucity of information on the latter, there have been articles detailing injuries sustained from helicopter crashes and while ejecting or parachuting from fixed wing aircraft. The following represents a new chapter added to the Pararescue Medical Operations Handbook, Sixth Edition (2014, editors Matt Wolf, MD, and Stephen Rush, MD, in press). It was designed to be a quick reference for PJs and their Special Operations flight surgeons to help with understanding of mechanism of injury with regard to pilot ejection, parachute, and helicopter accident injuries. It outlines the nature of the injuries sustained in such mishaps and provides an epidemiologic framework from which to approach the problem.

  12. Interplanetary Coronal Mass Ejections detected by HAWC

    NASA Astrophysics Data System (ADS)

    Lara, Alejandro

    The High Altitude Water Cherenkov (HAWC) observatory is being constructed at the volcano Sierra Negra (4100 m a.s.l.) in Mexico. HAWC’s primary purpose is the study of both: galactic and extra-galactic sources of high energy gamma rays. HAWC will consist of 300 large water Cherenkov detectors (WCD), instrumented with 1200 photo-multipliers. The Data taking has already started while construction continues, with the completion projected for late 2014. The HAWC counting rate will be sensitive to cosmic rays with energies above the geomagnetic cutoff of the site (˜ 8 GV). In particular, HAWC will detect solar energetic particles known as Ground Level Enhancements (GLEs), and the effects of Coronal Mass Ejections on the galactic cosmic ray flux, known as Forbush Decreases. In this paper, we present a description of the instrument and its response to interplanetary coronal mass ejections, and other solar wind large scale structures, observed during the August-December 2013 period.

  13. Pilot ejection, parachute, and helicopter crash injuries.

    PubMed

    McBratney, Colleen M; Rush, Stephen; Kharod, Chetan U

    2014-01-01

    USAF Pararescuemen (PJs) respond to downed aircrew as a fundamental mission for personnel recovery (PR), one of the Air Force's core functions. In addition to responding to these in Military settings, the PJs from the 212 Rescue Squadron routinely respond to small plane crashes in remote regions of Alaska. While there is a paucity of information on the latter, there have been articles detailing injuries sustained from helicopter crashes and while ejecting or parachuting from fixed wing aircraft. The following represents a new chapter added to the Pararescue Medical Operations Handbook, Sixth Edition (2014, editors Matt Wolf, MD, and Stephen Rush, MD, in press). It was designed to be a quick reference for PJs and their Special Operations flight surgeons to help with understanding of mechanism of injury with regard to pilot ejection, parachute, and helicopter accident injuries. It outlines the nature of the injuries sustained in such mishaps and provides an epidemiologic framework from which to approach the problem. PMID:25399374

  14. Ejection safety for advanced fighter helmets

    NASA Astrophysics Data System (ADS)

    Wiley, Larry L.; Brown, Randall W.; MacMillan, Robert T.

    1995-05-01

    The old saying, `Safety is paramount.' was never more true than it is in the area of ejection safety for high-speed fighter aircraft. The fighter aircraft of today has been designed to endure tremendous structural loading during dogfight or evasive maneuvers. It can fly faster, turn quicker, stay in the air longer (with in-flight refuel) and carry more bombs than its predecessor. Because of human physiological limits, the human has become the weak link in today's fighter aircraft. The fighter pilot must endure and function with peak performance in conditions that are much worse than anything the majority of us will ever encounter. When these conditions reach a point that human endurance is exceeded, devices such as anti-g suits and positive pressure breathing apparatus help the fighter pilot squeeze out that extra percentage of strength necessary to outperform the opponent. As fighter aircraft become more sophisticated, helmet trackers, helmet displays and noise cancellation devices are being added to the helmet. Yet the fighter pilot's helmet must remain lightweight and be aesthetically appealing, while still offering ballistic protection. It must function with existing life support equipment such as the Combined Advanced Technology Enhanced Design g-Ensemble (COMBAT-EDGE). It must not impede the pilot's ability to perform any action necessary to accomplish the planned mission. The helmet must protect the pilot during the harsh environment of ejection. When the pilot's only resort is to pull the handle and initiate the ejection sequence, the helmet becomes his salvation or instant death. This paper discusses the safety concerns relative to the catapult phase of ejecting from a high-speed fighter while wearing an advanced fighter helmet.

  15. Ejectable underwater sound source recovery assembly

    NASA Technical Reports Server (NTRS)

    Irick, S. C. (Inventor)

    1974-01-01

    An underwater sound source is described that may be ejectably mounted on any mobile device that travels over water, to facilitate in the location and recovery of the device when submerged. A length of flexible line maintains a connection between the mobile device and the sound source. During recovery, the sound source is located be particularly useful in the recovery of spent rocket motors that bury in the ocean floor upon impact.

  16. EPISODIC EJECTION FROM ACTIVE ASTEROID 311P/PANSTARRS

    SciTech Connect

    Jewitt, David; Agarwal, Jessica; Weaver, Harold; Mutchler, Max; Larson, Stephen

    2015-01-10

    We examine the development of the active asteroid 311P/PANSTARRS (formerly, 2013 P5) in the period from 2013 September to 2014 February using high resolution images from the Hubble Space Telescope. This multi-tailed object is characterized by a single, reddish nucleus of absolute magnitude H ≥ 18.98 ± 0.10, corresponding to an equal-area sphere of radius ≤200 ± 20 m (for assumed geometric albedo 0.29 ± 0.09). We set an upper limit to the radii of possible companion nuclei at ∼10 m. The nucleus ejected debris in nine discrete episodes, spread irregularly over a nine month interval, each time forming a distinct tail. Particles in the tails range from about 10 μm to at least 80 mm in radius, and were ejected at speeds <1 m s{sup –1}. The ratio of the total ejected dust mass to the nucleus mass is ∼3×10{sup –5}, corresponding to a global surface layer ∼2 mm thick, or to a deeper layer covering a smaller fraction of the surface. The observations are incompatible with an origin of the activity by impact or by the sublimation of entrapped ice. This object appears to be shedding its regolith by rotational (presumably YORP-driven) instability. Long-term fading of the photometry (months) is attributed to gradual dissipation of near-nucleus dust. Photometric variations on short timescales (<0.7 hr) are probably caused by fast rotation of the nucleus. However, because of limited time coverage and dilution of the nucleus signal by near-nucleus dust, we have not been able to determine the rotation period.

  17. Brachial artery vasomotion and transducer pressure effect on measurements by active contour segmentation on ultrasound

    SciTech Connect

    Cary, Theodore W.; Sultan, Laith R.; Sehgal, Chandra M.; Reamer, Courtney B.; Mohler, Emile R.

    2014-02-15

    Purpose: To use feed-forward active contours (snakes) to track and measure brachial artery vasomotion on ultrasound images recorded in both transverse and longitudinal views; and to compare the algorithm's performance in each view. Methods: Longitudinal and transverse view ultrasound image sequences of 45 brachial arteries were segmented by feed-forward active contour (FFAC). The segmented regions were used to measure vasomotion artery diameter, cross-sectional area, and distention both as peak-to-peak diameter and as area. ECG waveforms were also simultaneously extracted frame-by-frame by thresholding a running finite-difference image between consecutive images. The arterial and ECG waveforms were compared as they traced each phase of the cardiac cycle. Results: FFAC successfully segmented arteries in longitudinal and transverse views in all 45 cases. The automated analysis took significantly less time than manual tracing, but produced superior, well-behaved arterial waveforms. Automated arterial measurements also had lower interobserver variability as measured by correlation, difference in mean values, and coefficient of variation. Although FFAC successfully segmented both the longitudinal and transverse images, transverse measurements were less variable. The cross-sectional area computed from the longitudinal images was 27% lower than the area measured from transverse images, possibly due to the compression of the artery along the image depth by transducer pressure. Conclusions: FFAC is a robust and sensitive vasomotion segmentation algorithm in both transverse and longitudinal views. Transverse imaging may offer advantages over longitudinal imaging: transverse measurements are more consistent, possibly because the method is less sensitive to variations in transducer pressure during imaging.

  18. Brachial Neuritis With Phrenic Nerve Involvement in a Patient With a Possible Connective Tissue Disease

    PubMed Central

    Subash, Meera; Patel, Gaurav; Welker, John

    2014-01-01

    Background. Brachial neuritis (BN) is a rare inflammatory condition of peripheral nerves, usually involving the cervicobrachial plexus. These patients present with sudden onset of shoulder and arm pain that evolves into muscle weakness and atrophy.. Case Report. A 33-year-old woman presented with a 1-month history of diffuse pain in her thorax. She had no trauma or inciting incident prior to the onset of this pain and was initially treated for muscle spasms. The patient was seen in the emergency room multiple times and was treated with several courses of antibiotics for pneumonia on the basis of clinical symptoms and abnormal x-rays. The pleuritic chest pain persisted for at least 4 months, and the patient was eventually admitted for worsening pain and dyspnea. On physical examination, crackles were heard at both lung bases, and chest inspection revealed increased expansion in the upper thorax but poor expansion of the lower thorax and mild paradoxical respiration. “Sniff” test revealed no motion of the left hemidiaphragm and reduced motion on the right hemidiaphragm. Her computed tomography scan revealed bilateral atelectasis, more severe at the left base. She reported no symptoms involving her joints or skin or abdomen. Her presentation and clinical course are best explained by BN with a bilateral diaphragmatic weakness. However, she had a positive ANA, RF, anti-RNP antibody, and anti SS-A. Conclusion. Patients with BN can present with diffuse thoracic pain, pleuritic chest pain, and diaphragmatic weakness. Our patient may represent a case of connective tissue disease presenting with brachial plexus neuritis. PMID:26425609

  19. IMPULSIVE ACCELERATION OF CORONAL MASS EJECTIONS. I. STATISTICS AND CORONAL MASS EJECTION SOURCE REGION CHARACTERISTICS

    SciTech Connect

    Bein, B. M.; Berkebile-Stoiser, S.; Veronig, A. M.; Temmer, M.; Muhr, N.; Kienreich, I.; Utz, D.

    2011-09-10

    We use high time cadence images acquired by the STEREO EUVI and COR instruments to study the evolution of coronal mass ejections (CMEs) from their initiation through impulsive acceleration to the propagation phase. For a set of 95 CMEs we derived detailed height, velocity, and acceleration profiles and statistically analyzed characteristic CME parameters: peak acceleration, peak velocity, acceleration duration, initiation height, height at peak velocity, height at peak acceleration, and size of the CME source region. The CME peak accelerations we derived range from 20 to 6800 m s{sup -2} and are inversely correlated with the acceleration duration and the height at peak acceleration. Seventy-four percent of the events reach their peak acceleration at heights below 0.5 R{sub sun}. CMEs that originate from compact sources low in the corona are more impulsive and reach higher peak accelerations at smaller heights. These findings can be explained by the Lorentz force, which drives the CME accelerations and decreases with height and CME size.

  20. Potential Method of Predicting Coronal Mass Ejection

    NASA Astrophysics Data System (ADS)

    Imholt, Timothy; Roberts, J. A.; Scott, J. B.; University Of North Texas Team

    2000-10-01

    Coronal Mass Ejections (CME) may be described as a blast of gas and highly charged solar mass fragments ejected into space. These ejections, when directed toward Earth, have many different effects on terrestrial systems ranging from the Aurora Borealis to changes in wireless communications. The importance of an early prediction of these solar events cannot be overlooked. There are several models currently accepted and utilized to predict these events, however, with earlier prediction of both the event and the location on the sun where the event occur allows us to have earlier warnings as to when they will effect man-made systems. A better prediction could perhaps be achieved by utilizing low angular resolution radio telescope arrays to catalog data from the sun at different radio frequencies on a regular basis. Once this data is cataloged a better predictor for these CME's could be found. We propose a model that allows a prediction to be made that appears to be longer than 24 hours.

  1. Potential Method of Predicting Coronal Mass Ejection

    NASA Astrophysics Data System (ADS)

    Imholt, Timothy

    2001-10-01

    Coronal Mass Ejections (CME) may be described as a blast of gas and highly charged solar mass fragments ejected into space. These ejections, when directed toward Earth, have many different effects on terrestrial systems ranging from the Aurora Borealis to changes in wireless communication. The early prediction of these solar events cannot be overlooked. There are several models currently accepted and utilized to predict these events, however, with earlier prediction of both the event and the location on the sun where the event occurs allows us to have earlier warnings as to when they will affect man-made systems. A better prediction could perhaps be achieved by utilizing low angular resolution radio telescope arrays to catalog data from the sun at different radio frequencies on a regular basis. Once this data is cataloged a better predictor for these CME’s could be found. We propose a model that allows a prediction to be made that appears to be longer than 24 hours.

  2. Kinetics of Polymer Ejection from Capsid Confinement: Scaling Considerations and Computer Experiment

    NASA Astrophysics Data System (ADS)

    Milchev, A.; Binder, K.

    2012-08-01

    We investigate the ejection dynamics of a flexible polymer chain out of confined environment by means of scaling considerations and Monte Carlo simulations. Situations of this kind arise in different physical contexts, including a flexible synthetic polymer partially confined in a nanopore and a viral genome partially ejected from its capsid. In the case of cylindric confinement the entropic driving force which pulls the chain out of the pore is argued to be constant once a few persistent lengths are out of the pore. We demonstrate that in this case the ejection dynamics follows a √ {t}-law with elapsed time t. The mean ejection time τ depends nonmonotonically on chain length N. However, if the geometric constraints comprise a wider capsid chamber attached to a narrow exit tube, the mechanism of ejection changes and involves the surmounting of an activation barrier. The driving force then varies in time. One finds good agreement of theory and computer simulation with recent experiments with DNA.

  3. Avulsion of the brachial plexus in a great horned owl (Bubo virginaus)

    USGS Publications Warehouse

    Moore, M.P.; Stauber, E.; Thomas, N.J.

    1989-01-01

    Avulsion of the brachial plexus was documented in a Great Horned Owl (Bubo virginianus). A fractured scapula was also present. Cause of these injuries was not known but was thought to be due to trauma. Differentiation of musculoskeletal injury from peripheral nerve damage can be difficult in raptors. Use of electromyography and motor nerve conduction velocity was helpful in demonstrating peripheral nerve involvement. A brachial plexus avulsion was suspected on the basis of clinical signs, presence of electromyographic abnormalities in all muscles supplied by the nerves of the brachial plexus and absence of median-ulnar motor nerve conduction velocities.

  4. Aircrew ejections in the Republic of Bulgaria, 1953-93.

    PubMed

    Milanov, L

    1996-04-01

    We reviewed the ejections of 60 pilots who ejected from 54 aircraft of Soviet production in the Republic of Bulgaria from 1953-93. The following factors were correlated with the degree of injury during ejection: the fliers' height, weight, and age; type of aircraft and ejection seat; altitude and speed of the aircraft at ejection; and the reason for ejection. The act of ejection can be a life-saving procedure when the aircraft gets into a non-recoverable situation, especially when carried out at an altitude above of 300 m, or at ground level. Survival rate of pilots in those cases is 95-100% respectively, compared to the general survival rate, which is 83%. Of the 60 ejectees, 10 (16.7%) were killed, 14 (23.3%) suffered major injuries, 17 (28.3%) suffered minor injuries, and 19 (31.7%) were uninjured. PMID:8900991

  5. Role of osmotic and hydrostatic pressures in bacteriophage genome ejection

    NASA Astrophysics Data System (ADS)

    Lemay, Serge G.; Panja, Debabrata; Molineux, Ian J.

    2013-02-01

    A critical step in the bacteriophage life cycle is genome ejection into host bacteria. The ejection process for double-stranded DNA phages has been studied thoroughly in vitro, where after triggering with the cellular receptor the genome ejects into a buffer. The experimental data have been interpreted in terms of the decrease in free energy of the densely packed DNA associated with genome ejection. Here we detail a simple model of genome ejection in terms of the hydrostatic and osmotic pressures inside the phage, a bacterium, and a buffer solution or culture medium. We argue that the hydrodynamic flow associated with the water movement from the buffer solution into the phage capsid and further drainage into the bacterial cytoplasm, driven by the osmotic gradient between the bacterial cytoplasm and culture medium, provides an alternative mechanism for phage genome ejection in vivo; the mechanism is perfectly consistent with phage genome ejection in vitro.

  6. Modeling MHD accretion-ejection: episodic ejections of jets triggered by a mean-field disk dynamo

    SciTech Connect

    Stepanovs, Deniss; Fendt, Christian; Sheikhnezami, Somayeh E-mail: fendt@mpia.de

    2014-11-20

    We present MHD simulations exploring the launching, acceleration, and collimation of jets and disk winds. The evolution of the disk structure is consistently taken into account. Extending our earlier studies, we now consider the self-generation of the magnetic field by an α{sup 2}Ω mean-field dynamo. The disk magnetization remains on a rather low level, which helps to evolve the simulations for T > 10, 000 dynamical time steps on a domain extending 1500 inner disk radii. We find the magnetic field of the inner disk to be similar to the commonly found open field structure, favoring magneto-centrifugal launching. The outer disk field is highly inclined and predominantly radial. Here, differential rotation induces a strong toroidal component, which plays a key role in outflow launching. These outflows from the outer disk are slower, denser, and less collimated. If the dynamo action is not quenched, magnetic flux is continuously generated, diffuses outward through the disk, and fills the entire disk. We have invented a toy model triggering a time-dependent mean-field dynamo. The duty cycles of this dynamo lead to episodic ejections on similar timescales. When the dynamo is suppressed as the magnetization falls below a critical value, the generation of the outflows and also accretion is inhibited. The general result is that we can steer episodic ejection and large-scale jet knots by a disk-intrinsic dynamo that is time-dependent and regenerates the jet-launching magnetic field.

  7. Sex-specific effects of habitual aerobic exercise on brachial artery flow-mediated dilation in middle-aged and older adults.

    PubMed

    Pierce, Gary L; Eskurza, Iratxe; Walker, Ashley E; Fay, Tara N; Seals, Douglas R

    2011-01-01

    Brachial artery FMD (flow-mediated dilation) is impaired with aging and is associated with an increased risk of CVD (cardiovascular disease). In the present study, we determined whether regular aerobic exercise improves brachial artery FMD in MA/O (middle-aged/older) men and post-menopausal women. In sedentary MA/O adults (age, 55-79 years) without CVD, 8 weeks of brisk walking (6 days/week for approx. 50 min/day; randomized controlled design) increased treadmill time approx. 20% in both MA/O men (n=11) and post-menopausal women (n=15) (P<0.01), without altering body composition or circulating CVD risk factors. Brachial artery FMD increased >50% in the MA/O men (from 4.6±0.6 to 7.1±0.6%; P<0.01), but did not change in the post-menopausal women (5.1±0.8 compared with 5.4±0.7%; P=0.50). No changes occurred in the non-exercising controls. In a separate cross-sectional study (n=167), brachial artery FMD was approx. 50% greater in endurance-exercise-trained (6.4±0.4%; n=45) compared with sedentary (4.3±0.3%; n=60) MA/O men (P<0.001), whereas there were no differences between endurance-trained (5.3±0.7%, n=20) and sedentary (5.6±0.5%, n=42) post-menopausal women (P=0.70). Brachial artery lumen diameter, peak hyperaemic shear rate and endothelium-independent dilation did not differ with exercise intervention or in the endurance exercise compared with sedentary groups. In conclusion, regular aerobic exercise is consistently associated with enhanced brachial artery FMD in MA/O men, but not in post-menopausal women. Some post-menopausal women without CVD may be less responsive to habitual aerobic exercise than MA/O men.

  8. The fluid mechanics of bolus ejection from the oral cavity.

    PubMed

    Nicosia, M A; Robbins, J A

    2001-12-01

    The squeezing action of the tongue against the palate provides driving forces to propel swallowed material out of the mouth and through the pharynx. Transport in response to these driving forces, however, is dependent on the material properties of the swallowed bolus. Given the complex geometry of the oral cavity and the unsteady nature of this process, the mechanics governing the oral phase of swallowing are not well understood. In the current work, the squeezing flow between two approaching parallel plates is used as a simplified mathematical model to study the fluid mechanics of bolus ejection from the oral cavity. Driving forces generated by the contraction of intrinsic and extrinsic lingual muscles are modeled as a spatially uniform pressure applied to the tongue. Approximating the tongue as a rigid body, the motion of tongue and fluid are then computed simultaneously as a function of time. Bolus ejection is parameterized by the time taken to clear half the bolus from the oral cavity, t(1/2). We find that t(1/2) increases with increased viscosity and density and decreases with increased applied pressure. In addition, for low viscosity boluses (mu approximately 100 cP), density variations dominate the fluid mechanics while for high viscosity boluses (mu approximately 1000 cP), viscosity dominates. A transition region between these two regimes is found in which both properties affect the solution characteristics. The relationship of these results to the assessment and treatment of swallowing disorders is discussed. PMID:11716855

  9. Resting Doppler ankle brachial pressure index measurement: a literature review.

    PubMed

    Sihlangu, Dorcus; Bliss, Julie

    2012-07-01

    Peripheral vascular disease (PVD) is under-diagnosed in primary and acute settings. The use of Doppler ankle brachial pressure index (ABPI) is effective in diagnosing PVD , aid in determining aetiology of leg ulcers and is cost efficient in reducing the effects of atherosclerosis and cardiovascular events. The aim of this literature review was to review practitioners' experience in using Doppler ABPI, different skills used to measure ABPI and to examine practitioners' confidence in ABPI. The findings identified variation in method for Doppler measurement: including position of the artery, arm measurement, resting period and type of equipment for measuring blood pressure, variations in practitioners' training and experience have demonstrated variability in ABPI results. Although limited in number, the studies have demonstrated knowledge gap, and the need for training among health professionals. PMID:22875182

  10. Ankle brachial pressure index of normal, healthy, younger adults.

    PubMed

    Niblo, Jane; Coull, Alison

    Doppler ultrasound and ankle brachial pressure index (ABPI) calculations are used in the assessment of lower limb vascularity, specifically to determine arterial deficiency. ABPI is important as it is used as an indicator when deciding management options for the treatment of leg ulceration. This study aimed to investigate the range of ABPI measurement, using Doppler ultrasound and sphygmomanometry in 36 young healthy adults aged 18-55 years. The findings show a mean ABPI in the left leg of 1.19 and a mean ABPI of 1.17 in the right leg which, while within the normal range, are consistently in the upper range and significantly higher than the acknowledged 'normal' midpoint of 1.0. It would appear that younger people will have ABPIs within the upper aspect of the normal range and well above the established norm of 1.0. PMID:24151719

  11. Temporal pattern of pulse wave velocity during brachial hyperemia reactivity

    NASA Astrophysics Data System (ADS)

    Graf, S.; Valero, M. J.; Craiem, D.; Torrado, J.; Farro, I.; Zócalo, Y.; Valls, G.; Bía, D.; Armentano, R. L.

    2011-09-01

    Endothelial function can be assessed non-invasively with ultrasound, analyzing the change of brachial diameter in response to transient forearm ischemia. We propose a new technique based in the same principle, but analyzing a continuous recording of carotid-radial pulse wave velocity (PWV) instead of diameter. PWV was measured on 10 healthy subjects of 22±2 years before and after 5 minutes forearm occlusion. After 59 ± 31 seconds of cuff release PWV decreased 21 ± 9% compared to baseline, reestablishing the same after 533 ± 65 seconds. There were no significant changes observed in blood pressure. When repeating the study one hour later in 5 subjects, we obtained a coefficient of repeatability of 4.8%. In conclusion, through analysis of beat to beat carotid-radial PWV it was possible to characterize the temporal profiles and analyze the acute changes in response to a reactive hyperemia. The results show that the technique has a high sensitivity and repeatability.

  12. Brachial-Ankle Pulse Wave Velocity: Myths, Misconceptions, and Realities.

    PubMed

    Sugawara, Jun; Tanaka, Hirofumi

    2015-09-01

    A variety of techniques to evaluate central arterial stiffness have been developed and introduced. None of these techniques, however, have been implemented widely in regular clinical settings, except for brachial-ankle pulse wave velocity (baPWV). The most prominent procedural advantage of baPWV is its ease of use, since it only requires the wrapping of blood pressure cuffs on the 4 extremities. There is mounting evidence indicating the ability of baPWV to predict the risk of future cardiovascular events and total mortality. Additionally, the guidelines for the management of hypertension in Japan recommended the measurement of baPWV be included in the assessment of subclinical target organ damage. However, baPWV has not been fully accepted worldwide due to perceived theoretical and methodological issues. In this review, we address the most frequently mentioned questions and concerns regarding baPWV to shed some light on this simple and easy arterial stiffness measurement. PMID:26587459

  13. Ultraviolet Spectroscopy of Narrow Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Dobrzycka, D.; Raymond, J. C.; Biesecker, D. A.; Li, J.; Ciaravella, A.

    2003-05-01

    We present Ultraviolet Coronagraph Spectrometer (UVCS) observations of five narrow coronal mass ejections (CMEs) that were among 15 narrow CMEs originally selected by Gilbert and coworkers. Two events (1999 March 27, April 15) were ``structured,'' i.e., in white-light data they exhibited well-defined interior features, and three (1999 May 9, May 21, June 3) were ``unstructured,'' i.e., appeared featureless. In UVCS data the events were seen as 4°-13° wide enhancements of the strongest coronal lines H I Lyα and O VI λλ1032, 1037. We derived electron densities for several of the events from the Large Angle and Spectrometric Coronagraph Experiment (LASCO) C2 white-light observations. They are comparable to or smaller than densities inferred for other CMEs. We modeled the observable properties of examples of the structured (1999 April 15) and unstructured (1999 May 9) narrow CMEs at different heights in the corona between 1.5 and 2 Rsolar. The derived electron temperatures, densities, and outflow speeds are similar for those two types of ejections. They were compared with properties of polar coronal jets and other CMEs. We discuss different scenarios of narrow CME formation as either a jet formed by reconnection onto open field lines or a CME ejected by expansion of closed field structures. Overall, we conclude that the existing observations do not definitively place the narrow CMEs into the jet or the CME picture, but the acceleration of the 1999 April 15 event resembles acceleration seen in many CMEs, rather than constant speeds or deceleration observed in jets.

  14. OCT/PS-OCT imaging of brachial plexus neurovascular structures

    NASA Astrophysics Data System (ADS)

    Raphael, David T.; Zhang, Jun; Zhang, Yaoping; Chen, Zhongping; Miller, Carol; Zhou, Li

    2004-07-01

    Introduction: Optical coherence tomography (OCT) allows high-resolution imaging (less than 10 microns) of tissue structures. A pilot study with OCT and polarization-sensitive OCT (PS-OCT) was undertaken to image ex-vivo neurovascular structures (vessels, nerves) of the canine brachial plexus. Methods: OCT is an interferometry-based optical analog of B-mode ultrasound, which can image through non-transparent biological tissues. With approval of the USC Animal Care and Use Committee, segments of the supra- and infraclavicular brachial plexus were excised from euthanized adult dogs, and the ex-vivo specimens were placed in cold pH-buffered physiologic solution. An OCT beam, in micrometer translational steps, scanned the fixed-position bisected specimens in transverse and longitudinal views. Two-dimensional images were obtained from identified arteries and nerves, with specific sections of interest stained with hematoxylin-eosin for later imaging through a surgical microscope. Results: with the beam scan direction transverse to arteries, the resulting OCT images showed an identifiable arterial lumen and arterial wall tissue layers. By comparison, transverse beam OCT images of nerves revealed a multitude of smaller nerve bundles contained within larger circular-shaped fascicles. PS-OCT imaging was helpful in showing the characteristic birefringence exhibited by arrayed neural structures. Discussion: High-resolution OCT imaging may be useful in the optical identification of neurovascular structures during attempted regional nerve blockade. If incorporated into a needle-shaped catheter endoscope, such a technology could prevent intraneural and intravascular injections immediately prior to local anesthetic injection. The major limitation of OCT is that it can form a coherent image of tissue structures only to a depth of 1.5 - 2 mm.

  15. Neonatal brachial plexus palsy: incidence, prevalence, and temporal trends.

    PubMed

    Chauhan, Suneet P; Blackwell, Sean B; Ananth, Cande V

    2014-06-01

    Epidemiological knowledge of the incidence, prevalence, and temporal changes of neonatal brachial plexuses palsy (NBPP) should assist the clinician, avert unnecessary interventions, and help formulate evidence-based health policies. A summary of 63 publications in the English language with over 17 million births and 24,000 NBPPs is notable for six things. First, the rate of NBPP in the US and other countries is comparable: 1.5 vs. 1.3 per 1000 total births, respectively. Second, the rate of NBPP may be decreasing: 0.9, 1.0 and 0.5 per 1,000 births for publications before 1990, 1990-2000, and after 2000, respectively. Third, the likelihood of not having concomitant shoulder dystocia with NBPP was 76% overall, though it varied by whether the publication was from the US (78%) vs. other countries (47%). Fourth, the likelihood of NBPP being permanent (lasting at least 12 months) was 10-18% in the US-based reports and 19-23% in other countries. Fifth, in studies from the US, the rate of permanent NBPP is 1.1-2.2 per 10,000 births and 2.9-3.7 per 10,000 births in other nations. Sixth, we estimate that approximately 5000 NBPPs occur every year in the US, of which over 580-1050 are permanent, and that since birth, 63,000 adults have been afflicted with persistent paresis of their brachial plexus. The exceedingly infrequent nature of permanent NBPP necessitates a multi-center study to improve our understanding of the antecedent factors and to abate the long-term sequela.

  16. Morphometric Atlas Selection for Automatic Brachial Plexus Segmentation

    SciTech Connect

    Van de Velde, Joris; Wouters, Johan; Vercauteren, Tom; De Gersem, Werner; Duprez, Fréderic; De Neve, Wilfried; Van Hoof, Tom

    2015-07-01

    Purpose: The purpose of this study was to determine the effects of atlas selection based on different morphometric parameters, on the accuracy of automatic brachial plexus (BP) segmentation for radiation therapy planning. The segmentation accuracy was measured by comparing all of the generated automatic segmentations with anatomically validated gold standard atlases developed using cadavers. Methods and Materials: Twelve cadaver computed tomography (CT) atlases (3 males, 9 females; mean age: 73 years) were included in the study. One atlas was selected to serve as a patient, and the other 11 atlases were registered separately onto this “patient” using deformable image registration. This procedure was repeated for every atlas as a patient. Next, the Dice and Jaccard similarity indices and inclusion index were calculated for every registered BP with the original gold standard BP. In parallel, differences in several morphometric parameters that may influence the BP segmentation accuracy were measured for the different atlases. Specific brachial plexus-related CT-visible bony points were used to define the morphometric parameters. Subsequently, correlations between the similarity indices and morphometric parameters were calculated. Results: A clear negative correlation between difference in protraction-retraction distance and the similarity indices was observed (mean Pearson correlation coefficient = −0.546). All of the other investigated Pearson correlation coefficients were weak. Conclusions: Differences in the shoulder protraction-retraction position between the atlas and the patient during planning CT influence the BP autosegmentation accuracy. A greater difference in the protraction-retraction distance between the atlas and the patient reduces the accuracy of the BP automatic segmentation result.

  17. Large cervicothoracic myxoinflammatory fibroblastic sarcoma with brachial plexus invasion: A case report and literature review

    PubMed Central

    Jia, Xiaotian; Yang, Jianyun; Chen, Lin; Yu, Cong

    2016-01-01

    Myxoinflammatory fibroblastic sarcoma is a rare sarcoma that develops in patients of all ages, which usually presents as a slow-growing painless mass in the distal extremities. To date, myxoinflammatory fibroblastic sarcoma with invasion of the brachial plexus has rarely been reported in the literature. In this study, a case of large cervicothoracic sarcoma, which invaded the brachial plexus, is presented. The patient reported no sensory disturbance or dyskinesia. The tumor was completely resected without injury of the brachial plexus. The postoperative histological diagnosis was myxoinflammatory fibroblastic sarcoma. Follow-up examination performed 24 months after surgery revealed no tumor recurrence and no sensory disturbance or dyskinesia was reported. This study presents a rare case of large myxoinflammatory fibroblastic sarcoma with brachial plexus invasion that was successfully managed by surgery. PMID:27588121

  18. Restoration and protection of brachial plexus injury: hot topics in the last decade

    PubMed Central

    Zhang, Kaizhi; Lv, Zheng; Liu, Jun; Zhu, He; Li, Rui

    2014-01-01

    Brachial plexus injury is frequently induced by injuries, accidents or birth trauma. Upper limb function may be partially or totally lost after injury, or left permanently disabled. With the development of various medical technologies, different types of interventions are used, but their effectiveness is wide ranging. Many repair methods have phasic characteristics, i.e., repairs are done in different phases. This study explored research progress and hot topic methods for protection after brachial plexus injury, by analyzing 1,797 articles concerning the repair of brachial plexus injuries, published between 2004 and 2013 and indexed by the Science Citation Index database. Results revealed that there are many methods used to repair brachial plexus injury, and their effects are varied. Intervention methods include nerve transfer surgery, electrical stimulation, cell transplantation, neurotrophic factor therapy and drug treatment. Therapeutic methods in this field change according to the hot topic of research. PMID:25374596

  19. Brachial Plexus Injury from CT-Guided RF Ablation Under General Anesthesia

    SciTech Connect

    Shankar, Sridhar Sonnenberg, Eric van; Silverman, Stuart G.; Tuncali, Kemal; Flanagan, Hugh L.; Whang, Edward E.

    2005-06-15

    Brachial plexus injury in a patient under general anesthesia (GA) is not uncommon, despite careful positioning and, particularly, awareness of the possibility. The mechanism of injury is stretching and compression of the brachial plexus over a prolonged period. Positioning the patient within the computed tomography (CT) gantry for abdominal or chest procedures can simulate a surgical procedure, particularly when GA is used. The potential for brachial plexus injury is increased if the case is prolonged and the patient's arms are raised above the head to avoid CT image degradation from streak artifacts. We report a case of profound brachial plexus palsy following a CT-guided radiofrequency ablation procedure under GA. Fortunately, the patient recovered completely. We emphasize the mechanism of injury and detail measures to combat this problem, such that radiologists are aware of this potentially serious complication.

  20. Contralateral Spinal Accessory Nerve Transfer: A New Technique in Panavulsive Brachial Plexus Palsy.

    PubMed

    Zermeño-Rivera, Jaime; Gutiérrez-Amavizca, Bianca Ethel

    2015-06-01

    Brachial plexus avulsion results from excessive stretching and can occur secondary to motor vehicle accidents, mainly in motorcyclists. In a 28-year-old man with panavulsive brachial plexus palsy, we describe an alternative technique to repair brachial plexus avulsion and to stabilize and preserve shoulder function by transferring the contralateral spinal accessory nerve to the suprascapular nerve. We observed positive clinical and electromyographic results in sternocleidomastoid, trapezius, supraspinatus, infraspinatus, pectoralis, triceps, and biceps, with good outcome and prognosis for shoulder function at 12 months after surgery. This technique provides a unique opportunity for patients suffering from severe brachial plexus injuries and lacking enough donor nerves to obtain shoulder stability and mobility while avoiding bone fusion and preserving functionality of the contralateral shoulder with favorable postoperative outcomes.

  1. Dysphoric milk ejection reflex: A case report

    PubMed Central

    2011-01-01

    Dysphoric Milk Ejection Reflex (D-MER) is an abrupt emotional "drop" that occurs in some women just before milk release and continues for not more than a few minutes. The brief negative feelings range in severity from wistfulness to self-loathing, and appear to have a physiological cause. The authors suggest that an abrupt drop in dopamine may occur when milk release is triggered, resulting in a real or relative brief dopamine deficit for affected women. Clinicians can support women with D-MER in several ways; often, simply knowing that it is a recognized phenomenon makes the condition tolerable. Further study is needed. PMID:21645333

  2. Spontaneous Aerosol Ejection: Origin of Inorganic Particles in Biomass Pyrolysis.

    PubMed

    Teixeira, Andrew R; Gantt, Rachel; Joseph, Kristeen E; Maduskar, Saurabh; Paulsen, Alex D; Krumm, Christoph; Zhu, Cheng; Dauenhauer, Paul J

    2016-06-01

    At high thermal flux and temperatures of approximately 500 °C, lignocellulosic biomass transforms to a reactive liquid intermediate before evaporating to condensable bio-oil for downstream upgrading to renewable fuels and chemicals. However, the existence of a fraction of nonvolatile compounds in condensed bio-oil diminishes the product quality and, in the case of inorganic materials, catalyzes undesirable aging reactions within bio-oil. In this study, ablative pyrolysis of crystalline cellulose was evaluated, with and without doped calcium, for the generation of inorganic-transporting aerosols by reactive boiling ejection from liquid intermediate cellulose. Aerosols were characterized by laser diffraction light scattering, inductively coupled plasma spectroscopy, and high-speed photography. Pyrolysis product fractionation revealed that approximately 3 % of the initial feed (both organic and inorganic) was transported to the gas phase as aerosols. Large bubble-to-aerosol size ratios and visualization of significant late-time ejections in the pyrolyzing cellulose suggest the formation of film bubbles in addition to the previously discovered jet formation mechanism.

  3. Double ejections in the 23 July 2012 SEP event

    NASA Astrophysics Data System (ADS)

    Li, G.; Ding, L.; Sun, X.; Evans, R. M.; Shen, C.; Jiang, Y.; Gu, B.; Xu, F.; Zhang, Y.

    2013-12-01

    Recently,it has been proposed that extreme solar Energetic Particle Events (SEPs) are likely caused by twin CMEs. On July 23 2012, a massive eruption led to a large SEP, which is well observed in STEREO-A. Using the 171A and 304A bands of the EUVI imaging from spacecraftSTEREO-A,STEREO-B, and SDO, we report the observations of two coronal mass ejections in the July 23 2012 SEP event. Two ejections were identified with a time separation of ~8 minutes. In the first eruption, a flux rope can be seen with a rotation during the eruption. For the second eruption, there was a deflection of the propagation direction. These features resemble the numerical simulation of a sympathetic eruption investigated by Torok et al (2011). We propose that sympathetic eruptions from complex active regions (AR), as a special subset of the 'twin-CME' scenario, may provide an efficient acceleration site for high energy particles that are observed in large SEPs.

  4. Nerve Transfers in Birth Related Brachial Plexus Injuries: Where Do We Stand?

    PubMed

    Davidge, Kristen M; Clarke, Howard M; Borschel, Gregory H

    2016-05-01

    This article reviews the assessment and management of obstetrical brachial plexus palsy. The potential role of distal nerve transfers in the treatment of infants with Erb's palsy is discussed. Current evidence for motor outcomes after traditional reconstruction via interpositional nerve grafting and extraplexal nerve transfers is reviewed and compared with the recent literature on intraplexal distal nerve transfers in obstetrical brachial plexus injury. PMID:27094890

  5. Association of hemoglobin with ankle-brachial index in general population

    PubMed Central

    Chenglong, Zhang; Jing, Lei; Xia, Ke; Yang, Tianlun

    2016-01-01

    OBJECTIVES: Previous studies have demonstrated that both low and high hemoglobin concentrations are predictive of adverse cardiovascular outcomes in various populations. However, an association of hemoglobin with the ankle-brachial index, which is widely used as a screening test for peripheral arterial disease, has not yet been identified. METHODS: We examined 786 subjects (236 women and 550 men) who received routine physical check-ups. The ankle-brachial index and several hematological parameters, including the hemoglobin level, hematocrit and red blood cell count and other demographic and biochemical characteristics were collected. Univariate and multivariate linear regression analyses were performed to assess the relationships between the ankle-brachial index and the independent determinants. Receiver operating characteristic curve analysis was conducted to calculate the cut-off level of hemoglobin for a relatively low ankle-brachial index (less than 20% of all subjects, which was 1.02). RESULTS: The hemoglobin level, hematocrit and red blood cell count were correlated with the ankle-brachial index in the males (r=-0.274, r=-0.224 and r=-0.273, respectively, p<0.001 for all), but these associations were not significant in the females. Multivariate linear regression analysis revealed that the independent determinants of the ankle-brachial index included age, total cholesterol, high-density lipoprotein cholesterol and the white blood cell count for the females and age, hypertension, total cholesterol and hemoglobin (β=-0.001, p<0.001) for the males after adjusting for confounding factors. Receiver operating characteristic curve analysis revealed that the cut-off level of hemoglobin for predicting a low ankle-brachial index was 156.5 g/L in the males. CONCLUSIONS: A high hemoglobin concentration was independently correlated with a low ankle-brachial index in the healthy males, indicating that an elevation in this level may be associated with an increased

  6. Studies of limb-dislodging forces acting on an ejection seat occupant.

    PubMed

    Schneck, D J

    1980-03-01

    A mathematical theory is being developed in order to calculate the aerodynamic loading to which a pilot is exposed during high-speed ejections. Neglecting the initial effects of flow separation, results thus far indicate that a pilot's musculoskeletal system is not likely to withstand the tendency for limb-flailing if he is ejecting at Mach numbers in excess of about 0.7. This tendency depends very strongly upon the angle at which the pilot's limbs intercept a high-speed flow; the forces that cause limb dislodgement increase dramatically with speed of ejection. Examining the time-course of limb-dislodging forces after the initial onset of windblast, the theory further predicts the generation of a double vortex street pattern on the downstream side of the limbs of an ejection seat occupant. This results in the corresponding appearance of oscillating forces tending to cause lateral motion (vibration) of the limbs. The amplitude and frequency of these oscillating forces are also very dependent on the Mach number of ejection and the angle at which the pilot's limbs intercept the flow. However, even at moderate Mach numbers, the frequency can be as high as 100 cycles per second, and the amplitude rapidly exceeds a pilot's musculo-skeletal resistive powers for Mach numbers above 0.7. PMID:7362573

  7. Ejection of the Corona at State Transitions: a Common Behavior in Microquasars?

    NASA Astrophysics Data System (ADS)

    Prat, L.; Rodriguez, J.

    2009-05-01

    The onset of most microquasar outbursts is characterized by a state transition between a Low/Hard State (LHS) and a High/Soft State (HSS). Besides drastic spectral and timing changes, this transition often shows a discrete ejection event detectable in the radio range. However, the exact nature of the ejected material and the mechanisms that give birth to these phenomena are yet to be unraveled. Recent simultaneous radio and X-ray observations on several sources point to a coronal nature of the ejected material. In the cases of GRS 1915+105, XTE J1550-564, and the 2002 outburst of GX 339-4, the flux of the Compton component decreases sharply just before an ejection is detected in the radio range. Finally, in the case of H1743-322, drastic physical changes occurred in the corona just before the state transition, compatible with the disappearance of part of this medium. Thus, the behavior of at least 4 microquasars points in the direction of an ejection of the corona at the state transition, feature that is yet to be confirmed (or infirmed) in the case of other available sources.

  8. High-resolution imaging of ejection dynamics in laser-induced forward transfer

    NASA Astrophysics Data System (ADS)

    Pohl, R.; Visser, C. W.; Römer, G. R. B. E.; Sun, C.; Huis in't Veld, A. J.; Lohse, D.

    2014-03-01

    Laser-induced Forward Transfer (LIFT) is a 3D direct-write method suitable for precision printing of various materials. As the ejection mechanism of picosecond LIFT has not been visualized in detail, the governing physics are not fully understood yet. Therefore, this article presents an experimental imaging study on the ejection process of gold-based LIFT. The LIFT experiments were performed using a 6.7 picosecond Yb:YAG laser source equipped with a SHG. The beam was focused onto a 200 nm thick gold donor layer. The high magnification images were obtained using bright field illumination by a 6 ns pulsed Nd:YAG laser source and a 50× long-distance microscope objective that was combined with a 200 mm tube lens. For laser fluence levels up to two times the donor-transfer-threshold, the ejection of a single droplet was observed. The typical droplet radius was estimated to be less than 3 μm. A transition of ejection features towards higher fluence, indicates a second fluence-regime in the ejection process. For higher laser fluence, the formation of an elongated gold jet was observed. This jet fragments into multiple relatively small droplets, resulting in a spray of particles on the receiving substrate.

  9. Solar Mass Ejection Imager (SMEI) space experiment

    NASA Astrophysics Data System (ADS)

    Radick, Richard R.

    2001-12-01

    The Solar Mass Ejection Imager (SMEI) is a proof-of-concept space experiment designed to observe solar coronal mass ejections (CMEs) and forecast their arrival at Earth. SMEI will image CMEs by sensing sunlight scattered from the free electrons in these ejecta (i.e., Thomson scattering). SMEI will be launched by a Titan II rocket into a circular, 830-km, sun-synchronous orbit in mid-2002 as part of the Space Test Program's CORIOLIS mission. SMEI will image nearly the entire sky once per spacecraft orbit over a mission lifetime of three years. Successful operation of SMEI will represent a major step in improving space weather forecasts by providing one- to three-day predictions of geomagnetic storms at the Earth. The SMEI experiment is being designed and constructed by a team of scientists and engineers from the Air Force Research Laboratory, the University of Birmingham (UB) in the United Kingdom, the University of California at San Diego (UCSD), and Boston University. The Air Force, NASA, and UB are providing financial support.

  10. Particle Ejection and Levitation Technology (PELT)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Each of the six Apollo landers touched down at unique sites on the lunar surface. Aside from the Apollo 12 landing site located 180 meters from the Surveyor III lander, plume impingement effects on ground hardware during the landings were not a problem. The planned return to the Moon requires numerous landings at the same site. Since the top few centimeters of lunar soil are loosely packed regolith, plume impingement from the lander will eject the granular material at high velocities. A picture shows what the astronauts viewed from the window of the Apollo 14 lander. There was tremendous dust excavation beneath the vehicle. With high-vacuum conditions on the Moon (10 (exp -14) to 10 (exp -12) torr), motion of all particles is completely ballistic. Estimates derived from damage to Surveyor III caused by the Apollo 12 lander show that the speed of the ejected regolith particles varies from 100 m/s to 2,000 m/s. It is imperative to understand the physics of plume impingement to safely design landing sites for future Moon missions. Aerospace scientists and engineers have examined and analyzed images from Apollo video extensively in an effort to determine the theoretical effects of rocket exhaust impingement. KSC has joined the University of Central Florida (UCF) to develop an instrument that will measure the 3-D vector of dust flow caused by plume impingement during descent of landers. The data collected from the instrument will augment the theoretical studies and analysis of the Apollo videos.

  11. Heart failure with preserved ejection fraction

    PubMed Central

    ElGuindy, Ahmed; Yacoub, Magdi H

    2012-01-01

    Abstract Heart failure with preserved ejection fraction (HFpEF) has recently emerged as a major cause of cardiovascular morbidity and mortality. Contrary to initial beliefs, HFpEF is now known to be as common as heart failure with reduced ejection fraction (HFrEF) and carries an unacceptably high mortality rate. With a prevalence that has been steadily rising over the past two decades, it is very likely that HFpEF will represent the dominant heart failure phenotype over the coming few years. The scarcity of trials in this semi-discrete form of heart failure and lack of unified enrolment criteria in the studies conducted to date might have contributed to the current absence of specific therapies. Understanding the epidemiological, pathophysiological and molecular differences (and similarities) between these two forms of heart failure is cornerstone to the development of targeted therapies. Carefully designed studies that adhere to unified diagnostic criteria with the recruitment of appropriate controls and adoption of practical end-points are urgently needed to help identify effective treatment strategies. PMID:25610841

  12. Global Response to Local Ionospheric Mass Ejection

    NASA Technical Reports Server (NTRS)

    Moore, T. E.; Fok, M.-C.; Delcourt, D. C.; Slinker, S. P.; Fedder, J. A.

    2010-01-01

    We revisit a reported "Ionospheric Mass Ejection" using prior event observations to guide a global simulation of local ionospheric outflows, global magnetospheric circulation, and plasma sheet pressurization, and comparing our results with the observed global response. Our simulation framework is based on test particle motions in the Lyon-Fedder-Mobarry (LFM) global circulation model electromagnetic fields. The inner magnetosphere is simulated with the Comprehensive Ring Current Model (CRCM) of Fok and Wolf, driven by the transpolar potential developed by the LFM magnetosphere, and includes an embedded plasmaspheric simulation. Global circulation is stimulated using the observed solar wind conditions for the period 24-25 Sept 1998. This period begins with the arrival of a Coronal Mass Ejection, initially with northward, but later with southward interplanetary magnetic field. Test particles are launched from the ionosphere with fluxes specified by local empirical relationships of outflow to electrodynamic and particle precipitation imposed by the MIlD simulation. Particles are tracked until they are lost from the system downstream or into the atmosphere, using the full equations of motion. Results are compared with the observed ring current and a simulation of polar and auroral wind outflows driven globally by solar wind dynamic pressure. We find good quantitative agreement with the observed ring current, and reasonable qualitative agreement with earlier simulation results, suggesting that the solar wind driven global simulation generates realistic energy dissipation in the ionosphere and that the Strangeway relations provide a realistic local outflow description.

  13. Electrically induced drop detachment and ejection

    NASA Astrophysics Data System (ADS)

    Cavalli, Andrea; Preston, Daniel J.; Tio, Evelyn; Martin, David W.; Miljkovic, Nenad; Wang, Evelyn N.; Blanchette, Francois; Bush, John W. M.

    2016-02-01

    A deformed droplet may leap from a solid substrate, impelled to detach through the conversion of surface energy into kinetic energy that arises as it relaxes to a sphere. Electrowetting provides a means of preparing a droplet on a substrate for lift-off. When a voltage is applied between a water droplet and a dielectric-coated electrode, the wettability of the substrate increases in a controlled way, leading to the spreading of the droplet. Once the voltage is released, the droplet recoils, due to a sudden excess in surface energy, and droplet detachment may follow. The process of drop detachment and lift-off, prevalent in both biology and micro-engineering, has to date been considered primarily in terms of qualitative scaling arguments for idealized superhydrophobic substrates. We here consider the eletrically-induced ejection of droplets from substrates of finite wettability and analyze the process quantitatively. We compare experiments to numerical simulations and analyze how the energy conversion efficiency is affected by the applied voltage and the intrinsic contact angle of the droplet on the substrate. Our results indicate that the finite wettability of the substrate significantly affects the detachment dynamics, and so provide new rationale for the previously reported large critical radius for drop ejection from micro-textured substrates.

  14. Asymmetric Magnetic Reconnection in Coronal Mass Ejection Current Sheets

    NASA Astrophysics Data System (ADS)

    Pope, Crystal; Miralles, M. P.; Murphy, N. A.

    2012-01-01

    Flux rope models of coronal mass ejections (CMEs) predict the formation ofan elongated current sheet in the wake behind the rising plasmoid. These current sheets have been seen to drift or tilt over time by instruments including SOHO/LASCO and Hinode/XRT. We measure this in multiple observations including the 2008 April 9 "Cartwheel CME" and find an average drift that is far more than can be accounted for via the effects of solar rotation. The observed drift could be due to different parts of the current sheet actively reconnecting at different times (e.g., Savage et al. 2010), macroscopic effects from the rising flux rope pulling the plasma sheet along with it, or asymmetry in the magnetic reconnection process itself. These drift rates are compared with resistive magnetohydrodynamic (MHD) simulations of line-tied reconnection between magnetic fields of different strengths. The observed drift rates are comparable to predictions made by the simulations.

  15. Dipole Field Effects on Ion Ejections from a Paul Ion Trap

    NASA Technical Reports Server (NTRS)

    MacAskill, J. A.; Chutjian, A.

    2011-01-01

    Attempts at improving the quality of mass spectra obtained from a Paul trap mass spectrometer prompted an investigation of the effects of additional fields to supplement the primary rf quadrupole trapping field. Reported here are the results of the first in a series of tests that focuses on the application of a single dipole field to augment the trapping and subsequent ejections of ions stored within a Paul trap. Measurements are presented for a fixed quadrupole frequency with varying dipole frequencies. The presence of the dipole field during the quadrupole trapping phase causes ion ejections of single m/z species at discrete dipole frequencies. During the mass analysis phase, the varying dipole frequency produces a complex set of resonant structures that impact ejection time (mass range), as well as mass spectral peak intensity and width

  16. Radio Emmision during the interaction of two Interplanetary Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Lara, Alejandro; Niembro, Tatiana; González, Ricardo

    2016-07-01

    We show that some sporadic radio emission observed by the WIND/WAVES experiment in the decametric/kilometric bands are due to the interaction of two interplanetary Coronal Mass Ejections. We have performed hydrodynamic simulations of the evolution of two consecutive Coronal Mass ejections in the interplanetary medium. With these simulations it is possible to follow the density evolution of the merged structure, and therefore, compute the frequency limits of the possible plasma emission. We study four well documented ICME interaction events, and found radio emission at the time and frequencies predicted by the simulations. This emission may help to anticipate the complexity of the merged region before it reaches one AU.

  17. Ultrafast probing of ejection dynamics of Rydberg atoms and molecular fragments from electronically excited helium nanodroplets.

    PubMed

    Bünermann, Oliver; Kornilov, Oleg; Haxton, Daniel J; Leone, Stephen R; Neumark, Daniel M; Gessner, Oliver

    2012-12-01

    The ejection dynamics of Rydberg atoms and molecular fragments from electronically excited helium nanodroplets are studied with time-resolved extreme ultraviolet ion imaging spectroscopy. At excitation energies of 23.6 ± 0.2 eV, Rydberg atoms in n = 3 and n = 4 states are ejected on different time scales and with significantly different kinetic energy distributions. Specifically, n = 3 Rydberg atoms are ejected with kinetic energies as high as 0.85 eV, but their appearance is delayed by approximately 200 fs. In contrast, n = 4 Rydberg atoms appear within the time resolution of the experiment with considerably lower kinetic energies. Major features in the Rydberg atom kinetic energy distributions for both principal quantum numbers can be described within a simple elastic scattering model of localized perturbed atomic Rydberg atoms that are expelled from the droplet due to their repulsive interaction with the surrounding helium bath. Time-dependent kinetic energy distributions of He(2) (+) and He(3) (+) ions are presented that support the formation of molecular ions in an indirect droplet ionization process and the ejection of neutral Rydberg dimers on a similar time scale as the n = 3 Rydberg atoms.

  18. Linear theory on temporal instability of megahertz faraday waves for monodisperse microdroplet ejection.

    PubMed

    Tsai, Shirley C; Tsai, Chen S

    2013-08-01

    A linear theory on temporal instability of megahertz Faraday waves for monodisperse microdroplet ejection based on mass conservation and linearized Navier-Stokes equations is presented using the most recently observed micrometer- sized droplet ejection from a millimeter-sized spherical water ball as a specific example. The theory is verified in the experiments utilizing silicon-based multiple-Fourier horn ultrasonic nozzles at megahertz frequency to facilitate temporal instability of the Faraday waves. Specifically, the linear theory not only correctly predicted the Faraday wave frequency and onset threshold of Faraday instability, the effect of viscosity, the dynamics of droplet ejection, but also established the first theoretical formula for the size of the ejected droplets, namely, the droplet diameter equals four-tenths of the Faraday wavelength involved. The high rate of increase in Faraday wave amplitude at megahertz drive frequency subsequent to onset threshold, together with enhanced excitation displacement on the nozzle end face, facilitated by the megahertz multiple Fourier horns in resonance, led to high-rate ejection of micrometer- sized monodisperse droplets (>10(7) droplets/s) at low electrical drive power (<;1 W) with short initiation time (<;0.05 s). This is in stark contrast to the Rayleigh-Plateau instability of a liquid jet, which ejects one droplet at a time. The measured diameters of the droplets ranging from 2.2 to 4.6 μm at 2 to 1 MHz drive frequency fall within the optimum particle size range for pulmonary drug delivery. PMID:25004544

  19. Echocardiographic assessment of ejection fraction in left ventricular hypertrophy

    PubMed Central

    Wandt, B; Bojo, L; Tolagen, K; Wranne, B

    1999-01-01

    OBJECTIVE—To investigate the value of Simpson's rule, Teichholz's formula, and recording of mitral ring motion in assessing left ventricular ejection fraction (EF) in patients with left ventricular hypertrophy.
DESIGN—Left ventricular ejection fraction calculated by Simpson's rule and by Techholz's formula and estimated by mitral ring motion was compared with values obtained by radionuclide angiography.
SETTING—Secondary referral centre.
PATIENTS—16 patients with left ventricular hypertrophy and a clinical diagnosis of hypertrophic cardiomyopathy or hypertension.
RESULTS—Calculation by Teichholz's formula overestimated left ventricular ejection fraction by 10% (p = 0.002) and estimation based on mitral ring motion—that is, long axis measurements—underestimated ejection fraction by 19% (p = 0.002), without significant correlation between ring motion and ejection fraction. There was no significant difference between mean values of ejection fraction calculated by Simpson's rule and measured by the reference method, but a considerable scatter about the regression line with a standard error of the estimate of 9.3 EF%.
CONCLUSIONS—In patients with left ventricular hypertrophy the ejection fraction, calculated by Teichholz's formula or Simpson's rule, is a poor measure of left ventricular function. When mitral ring motion is used for the assessment in these patients the function should be expressed in ways other than by the ejection fraction.


Keywords: left ventricular hypertrophy; ejection fraction; mitral ring motion; atrioventricular plane displacement PMID:10409535

  20. Space probe/satellite ejection apparatus for spacecraft

    NASA Technical Reports Server (NTRS)

    Smyly, H. M.; Miller, C. D.; Cloyd, R. A.; Heller, C. (Inventor)

    1985-01-01

    An ejection apparatus for spinning and propelling objects for ejection from a spacecraft at a desired velocity and rotational speed is discussed. The apparatus includes a launch cradle on which the space object to be ejected rests. The cradle is rotatably supported by a central hub secured to the upper end of the pneumatic cylinder piston shaft. Release mechanisms consisting of a retractable pin and locking lug is utilized to hold the cradle and object to be ejected. The release mechanism has a fixed barrier member which holds the retractable pin in engagement with the locking lug until release by upward movement of the launch cradle beyond the barrier height.

  1. Space probe/satellite ejection apparatus for spacecraft

    NASA Technical Reports Server (NTRS)

    Smyly, H. M.; Miller, C. D.; Cloyd, R. A.; Heller, C. (Inventor)

    1984-01-01

    An ejection apparatus for spinning and propelling objects for ejection from a spacecraft at a desired velocity and rotational speed is discussed. The apparatus includes a launch cradle on which the space object to be ejected rests. The cradle is rotatably supported by a central hub secured to the upper end of the pneumatic cylinder piston shaft. Release mechanisms consisting of a retractable pin and locking lug is utilized to hold the cradle and object to be ejected. The release mechanism has a fixed barrier member which holds the retractable pin in engagement with the locking lug until release by upward movement of the launch cradle beyond the barrier height.

  2. Geometrical Properties of Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Cremades, Hebe; Bothmer, Volker

    Based on the SOHO/LASCO dataset, a collection of "structured" coronal mass ejections (CMEs) has been compiled within the period 1996-2002, in order to analyze their three-dimensional configuration. These CME events exhibit white-light fine structures, likely indicative of their possible 3D topology. From a detailed investigation of the associated low coronal and photospheric source regions, a generic scheme has been deduced, which considers the white-light topology of a CME projected in the plane of the sky as being primarily dependent on the orientation and position of the source region's neutral line on the solar disk. The obtained results imply that structured CMEs are essentially organized along a symmetry axis, in a cylindrical manner. The measured dimensions of the cylinder's base and length yield a ratio of 1.6. These CMEs seem to be better approximated by elliptic cones, rather than by the classical ice cream cone, characterized by a circular cross section.

  3. Solar Eruptions: Coronal Mass Ejections and Flares

    NASA Technical Reports Server (NTRS)

    Gopalswamy, Nat

    2012-01-01

    This lecture introduces the topic of Coronal mass ejections (CMEs) and solar flares, collectively known as solar eruptions. During solar eruptions, the released energy flows out from the Sun in the form of magnetized plasma and electromagnetic radiation. The electromagnetic radiation suddenly increases the ionization content of the ionosphere, thus impacting communication and navigation systems. Flares can be eruptive or confined. Eruptive flares accompany CMEs, while confined flares hav only electromagnetic signature. CMEs can drive MHD shocks that accelerate charged particles to very high energies in the interplanetary space, which pose radiation hazard to astronauts and space systems. CMEs heading in the direction of Earth arrive in about two days and impact Earth's magnetosphere, producing geomagnetic storms. The magnetic storms result in a number of effects including induced currnts that can disrupt power grids, railroads, and underground pipelines

  4. Coronal Mass Ejections: From Sun to Earth

    NASA Astrophysics Data System (ADS)

    Patsourakos, S.

    2016-06-01

    Coronal Mass Ejections (CMEs) are gigantic expulsions of magnetized plasmas from the solar corona into the interplanetary (IP) space. CMEs spawn ~ 1015 gr of mass and reach speeds ranging between several hundred to a few thousand km/s (e.g., Gopalswamy et al. 2009; Vourlidas et al. 2010). It takes 1-5 days for a CME to reach Earth. CMEs are one of the most energetic eruptive manifestations in the solar system and are major drivers of space weather via their magnetic fields and energetic particles, which are accelerated by CME-driven shocks. In this review we give a short account of recent, mainly observational, results on CMEs from the STEREO and SDO missions which include the nature of their pre-eruptive and eruptive configurations and the CME propagation from Sun to Earth. We conclude with a discussion of the exciting capabilities in CME studies that will soon become available from new solar and heliospheric instrumentation.

  5. An ice-cream cone model for coronal mass ejections

    NASA Astrophysics Data System (ADS)

    Xue, X. H.; Wang, C. B.; Dou, X. K.

    2005-08-01

    In this study, we use an ice-cream cone model to analyze the geometrical and kinematical properties of the coronal mass ejections (CMEs). Assuming that in the early phase CMEs propagate with near-constant speed and angular width, some useful properties of CMEs, namely the radial speed (v), the angular width (α), and the location at the heliosphere, can be obtained considering the geometrical shapes of a CME as an ice-cream cone. This model is improved by (1) using an ice-cream cone to show the near real configuration of a CME, (2) determining the radial speed via fitting the projected speeds calculated from the height-time relation in different azimuthal angles, (3) not only applying to halo CMEs but also applying to nonhalo CMEs.

  6. Brachial Plexus Block for Cancer-Related Pain: A Case Series.

    PubMed

    Zinboonyahgoon, Nantthasorn; Vlassakov, Kamen; Abrecht, Christ R; Srinivasan, Suresh; Narang, Sanjeet

    2015-01-01

    Neoplastic brachial plexopathy (NBP) is caused by a cancerous infiltration into the brachial plexus, presenting often as severe pain in the affected upper extremity. Such pain can be resistant to medical treatment. Invasive interventions such as brachial plexus neurolysis with phenol or cordotomy may result in severe complications including permanent neurological damage and death. Continuous brachial plexus and paravertebral block with local anesthetic have been reported to successfully control pain from NBP, but these techniques are logistically challenging and frequently have catheter-related complications. We report a series of patients who received single-shot brachial plexus blocks with a mixture of local anesthetic and corticosteroid (bupivacaine 0.25% with methyl-prednisolone 20-120 mg) for the treatment of refractory cancer-related pain in the brachial plexus territory, mostly from NBP. Theoretically, such blocks could provide immediate analgesia from the local anesthetic and a longer-lasting analgesia from the slow-release steroids. Responders reported a sustained decrease in their pain (lasting from 2 weeks to 10 months), a significant decrease in their opioid and non-opioid (ketamine, gabapentin) consumption, overall satisfaction with the block, and unchanged or improved function of their limb. The ideal candidate for this procedure is a patient who has pain that is predominantly neuropathic from a lesion within the brachial plexus and with anatomy amenable to ultrasound-guided nerve block. Our case series suggests that, in the appropriately selected patient, this technique can safely and effectively alleviate pain from NBP. The procedure is simple, spares limb function, and can be diagnostic, predicting response to more complex procedures. To the best of our knowledge, this is the first report using this technique for NBP.

  7. Postfixed Brachial Plexus Radiculopathy Due to Thoracic Disc Herniation in a Collegiate Wrestler: A Case Report

    PubMed Central

    Kuzma, Scott A.; Doberstein, Scott T.; Rushlow, David R.

    2013-01-01

    Objective: To present the unique case of a collegiate wrestler with C7 neurologic symptoms due to T1–T2 disc herniation. Background: A 23-year-old male collegiate wrestler injured his neck in a wrestling tournament match and experienced pain, weakness, and numbness in his left upper extremity. He completed that match and 1 additional match that day with mild symptoms. Evaluation by a certified athletic trainer 6 days postinjury showed radiculopathy in the C7 distribution of his left upper extremity. He was evaluated further by the team physician, a primary care physician, and a neurosurgeon. Differential Diagnosis: Cervical spine injury, stinger/burner, peripheral nerve injury, spinal cord injury, thoracic outlet syndrome, brachial plexus radiculopathy. Treatment: The patient initially underwent nonoperative management with ice, heat, massage, electrical stimulation, shortwave diathermy, and nonsteroidal anti-inflammatory drugs without symptom resolution. Cervical spine radiographs were negative for bony pathologic conditions. Magnetic resonance imaging showed evidence of T1–T2 disc herniation. The patient underwent surgery to resolve the symptoms and enable him to participate for the remainder of the wrestling season. Uniqueness: Whereas brachial plexus radiculopathy commonly is seen in collision sports, a postfixed brachial plexus in which the T2 nerve root has substantial contribution to the innervation of the upper extremity is a rare anatomic variation with which many health care providers are unfamiliar. Conclusions: The injury sustained by the wrestler appeared to be C7 radiculopathy due to a brachial plexus traction injury. However, it ultimately was diagnosed as radiculopathy due to a T1–T2 thoracic intervertebral disc herniation causing impingement of a postfixed brachial plexus and required surgical intervention. Athletic trainers and physicians need to be aware of the anatomic variations of the brachial plexus when evaluating and caring for

  8. ISAAC: A REXUS Student Experiment to Demonstrate an Ejection System with Predefined Direction

    NASA Astrophysics Data System (ADS)

    Balmer, G.; Berquand, A.; Company-Vallet, E.; Granberg, V.; Grigore, V.; Ivchenko, N.; Kevorkov, R.; Lundkvist, E.; Olentsenko, G.; Pacheco-Labrador, J.; Tibert, G.; Yuan, Y.

    2015-09-01

    ISAAC Infrared Spectroscopy to Analyse the middle Atmosphere Composition — was a student experiment launched from SSC's Esrange Space Centre, Sweden, on 29th May 2014, on board the sounding rocket REXUS 15 in the frame of the REXUS/BEXUS programme. The main focus of the experiment was to implement an ejection system for two large Free Falling Units (FFUs) (240 mm x 80 mm) to be ejected from a spinning rocket into a predefined direction. The system design relied on a spring-based ejection system. Sun and angular rate sensors were used to control and time the ejection. The flight data includes telemetry from the Rocket Mounted Unit (RMU), received and saved during flight, as well as video footage from the GoPro camera mounted inside the RMU and recovered after the flight. The FFUs' direction, speed and spin frequency as well as the rocket spin frequency were determined by analyzing the video footage. The FFU-Rocket-Sun angles were 64.3° and 104.3°, within the required margins of 90°+45°. The FFU speeds were 3.98 mIs and 3.74 mIs, lower than the expected 5± 1 mIs. The FFUs' spin frequencies were 1 .38 Hz and 1 .60 Hz, approximately half the rocket's spin frequency. The rocket spin rate slightly changed from 3. 163 Hz before the ejection to 3.1 17 Hz after the ejection of the two FFUs. The angular rate, sun sensor data and temperature on the inside of the rocket module skin were also recorded. The experiment design and results of the data analysis are presented in this paper.

  9. Full-halo coronal mass ejections: Arrival at the Earth

    NASA Astrophysics Data System (ADS)

    Shen, Chenglong; Wang, Yuming; Pan, Zonghao; Miao, Bin; Ye, Pinzhong; Wang, S.

    2014-07-01

    A geomagnetic storm is mainly caused by a frontside coronal mass ejection (CME) hitting the Earth and then interacting with the magnetosphere. However, not all frontside CMEs can hit the Earth. Thus, which CMEs hit the Earth and when they do so are important issues in the study and forecasting of space weather. In our previous work, the deprojected parameters of the full-halo coronal mass ejections (FHCMEs) that occurred from 1 March 2007 to 31 May 2012 were estimated, and there are 39 frontside events that could be fitted by the Graduated Cylindrical Shell model. In this work, we continue to study whether and when these frontside FHCMEs (FFHCMEs) hit the Earth. It is found that 59% of these FFHCMEs hit the Earth, and for central events, whose deviation angles ɛ, which are the angles between the propagation direction and the Sun-Earth line, are smaller than 45°, the fraction increases to 75%. After checking the deprojected angular widths of the CMEs, we found that all of the Earth-encountered CMEs satisfy a simple criterion that the angular width (ω) is larger than twice the deviation angle (ɛ). This result suggests that some simple criteria can be used to forecast whether a CME could hit the Earth. Furthermore, for Earth-encountered CMEs, the transit time is found to be roughly anticorrelated with the deprojected velocity, but some events significantly deviate from the linearity. For CMEs with similar velocities, the differences of their transit times can be up to several days. Such deviation is further demonstrated to be mainly caused by the CME geometry and propagation direction, which are essential in the forecasting of CME arrival.

  10. Perineural versus intravenous dexamethasone as adjuncts to local anaesthetic brachial plexus block for shoulder surgery.

    PubMed

    Rosenfeld, D M; Ivancic, M G; Hattrup, S J; Renfree, K J; Watkins, A R; Hentz, J G; Gorlin, A W; Spiro, J A; Trentman, T L

    2016-04-01

    This randomised, double-blind, placebo-controlled study compared the effect of perineural with intravenous dexamethasone, both administered concomitantly with interscalene brachial plexus block for shoulder surgery. Patients received 8 mg dexamethasone mixed with ropivacaine in the block injection (n = 42), 8 mg dexamethasone intravenously at the time of the block (n = 37), or intravenous saline (n = 41) at the time of the block. Perineural and intravenous dexamethasone resulted in prolonged mean (SD) duration of block to 16.9 (5.2) h and 18.2 (6.4) h, respectively, compared with 13.8 (3.8) h for saline (p = 0.001). Mean (SD) opioid consumption (morphine equivalents) during the first 24 h after postanaesthesia recovery arrival was 12.2 (9.3) mg in the perineural dexamethasone, 17.1 (15.9) mg in the intravenous dexamethasone and 24.1 (14.3) mg in the saline groups (p = 0.001). Dexamethasone via either route reduced anti-emetic use (p = 0.046). There was no effect on patient satisfaction. These results suggest that both perineural and intravenous dexamethasone are useful adjuncts to ropivacaine interscalene block, with the intravenous route preferred as this avoids the possibility of neural toxicity of dexamethasone. PMID:26899862

  11. Clinical aspects of patients with traumatic lesions of the brachial plexus following surgical treatment☆

    PubMed Central

    de Moraes, Frederico Barra; Kwae, Mário Yoshihide; da Silva, Ricardo Pereira; Porto, Celmo Celeno; Magalhães, Daniel de Paiva; Paulino, Matheus Veloso

    2015-01-01

    Objective To evaluate sociodemographic and clinical aspects of patients undergoing operations due to traumatic lesions of the brachial plexus. Method This was a retrospective study in which the medical files of a convenience sample of 48 patients operated between 2000 and 2010 were reviewed. The following were evaluated: (1) range of motion (ROM) of the shoulder, elbow and wrist/hand, in degrees; (2) grade of strength of the shoulder, elbow and wrist/hand; (3) sensitivity; and (4) visual analogue scale (VAS) (from 0 to 10). The Student's t, chi-square, Friedman, Wilcoxon and Kruskal–Wallis tests were used (p < 0.05). Results The patients’ mean age was 30.6 years; 60.4% of them had suffered motorcycle accidents and 52.1%, multiple trauma. The mean length of time until surgery was 8.7 months (range: 2–48). Thirty-one patients (64.6%) presented complete rupture of the plexus. The frequent operation was neurosurgery in 39 cases (81.3%). The ROM achieved was ≥30° in 20 patients (41.6%), with a range from 30° to 90° and mean of 73° (p = 0.001). Thirteen (27.1%) already had shoulder strength ≥M3 (p = 0.001). Twenty-seven patients (56.2%) had elbow flexion ≥80°, with a range from 30° to 160° and mean of 80.6° (p < 0.001). Twenty-two had strength ≥M3 (p < 0.001). Twenty-two patients (45.8%) had wrist extension ≥30° starting from flexion of 45°, with a range from 30° to 90° and mean of 70° (p = 0.003). Twenty-seven (56.3%) presented wrist/hand extension strength ≥M3 (p = 0.002). Forty-five (93.8%) had hypoesthesia and three (6.2%) had anesthesia (p = 0.006). The initial VAS was 4.5 (range: 1.0–9.0) and the final VAS was 3.0 (range: 1.0–7.0) (p < 0.001). Conclusion Traumatic lesions of the brachial plexus were more prevalent among young adults (21–40 years), men, people living in urban areas, manual workers and motorcycle accidents, with multiple trauma and total rupture of the plexus. Neurosurgery, with a second

  12. On Modeling of Ejection Process in a Training Combat Aircraft

    NASA Astrophysics Data System (ADS)

    Głowiński, Sebastian; Krzyżyński, Tomasz

    2011-09-01

    The paper deals with modeling and simulation of motion trajectory of an ejection seat in the training-combat aircraft TS-11 "Iskra". The ejection seat and its operation are characterized. Mathematical and computer models are elaborated with the help of MATLAB-Simulink applications. Additionally, simulations are conducted for various velocities of the aircraft.

  13. Fighter Pilot Ejection Study as an Educational Tool

    ERIC Educational Resources Information Center

    Robinson, Garry; Jovanoski, Zlatko

    2010-01-01

    In this article, we apply the well-known equations of projectile motion to the case of a fighter pilot ejecting from an aircraft, the aim being to establish under what conditions there is danger of impact with the rear vertical stabilizer. The drag force on the pilot after ejection is assumed to vary as the velocity squared and the aircraft motion…

  14. Clinical usefulness of ankle brachial index and brachial-ankle pulse wave velocity in patients with ischemic stroke

    PubMed Central

    Lee, Hyung-Suk; Lee, Hye Lim; Han, Ho-seong; Yeo, Minju; Kim, Ji Seon; Lee, Sung-Hyun; Lee, Sang-Soo; Shin, Dong-Ick

    2016-01-01

    Abstract Ankle brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) are widely used noninvasive modalities to evaluate atherosclerosis. Recently, evidence has increased supporting the use of ABI and baPWV as markers of cerebrovascular disease. This study sought to examine the relationship between ABI and baPWV with ischemic stroke. This study also aimed to determine which pathogenic mechanism, large artery disease (LAD) or small vessel disease (SVD), is related to ABI or baPWV. Retrospectively, 121 patients with ischemic stroke and 38 subjects with no obvious ischemic stroke history were recruited. First, ABI and baPWV were compared between the groups. Then, within the stroke group, the relevance of ABI and baPWV with regard to SVD and LAD, which were classified by brain magnetic resonance image (MRI) and magnetic resonance angiography (MRA) or computed tomography angiography (CTA) findings, was assessed. The baPWV was higher in the stroke group than non-stroke group (1,944.18±416.6 cm/s vs. 1,749.76±669.6 cm/s, P<0.01). Regarding LAD, we found that mean ABI value was lower in the group with extracranial large artery stenosis (P<0.01), and there was an inverse linear correlation between ABI and the grade of extracranial large artery stenosis (P<0.01). For SVD, there was a significant correlation between SVD and baPWV (2,057.6±456.57 cm/s in the SVD (+) group vs. 1,491±271.62 cm/s in the SVD (-) group; P<0.01). However, the grade of abnormalities detected in SVD did not correlate linearly with baPWV. These findings show that baPWV is a reliable surrogate marker of ischemic stroke. Furthermore, baPWV and ABI can be used to indicate the presence of small vessel disease and large arterial disease, respectively. PMID:27533937

  15. Spinal injuries caused by the acceleration of ejection.

    PubMed

    Lewis, M E

    2002-03-01

    The speed and altitude at which modern military aircraft operate are such that escape can only be achieved by some means of forcibly propelling the aircrew clear of the aircraft. The most common method of doing this is by use of an ejection seat. The use of such seats, whilst generally life saving, exposes aircrew to forces that may be at the limits of human tolerance. Each phase of the ejection sequence is associated with characteristic injury patterns and of particular concern is the occurrence of spinal compression fractures, which are caused by the upward acceleration of the ejection seat. Thorough investigation of aircrew who eject is necessary and magnetic resonance imaging of the spines of these aircrew is now becoming mandatory. Aircrew who sustain stable anterior wedge compression fractures usually require no invasive treatment, but are prevented from flying aircraft fitted with ejection seats for 3-4 months. PMID:12024887

  16. A case of relapsing-remitting facial palsy and ipsilateral brachial plexopathy caused by HSV-1.

    PubMed

    Alstadhaug, Karl B; Kvarenes, Hanne W; Prytz, Jan; Vedeler, Christian

    2016-05-01

    The etiologies of Bell's palsy and brachial neuritis remain uncertain, and the conditions rarely co-occur or reoccur. Here we present a woman in her twenties who had several relapsing-remitting episodes with left-sided facial palsy and brachial neuropathy. The episodes always started with painful left-sided oral blisters. Repeat PCRs HSV-1 DNA from oral vesicular lesions were positive. Extensive screening did not reveal any other underlying cause. Findings on MRI T2-weighted brachial plexus STIR images, using a 3.0-Tesla scanner during an episode, were compatible with brachial plexus neuritis. Except a mannose-binding lectin deficiency, a congenital complement deficiency that is frequently found in the general Caucasian population, no other immunodeficiency was demonstrated in our patient. In vitro resistance to acyclovir was tested negative, but despite prophylactic treatment with the drug in high doses, relapses recurred. To our knowledge, this is the first ever reported documentation of relapsing-remitting facial and brachial plexus neuritis caused by HSV-1. PMID:26991053

  17. Above Elbow Amputation Under Brachial Plexus Block at Supraclavicular and Interscalene Levels

    PubMed Central

    Ahmad, Hassan; Yadagiri, Manjula; Macrosson, Duncan; Majeed, Amer

    2015-01-01

    Introduction: The brachial plexus block is a commonly performed procedure in the anesthetic practice today. It is performed for analgesia as well as anesthesia for upper limb procedures. It has been used for amputation and replantation surgeries of the upper limb. Case presentation: We present the case of a 68-year-old gentleman who had brachial plexus block at supraclavicular and interscalene levels as the sole anesthetic for undergoing above elbow amputation. He was deemed to be very high risk for a general anesthetic as he suffered from severe chronic obstructive pulmonary disease (COPD) and a very poor exercise tolerance (NYHA Class III). The supraclavicular brachial plexus block was supplemented with an interscalene brachial plexus block due to inadequate surgical anesthesia encountered with the former. The procedure was successfully completed under regional anesthesia. Conclusions: The brachial plexus block can be performed at different levels in the same patient to achieve desired results, while employing sound anatomical knowledge and adhering to the maximum safe dose limit of the local anesthetic. PMID:26705518

  18. Coronal mass ejections and the evolution of the large-scale corona

    NASA Technical Reports Server (NTRS)

    Linker, J. A.; Mikic, Z.

    1995-01-01

    Coronal mass ejections (CMEs) are dynamic, large-scale events in the solar corona that expel plasma and magnetic fields into the solar wind. The structure of the large-scale corona influences CME occurrence; for example, CMEs are most frequently observed to be disruptions of coronal or helmet streamer configurations on the Sun. We have investigated the evolution of the large-scale corona in the presence of differential rotation, using time-dependent magnetohydrodynamic (MHD) simulations in two and three dimensions. An equilibrium coronal configuration is first computed by superimposing a Parker solar wind flow on an initial potential field, the equations are integrated in time until a steady-state is reached. When differential rotation is introduced, we find that the configuration does not reach a steady state; the closed field regions (helmet streamers) disrupt recurrently, ejecting plasmoids into the solar wind. Our results suggest that differential rotation may be one of the mechanisms by which mass ejections are initiated. We will describe the evolution of the polarization brightness (pB) for the resulting configurations, as well as the propagation of the ejected plasmoids in the solar wind, and we will compare the effects of differential rotation with other possible initiation mechanisms, such as the emergence of new magnetic flux.

  19. Dynamical mass ejection from binary neutron star mergers

    NASA Astrophysics Data System (ADS)

    Radice, David; Galeazzi, Filippo; Lippuner, Jonas; Roberts, Luke F.; Ott, Christian D.; Rezzolla, Luciano

    2016-08-01

    We present fully general-relativistic simulations of binary neutron star mergers with a temperature and composition dependent nuclear equation of state. We study the dynamical mass ejection from both quasi-circular and dynamical-capture eccentric mergers. We systematically vary the level of our treatment of the microphysics to isolate the effects of neutrino cooling and heating and we compute the nucleosynthetic yields of the ejecta. We find that eccentric binaries can eject significantly more material than quasi-circular binaries and generate bright infrared and radio emission. In all our simulations the outflow is composed of a combination of tidally- and shock-driven ejecta, mostly distributed over a broad ˜60° angle from the orbital plane, and, to a lesser extent, by thermally driven winds at high latitudes. Ejecta from eccentric mergers are typically more neutron rich than those of quasi-circular mergers. We find neutrino cooling and heating to affect, quantitatively and qualitatively, composition, morphology, and total mass of the outflows. This is also reflected in the infrared and radio signatures of the binary. The final nucleosynthetic yields of the ejecta are robust and insensitive to input physics or merger type in the regions of the second and third r-process peaks. The yields for elements on the first peak vary between our simulations, but none of our models is able to explain the Solar abundances of first-peak elements without invoking additional first-peak contributions from either neutrino and viscously-driven winds operating on longer time-scales after the mergers, or from core-collapse supernovae.

  20. CONSEQUENCES OF THE EJECTION AND DISRUPTION OF GIANT PLANETS

    SciTech Connect

    Guillochon, James; Ramirez-Ruiz, Enrico; Lin, Douglas

    2011-05-10

    The discovery of Jupiter-mass planets in close orbits about their parent stars has challenged models of planet formation. Recent observations have shown that a number of these planets have highly inclined, sometimes retrograde orbits about their parent stars, prompting much speculation as to their origin. It is known that migration alone cannot account for the observed population of these misaligned hot Jupiters, which suggests that dynamical processes after the gas disk dissipates play a substantial role in yielding the observed inclination and eccentricity distributions. One particularly promising candidate is planet-planet scattering, which is not very well understood in the nonlinear regime of tides. Through three-dimensional hydrodynamical simulations of multi-orbit encounters, we show that planets that are scattered into an orbit about their parent stars with closest approach distance being less than approximately three times the tidal radius are either destroyed or completely ejected from the system. We find that as few as 9 and as many as 12 of the currently known hot Jupiters have a maximum initial apastron for scattering that lies well within the ice line, implying that these planets must have migrated either before or after the scattering event that brought them to their current positions. If stellar tides are unimportant (Q{sub *} {approx}> 10{sup 7}), disk migration is required to explain the existence of the hot Jupiters present in these systems. Additionally, we find that the disruption and/or ejection of Jupiter-mass planets deposits a Sun's worth of angular momentum onto the host star. For systems in which planet-planet scattering is common, we predict that planetary hosts have up to a 35% chance of possessing an obliquity relative to the invariable plane of greater than 90{sup 0}.

  1. Status of the Solar Mass Ejection Imager

    NASA Astrophysics Data System (ADS)

    Johnston, J. C.; Radick, R. R.; Webb, D. F.

    2001-05-01

    The Solar Mass Ejection Imager (SMEI) is a proof-of-concept experiment designed to detect and track coronal mass ejections (CMEs) as they propagate from the Sun through interplanetary space to the Earth and beyond. SMEI will Image CMEs by sensing sunlight scattered from the free electrons in these structures (Thomson scattering). SMEI will be launched by a Titan II rocket into a circular, sun-synchronous (830 km) orbit in 2002 as part of the Space Test Program's CORIOLIS mission. SMEI will image the entire sky once per spacecraft orbit over a mission lifetime of three years. The major subsystems of SMEI are three electronic camera assemblies and a data-handling unit. Each camera consists of a baffle, a radiator, a bright object sensor, an electronics box, and a strongbox containing a shutter, optics and a CCD. Each camera images a 3x60 degree field. Together, they view a 180-degree slice of sky, and sweep over the entire sky once per orbit. SMEI's basic data product will be a 100-minute cadence of all-sky maps of heliospheric brightness, with stars removed, having an angular resolution of about one degree and a photometric precision of about 0.1%. Successful operation of SMEI will represent a major step in improving space weather forecasts. When combined with in-situ solar wind measurements from upstream monitors such as WIND and ACE, SMEI will provide one- to three-day predictions of impending geomagnetic storms at the Earth. SMEI will complement missions such as SoHO, GOES SXI, Solar-B, and STEREO by providing data relating solar drivers to terrestrial effects. Other benefits of SMEI will include observations of variable stars, extra-Solar planetary transits, novae and supernovae, comets and asteroids. The SMEI experiment is being designed and constructed by a team of scientists and engineers from the Air Force Research Laboratory, the University of Birmingham (UB) in the United Kingdom, the University of California at San Diego (UCSD), and Boston University. The

  2. Prevalence of an abnormal ankle-brachial index in patients with primary antiphospholipid syndrome: preliminary data

    PubMed Central

    Baron, M; Khamashta, M; Hughes, G; D'Cruz, D

    2005-01-01

    Methods: An 8 MHz Doppler probe was used in the arms and legs to assess the ABI in 43 patients with primary APS (mean (SD) age 40.2 (7.9) years) and 49 healthy subjects (aged 41.0 (11.7)) matched for age and sex. Data on traditional cardiovascular risk factors, such as hypertension, hypercholesterolaemia, presence of diabetes mellitus, nephrotic syndrome or renal failure, smoking, and other variables, were collected at that time for all subjects. A ratio of the highest blood pressure from the posterior tibial or pedal arteries of each leg to the highest blood pressure from the brachial arteries <1.00 was considered abnormal. Results: Abnormal ABIs were found in 8/43 (19%) patients with primary APS and 2/49 (4%) controls (p = 0.026). No correlation between abnormal ABI and traditional cardiovascular risk factors nor with the presence of aPL was found. Conclusion: Abnormal ABIs are more common in primary APS than in healthy controls, possibly indicating a subclinical atherosclerotic process in these patients. PMID:15608314

  3. Hand Function in Children with an Upper Brachial Plexus Birth Injury: Results of the Nine-Hole Peg Test

    ERIC Educational Resources Information Center

    Immerman, Igor; Alfonso, Daniel T.; Ramos, Lorna E.; Grossman, Leslie A.; Alfonso, Israel; Ditaranto, Patricia; Grossman, John A. I.

    2012-01-01

    Aim: The aim of this study was to evaluate hand function in children with Erb upper brachial plexus palsy. Method: Hand function was evaluated in 25 children (eight males; 17 females) with a diagnosed upper (C5/C6) brachial plexus birth injury. Of these children, 22 had undergone primary nerve reconstruction and 13 of the 25 had undergone…

  4. Constraint-Induced Movement Therapy for Children with Obstetric Brachial Plexus Palsy: Two Single-Case Series

    ERIC Educational Resources Information Center

    Buesch, Francisca Eugster

    2010-01-01

    The objective of this pilot study was to investigate the feasibility of constraint-induced movement therapy (CIMT) in children with obstetric brachial plexus palsy and receive preliminary information about functional improvements. Two patients (age 12 years) with obstetric brachial plexus palsy were included for a 126-h home-based CIMT…

  5. Characteristic features of hereditary neuropathy with liability to pressure palsy (HNPP) presenting with brachial plexopathy in soldiers.

    PubMed

    Kim, Kyoung-Eun

    2014-11-15

    A brachial plexus lesion is not common in hereditary neuropathy with liability to pressure palsy (HNPP). We report the clinical and electrodiagnostic features of young soldiers with HNPP presenting with brachial plexopathy. By reviewing 2year medical records from Korean military hospitals, we identified soldiers with brachial plexus lesions. Among them, patients diagnosed with HNPP were determined and clinical and electrophysiological findings were compared between HNPP and non-HNPP patients with a brachial plexus lesion. Thirteen patients (6.8%) were diagnosed with HNPP among 189 patients with a brachial plexus lesion. Push-ups, as either a punishment or an exercise, was the most frequent preceding event in HNPP patients (76.9%), whereas it was rare in non-HNPP patients. The distal motor latency of the median nerve showed the highest sensitivity (90.9%) and specificity (100%) for HNPP in patients with a brachial plexus lesion. In conclusion, HNPP should be suspected in patients with brachial plexopathy if brachial plexopathy develops after push-ups or if the distal motor latency of median nerves is prolonged.

  6. Characteristic features of hereditary neuropathy with liability to pressure palsy (HNPP) presenting with brachial plexopathy in soldiers.

    PubMed

    Kim, Kyoung-Eun

    2014-11-15

    A brachial plexus lesion is not common in hereditary neuropathy with liability to pressure palsy (HNPP). We report the clinical and electrodiagnostic features of young soldiers with HNPP presenting with brachial plexopathy. By reviewing 2year medical records from Korean military hospitals, we identified soldiers with brachial plexus lesions. Among them, patients diagnosed with HNPP were determined and clinical and electrophysiological findings were compared between HNPP and non-HNPP patients with a brachial plexus lesion. Thirteen patients (6.8%) were diagnosed with HNPP among 189 patients with a brachial plexus lesion. Push-ups, as either a punishment or an exercise, was the most frequent preceding event in HNPP patients (76.9%), whereas it was rare in non-HNPP patients. The distal motor latency of the median nerve showed the highest sensitivity (90.9%) and specificity (100%) for HNPP in patients with a brachial plexus lesion. In conclusion, HNPP should be suspected in patients with brachial plexopathy if brachial plexopathy develops after push-ups or if the distal motor latency of median nerves is prolonged. PMID:25175852

  7. Radio-quiet Fast Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Gopalswamy, N.; Aguilar-Rodriguez, E.; Kaiser, M. L.; Howard, R. A.

    2004-12-01

    Coronal mass ejections (CMEs) drive shocks in the interplanetary medium that produce type II radio emission. These CMEs are faster and wider on the average, than the general population of CMEs. However, when we start from fast (speed > 900 km/s) and wide (angular width > 60 degrees), more than half of them are not associated with radio bursts. In order to understand why these CMEs are radio quiet, we collected all the fast and wide (FW) CMEs detected by the Solar and Heliospheric Observatory (SOHO) mission's Large Angle and Spectrometric Coronagraph (LASCO) and isolated those without associated type II radio bursts. The radio bursts were identified in the dynamic spectra of the Radio and Plasma Wave (WAVES) Experiment on board the Wind spacecraft. We also checked the list against metric type II radio bursts reported in Solar Geophysical Data and isolated those without any radio emission. This exercise resulted in about 140 radio-quiet FW CMEs. We identified the source regions of these CMEs using the Solar Geophysical Data listings, cross-checked against the eruption regions in the SOHO/EIT movies. We explored a number of possibilities for the radio-quietness: (i) Source region being too far behind the limb, (ii) flare size, (iii) brightness of the CME, and (iv) the density of the ambient medium. We suggest that a combination of CME energy and the Alfven speed profile of the ambient medium is primarily responsible for the radio-quietness of these FW CMEs.

  8. Why are halo coronal mass ejections faster?

    NASA Astrophysics Data System (ADS)

    Zhang, Qing-Min; Guo, Yang; Chen, Peng-Fei; Ding, Ming-De; Fang, Cheng

    2010-05-01

    Halo coronal mass ejections (CMEs) have been to be significantly faster than normal CMEs, which is a long-standing puzzle. In order to solve the puzzle, we first investigate the observed properties of 31 limb CMEs that clearly display loop-shaped frontal loops. The observational results show a strong tendency that slower CMEs are weaker in white-light intensity. Then, we perform a Monte Carlo simulation of 20000 artificial limb CMEs that have an average velocity of ~523 km s-1. The Thomson scattering of these events is calculated when they are assumed to be observed as limb and halo events, respectively. It is found that the white-light intensity of many slow CMEs becomes remarkably reduced when they turn from being viewed as a limb event to being viewed as a halo event. When the intensity is below the background solar wind fluctuation, it is assumed that they would be missed by coronagraphs. The average velocity of “detectable" halo CMEs is ~922 km s-1 very close to the observed value. This also indicates that wider events are more likely to be recorded. The results soundly suggest that the higher average velocity of halo CMEs is due to that a majority of slow events and some of narrow fast events carrying less material are so faint that they are blended with the solar wind fluctuations, and therefore are not observed.

  9. Planet scattering around binaries: ejections, not collisions

    NASA Astrophysics Data System (ADS)

    Smullen, Rachel A.; Kratter, Kaitlin M.; Shannon, Andrew

    2016-09-01

    Transiting circumbinary planets discovered by Kepler provide unique insight into binary star and planet formation. Several features of this new found population, for example the apparent pile-up of planets near the innermost stable orbit, may distinguish between formation theories. In this work, we determine how planet-planet scattering shapes planetary systems around binaries as compared to single stars. In particular, we look for signatures that arise due to differences in dynamical evolution in binary systems. We carry out a parameter study of N-body scattering simulations for four distinct planet populations around both binary and single stars. While binarity has little influence on the final system multiplicity or orbital distribution, the presence of a binary dramatically affects the means by which planets are lost from the system. Most circumbinary planets are lost due to ejections rather than planet-planet or planet-star collisions. The most massive planet in the system tends to control the evolution. Systems similar to the only observed multiplanet circumbinary system, Kepler-47, can arise from much more tightly packed, unstable systems. Only extreme initial conditions introduce differences in the final planet populations. Thus, we suggest that any intrinsic differences in the populations are imprinted by formation.

  10. STREAMER WAVES DRIVEN BY CORONAL MASS EJECTIONS

    SciTech Connect

    Chen, Y.; Song, H. Q.; Li, B.; Xia, L. D.; Wu, Z.; Fu, H.; Li Xing

    2010-05-01

    Between 2004 July 5 and July 7, two intriguing fast coronal mass ejection (CME)-streamer interaction events were recorded by the Large Angle and Spectrometric Coronagraph. At the beginning of the events, the streamer was pushed aside from its equilibrium position upon the impact of the rapidly outgoing and expanding ejecta; then, the streamer structure, mainly the bright streamer belt, exhibited elegant large-scale sinusoidal wavelike motions. The motions were apparently driven by the restoring magnetic forces resulting from the CME impingement, suggestive of magnetohydrodynamic kink mode propagating outward along the plasma sheet of the streamer. The mode is supported collectively by the streamer-plasma sheet structure and is therefore named 'streamer wave' in the present study. With the white light coronagraph data, we show that the streamer wave has a period of about 1 hr, a wavelength varying from 2 to 4 solar radii, an amplitude of about a few tens of solar radii, and a propagating phase speed in the range 300-500 km s{sup -1}. We also find that there is a tendency for the phase speed to decline with increasing heliocentric distance. These observations provide good examples of large-scale wave phenomena carried by coronal structures and have significance in developing seismological techniques for diagnosing plasma and magnetic parameters in the outer corona.

  11. Reversal of phantom pain and hand-to-face remapping after brachial plexus avulsion.

    PubMed

    Tsao, Jack W; Finn, Sacha B; Miller, Matthew E

    2016-06-01

    Following left brachial plexus avulsion, a 20-year-old man had phantom limb pain and remapping of sensation from his paralyzed hand onto his face. Mirror therapy (15 min daily, 5 days/week) led immediately to good movement of the phantom limb with decreased pain. Within 2 weeks following nerve graft surgery, remapping of hand sensation onto the face disappeared along with resolution of phantom limb pain. Mirror therapy coupled with nerve grafting may relieve phantom limb pain due to brachial plexus avulsion and reverse hand-to-face remapping, suggesting that both peripheral and central mechanisms mediate development of phantom limb pain and cortical reorganization/neuroplasticity after brachial plexus avulsion. PMID:27547774

  12. A new rat model of neuropathic pain: complete brachial plexus avulsion.

    PubMed

    Wang, Le; Yuzhou, Liu; Yingjie, Zhou; Jie, Lao; Xin, Zhao

    2015-03-01

    Brachial plexus avulsion (BPA) is one of the major injuries in motor vehicle accidents and may result in neuropathic pain. Accumulating evidence suggests that 30-80% of BPA developed neuropathic pain in human. In our study, complete brachial plexus avulsion (C5-T1) rats model leads to the results that 37.5% of rats had long-lasting (up to 6 months) mechanical allodynia and cold allodynia. We observed the activation of astrocyte and microglial in cervical spinal cord after BPA. Complete brachial plexus avulsion mimics human nerve root traction injury following traffic accidents. The complete BPA rat model approach human injuries and can be used for further investigations. PMID:25596440

  13. Does C5 or C6 Radiculopathy Affect the Signal Intensity of the Brachial Plexus on Magnetic Resonance Neurography?

    PubMed

    Seo, Tae Gyu; Kim, Du Hwan; Kim, In-Soo; Son, Eun Seok

    2016-04-01

    Patients with C5 or C6 radiculopathy complain of shoulder area pain or shoulder girdle weakness. Typical idiopathic neuralgic amyotrophy (INA) is also characterized by severe shoulder pain, followed by paresis of shoulder girdle muscles. Recent studies have demonstrated that magnetic resonance neurography (MRN) of the brachial plexus and magnetic resonance imaging (MRI) of the shoulder in patients with INA show high signal intensity (HSI) or thickening of the brachial plexus and changes in intramuscular denervation of the shoulder girdle. We evaluated the value of brachial plexus MRN and shoulder MRI in four patients with typical C5 or C6 radiculopathy. HSI of the brachial plexus was noted in all patients and intramuscular changes were observed in two patients who had symptoms over 4 weeks. Our results suggest that HSI or thickening of the brachial plexus and changes in intramuscular denervation of the shoulder girdle on MRN and MRI may not be specific for INA. PMID:27152289

  14. Does C5 or C6 Radiculopathy Affect the Signal Intensity of the Brachial Plexus on Magnetic Resonance Neurography?

    PubMed Central

    Seo, Tae Gyu; Kim, In-Soo; Son, Eun Seok

    2016-01-01

    Patients with C5 or C6 radiculopathy complain of shoulder area pain or shoulder girdle weakness. Typical idiopathic neuralgic amyotrophy (INA) is also characterized by severe shoulder pain, followed by paresis of shoulder girdle muscles. Recent studies have demonstrated that magnetic resonance neurography (MRN) of the brachial plexus and magnetic resonance imaging (MRI) of the shoulder in patients with INA show high signal intensity (HSI) or thickening of the brachial plexus and changes in intramuscular denervation of the shoulder girdle. We evaluated the value of brachial plexus MRN and shoulder MRI in four patients with typical C5 or C6 radiculopathy. HSI of the brachial plexus was noted in all patients and intramuscular changes were observed in two patients who had symptoms over 4 weeks. Our results suggest that HSI or thickening of the brachial plexus and changes in intramuscular denervation of the shoulder girdle on MRN and MRI may not be specific for INA. PMID:27152289

  15. Relationship between brachial artery blood flow and total [hemoglobin+myoglobin] during post-occlusive reactive hyperemia.

    PubMed

    Bopp, Christopher M; Townsend, Dana K; Warren, Steve; Barstow, Thomas J

    2014-01-01

    The associations between macrovascular and microvascular responses reported previously during post-occlusive reactive hyperemia have been inconsistent. The purpose of this study was therefore to determine the temporal relationship between the reactive hyperemic responses within a conduit artery and the downstream microvessels. Conduit artery blood flow was measured in the brachial artery with pulsed Doppler ultrasound. A potential analog of microvascular flow, changes in skeletal muscle total[hemoglobin+myoglobin] (T[Hb+Mb]), was assessed with near-infrared spectroscopy (NIRS). We found a high degree of correlation between these two measures (r=0.91). Cross-correlation analysis revealed two distinct response patterns. In 10 of our 15 subjects there was time displacement between peak brachial artery blood flow (BABF) and T[Hb+Mb] responses; in the remaining 5 the peaks were coincident. Granger causality testing suggested that reactive hyperemia in the macrovessel determined hyperemia in the downstream microvessels in all 15 study subjects. Time constants for the on (τ1) and off (τ2) kinetics of each response were calculated; our initial hypothesis was that τ1 and τ2 for T[Hb+Mb] would correlate with τ1 and τ2 for BABF, respectively. However, only for τ2 was this observed (r=0.52; p<0.05). No similar relationship was observed for τ1. Adipose tissue thickness did not influence either time constant for T[Hb+Mb]. Taken together, our results show that the temporal characteristics of the hyperemic response in the conduit artery are qualitatively reflected in the downstream microvasculature, but mechanisms for quantitative differences remain to be identified.

  16. Effect of adding tetracaine to bupivacaine on duration of analgesia in supraclavicular brachial plexus nerve blocks for ambulatory shoulder surgery

    PubMed Central

    Pearson, Linda T.; Lowry, Benjamin P.; Culp, William C.; Kitchings, Olen E.; Meyer, Tricia A.; McAllister, Russell K.; Roberson, Charles R.

    2015-01-01

    The objective of this study was to determine if the addition of 1% tetracaine to 0.25% bupivacaine prolonged the duration of postoperative analgesia of supraclavicular brachial plexus nerve blockade for patients undergoing ambulatory shoulder surgery. We conducted a prospective, double-blinded, randomized controlled clinical study at an ambulatory surgery center utilizing ultrasound- and nerve stimulation-guided supraclavicular nerve blockade for postoperative analgesia. The control group received 30 mL of 0.25% bupivacaine plus 4 mL preservative-free saline. The study group received 30 mL of 0.25% bupivacaine plus 4 mL of 1% tetracaine. Patients documented their visual analog scale scores and intake of pain medications for 3 days. Primary outcomes included time of first postoperative pain, time of first postoperative pain pill, and time of return of motor and sensory function. Secondary outcomes included pain score and pain medication intake trends and adverse events secondary to the nerve block. A total of 84 patients completed the study, 42 patients in each group. The study group was statistically significantly older than the control group (mean age, 54 vs 48 years; P = 0.04). The mean duration of analgesia was 16.6 ± 8.3 h for the control group and 17.1 ± 7.3 h for the study group (P = 0.69). No outcomes were statistically different. In conclusion, there was no significant difference in duration of postoperative analgesia with the addition of 1% tetracaine to 0.25% bupivacaine in supraclavicular brachial plexus nerve blockade. No differences were identified in postoperative pain medications, pain scores, or complications. PMID:26130874

  17. Ejection of solvated ions from electrosprayed methanol/water nanodroplets studied by molecular dynamics simulations.

    PubMed

    Ahadi, Elias; Konermann, Lars

    2011-06-22

    The ejection of solvated small ions from nanometer-sized droplets plays a central role during electrospray ionization (ESI). Molecular dynamics (MD) simulations can provide insights into the nanodroplet behavior. Earlier MD studies have largely focused on aqueous systems, whereas most practical ESI applications involve the use of organic cosolvents. We conduct simulations on mixed water/methanol droplets that carry excess NH(4)(+) ions. Methanol is found to compromise the H-bonding network, resulting in greatly increased rates of ion ejection and solvent evaporation. Considerable differences in the water and methanol escape rates cause time-dependent changes in droplet composition. Segregation occurs at low methanol concentration, such that layered droplets with a methanol-enriched periphery are formed. This phenomenon will enhance the partitioning of analyte molecules, with possible implications for their ESI efficiencies. Solvated ions are ejected from the tip of surface protrusions. Solvent bridging prior to ion secession is more extensive for methanol/water droplets than for purely aqueous systems. The ejection of solvated NH(4)(+) is visualized as diffusion-mediated escape from a metastable basin. The process involves thermally activated crossing of a ~30 kJ mol(-1) free energy barrier, in close agreement with the predictions of the classical ion evaporation model. PMID:21591733

  18. A cadaveric microanatomical study of the fascicular topography of the brachial plexus.

    PubMed

    Sinha, Sumit; Prasad, G Lakshmi; Lalwani, Sanjeev

    2016-08-01

    OBJECT Mapping of the fascicular anatomy of the brachial plexus could provide the nerve surgeon with knowledge of fascicular orientation in spinal nerves of the brachial plexus. This knowledge might improve the surgical outcome of nerve grafting in brachial plexus injuries by anastomosing related fascicles and avoiding possible axonal misrouting. The objective of this study was to map the fascicular topography in the spinal nerves of the brachial plexus. METHODS The entire right-sided brachial plexus of 25 adult male cadavers was dissected, including all 5 spinal nerves (C5-T1), from approximately 5 mm distal to their exit from the intervertebral foramina, to proximal 1 cm of distal branches. All spinal nerves were tagged on the cranial aspect of their circumference using 10-0 nylon suture for orientation. The fascicular dissection of the C5-T1 spinal nerves was performed under microscopic magnification. The area occupied by different nerve fascicles was then expressed as a percentage of the total cross-sectional area of a spinal nerve. RESULTS The localization of fascicular groups was fairly consistent in all spinal nerves. Overall, 4% of the plexus supplies the suprascapular nerve, 31% supplies the medial cord (comprising the ulnar nerve and medial root of the median nerve [MN]), 27.2% supplies the lateral cord (comprising the musculocutaneous nerve and lateral root of the MN), and 37.8% supplies the posterior cord (comprising the axillary and radial nerves). CONCLUSIONS The fascicular dissection and definitive anatomical localization of fascicular groups is feasible in plexal spinal nerves. The knowledge of exact fascicular location might be translatable to the operating room and can be used to anastomose related fascicles in brachial plexus surgery, thereby avoiding the possibility of axonal misrouting and improving the results of plexal reconstruction.

  19. Outcome in adolescence of brachial plexus birth palsy

    PubMed Central

    Hulleberg, Gunn; Elvrum, Ann-Kristin G; Brandal, Merethe; Vik, Torstein

    2014-01-01

    Background and purpose — The frequency and severity of a permanent lesion after brachial plexus birth palsy (BPBP) and its impact on activities of daily living are not well documented. We therefore investigated the outcome of BPBP in adolescents, regarding arm function and consequences for activity and participation. Participants and methods — Of 30,574 babies born at St. Olavs University Hospital in 1991–2000, 91 had BPBP (prevalence 3 per 1,000), and 69 of these individuals were examined at a median age of 14 (10–20) years. The examination included the modified Mallet classification, range of motion, shoulder rotation and grip strength, Assisting Hand Assessment, and Canadian Occupational Performance Measure. Of the 22 subjects who were not examined, 3 could not be traced and 19 reported having no problems in the affected arm. Results — At follow-up, 17 adolescents had a permanent lesion (i.e. individual Mallet subscore below 4) with a median Mallet total score of 15 (9–19), while 52 had good or normal shoulder function (median Mallet total score 25 (23–25)). All participants with a permanent lesion had reduced active shoulder rotation (≤ 15°), 16 had elbow extension deficit, and 10 had subnormal grip strength. External rotation was considerably weaker in the affected shoulder. In addition, they had ineffective use of the affected arm in bimanual activities. Even so, all except 1 were independent in activities of daily living, although 15 experienced minor difficulties. Interpretation — Every fourth to fifth child with BPBP had a permanent lesion as an adolescent. External rotation was the most impaired movement. Despite ineffective use of the affected arm in bimanual activities, all of the participants except one were independent in activities of daily living. PMID:25238434

  20. An electronic circuit that detects left ventricular ejection events by processing the arterial pressure waveform

    NASA Technical Reports Server (NTRS)

    Gebben, V. D.; Webb, J. A., Jr.

    1972-01-01

    An electronic circuit for processing arterial blood pressure waveform signals is described. The circuit detects blood pressure as the heart pumps blood through the aortic valve and the pressure distribution caused by aortic valve closure. From these measurements, timing signals for use in measuring the left ventricular ejection time is determined, and signals are provided for computer monitoring of the cardiovascular system. Illustrations are given of the circuit and pressure waveforms.

  1. Iatrogenic brachial artery injury during pinning of supracondylar fracture of humerus: A rare injury.

    PubMed

    Vishal, Kumar; Arjun, R H H; Sameer, Aggarwal; Rakesh, John; Rama, Kishan

    2015-01-01

    Complications following supracondylar fracture of humerus are well-known. Pre- and post-operative complications have been documented in the literature. Neurovascular injury due to fracture fragments following this type of fracture is described. Iatrogenic brachial artery during surgical treatment of this fracture is unknown to the literature. So we report a rare case of iatrogenic brachial artery injury during pinning of supracondylar fracture of humerus and try to create awareness to the surgeons that such injuries can occur with improper operative techniques. PMID:26777716

  2. Brachial Artery Aneurysm in a 7-Month-Old Infant: Case Report and Literature Review

    PubMed Central

    Gangopadhyay, Noopur; Chong, Tae; Chhabra, Avneesh

    2016-01-01

    Summary: Congenital upper extremity aneurysms are very rare and can be challenging to diagnose and treat. Although they can present as an isolated finding, they are often associated with other systemic conditions. We present a rare case of brachial artery aneurysm in a 7-month-old boy. The patient was evaluated with ultrasound, magnetic resonance angiography, and vein mapping before surgical reconstruction. After excision of the aneurysm, the brachial artery was reconstructed with an interposition saphenous vein graft. Because of potentially associated diagnoses and the possibility of concurrent aneurysms, this condition requires multidisciplinary management. PMID:27014554

  3. Hereditary Neuropathy with Liability to Pressure Palsy Presenting as an Acute Brachial Plexopathy: A Lover's Palsy

    PubMed Central

    Wedderburn, Sarah; Pateria, Puraskar; Panegyres, Peter K.

    2014-01-01

    It is generally regarded that patients with hereditary neuropathy to pressure palsies, due to a deletion in the PMP22 gene, show recurrent pressure palsy and generalised peripheral neuropathy (pes cavus and hammer toes sometimes develop). Brachial plexopathy is rarely identified as a first presentation of hereditary neuropathy to pressure palsies. We describe a young man who developed a painless flail upper limb with a clinical diagnosis of a brachial plexopathy after his partner slept on his arm – a PMP22 deletion was found. His father, who had a symmetrical polyneuropathy without recurrent mononeuropathies, shared the PMP22 deletion. PMID:25685136

  4. Improved Measurement of Ejection Velocities From Craters Formed in Sand

    NASA Technical Reports Server (NTRS)

    Cintala, Mark J.; Byers, Terry; Cardenas, Francisco; Montes, Roland; Potter, Elliot E.

    2014-01-01

    A typical impact crater is formed by two major processes: compression of the target (essentially equivalent to a footprint in soil) and ejection of material. The Ejection-Velocity Measurement System (EVMS) in the Experimental Impact Laboratory has been used to study ejection velocities from impact craters formed in sand since the late 1990s. The original system used an early-generation Charge-Coupled Device (CCD) camera; custom-written software; and a complex, multicomponent optical system to direct laser light for illumination. Unfortunately, the electronic equipment was overtaken by age, and the software became obsolete in light of improved computer hardware.

  5. A Model for Stealth Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Lynch, Benjamin J.; Masson, Sophie; Li, Yan; DeVore, C. Richard; Luhmann, Janet; Antiochos, Spiro K.; Fisher, George H.

    2016-05-01

    Stealth coronal mass ejections (CMEs) are events in which there are almost no observable signatures of the CME eruption in the low corona but often a well-resolved slow flux rope CME observed in the coronagraph data. We present results from a three-dimensional numerical magnetohydrodynamics (MHD) simulation of the 2008 June 1-2 slow streamer blowout CME that Robbrecht et al. [2009] called “the CME from nowhere.” We model the global coronal structure using a 1.4 MK isothermal solar wind and a low-order potential field source surface representation of the Carrington Rotation 2070 magnetogram synoptic map. The bipolar streamer belt arcade is energized by simple shearing flows applied in the vicinity of the helmet streamer’s polarity inversion line. The slow expansion of the energized helmet-streamer arcade results in the formation of a radial current sheet. The subsequent onset of expansion-driven flare reconnection initiates the stealth CME while gradually releasing ~1.5E+30 erg of stored magnetic energy over the 20+ hour eruption duration. We show the energy flux available for flare heating and flare emission during the eruption is approximately two orders of magnitude below the energy flux required to heat the ambient background corona, thus confirming the “stealth” character of the 2008 June 1-2 CME’s lack of observable on disk signatures. We also present favorable comparisons between our simulation results and the multi-viewpoint SOHO-LASCO and STEREO-SECCHI coronagraph observations of the pre-eruption streamer structure and the initiation and evolution of the stealth streamer blowout CME.

  6. Stealth Coronal Mass Ejections: A Perspective

    NASA Astrophysics Data System (ADS)

    Howard, Timothy A.; Harrison, Richard A.

    2013-07-01

    "Stealth CME" has become a commonly used term in recent studies of solar activity. It refers to a coronal mass ejection (CME) with no apparent solar surface association, and therefore has no easily identifiable signature to locate the region on the Sun from which the CME erupted. We review the literature and express caution in categorising CMEs in this way. CMEs were discovered some 40 years ago and there have been numerous statistical studies of associations with phenomena in the solar atmosphere which clearly identify a range of associations, from bright flares and large prominence eruptions to small flares, and even a lack of flares or any identifiable surface activity at all. In this sense the stealth CME concept is not new. One major question relates to whether the range of associations reveal different CME classes, i.e. different CME launch processes, or are indicative of a spectrum of coronal responses to one common process. We favour the latter and stress that this spectrum must be considered in the description of the CME launch, meaning that the physics of a so-called stealth CME must not be fundamentally different from a CME associated with major surface events. On the other hand we also stress that the use of a stealth CME category implies that all surface activity could indeed be detected using modern instrumentation. We argue that this may not be the case, and that even in the SDO era of full-Sun, high resolution imaging, we are restricted by instrument sensitivity and bandwidth issues. Thus, having reviewed the case for stealth CMEs as a distinct category, we stress the need to keep the concept in perspective.

  7. How much dust does Enceladus eject?

    NASA Astrophysics Data System (ADS)

    Kempf, Sascha; Horanyi, Mihaly; Schmidt, Jürgen; Southworth, Ben

    2015-04-01

    There is an ongoing argument how much dust per second the ice volcanoes on Saturn's ice moon Enceladus eject. By adjusting their plume model to the dust flux measured by the Cassini dust detector during the close Enceladus flyby in 2005, as well as to the plume brightness in Cassini imaging, Schmidt et al. (2008) obtained a total dust production rate in the plumes of about 5 kg/s. On the other hand, Ingersoll and Ewald (2011) derived a dust production rate of 51 kg/s from photometry of very high phase-angle images of the plume, a method that is sensitive also to particles in the size range of microns and larger. Knowledge of the production rate is essential for estimating the dust to gas mass ratio, which in turn is an important constraint for finding the plume source mechanism. Here we report on numerical simulations of the Enceladus dust plume. We run a large number of dynamical simulations including gravity and Lorentz force to investigate the earliest phase of the ring particle life span. The magnetic field in the vicinity of Enceladus is based on the model by Simon et al. (2012). The evolution of the electrostatic charge carried by the initially uncharged grains is treated self-consistently. Our numerical simulations reproduce dust measurements by the Cassini Cosmic Dust Analyzer (CDA) during Cassini plume traversals as well as the snowfall pattern derived from ISS observations of the Enceladus surface (Schenk et al, 2011, EPSC abstract). Based on our simulation results we are able to draw conclusions about the dust production rate as well as wether the Enceladus dust plume constitutes a dusty plasma.

  8. ROTATION OF CORONAL MASS EJECTIONS DURING ERUPTION

    SciTech Connect

    Lynch, B. J.; Li, Y.; Luhmann, J. G.; Antiochos, S. K.; DeVore, C. R. E-mail: yanli@ssl.berkeley.edu E-mail: spiro.k.antiochos@nasa.gov

    2009-06-01

    Understanding the connection between coronal mass ejections (CMEs) and their interplanetary counterparts (ICMEs) is one of the most important problems in solar-terrestrial physics. We calculate the rotation of erupting field structures predicted by numerical simulations of CME initiation via the magnetic breakout model. In this model, the initial potential magnetic field has a multipolar topology and the system is driven by imposing a shear flow at the photospheric boundary. Our results yield insight on how to connect solar observations of the orientation of the filament or polarity inversion line (PIL) in the CME source region, the orientation of the CME axis as inferred from coronagraph images, and the ICME flux rope orientation obtained from in situ measurements. We present the results of two numerical simulations that differ only in the direction of the applied shearing motions (i.e., the handedness of the sheared-arcade systems and their resulting CME fields). In both simulations, eruptive flare reconnection occurs underneath the rapidly expanding sheared fields transforming the ejecta fields into three-dimensional flux rope structures. As the erupting flux ropes propagate through the low corona (from 2 to 4 R{sub sun}) the right-handed breakout flux rope rotates clockwise and the left-handed breakout flux rope rotates counterclockwise, in agreement with recent observations of the rotation of erupting filaments. We find that by 3.5 R {sub sun} the average rotation angle between the flux rope axes and the active region PIL is approximately 50 deg. We discuss the implications of these results for predicting, from the observed chirality of the pre-eruption filament and/or other properties of the CME source region, the direction and amount of rotation that magnetic flux rope structures will experience during eruption. We also discuss the implications of our results for CME initiation models.

  9. QUASI-PERIODIC OSCILLATIONS IN LASCO CORONAL MASS EJECTION SPEEDS

    SciTech Connect

    Shanmugaraju, A.; Moon, Y.-J.; Cho, K.-S.; Bong, S. C.; Gopalswamy, N.; Akiyama, S.; Yashiro, S.; Umapathy, S.; Vrsnak, B. E-mail: moonyj@khu.ac.k

    2010-01-01

    Quasi-periodic oscillations in the speed profile of coronal mass ejections (CMEs) in the radial distance range 2-30 solar radii are studied. We considered the height-time data of the 307 CMEs recorded by the Large Angle and Spectrometric Coronagraph (LASCO) during 2005 January-March. In order to study the speed-distance profile of the CMEs, we have used only 116 events for which there are at least 10 height-time measurements made in the LASCO field of view. The instantaneous CME speed is estimated using a pair of height-time data points, providing the speed-distance profile. We found quasi-periodic patterns in at least 15 speed-distance profiles, where the speed amplitudes are larger than the speed errors. For these events we have determined the speed amplitude and period of oscillations. The periods of quasi-periodic oscillations are found in the range 48-240 minutes, tending to increase with height. The oscillations have similar properties as those reported by Krall et al., who interpreted them in terms of the flux-rope model. The nature of forces responsible for the motion of CMEs and their oscillations are discussed.

  10. POST-CORONAL MASS EJECTION PLASMA OBSERVED BY HINODE

    SciTech Connect

    Landi, E.; Raymond, J. C.; Miralles, M. P.; Hara, H.

    2012-05-20

    In the present work we study the evolution of an active region after the eruption of a coronal mass ejection (CME) using observations from the EIS and XRT instruments on board Hinode. The field of view includes a post-eruption arcade, a current sheet, and a coronal dimming. The goal of this paper is to provide a comprehensive set of measurements for all these aspects of the CME phenomenon made on the same CME event. The main physical properties of the plasma along the line of sight-electron density, thermal structure, plasma composition, size, and, when possible, mass-are measured and monitored with time for the first three hours following the CME event of 2008 April 9. We find that the loop arcade observed by EIS and XRT may not be related to the post-eruption arcade. Post-CME plasma is hotter than the surrounding corona, but its temperature never exceeds 3 MK. Both the electron density and thermal structure do not show significant evolution with time, while we found that the size of the loop arcade in the Hinode plane of the sky decreased with time. The plasma composition is the same in the current sheet, in the loop arcade, and in the ambient plasma, so all these plasmas are likely of coronal origin. No significant plasma flows were detected.

  11. Photogrammetric Trajectory Estimation of Foam Debris Ejected From an F-15 Aircraft

    NASA Technical Reports Server (NTRS)

    Smith, Mark S.

    2006-01-01

    Photogrammetric analysis of high-speed digital video data was performed to estimate trajectories of foam debris ejected from an F-15B aircraft. This work was part of a flight test effort to study the transport properties of insulating foam shed by the Space Shuttle external tank during ascent. The conical frustum-shaped pieces of debris, called "divots," were ejected from a flight test fixture mounted underneath the F-15B aircraft. Two onboard cameras gathered digital video data at two thousand frames per second. Time histories of divot positions were determined from the videos post flight using standard photogrammetry techniques. Divot velocities were estimated by differentiating these positions with respect to time. Time histories of divot rotations were estimated using four points on the divot face. Estimated divot position, rotation, and Mach number for selected cases are presented. Uncertainty in the results is discussed.

  12. Incidence of hemidiaphragmatic paresis after peripheral nerve stimulator versus ultrasound guided interscalene brachial plexus block

    PubMed Central

    Ghodki, Poonam Sachin; Singh, Noopur Dasmit

    2016-01-01

    Background and Aims: We compared interscalene brachial plexus block (ISBPB) using peripheral nerve stimulation (PNS) and ultrasound (US) techniques. The primary outcomes were the incidence of hemidiaphragmatic paresis (HDP) and the duration of the block. Secondary outcomes were the block success rate, time to conduct the block, onset of sensory block, and dermatomal spread, postoperative pain by Numeric Rating Scale (NRS), duration of postoperative analgesia and incidence of complications. Material and Methods: We conducted a prospective, randomized, and observer-blinded study in 60 patients undergoing shoulder arthroscopy under block plus general anesthesia. ISBPB was performed with 10 ml of 0.5% bupivacaine using either PNS (Group PNS, n = 30) or US (Group US, n = 30). Hemidiaphragmatic function, the primary outcome, was assessed by ultrasonographic evaluation of diaphragmatic movement and pulmonary function tests using a bedside spirometer (forced vital capacity, forced expiratory volume in 1 s and peak expiratory flow rate). General anesthesia was administered to all the patients for surgery. P < 0.05 test was considered to be statistically significant. Results: Twelve patients in Group PNS had HDP and none in Group US (P < 0.0001). PFTs were also significantly reduced in Group PNS (P < 0.0001). The time to conduct the block and sensory onset time both were less in Group US (P < 0.05). The groups did not differ in block success rate, duration of analgesia, and NRS. Other complications like incidence of Horner's syndrome and vascular puncture were comparable in both the groups. Conclusions: PNS guided ISBPB with 10 ml of 0.5% bupivacaine is associated with a higher incidence of HDP as compared to US guided ISBPB. There is no significant difference in quality or duration of analgesia in the two groups. PMID:27275045

  13. Comet ejection and dynamics of nonspherical dust particles and meteoroids

    SciTech Connect

    Gustafson, B.A.S.

    1989-02-01

    This paper generalizes the formalism for calculating the ejection velocity of meteoroids and dust from comets and the forces to which such objects are subject in interplanetary space, including the dust tail of comets. It is found that spheres have the smallest cross section of any geometrical figures of the same valume averaged over random orientations, so for a fixed volume and mass, both the ejection velocity and beta reaches a minimum for bodies of spherical shapes. Flakes in random orientation are ejected near 70 percent of the highest ejection velocity for any orientation. Needles in random orientation escape a comet at nearly 90 percent of their maximum velocities. Randomly oriented cylinders of finite thickness escape at lower velocities that are slightly closer to their maximum velocities. The average beta acting on spin-aligned, perfectly absorbing needles is more than half that acting on a sphere of the same material and radius. 16 references.

  14. Mass ejected by impacts with materials of various strengths

    SciTech Connect

    Canavan, G.H.

    1997-02-01

    Similarity solutions are used to discuss impacts on asteroids of various strengths, concentrating on the voids produced, the mass ejected, and its thermodynamic and mechanical state. Numerical calculations have advantages and limitations for the next step in complexity.

  15. Particle ejection during mergers of dark matter halos

    SciTech Connect

    Carucci, Isabella P.; Sparre, Martin; Hansen, Steen H.; Joyce, Michael E-mail: sparre@dark-cosmology.dk E-mail: joyce@lpnhe.in2p3.fr

    2014-06-01

    Dark matter halos are built from accretion and merging. During merging some of the dark matter particles may be ejected with velocities higher than the escape velocity. We use both N-body simulations and single-particle smooth-field simulations to demonstrate that rapid changes to the mean field potential are responsible for such ejection, and in particular that dynamical friction plays no significant role in it. Studying a range of minor mergers, we find that typically between 5–15% of the particles from the smaller of the two merging structures are ejected. We also find that the ejected particles originate essentially from the small halo, and more specifically are particles in the small halo which pass later through the region in which the merging occurs.

  16. Assessment of variation in depth of brachial plexus using ultrasound for supraclavicular brachial plexus block in patients undergoing elective upper limb surgery

    PubMed Central

    Mistry, Tuhin; Mangal, Vandana; Sharma, Gaurav; Agrawal, Aachu

    2016-01-01

    Background and Aims: Supraclavicular approach to the brachial plexus may be associated with complications such as pneumothorax, inadvertent vascular puncture, inter-scalene block and neurovascular injuries. The present study was conceived to find out the variation in depth of brachial plexus to suggest the minimum length of needle required to effectively perform the block, thus preventing possible complications. Methods: After approval from our Institutional Ethical Committee, informed and written consent was obtained from each of the ninety American Society of Anesthesiologists Physical Status I and II patients recruited, of either sex in the age group of 20–50 years. Supraclavicular fossa was scanned using a high-frequency linear probe, and the distances (shortest distance [SD] from skin to the most superficial neural element and longest distance [LD] from skin to the most deep neural element) were measured using on-screen callipers on optimal frozen image. Pearson correlation was used to find out the relation between these two distances and demographic parameters. Results: Mean SD was 0.60 ± 0.262 cm, and mean LD was found to be 1.34 ± 0.385 cm. We observed significant correlation between these two distances with weight and body mass index (BMI). Conclusion: Significant correlation was observed between SD and LD with weight and BMI. We suggest that a needle with a shaft length of 3 cm will be sufficient to reach the sheath of the brachial plexus during performance of the block. PMID:27330200

  17. Ejection of gaseous clumps from gravitationally unstable protostellar disks

    NASA Astrophysics Data System (ADS)

    Vorobyov, E. I.

    2016-05-01

    Aims: We investigate the dynamics of gaseous clumps formed via gravitational fragmentation in young protostellar disks, focusing on the fragments that are ejected from the disk via many-body gravitational interaction. Methods: Numerical hydrodynamics simulations were employed to study the evolution of young protostellar disks that were formed from the collapse of rotating pre-stellar cores. Results: The protostellar disks that formed in our models undergo gravitational fragmentation driven by continuing mass-loading from parental collapsing cores. Several fragments can be ejected from the disk during the early evolution, but the low-mass fragments (<15 MJup) disperse, which creates spectacular bow-type structures while passing through the disk and collapsing core. The least massive fragment that survived the ejection (21 MJup) straddles the planetary-mass limit, while the most massive ejected fragments (145 MJup) can break up into several pieces, leading to the ejection of wide separation binary clumps in the brown-dwarf mass range. About half of the ejected fragments are gravitationally bound, the majority are supported by rotation against gravity, and all fragments have the specific angular momentum that is much higher than that expected for brown dwarfs. We found that the internal structure of the ejected fragments is distinct from what would be expected for gravitationally contracting clumps formed via molecular cloud fragmentation, which can help in differentiating their origin. Conclusions: The ejection of fragments is an important process, which is inherent to massive protostellar disks, and which produces freely floating pre-brown dwarf cores, regulates the disk and stellar masses and, potentially, enriches the intracluster medium with processed dust and complex organics.

  18. Investigation on occupant ejection in high severity rear impact based on post mortem human subject sled tests.

    PubMed

    Petit, Philippe; Luet, Carole; Potier, Pascal; Vallancien, Guy

    2011-11-01

    Occupant protection in rear impact involves two competing challenges. On one hand, allowing a deformation of the seat would act as an energy absorber in low severity impacts and would consequently decrease the risk of neck injuries. However, on the other hand, large deformations of the seat may increase the likelihood of occupant ejection in high severity cases. Green et al. 1987 analyzed a total of 919 accidents in Great Britain. They found that occupant ejection resulted in a risk of severe injuries and fatalities between 3.6 and 4.5 times higher than those cases where no ejection was observed. The sample included single front, side and rear impacts as well as multiple impacts and rollover. The rate of belt use in the sample was 50%. While this analysis included all forms of impact scenarios, nevertheless, it highlights the relative injury severity of occupant ejection. Extensive literature search has found no full-scale rear impact tests involving Post Mortem Human Subjects (PMHS) conducted in a laboratory environment and resulting in ejection. This paper describes a total of 10 sled tests conducted on 3 belted PMHS using a simplified seat design composed of rigid plates assembled such that the angular and linear stiffness of the seatback (including the foam) was modeled. The initial angular position and the range of motion of the seatback, the size of the PMHS, the slack length of the seatbelt, the angular stiffness of the seatback, and the use of headrest were varied in the test matrix while the pulse was kept constant (triangular acceleration with a peak of 17 G at 30 ms and a duration of 95 ms). In the test series, the tests were not run randomly but the likelihood of occupant ejection was increased systematically until ejection occurred. PMHS seat ejection was observed only for the 95th percentile, initially positioned with a seatback angle relative to the vertical equal to 22°, a range of seatback angular motion equal to 44° and no headrest. Repeating

  19. Investigation on occupant ejection in high severity rear impact based on post mortem human subject sled tests.

    PubMed

    Petit, Philippe; Luet, Carole; Potier, Pascal; Vallancien, Guy

    2011-11-01

    Occupant protection in rear impact involves two competing challenges. On one hand, allowing a deformation of the seat would act as an energy absorber in low severity impacts and would consequently decrease the risk of neck injuries. However, on the other hand, large deformations of the seat may increase the likelihood of occupant ejection in high severity cases. Green et al. 1987 analyzed a total of 919 accidents in Great Britain. They found that occupant ejection resulted in a risk of severe injuries and fatalities between 3.6 and 4.5 times higher than those cases where no ejection was observed. The sample included single front, side and rear impacts as well as multiple impacts and rollover. The rate of belt use in the sample was 50%. While this analysis included all forms of impact scenarios, nevertheless, it highlights the relative injury severity of occupant ejection. Extensive literature search has found no full-scale rear impact tests involving Post Mortem Human Subjects (PMHS) conducted in a laboratory environment and resulting in ejection. This paper describes a total of 10 sled tests conducted on 3 belted PMHS using a simplified seat design composed of rigid plates assembled such that the angular and linear stiffness of the seatback (including the foam) was modeled. The initial angular position and the range of motion of the seatback, the size of the PMHS, the slack length of the seatbelt, the angular stiffness of the seatback, and the use of headrest were varied in the test matrix while the pulse was kept constant (triangular acceleration with a peak of 17 G at 30 ms and a duration of 95 ms). In the test series, the tests were not run randomly but the likelihood of occupant ejection was increased systematically until ejection occurred. PMHS seat ejection was observed only for the 95th percentile, initially positioned with a seatback angle relative to the vertical equal to 22°, a range of seatback angular motion equal to 44° and no headrest. Repeating

  20. Energetic Correlation Between Solar Flares and Coronal Mass Ejections

    NASA Technical Reports Server (NTRS)

    Dennis, Brian R.; Medlin, Drew A.; Haga, Leah; Schwartz, Richard a.; Tolbert, A. Kimberly

    2007-01-01

    We find a strong correlation between the kinetic energies (KEs) of the coronal mass ejections (CMEs) and the radiated energies of the associated solar flares for the events that occurred during the period of intense solar activity between 18 October and 08 November 2003. CME start times, speeds, mass and KEs were taken from Gopalswamy et al. (2005), who used SOHO/LASCO observations. The GOES observations of the associated flares were analyzed to find the peak soft X-ray (SXR) flux, the radiated energy in SXRs (L(sub sxR)), and the radiated energy from the emitting plasma across all wavelengths (L(sub hot)). RHESSI observations were also used to find the energy in non-thermal electrons, ions, and the plasma thermal energy for some events. For two events, SORCE/TIM observations of the total solar irradiance during a flare were also available to give the total radiated flare energy (L(sub total)).W e find that the total flare energies of the larger events are of the same order of magnitude as the CME KE with a stronger correlation than has been found in the past for other time intervals.

  1. Multivalent counterions inhibit DNA ejection from viral capsid

    NASA Astrophysics Data System (ADS)

    Nguyen, Toan

    2008-03-01

    Viral DNA packaged inside a bacteriophage is tighly bent. This stored bending energy of DNA is believed to be the main driving force to eject viral DNA into host cell upon capsid binding. One can control the amount of ejected DNA by subjecting the virus to a solution of PEG8000 molecules. The molecules cannot penetrate the viral capsid, therefore, they exert an osmotic pressure on the virus preventing DNA ejection. Experiments showed that for a given osmotic pressure, the degree of ejection also depends on the concentration of small ions in solution. Interestingly, for multivalent ions (such as Mg2+, Spd3+ or HexCo3+), this dependence is non-monotonic. We propose a simple electrostatic theory to explain this non-monotonic behavior. This is based on the fact that DNA molecules can invert its net charge at high enough multivalent counterion concentration. In other words, as multivalent counterion concentration is increased from zero, charge of DNA molecules change from negative to positive. At the concentration where DNA net charge is zero, the DNA molecules experience an attraction between different segments and DNA ejected amount is reduced. At low or high counterion concentration, DNA segments are charged (negatively or positively), repel each other and DNA ejected amount is increased. Fitting the result of the theory to experimental data, we obtain a numerical value for Mg2+ mediated DNA - DNA attraction energy to be -0.008kT per base.

  2. Discrepancy between simultaneous digital skin microvascular and brachial artery macrovascular post-occlusive hyperemia in systemic sclerosis

    PubMed Central

    Roustit, Matthieu; Simmons, Grant H.; Baguet, Jean-Philippe; Carpentier, Patrick H.; Cracowski, Jean-Luc

    2008-01-01

    Objective Vascular impairment, a main feature of the pathogenesis of systemic sclerosis (SSc), involves both the macro- and the microvasculature. We compared and correlated simultaneously measured skin microvascular and brachial artery macrovascular post-occlusive hyperemia in 3 groups: patients with SSc, patients with primary Raynaud’s phenomenon (RP), and healthy volunteers. Methods Thirty-three healthy volunteers, 36 patients with primary RP, and 42 patients with SSc were enrolled. For each subject, brachial artery flow-mediated dilation (FMD) and cutaneous post-occlusive reactive hyperemia (PORH) were simultaneously recorded after 5-minute occlusion of the brachial artery. Local thermal hyperemia, nitroglycerin-mediated dilation (NMD), intima-media thickness (IMT), and pulse wave velocity (PWV) were also assessed. Results Digital cutaneous peak PORH was altered in patients with primary RP and SSc compared to healthy controls, whereas FMD was not significantly different among all groups. We observed a correlation between digital peak cutaneous vascular conductance and brachial FMD in healthy controls (r = 0.49; p = 0.004), but not in patients with primary RP or SSc. Thermal hyperemia was altered only in patients with SSc. Brachial NMD, IMT, and PWV were not different among all groups. Conclusion We observed a loss of the correlation between brachial FMD and digital cutaneous PORH in patients with SSc and primary RP. Microvascular function is impaired in SSc, whereas brachial artery endothelial function is normal. (J Rheumatol First Release June 15 2008) PMID:18597404

  3. Radiation-induced brachial plexopathy: Neurological follow-up in 161 recurrence-free breast cancer patients

    SciTech Connect

    Olsen, N.K.; Pfeiffer, P.; Johannsen, L.; Schroder, H.; Rose, C. )

    1993-04-30

    The purpose was to assess the incidence and clinical manifestations of radiation-induced brachial plexopathy in breast cancer patients, treated according to the Danish Breast Cancer Cooperative Group protocols. One hundred and sixty-one recurrence-free breast cancer patients were examined for radiation-induced brachial plexopathy after a median follow-up period of 50 months (13-99 months). After total mastectomy and axillary node sampling, high-risk patients were randomized to adjuvant therapy. One hundred twenty-eight patients were treated with postoperative radiotherapy with 50 Gy in 25 daily fractions over 5 weeks. In addition, 82 of these patients received cytotoxic therapy (cyclophosphamide, methotrexate, and 5-fluorouracil) and 46 received tamoxifen. Five percent and 9% of the patients receiving radiotherapy had disabling and mild radiation-induced brachial plexopathy, respectively. Radiation-induced brachial plexopathy was more frequent in patients receiving cytotoxic therapy (p = 0.04) and in younger patients (p = 0.04). The clinical manifestations were paraesthesia (100%), hypaesthesia (74%), weakness (58%), decreased muscle stretch reflexes (47%), and pain (47%). The brachial plexus is more vulnerable to large fraction size. Fractions of 2 Gy or less are advisable. Cytotoxic therapy adds to the damaging effect of radiotherapy. Peripheral nerves in younger patients seems more vulnerable. Radiation-induced brachial plexopathy occurs mainly as diffuse damage to the brachial plexus. 24 refs., 9 tabs.

  4. Are halo coronal mass ejections special events?

    NASA Astrophysics Data System (ADS)

    Lara, Alejandro; Gopalswamy, Nat; Xie, Hong; Mendoza-Torres, Eduardo; PéRez-EríQuez, RomáN.; Michalek, Gregory

    2006-06-01

    We revisited the properties of wide coronal mass ejections (CMEs) called halo CMEs. Using the large LASCO/SOHO CMEs data set, from 1996 to 2004, we examined the statistical properties of (partial and full) halo CMEs and compare with the same properties of "normal" width (lower than 120°) CMEs. We found that halo CMEs have different properties than "normal" CMEs, which cannot be explained merely by the current geometric interpretation that they are seen as halos because they are traveling in the Sun Earth direction. We found that the CME width distribution is formed by, at least, three different populations: Two gaussians: a narrow and a medium distribution centered at ˜17° and ˜38°, respectively; the narrow population most likely corresponds to the "true" observed widths, whereas the medium width population is the product of projection effects. The third distribution corresponds to wider CMEs (80° < W < 210°) which behaves as a power law. Partial and full halo CMEs wider than these do not follow any particular distribution. This lack of regularity may be due to the small number of such events. In particular, we found (and test by a statistical approach) that the number of observed full halo CMEs is lower than expected. The CME speed follows a log-normal distribution, except for the very low speed CME population, which follows a gaussian distribution centered at ˜100 km/s and is probably due to projection effects. When the CMEs are divided by width into nonhalo, partial halo, and full halo, we found that the peaks of the distributions are shifted toward higher speeds, ˜300, ˜400 and ˜600 km/s for nonhalo, partial halo, and full halo CMEs, respectively. This confirms that halo CMEs tend to be high speed CMEs. The acceleration of full halo CMEs tends to be more negative compared with nonhalo and partial halo CMEs. We introduce a new observational CME parameter: The final observed distance (FOD), i.e., the highest point within the coronograph field of view

  5. A Novel Approach to Brachial Plexus Catheter Management: A Brachial Plexus Test Dose for Phrenic Nerve Paralysis and Patient-Controlled, Demand-Only Dosing for a Patient With Extreme Obesity.

    PubMed

    Meier, Adam W; Lin, Shin-E; Hanson, Neil A; Auyong, David B

    2016-09-15

    A 53-year-old woman with extreme obesity (body mass index = 82 kg/m) presented for an open reduction and internal fixation of the proximal humerus. This report describes the novel management of her continuous brachial plexus catheter in the setting of her comorbidities. Phrenic nerve paralysis from brachial plexus blocks can cause clinically significant dyspnea in obese patients. Brachial plexus catheters can be used effectively for these patients with some modification to routine management. We detail our use of a short-acting chloroprocaine test dose for phrenic paralysis and demand-only dosing to provide effective analgesia while avoiding respiratory complications associated with these blocks. PMID:27464944

  6. Luxation de l’épaule compliquée de paralysie du plexus brachial

    PubMed Central

    Lukulunga, Loubet Unyendje; Moussa, Abdou Kadri; Mahfoud, Mustapha; EL Bardouni, Ahmed; Berrada, Mohamed Saleh; El Yaacoubi, Moradh

    2014-01-01

    Les auteurs rapportent l'observation d'une paralysie totale du plexus brachial survenue trois mois après un épisode de luxation antéro-interne sous coracoïdienne associée à une fracture du trochiter chez une patiente âgée de 88 ans. PMID:25426187

  7. Valproic acid protection against the brachial plexus root avulsion-induced death of motoneurons in rats.

    PubMed

    Wu, Dianxiu; Li, Qiang; Zhu, Xiaojuan; Wu, Guangzhi; Cui, Shusen

    2013-10-01

    In this study, the role of valproic acid (VPA) in protecting motoneuron after brachial plexus root avulsion was investigated in adult rats. Sixty rats were used in this study, and underwent the brachial plexus root avulsion injury, which was created by using a micro-hemostat forceps to pull out brachial plexus root from the intervertebral foramen. The animals were divided into two groups, VPA group administered with VPA dissolved in drinking water (300 mg/kg) daily, and control group had drinking water every day. The spinal cords (C5-T1) were harvested at day 1, 2, 3, 7, 14, and 28 for immunohistochemistry analysis, TUNEL staining, Nissl staining, and electron microscopy, respectively. The results showed that with VPA administration, the survival of motoneurons was promoted and the cell apoptosis was inhibited. The number of c-Jun and Bcl-2 positive motoneurons was increased immediately after avulsion both in control and VPA group, however, the percent of c-Jun positive motoneurons was decreased and the percent of Bcl-2 positive motoneurons was increased by VPA treatment significantly. Our results indicated that motoneurons were protected by VPA against cell death induced by brachial plexus root avulsion through c-Jun inhibition and Bcl-2 induction. PMID:23843283

  8. Brachial plexus injury management in military casualties: who, what, when, why, and how.

    PubMed

    Chambers, James A; Hiles, Claire L; Keene, Brian P

    2014-06-01

    The Global War on Terrorism has achieved an unprecedented 90% casualty survival rate because of far forward surgical support, rapid transport, and body armor. Despite the remarkable protection body armor affords, peripheral nerve injuries continue to occur. The brachial plexus in particular is still susceptible to penetrating trauma through the axilla as well as blunt mechanisms. We report 1,818 individuals with reported cases of peripheral nerve injury, 97 of which had brachial plexus injury incident from Operation Iraqi Freedom and Operation Enduring Freedom. We suspect that true prevalence is higher as initial focus on vascular and orthopedic reconstruction in complex shoulder injuries may overlook brachial plexus lesions. Accordingly, emergency physicians, general and orthopedic trauma surgeons, and vascular surgeons should all consider the possibility of brachial plexus and other peripheral nerve injury for early and appropriate referral to surgeons (plastic, orthopedic, or neurosurgical) for further evaluation and reconstruction. The latter group should be familiar with appropriate modern diagnostic and initial as well as salvage therapeutic options.

  9. Cost analysis of brachial plexus injuries: variability of compensation by insurance companies before and after surgery.

    PubMed

    Felici, N; Zaami, S; Ciancolini, G; Marinelli, E; Tagliente, D; Cannatà, C

    2014-04-01

    Traumatic paralysis of the brachial plexus is an extremely disabling pathology. The type of trauma most frequently suffered by this group of patients is due to motorcycle injuries. It therefore affects a population of young patients. In the majority of cases, these patients receive compensation for permanent damage from insurance companies. Surgery of the brachial plexus enables various forms of functional recovery, depending on the number of roots of the brachial plexus involved in the injury. The aim of this study is to compare the functional deficit and the extent of the related compensation before and after surgical intervention, and to evaluate the saving in economic terms (understood as the cost of compensation paid by insurance companies) obtainable through surgical intervention. The authors analysed the functional recovery obtained through surgery in 134 patients divided into 4 groups on the basis of the number of injured roots. The levels of compensation payable to the patient before surgical intervention, and 3 years after, were then compared. The results showed that the saving obtainable through surgical treatment of brachial plexus injuries may exceed 65% of the economic value of the compensation that would have been attributable to the same patients if they had not undergone surgical treatment.

  10. Digital infarction in a hemodialysis patient due to embolism from a thrombosed brachial arteriovenous fistula.

    PubMed

    Yj, Anupama

    2015-10-01

    Acute onset of digital ischemia and infarction is an unusual complication in patients undergoing hemodialysis. This is a report of a patient on regular hemodialysis who presented with acute distal extremity ischemia, progressing to digital infarction and on evaluation was found to have thrombosis of brachial arteriovenous fistula with embolization to the distal arteries causing digital artery occlusion.

  11. A young man with intimomedial mucoid degeneration of the brachial artery.

    PubMed

    Raber, Menno H; Meerwaldt, Robbert; van Det, Rob J

    2011-03-01

    Intimomedial mucoid degeneration is a rare disorder and has been described as a distinctly different entity from Erdheim's cystic medial necrosis. Most studies show a strong predominance in African American females with hypertension. In our case report, we describe the presence of a large brachial aneurysm in a young white male with intimomedial mucoid degeneration. PMID:21215586

  12. Changes in Spinal Cord Architecture after Brachial Plexus Injury in the Newborn

    ERIC Educational Resources Information Center

    Korak, Klaus J.; Tam, Siu Lin; Gordon, Tessa; Frey, Manfred; Aszmann, Oskar C.

    2004-01-01

    Obstetric brachial plexus palsy is a devastating birth injury. While many children recover spontaneously, 20-25% are left with a permanent impairment of the affected limb. So far, concepts of pathology and recovery have focused on the injury of the peripheral nerve. Proximal nerve injury at birth, however, leads to massive injury-induced…

  13. Unusual clinic presentation of polyarteritis nodosa: involvement of axillary and brachial artery.

    PubMed

    Kocyigit, Ismail; Koyuncu, Sumeyra; Mavili, Ertugrul; Unal, Aydin; Tokmak, Turgut Tursem; Cilan, Havva; Kavuncuoglu, Feridun; Oymak, Oktay; Utas, Cengiz

    2011-01-01

    Polyarteritis nodosa (PAN) is a necrotizing inflammatory vasculitis of small- and medium-sized muscular arteries. Multiple organs, especially the kidney, skin, peripheric nerves, striated muscles, and intestine, are affected. In this case report, a patient with renal and hepatic involvement and axillary and brachial artery aneurysm resulting in shoulder hematoma and pain due to underlying PAN is presented.

  14. Constraining the brachial plexus does not compromise regional control in oropharyngeal carcinoma

    PubMed Central

    2013-01-01

    Background Accumulating evidence suggests that brachial plexopathy following head and neck cancer radiotherapy may be underreported and that this toxicity is associated with a dose–response. Our purpose was to determine whether the dose to the brachial plexus (BP) can be constrained, without compromising regional control. Methods The radiation plans of 324 patients with oropharyngeal carcinoma (OPC) treated with intensity-modulated radiation therapy (IMRT) were reviewed. We identified 42 patients (13%) with gross nodal disease <1 cm from the BP. Normal tissue constraints included a maximum dose of 66 Gy and a D05 of 60 Gy for the BP. These criteria took precedence over planning target volume (PTV) coverage of nodal disease near the BP. Results There was only one regional failure in the vicinity of the BP, salvaged with neck dissection (ND) and regional re-irradiation. There have been no reported episodes of brachial plexopathy to date. Conclusions In combined-modality therapy, including ND as salvage, regional control did not appear to be compromised by constraining the dose to the BP. This approach may improve the therapeutic ratio by reducing the long-term risk of brachial plexopathy. PMID:23835205

  15. A young man with intimomedial mucoid degeneration of the brachial artery.

    PubMed

    Raber, Menno H; Meerwaldt, Robbert; van Det, Rob J

    2011-03-01

    Intimomedial mucoid degeneration is a rare disorder and has been described as a distinctly different entity from Erdheim's cystic medial necrosis. Most studies show a strong predominance in African American females with hypertension. In our case report, we describe the presence of a large brachial aneurysm in a young white male with intimomedial mucoid degeneration.

  16. The Association of Homocysteine and Related Factors to Brachial Artery Diameter and Flow-Mediated Dilation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brachial artery flow-mediated dilation (BAFMD) has been proposed as a measurement of the degree and severity of cardiovascular disease. The purpose of this study was to (1) evaluate the associations between BAFMD and homocysteine, folate, vitamin B12, vitamin B6, (2) examine the influence of 5,10-me...

  17. Bilateral brachial plexus blocks in a patient of hypertrophic obstructive cardiomyopathy with hypertensive crisis.

    PubMed

    Pai, Rohini V Bhat; Hegde, Harihar V; Santhosh, McB; Roopa, S; Deshpande, Shrinivas S; Rao, P Raghavendra

    2013-01-01

    Hypertrophic obstructive cardiomyopathy (HOCM) is a challenge to anesthesiologists due to the complex pathophysiology involved and various perioperative complications associated with it. We present a 50-year-old man, a known case of HOCM, who successfully underwent emergency haemostasis, and debridement of the traumatically amputated right upper limb and the contused lacerated wound on the left forearm under bilateral brachial plexus blocks. His co-morbidities included hypertension (in hypertensive crisis) and diabetes mellitus. He was full stomach and also had an anticipated difficult airway. The management included invasive pressure monitoring and labetalol infusion for emergent control of blood pressure. The regional anaesthesia technique required careful consideration to the dosage of local anaesthetics and staggered performance of brachial plexus blocks on each of the upper limbs to avoid local anaesthetic toxicity. Even though bilateral brachial plexus blocks are rarely indicated, it seemed to be the most appropriate anaesthetic technique in our patient. With careful consideration of the local anaesthetic toxicity and meticulous technique, bilateral brachial plexus blocks can be successfully performed in those patients where general anaesthesia is deemed to be associated with higher risk.

  18. M2-F1 ejection seat test at South Edwards

    NASA Technical Reports Server (NTRS)

    1963-01-01

    The M2-F1 was fitted with an ejection seat before the airtow flights began. The project selected the seat used in the T-37 as modified by the Weber Company to use a rocket rather than a ballistic charge for ejection. To test the ejection seat, the Flight Research Center's Dick Klein constructed a plywood mockup of the M2-F1's top deck and canopy. On the first firings, the test was unsuccessful, but on the final test the dummy in the seat landed safely. The M2-F1 ejection seat was later used in the two Lunar Landing Research Vehicles and the three Lunar Landing Training Vehicles. Three of them crashed, but in each case the pilot ejected from the vehicle successfully. The wingless, lifting body aircraft design was initially conceived as a means of landing an aircraft horizontally after atmospheric reentry. The absence of wings would make the extreme heat of re-entry less damaging to the vehicle. In 1962, Dryden management approved a program to build a lightweight, unpowered lifting body as a prototype to flight test the wingless concept. It would look like a 'flying bathtub,' and was designated the M2-F1, the 'M' referring to 'manned' and 'F' referring to 'flight' version. It featured a plywood shell placed over a tubular steel frame crafted at Dryden. Construction was completed in 1963. The first flight tests of the M2-F1 were over Rogers Dry Lake at the end of a tow rope attached to a hopped-up Pontiac convertible driven at speeds up to about 120 mph. This vehicle needed to be able to tow the M2-F1 on the Rogers Dry Lakebed adjacent to NASA's Flight Research Center (FRC) at a minimum speed of 100 miles per hour. To do that, it had to handle the 400-pound pull of the M2-F1. Walter 'Whitey' Whiteside, who was a retired Air Force maintenance officer working in the FRC's Flight Operations Division, was a dirt-bike rider and hot-rodder. Together with Boyden 'Bud' Bearce in the Procurement and Supply Branch of the FRC, Whitey acquired a Pontiac Catalina convertible with

  19. Are Quasars Ejected from the Nucleus of NGC 4258?

    NASA Astrophysics Data System (ADS)

    Kondratko, P. T.; Greenhill, L. J.; Moran, J. M.

    2001-12-01

    The H2O maser in NGC 4258 traces a thin, almost edge-on, and slightly warped molecular disk around a supermassive black hole. Extensive measurements of the positions, three dimensional velocity vectors, and accelerations of dozens of masers are well explained by a simple disk model. However, discovery of two quasars with redshifts 0.39 and 0.65 symmetrically displaced by ~ 9' from the nucleus of NGC 4258 and located approximately at the position angle of the maser disk has fueled an alternative hypothesis by G. Burbidge, E.M. Burbidge, and co-workers. They proposed that the two quasars were ejected from the nucleus, are dynamically associated with the maser, and possess redshifts which are primarily non-cosmological in origin. We use 3 epochs of 20 cm VLBA images of one of the quasars and of NGC 4258 to derive an upper limit on the quasar proper motion of 0.4 mas year-1 (0.05 c) in the putative direction of ejection and with respect to the continuum emission from NGC 4258. This upper limit excludes the Ozernoy model in which the redshifts of the two quasars are primarily due to the transverse Doppler effect caused by a tranverse velocity of 6.6 mas year-1 (0.75 c). In addition to fixing an upper limit on the quasar proper motion, the images of NGC 4258 jet reveal a dominant, apparently stationary component located approximately ~ 6 mas north from the black hole and corresponding to the northern core of the jet. The distance of the core from the black hole scales with λ as expected in the standard model of Blandford and Königl. The southern jet core is undetected perhaps due to high optical depth associated with a hot, ionized wind or with an ionized material in the disk. The jet in the immediate vicinity of the central engine is characterized by γ >4.3, which appears to be relatively stable over time.

  20. RADIAL FLOW PATTERN OF A SLOW CORONAL MASS EJECTION

    SciTech Connect

    Feng, Li; Gan, Weiqun; Inhester, Bernd

    2015-06-01

    Height–time plots of the leading edge of coronal mass ejections (CMEs) have often been used to study CME kinematics. We propose a new method to analyze the CME kinematics in more detail by determining the radial mass transport process throughout the entire CME. Thus, our method is able to estimate not only the speed of the CME front but also the radial flow speed inside the CME. We have applied this method to a slow CME with an average leading edge speed of about 480 km s{sup −1}. In the Lagrangian frame, the speeds of the individual CME mass elements stay almost constant within 2 and 15 R{sub S}, the range over which we analyzed the CME. Hence, we have no evidence of net radial forces acting on parts of the CME in this range or of a pile up of mass ahead of the CME. We find evidence that the leading edge trajectory obtained by tie-pointing may gradually lag behind the Lagrangian front-side trajectories derived from our analysis. Our results also allow a much more precise estimate of the CME energy. Compared with conventional estimates using the CME total mass and leading edge motion, we find that the latter may overestimate the kinetic energy and the gravitational potential energy.

  1. Acceleration and Deceleration of Coronal Mass Ejection (CME) Propagation

    NASA Astrophysics Data System (ADS)

    Shen, F.; Wu, S.; Feng, X. S.; Wu, C.

    2011-12-01

    A major challenge to the space weather forecasting community is accurate prediction of coronal mass ejections (CME) induced Shock Arrival Time (SAT) at Earth's environment. In order to improve the current accuracy, it is necessary to understand the physical processes of the acceleration and deceleration of the CME propagation in the heliosphere. We present a three-dimensional (3D) magnetohydrodynamic (MHD) simulation of the evolution of two interacting CMEs in a realistic ambient solar wind for the March 28-31, 2001 event. The forces which caused the acceleration and deceleration are analyzed in detail. The force which caused the acceleration are Lorenz force and pressure gradient and the forces which caused the deceleration are aerodynamic drag and the Sun's gravity. In addition the momentum exchange between the solar wind and the moving CMEs can cause acceleration and deceleration of the CME which are now analyzed. In this specific CME event (March 28-31, 2001), we also investigate the interactions of two CMEs causing the acceleration and deceleration of the CMEs.

  2. Observations of Coronal Mass Ejections with the Coronal Multichannel Polarimeter

    NASA Astrophysics Data System (ADS)

    Tian, H.; Tomczyk, S.; McIntosh, S. W.; Bethge, C.; de Toma, G.; Gibson, S.

    2013-12-01

    The Coronal Multichannel Polarimeter (CoMP) measures not only the polarization of coronal emission, but also the full radiance profiles of coronal emission lines. For the first time, CoMP observations provide high-cadence image sequences of the coronal line intensity, Doppler shift, and line width simultaneously over a large field of view. By studying the Doppler shift and line width we may explore more of the physical processes of the initiation and propagation of coronal mass ejections (CMEs). Here we identify a list of CMEs observed by CoMP and present the first results of these observations. Our preliminary analysis shows that CMEs are usually associated with greatly increased Doppler shift and enhanced line width. These new observations provide not only valuable information to constrain CME models and probe various processes during the initial propagation of CMEs in the low corona, but also offer a possible cost-effective and low-risk means of space-weather monitoring.

  3. MAGNETIC FIELD STRUCTURES TRIGGERING SOLAR FLARES AND CORONAL MASS EJECTIONS

    SciTech Connect

    Kusano, K.; Bamba, Y.; Yamamoto, T. T.; Iida, Y.; Toriumi, S.; Asai, A.

    2012-11-20

    Solar flares and coronal mass ejections, the most catastrophic eruptions in our solar system, have been known to affect terrestrial environments and infrastructure. However, because their triggering mechanism is still not sufficiently understood, our capacity to predict the occurrence of solar eruptions and to forecast space weather is substantially hindered. Even though various models have been proposed to determine the onset of solar eruptions, the types of magnetic structures capable of triggering these eruptions are still unclear. In this study, we solved this problem by systematically surveying the nonlinear dynamics caused by a wide variety of magnetic structures in terms of three-dimensional magnetohydrodynamic simulations. As a result, we determined that two different types of small magnetic structures favor the onset of solar eruptions. These structures, which should appear near the magnetic polarity inversion line (PIL), include magnetic fluxes reversed to the potential component or the nonpotential component of major field on the PIL. In addition, we analyzed two large flares, the X-class flare on 2006 December 13 and the M-class flare on 2011 February 13, using imaging data provided by the Hinode satellite, and we demonstrated that they conform to the simulation predictions. These results suggest that forecasting of solar eruptions is possible with sophisticated observation of a solar magnetic field, although the lead time must be limited by the timescale of changes in the small magnetic structures.

  4. Effect of solar Coronal Mass Ejections on the ionosphere

    NASA Astrophysics Data System (ADS)

    Sheiner, Olga; Fridman, Vladimir; Rakhlin, Alexander; Pershin, Alexsander; Vybornov, Feodor

    The influence of solar processes on the state of near-earth space is constantly the object of serious study. First of all the solar radiation affects the parameters of the ionosphere and ionizing processes in it. The basic level indicator of the ionized particles is the critical frequency f0F2 of the reflection of radio signal during sounding of ionosphere. Understanding of the role of Coronal Mass Ejections (CME) in global solar-terrestrial processes allow us to put up the problem about their possible influence on near Earth’ processes and ionosphere behavior. Earlier the authors proposed the procedure of the detection the influence of CMEs on the differential parameters of the upper ionosphere Deltaf0F2 as more sensitive in comparison with the traditional methods. First results were based on the data of regular observations of critical frequency f0F2 during the cycle of solar activity (1975-1986). To verify the relationship discovered we used in the proposed study the data of critical frequency f0F2, determined from uniform ionograms obtained with the modern digital Ionosonde CADI. This ionosonde is installed at the landfill NIRFI "Vasilsursk" (near Nizhny Novgorod), and working program of regular observations allowed to obtain ionograms at least once in 1 minutes. The accuracy of determining the critical frequency was less than ± 50 kHz. There are many examples of time coincidence between the periods of CMEs existence and negative deflection in Deltaf0F2 behaviour.

  5. The 3D structure of Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Patsourakos, Spiros

    2016-07-01

    Coronal Mass Ejections (CMEs) represent one of the most powerful energy release phenomena in the entire solar system and are a major driver of space weather. Prior to 2006, our observational access to CMEs was limited to single viewpoint remote sensing observations in the inner/outer corona, and in-situ observations further away, e.g. at 1 AU. Taking all these factors together, turned out to be a major obstacle in our understanding and characterizing of the 3D structure and evolution of CMEs. The situation improved dramatically with the availability of multi-viewpoint imaging observations of CMEs, all way through from the Sun to 1 AU, from the STEREO mission since 2006, combined with observations from other missions (SOHO, Hinode, SDO, IRIS). With this talk we will discuss several key recent results in CME science resulting from the analysis of multi-viewpoint observations. This includes: (1) shape and structure; (2) kinematics and energetics; (3) trajectories, deflections and rotations; (4) arrival times and velocities at 1 AU; (5) magnetic field structure; (6) relationships with coronal and interplanetary shocks and solar energetic particles. The implications of these results in terms of CME theories and models will be also addressed. We will conclude with a discussion of important open issues in our understanding of CMEs and how these could be addressed with upcoming (Solar Orbiter, Solar Probe Plus) and under-study missions (e.g., L5).

  6. Characterizing the original ejection velocity field of the Koronis family

    NASA Astrophysics Data System (ADS)

    Carruba, V.; Nesvorný, D.; Aljbaae, S.

    2016-06-01

    An asteroid family forms as a result of a collision between an impactor and a parent body. The fragments with ejection speeds higher than the escape velocity from the parent body can escape its gravitational pull. The cloud of escaping debris can be identified by the proximity of orbits in proper element, or frequency, domains. Obtaining estimates of the original ejection speed can provide valuable constraints on the physical processes occurring during collision, and used to calibrate impact simulations. Unfortunately, proper elements of asteroids families are modified by gravitational and non-gravitational effects, such as resonant dynamics, encounters with massive bodies, and the Yarkovsky effect, such that information on the original ejection speeds is often lost, especially for older, more evolved families. It has been recently suggested that the distribution in proper inclination of the Koronis family may have not been significantly perturbed by local dynamics, and that information on the component of the ejection velocity that is perpendicular to the orbital plane (vW), may still be available, at least in part. In this work we estimate the magnitude of the original ejection velocity speeds of Koronis members using the observed distribution in proper eccentricity and inclination, and accounting for the spread caused by dynamical effects. Our results show that (i) the spread in the original ejection speeds is, to within a 15% error, inversely proportional to the fragment size, and (ii) the minimum ejection velocity is of the order of 50 m/s, with larger values possible depending on the orbital configuration at the break-up.

  7. From SOHO to STEREO: Understanding Propagation of Coronal Mass Ejections

    NASA Technical Reports Server (NTRS)

    Gopalswamy, Natchimuthuk

    2011-01-01

    Direct comparison between coronal mass ejections (CMEs) from near the Sun and their solar wind counterparts became possible roughly a decade after the discovery of CMEs (Lindsay et aL 1999). This comparison revealed that fast CMEs decelerate and slow CMEs accelerate due to the interaction with the solar wind. Gopalswamy et al (2000) quantified this interaction as an interplanetary acceleration which is useful in predicting the arrival time and speed of CMEs at 1 AU. The interplanetary acceleration is essentially due to the aerodynamic drag between the CME and the solar wind because the propelling force and the solar gravity are effective only near the Sun. Combined remote-sensing and in situ observations from SOHO and Wind/ACE have helped us estimate the influence of the solar wind on the propagation of CMEs. However, these measurements have severe limitations because the remote sensed and in-situ observations correspond to different portions of the CME. Furthermore, the true speeds of Earth-directed CMEs cannot be measured accurately from a spacecraft located along the Sun-Earth line. There have been attempts to model the CME as a cone and get the space speed of the CME, which did improve the travel time predictions. Instruments on board the Solar Terrestrial Relations Observatory (STEREO) mission were able to provide observations of Earth-arriving CMEs without projection effects, while the same CMEs were observed at Sun-Earth L1 by Wind and ACE spacecraft. The quadrature between STEREO and L1 spacecraft presented an ideal situation to study the interplanetary evolution of CMEs and test earlier model results. The quadrature observations did improve the CME travel time predictions, but additional factors such as the unusually slow solar wind, CME cannibalism, and coronal-hole deflection need to be considered to reconcile the difference between observed and predicted travel times. This point is illustrated using the 2011 February 15 CME

  8. Comparison of Brachial Vein Versus Internal Jugular Vein Approach for Access to the Right Side of the Heart With or Without Myocardial Biopsy.

    PubMed

    Harwani, Neha; Chukwu, Ebere; Alvarez, Manrique; Thohan, Vinay

    2015-09-01

    Right heart catheterization (RHC) and endomyocardial biopsy are mainstay procedures for patients with heart failure and heart transplantation. Approaches are predominantly neck (internal jugular) or leg (femoral vein). We describe a novel arm (brachial/basilica vein) approach. Over 5.5 years, 1,130 right-sided cardiac procedures in 276 patients were analyzed retrospectively and divided into either neck or arm approach. Comparative analyses of procedural success, time, safety, efficacy, and cost were performed. Patient preference was assessed for those who had both neck and arm approaches. In patients receiving RHC (174 neck and 121 arm cases) and in those receiving RHC + biopsy (594 neck and 141 arm cases), mean elapsed and fluoroscopic times (minutes), respectively, were 60 ± 20 versus 62 ± 19 and 3.43 ± 3.8 versus 4.99 ± 5.2 (RHC neck vs arm, respectively), and 55 ± 19 versus 63 ± 17 and 4.14 ± 3.4 versus 5.22 ± 2.6 (RHC + biopsy neck vs arm, respectively). Procedural complications were low (n = 7, 0.6%) and restricted to the neck approach. Patients surveyed preferred the arm approach. In conclusion, RHC and endomyocardial biopsy through the brachial vein can be performed safely, timely, effectively, and at equivalent cost compared with a neck approach. We advocate that an arm approach be the preferred method for these procedures.

  9. Morphology of ejected debris from laser super-heated fused silica following exit surface laser-induced damage

    NASA Astrophysics Data System (ADS)

    Demos, Stavros G.; Negres, Raluca A.; Raman, Rajesh N.; Feit, Michael D.; Manes, Kenneth R.; Rubenchik, Alexander M.

    2015-11-01

    Laser induced damage (breakdown) initiated on the exit surface of transparent dielectric materials using nanosecond pulses creates a volume of superheated material reaching localized temperatures on the order of 1 eV and pressures on the order of 10 GPa or larger. This leads to material ejection and the formation of a crater. The volume of this superheated material depends largely on the laser parameters such as fluence and pulse duration. To elucidate the material behaviors involved, we examined the morphologies of the ejected superheated material particles and found distinctive morphologies. We hypothesize that these morphologies arise from the difference in the structure and physical properties (such as the dynamic viscosity and presence of instabilities) of the superheated material at the time of ejection of each individual particle. Some of the ejected particles are on the order of 1 µm in diameter and appear as "droplets". Another subgroup appears to have stretched, foam-like structure that can be described as material globules interconnected via smaller in diameter columns. Such particles often contain nanometer size fibers attached on their surface. In other cases, only the globules have been preserved suggesting that they may be associated with a collapsed foam structure under the dynamic pressure as it traverses in air. These distinct features originate in the structure of the superheated material during volume boiling just prior to the ejection of the particles.

  10. A case of difficult catheterization of the contralateral limb of the Ovation Abdominal Stent Graft System in challenging aortoiliac anatomy, facilitated through the brachial access: a word of caution.

    PubMed

    Georgakarakos, Efstratios; Ioannou, Chris V; Kontopodis, Nikolaos; Tsetis, Dimitrios

    2015-02-01

    The Ovation Stent Graft System is a new trimodular endoprosthesis for the treatment of abdominal aortic aneurysms. A long nitinol stent with anchors serves the suprarenal fixation, whereas inflatable rings in the main body achieve sealing. This dissociation precludes the presence of a nitinol skeleton in the endograft, thus, avoiding competing for the same space within the delivery system, enabling the latter to achieve ultra-low profiles. However, the lack of nitinol support may render the endograft's docking limb prone to collapse in cases of narrow aortoiliac anatomy. We present a case of challenging contralateral limb catheterization, facilitated effectively through the brachial access. Preparing for the brachial route remains a useful and time-sparing adjunctive measure that guarantees the device's safety and effectiveness in challenging anatomies. PMID:25433281

  11. Diagnostic Value and Surgical Implications of the 3D DW-SSFP MRI On the Management of Patients with Brachial Plexus Injuries

    PubMed Central

    Qin, Ben-Gang; Yang, Jian-Tao; Yang, Yi; Wang, Hong-Gang; Fu, Guo; Gu, Li-Qiang; Li, Ping; Zhu, Qing-Tang; Liu, Xiao-Lin; Zhu, Jia-Kai

    2016-01-01

    Three-dimensional diffusion-weighted steady-state free precession (3D DW-SSFP) of high-resolution magnetic resonance has emerged as a promising method to visualize the peripheral nerves. In this study, the application value of 3D DW-SSFP brachial plexus imaging in the diagnosis of brachial plexus injury (BPI) was investigated. 33 patients with BPI were prospectively examined using 3D DW-SSFP MR neurography (MRN) of brachial plexus. Results of 3D DW-SSFP MRN were compared with intraoperative findings and measurements of electromyogram (EMG) or somatosensory evoked potentials (SEP) for each injured nerve root. 3D DW-SSFP MRN of brachial plexus has enabled good visualization of the small components of the brachial plexus. The postganglionic section of the brachial plexus was clearly visible in 26 patients, while the preganglionic section of the brachial plexus was clearly visible in 22 patients. Pseudomeningoceles were commonly observed in 23 patients. Others finding of MRN of brachial plexus included spinal cord offset (in 16 patients) and spinal cord deformation (in 6 patients). As for the 3D DW-SSFP MRN diagnosis of preganglionic BPI, the sensitivity, the specificity and the accuracy were respectively 96.8%, 90.29%, and 94.18%. 3D DW-SSFP MRN of brachial plexus improve visualization of brachial plexus and benefit to determine the extent of injury. PMID:27782162

  12. Coupled thermal analysis applied to the study of the rod ejection accident

    SciTech Connect

    Gonnet, M.

    2012-07-01

    An advanced methodology for the assessment of fuel-rod thermal margins under RIA conditions has been developed by AREVA NP SAS. With the emergence of RIA analytical criteria, the study of the Rod Ejection Accident (REA) would normally require the analysis of each fuel rod, slice by slice, over the whole core. Up to now the strategy used to overcome this difficulty has been to perform separate analyses of sampled fuel pins with conservative hypotheses for thermal properties and boundary conditions. In the advanced methodology, the evaluation model for the Rod Ejection Accident (REA) integrates the node average fuel and coolant properties calculation for neutron feedback purpose as well as the peak fuel and coolant time-dependent properties for criteria checking. The calculation grid for peak fuel and coolant properties can be specified from the assembly pitch down to the cell pitch. The comparative analysis of methodologies shows that coupled methodology allows reducing excessive conservatism of the uncoupled approach. (authors)

  13. Determination of left ventricular ejection fraction in technetium-99m-methoxy isobutyl isonitrile radionuclide angiocardiography

    NASA Astrophysics Data System (ADS)

    Davis, Malcolm H.; Rezaie, Bahman; Weiland, Frederick L.

    1992-06-01

    Abnormal left ventricular function is a diagnostic indication of cardiac disease. Left ventricular function is most commonly quantified by ejection fraction measurements. This paper presents a novel approach for the measurement of left ventricular ejection fraction (L VEF) using the recently introduced myocardial imaging agent, technetium-99m methoxy isobutyl isonitrile (99mTc-sestamibi). The approach utilizes computer image processing techniques to determine L VEF in equilibrium 99mTc-sestamibi multiple gated radionuclide angiography (RNA). Equilibrium RNA is preferred to first-pass RNA techniques due to the higher signal-to-noise ratio of equilibrium RNA resulting from longer image acquisition times. Data from 23 patients, symptomatic of cardiac disease, indicate that L VEFs determined using this radionuclide technique correlate well with contrast x-ray single plane cineangiography (r equals 0.83, p < 0.0000003).

  14. Swapping Rocks: Ejection and Exchange of Surface Material Among the Terrestrial Planets

    NASA Astrophysics Data System (ADS)

    Melosh, H. J.; Tonks, W. B.

    1993-07-01

    The discovery of meteorites originating from both the Moon and Mars has led to the realization that major impacts can eject material from planetary-sized objects. Although there is not yet any direct proof, there appears to be no reason why such impacts cannot eject material from the surfaces of Earth and Venus as well. Because of this possibility, and in view of the implications of such exchange for biological evolution, we examined the orbital evolution and ultimate fate of ejecta from each of the terrestrial planets. This work employed an Opik-type orbital evolution model in which both planets and ejected particles follow elliptical orbits about the Sun, with uniformly precessing arguments of perihelion and ascending nodes. An encounter takes place when the particle passes within the sphere of influence of the planet. When this occurs, the encounter is treated as a two-body scattering event, with a randomly chosen impact parameter within the sphere of influence. If the impact parameter is less than the planet's radius, an impact is scored. Otherwise, the scattered particle either takes up a new Keplerian orbit or is ejected from the solar system. We incorporated several different space erosion models and examined the full matrix of possible outcomes of ejection from each planet in random directions with velocities at great distance from the planet of 0.5, 2.5, and 5.0 km/s. Each run analyzed the evolution of 5000 particles to achieve sufficient statistical resolution. Both the ultimate fate and median transit times of particles was recorded. The results show very little dependence on velocity of ejection. Mercury ejecta is nearly all reaccreted by Mercury or eroded in space--very little ever evolves to cross the orbits of the other planets (a few percent impact Venus). The median time between ejection and reimpact is about 30 m.y. for all erosion models. Venus ejecta is mostly reaccreted by Venus, but a significant fraction (about 30%) falls on the Earth with a

  15. DNA heats up: energetics of genome ejection from phage revealed by isothermal titration calorimetry.

    PubMed

    Jeembaeva, Meerim; Jönsson, Bengt; Castelnovo, Martin; Evilevitch, Alex

    2010-02-01

    Most bacteriophages are known to inject their double-stranded DNA into bacteria upon receptor binding in an essentially spontaneous way. This downhill thermodynamic process from the intact virion to the empty viral capsid plus released DNA is made possible by the energy stored during active packaging of the genome into the capsid. Only indirect measurements of this energy have been available until now, using either single-molecule or osmotic suppression techniques. In this work, we describe for the first time the use of isothermal titration calorimetry to directly measure the heat released (or, equivalently, the enthalpy) during DNA ejection from phage lambda, triggered in solution by a solubilized receptor. Quantitative analyses of the results lead to the identification of thermodynamic determinants associated with DNA ejection. The values obtained were found to be consistent with those previously predicted by analytical models and numerical simulations. Moreover, the results confirm the role of DNA hydration in the energetics of genome confinement in viral capsids.

  16. Simulation of a liquid droplet ejection device using multi-actuator

    NASA Astrophysics Data System (ADS)

    Ono, Yoshihiro; Yoshino, Michitaka; Yasuda, Akira; Tanuma, Chiaki

    2016-07-01

    An equivalent circuit model for a liquid droplet ejection device using a multiactuator has been developed. The equivalent circuit was simplified using a gyrator in the synthesis of the outputs of many elements. The simulation was performed for an inkjet head having three piezoelectric elements using MATLAB/Simulink. In this model, the pressure chamber is filled with a Newtonian fluid. For this reason, the model assumed only the resistance component of the pressure chamber and the nozzle as a load. Furthermore, since the resistance component of the inlet is much larger than that of the nozzle, it is not considered in this model. As a result, by providing a time difference between the driving signals of the piezoelectric elements, we found that the pressure of the ink chamber could be arbitrarily controlled. By this model, it becomes possible to control the pressure in the ink chamber of the inkjet head required for the ejection of various inks.

  17. Generalization and Optimization of Biological and Biomimetic Ejection Mechanisms

    NASA Astrophysics Data System (ADS)

    Dabiri, John O.; Milano, Michele; Gharib, Morteza

    2003-11-01

    Unsteady mechanisms for fluid ejection are found in biological systems from jellyfish to the human heart. An understanding of these mechanisms is needed to correct pathologies in natural systems and to design biomimetic systems. In particular, the formation process of the recurring vortex ring motif must be studied. It has been previously shown that ring formation is limited by the energy available from the vortex generator, and that ejection efficiency is maximized as the limit is reached. To assess the ability of biological systems to extend this limit, we derive a set of nondimensional criteria that facilitate comparison of ejection mechanisms with dissimilar kinematics. We optimize the derived criteria by means of an evolutionary algorithm, to design optimal ejection mechanisms. The results obtained are compared with some natural systems to derive general principles for the design of better unsteady ejection mechanisms. Additionally, the generalized criteria clarify the effect of previous suggestions for extending the vortex ring formation limit. This work is supported by a grant from the National Science Foundation.

  18. Inhibition of DNA ejection from bacteriophage by Mg+2 counterions

    NASA Astrophysics Data System (ADS)

    Lee, Sell; Tran, C. V.; Nguyen, T. T.

    2011-03-01

    The problem of inhibiting viral DNA ejection from bacteriophages by multivalent counterions, specifically Mg+2 counterions, is studied. Experimentally, it is known that MgSO4 salt has a strong and nonmonotonic effect on the amount of DNA ejected. There exists an optimal concentration at which the minimum amount of DNA is ejected from the virus. At lower or higher concentrations, more DNA is ejected from the capsid. We propose that this phenomenon is the result of DNA overcharging by Mg+2 multivalent counterions. As Mg+2 concentration increases from zero, the net charge of DNA changes from negative to positive. The optimal inhibition corresponds to the Mg+2 concentration where DNA is neutral. At lower/higher concentrations, DNA genome is charged. It prefers to be in solution to lower its electrostatic self-energy, which consequently leads to an increase in DNA ejection. By fitting our theory to available experimental data, the strength of DNA-DNA short range attraction energies, mediated by Mg+2, is found to be -0.004 kBT per nucleotide base. This and other fitted parameters agree well with known values from other experiments and computer simulations. The parameters are also in agreement qualitatively with values for tri- and tetravalent counterions.

  19. Inhibition of DNA ejection from bacteriophage by Mg^+2 counterions

    NASA Astrophysics Data System (ADS)

    Lee, Seil; Tran, Cathy V.; Nguyen, Toan T.

    2009-03-01

    The problem of inhibiting viral DNA ejection from bacteriophages by multivalent counterions, especially Mg^+2 counterions, is studied. Experimentally, it is known that MgSO4 salt has a strong and non-monotonic effect on the amount of DNA ejected. There exists an optimal concentration at which the least DNA is ejected from the virus. At lower or higher concentrations, more DNA is ejected from the capsid. We propose that this phenomenon is the result of DNA overcharging by Mg^+2 multivalent counterions. As Mg^+2 concentration increases from zero, DNA net charge changes from negative to positive. The optimal inhibition corresponds to the Mg^+2 concentration where DNA is neutral. At lower/higher concentrations, DNA genome is charged. It prefers to be in solution to lower its electrostatic self-energy, which consequently leads to an increase in DNA ejection. Our theory fits experimental data well. The strength of DNA-DNA short range attraction, mediated by Mg^+2, is found to be -0.003 kBT per nucleotide base.

  20. Could Jupiter or Saturn Have Ejected a Fifth Giant Planet?

    NASA Astrophysics Data System (ADS)

    Cloutier, Ryan; Tamayo, Daniel; Valencia, Diana

    2015-11-01

    Models of the dynamical evolution of the early solar system that follow the dispersal of the gaseous protoplanetary disk have been widely successful in reconstructing the current orbital configuration of the giant planets. Statistically, some of the most successful dynamical evolution simulations have initially included a hypothetical fifth giant planet, of ice giant (IG) mass, which gets ejected by a gas giant during the early solar system’s proposed instability phase. We investigate the likelihood of an IG ejection (IGE) event by either Jupiter or Saturn through constraints imposed by the current orbits of their wide-separation regular satellites Callisto and Iapetus, respectively. We show that planetary encounters that are sufficient to eject an IG often provide excessive perturbations to the orbits of Callisto and Iapetus, making it difficult to reconcile a planet ejection event with the current orbit of either satellite. Quantitatively, we compute the likelihood of reconciling a regular Jovian satellite orbit with the current orbit of Callisto following an IGE by Jupiter of ∼42%, and conclude that such a large likelihood supports the hypothesis of a fifth giant planet’s existence. A similar calculation for Iapetus reveals that it is much more difficult for Saturn to have ejected an IG and reconciled a Kronian satellite orbit with that of Iapetus (likelihood ∼1%), although uncertainties regarding the formation of Iapetus, with its unusual orbit, complicates the interpretation of this result.

  1. Reducing Space Charge Effects in a Linear Ion Trap by Rhombic Ion Excitation and Ejection

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaohua; Wang, Yuzhuo; Hu, Lili; Guo, Dan; Fang, Xiang; Zhou, Mingfei; Xu, Wei

    2016-07-01

    Space charge effects play important roles in ion trap operations, which typically limit the ion trapping capacity, dynamic range, mass accuracy, and resolving power of a quadrupole ion trap. In this study, a rhombic ion excitation and ejection method was proposed to minimize space charge effects in a linear ion trap. Instead of applying a single dipolar AC excitation signal, two dipolar AC excitation signals with the same frequency and amplitude but 90° phase difference were applied in the x- and y-directions of the linear ion trap, respectively. As a result, mass selective excited ions would circle around the ion cloud located at the center of the ion trap, rather than go through the ion cloud. In this work, excited ions were then axially ejected and detected, but this rhombic ion excitation method could also be applied to linear ion traps with ion radial ejection capabilities. Experiments show that space charge induced mass resolution degradation and mass shift could be alleviated with this method. For the experimental conditions in this work, space charge induced mass shift could be decreased by ~50%, and the mass resolving power could be improved by ~2 times at the same time.

  2. Studies of hydrodynamic events in stellar evolution. III Ejection of planetary nebulae

    NASA Technical Reports Server (NTRS)

    Kutter, G. S.; Sparks, W. M.

    1974-01-01

    Investigation of the dynamic behavior of the hydrogen-rich envelope (0.101 solar mass) of an evolved star (1.1 solar mass) as the luminosity rises to 19,000 solar luminosities during the second ascent of the red-giant branch. For luminosities in the range 3100 less than L less than 19,000 solar luminosities the H-rich envelope pulsates like a long-period variable (LPV) with periods of the order of a year. As L reaches 19,000 solar luminosities, the entire H-rich envelope is ejected as a shell with speeds of a few times 10 km sec. The ejection occurs on a time scale of a few LPV pulsation periods. This ejection is shown to be related to the formation of a planetary nebula. The computations are based on an implicit hydrodynamic computer code. Tand rho-dependent opacities and excitation and ionization energies are included. As the H-rich envelope is accelerated off the stellar core, the gap between envelope and core is approximated by a vacuum filled with radiation.

  3. Venous thrombosis in subclavian, axillary, brachial veins with extension to internal jugular vein, right sigmoid sinus and simultaneous pulmonary embolism

    PubMed Central

    Tamizifar, Babak; Beigi, Arash; Rismankarzadeh, Maryam

    2013-01-01

    We present a rare case of Venous Thrombosis in Subclavian, Axillary, Brachial Veins with extension to Internal Jugular vein, right sigmoid sinus and simultaneous Pulmonary embolism during the treatment with low molecular weight heparin. PMID:23901341

  4. The ejection anisotropy in the Coulomb explosion of some alkyl halide molecules under strong ps laser fields

    NASA Astrophysics Data System (ADS)

    Kaziannis, S.; Kosmidis, C.

    2009-01-01

    The ejection anisotropy of Coulomb explosion fragments released from alkyl halide molecules (C 2H 5X, 1-C 3H 7X and 1-C 4H 9X, where X = Br, Cl) under strong 35 ps laser irradiation is studied by means of time-of-flight mass spectrometry. By comparing the angular distributions widths of the halogen fragment ions originating from multiply charged molecular ions it is concluded that the ejection anisotropy presents a weak dependence on the mass of the halogen atom, observed especially in the case of ethyl halide molecules, while a stronger dependence is found on the size of the alkyl chain.

  5. Polarization instability of Raman solitons ejected during supercontinuum generation.

    PubMed

    Chao, Qing; Wagner, Kelvin H

    2015-12-28

    We numerically investigate polarization instability of soliton fission and the polarization dynamics of Raman solitons ejected during supercontinuum generation in a photonics crystal fiber using the coupled vector generalized nonlinear Schrödinger equations for both linear and circular birefringent fibers. The evolution of the state of polarizations of the ejected Raman soliton as representated on the Poincaré sphere is affected by both nonlinear and linear polarization rotations on the Poincaré sphere. The polarization dynamics reveal the presence of a polarization separatrix and the emergence of stable slow and unstable fast eigen-polarizations for the Raman solitons ejected in the supercontinuum generation process. Circularly birefringent fiber is investigated and found to simplify the nonlinear polarization dynamics. PMID:26832032

  6. Ejection of a rear facing, golf cart passenger.

    PubMed

    Schau, Kyle; Masory, Oren

    2013-10-01

    The following report details the findings of a series of experiments and simulations performed on a commercially available, shuttle style golf cart during several maneuvers involving rapid accelerations of the vehicle. It is determined that the current set of passive restraints on these types of golf carts are not adequate in preventing ejection of a rear facing passenger during rapid accelerations in the forward and lateral directions. Experimental data and simulations show that a hip restraint must be a minimum of 13 in. above the seat in order to secure a rear facing passenger during sharp turns, compared to the current restraint height of 5 in. Furthermore, it is determined that a restraint directly in front of the rear facing passenger is necessary to prevent ejection. In addressing these issues, golf cart manufacturers could greatly reduce the likelihood of injury due to ejection of a rear facing, golf cart passenger. PMID:23958856

  7. The Numerical Simulation of Flow around Ejection System

    NASA Astrophysics Data System (ADS)

    Zhang, Dalin; Wei, Tao

    Aerodynamic characteristics of an Ejection Seat System at different angles of attack are studied by the numerical method and the flow mechanisms for such flows are carefully analyzed. The governing equations are Reynolds-averaged Navier-Stokes equations which are solved by the unstructured finite volume method. Upwind Osher scheme is used for spatial discretization and five-stage Runge-Kutta scheme is applied for temporal discretization. The DES model based on S-A one equation turbulence model is adopted. Parallel computation is based on the domain decomposition method and multi-block is achieved by using METIS system. The experimental data is used to validate this method. This research is helpful to understand the aerodynamic characteristics and flow mechanisms of Ejection Seat System at different angles of attack and Mach numbers, and can provide reasonable reference for Ejection Seat System design.

  8. Lil HAL: digital kneeboard for ejection seat aircraft

    NASA Astrophysics Data System (ADS)

    Parisi, Vince

    2004-09-01

    In the last few years, airlines, commercial air carriers and the military have begun to introduce electronic tools into the cockpit to replace paper versions of flight publications, flight plans, departure and approach plates, maps, etc. These devices have varied from the common laptop to the smaller pen-tablet type computers. In some instances these devices have been connected to aircraft data buses to collect maintenance data, fault codes and other useful information. None of these devices, however, have been found satisfactory in ejection seat aircraft due to their size, weight, and dynamic characteristics when subjected to the inertial and aerodynamic forces that occur during an ejection. This paper describes an electronic digital kneeboard suitable for use in an ejection seat aircraft. The kneeboard consists of a look at helmet-mounted display, a small streamlined kneeboard input device, a carry-on/carry-off computer and its associated support interfaces.

  9. Restraint effectiveness, occupant ejection from cars, and fatality reductions.

    PubMed

    Evans, L

    1990-04-01

    The effectiveness of air cushion restraint systems, or airbags, in preventing fatalities is estimated by assuming that they do not affect ejection probability, and protect only in frontal, or near frontal, crashes with impact-reducing effectiveness equal to that of lap/shoulder belts. In order to compute airbag effectiveness, lap/shoulder belt effectiveness and the fraction of fatalities preventable by eliminating ejection are estimated using Fatal Accident Reporting System (FARS) data. Ejection prevention is found to account for almost half of the effectiveness of lap/shoulder belts (essentially all for lap belts only). Airbag effectiveness is estimated as (18 +/- 4)% in preventing fatalities to drivers and (13 +/- 4)% to right front passengers. Drivers switching from lap/shoulder belt to airbag-only protection increase their fatality risk by 41%. PMID:2331291

  10. Ejection of a rear facing, golf cart passenger.

    PubMed

    Schau, Kyle; Masory, Oren

    2013-10-01

    The following report details the findings of a series of experiments and simulations performed on a commercially available, shuttle style golf cart during several maneuvers involving rapid accelerations of the vehicle. It is determined that the current set of passive restraints on these types of golf carts are not adequate in preventing ejection of a rear facing passenger during rapid accelerations in the forward and lateral directions. Experimental data and simulations show that a hip restraint must be a minimum of 13 in. above the seat in order to secure a rear facing passenger during sharp turns, compared to the current restraint height of 5 in. Furthermore, it is determined that a restraint directly in front of the rear facing passenger is necessary to prevent ejection. In addressing these issues, golf cart manufacturers could greatly reduce the likelihood of injury due to ejection of a rear facing, golf cart passenger.

  11. Experimental investigation on ejecting low-temperature cooling superconducting magnets

    NASA Astrophysics Data System (ADS)

    Liu, Bin; Zhang, Qiang; Tong, Ming-wei; Hu, Peng; Wu, Shuang-ying; Cai, Qin; Qin, Zeng-hu

    2013-10-01

    With the development of the high-temperature superconducting (HTS) materials and refrigeration technologies, using ejecting refrigeration to cool the superconducting materials becomes the direction of HTS applications. In this paper, an experimental study has been carried out on the basis of the theory of analyzing the ejecting low-temperature cooling superconducting magnet. The relationship between area ratios and refrigeration performance at different system pressures was derived. In addition, the working fluid flow and suction chamber pressure of the ejector with different area ratios at various inlet pressures have been examined to obtain the performance of ejectors under different working conditions. The result shows that the temperature of liquid nitrogen can be reduced to 70 K by controlling the inlet water pressure when the pressurized water at 20 °C is used to eject the saturated liquid nitrogen, which can provide the stable operational conditions for the HTS magnets cooling.

  12. Capstan Friction Model for DNA Ejection from Bacteriophages

    NASA Astrophysics Data System (ADS)

    Ghosal, Sandip

    2012-12-01

    Bacteriophages infect cells by attaching to the outer membrane and injecting their DNA into the cell. The phage DNA is then transcribed by the cell’s transcription machinery. A number of physical mechanisms by which DNA can be translocated from the phage capsid into the cell have been identified. A fast ejection driven by the elastic and electrostatic potential energy of the compacted DNA within the viral capsid appears to be used by most phages, at least to initiate infection. In recent in vitro experiments, the speed of DNA translocation from a λ phage capsid has been measured as a function of ejected length over the entire duration of the event. Here, a mechanical model is proposed that is able to explain the observed dependence of exit velocity on ejected length, and that is also consistent with the accepted picture of the geometric arrangement of DNA within the viral capsid.

  13. Interplanetary Coronal Mass Ejections Observed by MESSENGER and Venus Express

    NASA Astrophysics Data System (ADS)

    Good, S. W.; Forsyth, R. J.

    2016-01-01

    Interplanetary coronal mass ejections (ICMEs) observed by the MESSENGER and Venus Express spacecraft have been catalogued and analysed. The ICMEs were identified by a relatively smooth rotation of the magnetic field direction consistent with a flux rope structure, coinciding with a relatively enhanced magnetic field strength. A total of 35 ICMEs were found in the surveyed MESSENGER data (primarily from March 2007 to April 2012), and 84 ICMEs in the surveyed Venus Express data (from May 2006 to December 2013). The ICME flux rope configurations have been determined. Ropes with northward leading edges were about four times more common than ropes with southward leading edges, in agreement with a previously established solar cycle dependence. Ropes with low inclinations to the solar equatorial plane were about four times more common than ropes with high inclinations, possibly an observational effect. Left- and right-handed ropes were observed in almost equal numbers. In addition, data from MESSENGER, Venus Express, STEREO-A, STEREO-B and ACE were examined for multipoint signatures of the catalogued ICMEs. For spacecraft separations below 15° in heliocentric longitude, the second spacecraft observed the ICME flux rope in 82 % of cases; this percentage dropped to 49 % for separations between 15 and 30°, to 18 % for separations between 30 and 45°, and to 12 % for separations between 45 and 60°. As the spacecraft separation increased, it became increasingly likely that only the sheath and not the flux rope of the ICME was observed, in agreement with the notion that ICME flux ropes are smaller in longitudinal extent than the shocks or discontinuities that they often drive. Furthermore, this study has identified 23 ICMEs observed by pairs of spacecraft close to radial alignment. A detailed analysis of these events could lead to a better understanding of how ICMEs evolve during propagation.

  14. Ventricular ejection force in growth-retarded fetuses.

    PubMed

    Rizzo, G; Capponi, A; Rinaldo, D; Arduini, D; Romanini, C

    1995-04-01

    The objective of this study was to determine whether in growth-retarded fetuses secondary to uteroplacental insufficiency the cardiac ventricles exert a force different from that of appropriately grown fetuses. Doppler echocardiographic studies were performed in 156 appropriately grown fetuses (gestational age 18-38 weeks) and in 72 growth-retarded fetuses (gestational age 24-36 weeks) free from structural and chromosomal abnormalities and characterized by Doppler changes in the umbilical artery and middle cerebral artery suggesting uteroplacental insufficiency as the most likely etiology of the growth defect. Right and left ventricular ejection force values were calculated from velocity waveforms recorded at the level of aortic and pulmonary valves, according to Newton's second law of motion. In appropriately grown fetuses, left and right ventricular ejection force values significantly increased with advancing gestation and the two ventricles exerted similar force. In growth-retarded fetuses, the ventricular ejection force was significantly and symmetrically decreased in both ventricles. Among growth-retarded fetuses, a poorer perinatal outcome was observed in those fetuses in which the ejection force of both ventricles was below the 5th centile of the normal limits for gestation. In 12 growth-retarded fetuses followed longitudinally during the last week preceding intrauterine death or Cesarean section due to antepartum heart-rate late decelerations, a significant decrease of ejection force was found in both ventricles. Finally, a significant relationship was found between the severity of acidosis and right and left ventricular ejection force values in 22 fetuses in which Doppler recordings were performed immediately before cordocentesis.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Exercise Intolerance In Heart Failure With Preserved Ejection Fraction

    PubMed Central

    Gupte, Anisha A.; Hamilton, Dale J.

    2016-01-01

    More than 50% of Americans with heart failure have preserved ejection fraction (HFpEF). Exercise intolerance is a hallmark of HFpEF, but the pathophysiology is not well understood. Diverse etiologies and incomplete mechanistic understanding have resulted in ineffective management strategies to improve the outcomes of HFpEF. Traditional therapies that have been beneficial in the treatment of heart failure with reduced ejection fraction (HFrEF), neurohormonal blockade in particular, have not been effective in treating HFpEF. In this review, we address underlying mechanisms of HFpEF and present the rationale supporting exercise as a component of comprehensive management. PMID:27486493

  16. Forces in magnetospheric launching of micro-ejections

    NASA Astrophysics Data System (ADS)

    Cemeljic, Miljenko

    2013-07-01

    In 2D-axisymmetric simulations with our resistive MHD code Zeus-347 we show that micro-ejections, a quasi-stationary fast ejecta of matter of small mass and angular momentum fluxes, can be launched from a purely resistive magnetosphere above the disk gap. They are produced by a combination of pressure gradient and magnetic forces, in presence of ongoing magnetic reconnection along the boundary layer between the star and the disk, where a current sheet is formed. Mass flux of micro-ejections increases with increasing magnetic field strength and stellar rotation rate.

  17. Coronal mass ejections and magnetic flux ropes in interplanetary space

    NASA Technical Reports Server (NTRS)

    Gosling, J. T.

    1990-01-01

    Coronal mass ejections (CMEs) are formed in the solar corona by the ejection of material from closed field regions that were not previously participating in the solar wind expansion. CMEs commonly exhibit a signature consisting of a counterstreaming flux of suprathermal electrons with energies above about 80 eV, indicating closed field structures that are either rooted at both ends in the sun or entirely disconnected from it. About 30 percent of all CME events at 1 AU exhibit large, coherent internal field rotations typical of magnetic flux ropes. It is suggested that interplanetary magnetic flux ropes form as a result of reconnection within rising, previously sheared coronal magnetic loops.

  18. Nuclear cardiac ejection fraction and cardiac index in abdominal aortic surgery

    SciTech Connect

    Fiser, W.P.; Thompson, B.W.; Thompson, A.R.; Eason, C.; Read, R.C.

    1983-11-01

    Since atherosclerotic heart disease results in more than half of the perioperative deaths that follow abdominal aortic surgery, a prospective protocol was designed for preoperative evaluation and intraoperative hemodynamic monitoring. Twenty men who were prepared to undergo elective operation for aortoiliac occlusive disease (12 patients) and abdominal aortic aneurysm (eight patients) were evaluated with a cardiac scan and right heart catheterization. The night prior to operation, each patient received volume loading with crystalloid based upon ventricular performance curves. At the time of the operation, all patients were anesthetized with narcotics and nitrous oxide, and hemodynamic parameters were recorded throughout the operation. Aortic crossclamping resulted in a marked depression in CI in all patients. CI remained depressed after unclamping in the majority of patients. There were two perioperative deaths, both from myocardial infarction or failure. Both patients had ejection fractions less than 30% and initial CIs less than 2 L/M2, while the survivors' mean ejection fraction was 63% +/- 1 and their mean CI was 3.2 L/M2 +/- 0.6. The authors conclude that preoperative evaluation of ejection fraction can select those patients at a high risk of cardiac death from abdominal aortic operation. These patients should receive intensive preoperative monitoring with enhancement of ventricular performance.

  19. Genetic predisposition in patients with hypertension and normal ejection fraction to oxidative stress.

    PubMed

    Fazakas, Ádám; Szelényi, Zsuzsanna; Szénási, Gábor; Nyírő, Gábor; Szabó, Péter M; Patócs, Attila; Tegze, Narcis; Fekete, Bertalan C; Molvarec, Attila; Nagy, Bálint; Jakus, Judit; Örsi, Ferenc; Karádi, István; Vereckei, András

    2016-02-01

    The role of oxidative stress (OXS) due to myocardial nitric oxide synthase (NOS) uncoupling related to oxidative depletion of its cofactor tetrahydrobiopterin (BH4) emerged in the pathogenesis of heart failure with preserved ejection fraction. We determined the prevalence of six single nucleotide polymorphisms (SNPs) of genes encoding enzymes related to OXS, BH4 metabolism, and NOS function in ≥60-year-old 94 patients with hypertension and 18 age-matched controls with normal ejection fraction. Using echocardiography, 56/94 (60%) patients with hypertension had left ventricular (LV) diastolic dysfunction (HTDD+ group) and 38/94 (40%) patients had normal LV diastolic function (HTDD- group). Four SNPs (rs841, rs3783641, rs10483639, and rs807267) of guanosine triphosphate cyclohydrolase-1, the rate-limiting enzyme in BH4 synthesis, one (rs4880) of manganese superoxide dismutase, and one (rs1799983) of endothelial NOS genes were genotyped using real-time polymerase chain reaction method and Taqman probes. Protein carbonylation, BH4, and total biopterin levels were measured from plasma samples. No between-groups difference in minor allele frequency of SNPs was found. We calculated a genetic score indicating risk for OXS based on the minor allele frequencies of the SNPs. A high genetic risk for OXS was significantly associated with HTDD+ even after adjustment for confounding variables (odds ratio [95% confidence interval]:4.79 [1.12-20.54]; P = .035). In both patient groups protein carbonylation (P < .05 for both), plasma BH4 (P < .01 for both) and in the HTDD+ group total biopterin (P < .05) increased versus controls. In conclusion, in patients with hypertension and normal ejection fraction, a potential precursor of heart failure with preserved ejection fraction, a partly genetically determined increased OXS, seems to be associated with the presence of LV diastolic dysfunction. PMID:26778769

  20. Energy ejection in the collapse of a cold spherical self-gravitating cloud

    NASA Astrophysics Data System (ADS)

    Joyce, M.; Marcos, B.; Sylos Labini, F.

    2009-08-01

    When an open system of classical point particles interacting by Newtonian gravity collapses and relaxes violently, an arbitrary amount of energy may, in principle, be carried away by particles which escape to infinity. We investigate here, using numerical simulations, how this released energy and other related quantities (notably the binding energy and size of the virialized structure) depend on the initial conditions, for the one-parameter family of starting configurations given by randomly distributing N cold particles in a spherical volume. Previous studies have established that the minimal size reached by the system scales approximately as N1/3, a behaviour which follows trivially when the growth of perturbations (which regularize the singularity of the cold collapse in the N -> ∞ limit) is assumed to be unaffected by the boundaries. Our study shows that the energy ejected grows approximately in proportion to N1/3, while the fraction of the initial mass ejected grows only very slowly with N, approximately logarithmically, in the range of N simulated. We examine in detail the mechanism of this mass and energy ejection, showing explicitly that it arises from the interplay of the growth of perturbations with the finite size of the system. A net lag of particles compared to their uniform spherical collapse trajectories develops first at the boundaries and then propagates into the volume during the collapse. Particles in the outer shells are then ejected as they scatter through the time-dependent potential of an already re-expanding central core. Using modified initial configurations, we explore the importance of fluctuations at different scales and discreteness (i.e. non-Vlasov) effects in the dynamics.

  1. Erythropoietin Attenuates the Apoptosis of Adult Neurons After Brachial Plexus Root Avulsion by Downregulating JNK Phosphorylation and c-Jun Expression and Inhibiting c-PARP Cleavage.

    PubMed

    Li, Kai; Cao, Rang-Juan; Zhu, Xiao-Juan; Liu, Xing-Yu; Li, Long-Yun; Cui, Shu-Sen

    2015-08-01

    In the present study, the effects of erythropoietin (EPO) on preventing adult neurons from apoptosis (introduced by brachial plexus avulsion) were examined, and the mechanism was analyzed. Fifty injury rat models were established in this study by using micro-hemostat forceps to pull out brachial plexus root from the intervertebral foramen in supine position. These models were divided into EPO group (avulsion + 1000 U/kg subcutaneously on alternate days) and control group (avulsion + normal saline). C5-T1 spinal cord was harvested at days 1, 2, 4, 7, and 14. Compared with the control group, the apoptosis of spinal motoneurons was significantly decreased on days 4 and 7 in the EPO group, which was also approved by TUNEL examination results. The detection of p-JNK and expression of c-Jun and cleavage of cleaved PARP (c-PARP) were also examined by immunohistochemistry and were increased immediately at day 1, and peaked at day 2, day 2, and day 4 in control group, respectively. However, the amounts were decreased and delayed by EPO treatment significantly at the same time points. In conclusion, the apoptosis of adult spinal motorneurons was associated with JNK phosphorylation, c-Jun expression, and caspase activity, and EPO-mediated neuronal protective effect is proved by downregulating the JNK phosphorylation and c-Jun expression and inhibiting of c-PARP cleavage. PMID:25877688

  2. Knee megaprosthesis: a salvage solution for severe open and complex distal femoral fracture associated with an ipsilateral brachial plexus injury (a case report with literature review).

    PubMed

    Ennaciri, Badr; Vasile, Christian; Lebredonchel, Thierry; Berrada, Mohamed Saleh; Montbarbon, Eric; Beaudouin, Emmanuel

    2015-01-01

    Complex distal femoral fractures in the young patient often occur as a result of high velocity trauma. Timely recognition and treatment is everything in such a situation, and it needs a robust staged management pathway to optimize the chance of limb preservation. We report a case of a motorcyclist admitted to the department of orthopedics at Chambery hospital, France, with a complex comminuted and open distal femoral fracture of the left leg, associated with a brachial plexus injury to the ipsilateral upper limb. On arrival to the emergency department, damage control stabilization and surgery was commenced, debridement of contaminated non-viable tissue, abundant antiseptic lavage and application of external fixation coupled with the use of antibiotic spacer. Following normalization of inflammatory markers and ensuring no clinical signs of infection, subsequent management consisted of joint reconstruction to achieve a functional knee. The external fixator and femoral spacer was removed and a modular megaprosthesis was implanted with a lateral gastrocnemius flap to cover the exposed knee joint and reinforce the extensor apparatus. Nerve graft to the left brachial plexus injury was performed at University Hospital of Grenoble. Our patient entered an intensive rehabilitation program and at 1 year follow-up achieved good knee function and sensation to the left upper limb. PMID:26421102

  3. Brachial approach to NOGA-guided procedures: electromechanical mapping and transendocardial stem-cell injections.

    PubMed

    Banovic, Marko; Ostojic, Miodrag C; Bartunek, Jozef; Nedeljkovic, Milan; Beleslin, Branko; Terzic, Andre

    2011-01-01

    Several methods are available for delivering stem cells to the heart. Recent studies have highlighted the advantages of injecting the cells directly into the myocardium in order to increase myocardial retention of cells. A particular focus has been on percutaneous transendocardial injection, facilitated by electromechanical mapping.The NOGA XP Cardiac Navigation System has a multicomponent catheter that is designed to guide and deliver transendocardial injections via a transfemoral approach, without a guidewire. However, this method may not be feasible in some patients who have peripheral vascular disease. Herein, we describe the case of a 68-year-old man whose tortuous, sharply angled iliac arteries precluded a femoral approach to transendocardial injection. To overcome the anatomic and mechanical challenges, we used a brachial approach. We believe that this is the 1st report of using the brachial route for transendocardial injection, and that it can be a viable alternative to the transfemoral approach in selected patients.

  4. Prolonged hemidiaphragmatic paresis following continuous interscalene brachial plexus block: A case report.

    PubMed

    Shinn, Helen Ki; Kim, Byung-Gun; Jung, Jong Kwon; Kwon, Hee Uk; Yang, Chunwoo; Won, Jonghun

    2016-06-01

    Interscalene brachial plexus block provides effective anesthesia and analgesia for shoulder surgery. One of the disadvantages of this technique is the risk of hemidiaphragmatic paresis, which can occur as a result of phrenic nerve block and can cause a decrease in the pulmonary function, limiting the use of the block in patients with reduced functional residual capacity or a preexisting pulmonary disease. However, it is generally transient and is resolved over the duration of the local anesthetic's action.We present a case of a patient who experienced prolonged hemidiaphragmatic paresis following a continuous interscalene brachial plexus block for the postoperative pain management of shoulder surgery, and suggest a mechanism that may have led to this adverse effect.Nerve injuries associated with peripheral nerve blocks may be caused by several mechanisms. Our findings suggest that perioperative nerve injuries can occur as a result of combined mechanical and chemical injuries. PMID:27310984

  5. Brachial vs. central systolic pressure and pulse wave transmission indicators: a critical analysis.

    PubMed

    Izzo, Joseph L

    2014-12-01

    This critique is intended to provide background for the reader to evaluate the relative clinical utilities of brachial cuff systolic blood pressure (SBP) and its derivatives, including pulse pressure, central systolic pressure, central augmentation index (AI), and pulse pressure amplification (PPA). The critical question is whether the newer indicators add sufficient information to justify replacing or augmenting brachial cuff blood pressure (BP) data in research and patient care. Historical context, pathophysiology of variations in pulse wave transmission and reflection, issues related to measurement and model errors, statistical limitations, and clinical correlations are presented, along with new comparative data. Based on this overview, there is no compelling scientific or practical reason to replace cuff SBP with any of the newer indicators in the vast majority of clinical situations. Supplemental value for central SBP may exist in defining patients with exaggerated PPA ("spurious systolic hypertension"), managing cardiac and aortic diseases, and in studies of cardiovascular drugs, but there are no current standards for these possibilities.

  6. Multiple unilateral variations in medial and lateral cords of brachial plexus and their branches

    PubMed Central

    Goel, Shivi; Kumar, Ashwani; Mehta, Vandana; Suri, Rajesh Kumar

    2014-01-01

    During routine dissection of the upper extremity of an adult male cadaver, multiple variations in branches of medial and lateral cords of brachial plexus were encountered. Three unique findings were observed. First, intercordal neural communications between the lateral and medial cords were observed. Second, two lateral pectoral nerves and one medial pectoral nerve were seen to arise from the lateral and medial cord respectively. The musculocutaneous nerve did not pierce the coracobrachialis. Finally, the ulnar nerve arose by two roots from the medial cord. Knowledge of such variations is of interest to anatomists, radiologists, neurologists, anesthesiologists, and surgeons. The aim of our study is to provide additional information about abnormal brachial plexus and its clinical implications. PMID:24693486

  7. Multiple unilateral variations in medial and lateral cords of brachial plexus and their branches.

    PubMed

    Goel, Shivi; Rustagi, Shaifaly Madan; Kumar, Ashwani; Mehta, Vandana; Suri, Rajesh Kumar

    2014-03-01

    During routine dissection of the upper extremity of an adult male cadaver, multiple variations in branches of medial and lateral cords of brachial plexus were encountered. Three unique findings were observed. First, intercordal neural communications between the lateral and medial cords were observed. Second, two lateral pectoral nerves and one medial pectoral nerve were seen to arise from the lateral and medial cord respectively. The musculocutaneous nerve did not pierce the coracobrachialis. Finally, the ulnar nerve arose by two roots from the medial cord. Knowledge of such variations is of interest to anatomists, radiologists, neurologists, anesthesiologists, and surgeons. The aim of our study is to provide additional information about abnormal brachial plexus and its clinical implications.

  8. Clinico-embryological perspective of a rare accessory brachial muscle with possible musculocutaneous nerve compression.

    PubMed

    Mehta, V; Yadav, Y; Arora, Jyoti; Kumar, H; Suri, R K; Rath, G

    2009-03-01

    Both brachialis and biceps brachii are primary flexors of the arm and elbow from the biomechanical perspective. Numerous reports exist in anatomical literature regarding accessory heads of biceps brachii, although such accessory bellies in relation to brachialis muscle are less frequently elucidated. We report a unilateral case of a rare accessory muscle interposed between the biceps brachii and brachialis, having the musculocutaneous nerve (MCN) entrapped between the two. Furthermore, the muscle divided into two slips, upper slip was attached to biceps brachii and the other gained insertion to the brachial fascia. Innervation to this accessory muscle was derived from MCN. The embryological basis for such supernumerary muscle is discussed. Additionally, the case is considered under surgical and clinical perspective, highlighting the importance of familiarity with such variations. Anatomical variations of the brachial musculature may cause diagnostic perplexities while interpreting MRI or CT scans.

  9. Iatrogenic brachial artery injury during anterolateral plating of humeral shaft fracture.

    PubMed

    Kumar, Vishal; Behera, Prateek; Aggarwal, Sameer; Meena, Umesh Kumar

    2013-01-01

    There are several well defined indications for surgical management of humeral shaft fractures. Operative procedures on the humerus are associated with their own complications. Iatrogenic brachial artery injury as a complication of humeral shaft plating has not been reported previously. We report a case of a 48 years old female, who received operation at a district hospital and was referred to us when the surgeon could not palpate the pulse. CT angiogram showed that there was segmental non-opacification of the brachial artery. There was distal reformation and the thrombosis was decided to be managed conservatively. We believe that the arterial injury was a result of improper surgical technique and the segmental block might be due to improper use of plate holding forceps. This case report makes us aware of a rare complication of operative management of humeral shaft fractures and that basic principles of surgery must be always followed to prevent such injuries. PMID:24295587

  10. Brachial plexus injury with emphasis on axillary nerve paralysis after thoracoscopic sympathicotomy for axillary hyperhidrosis.

    PubMed

    Chon, Soon-Ho; Suk Choi, Matthew Seung

    2006-12-01

    Thoracic sympathicotomy for the treatment of axillary hyperhidrosis with the use of 2 mm thoracoscope and instruments is a simple and safe procedure. Nerve paralysis of any type after thoracic sympathicotomy is an extremely rare event. We report a 44-year-old woman who developed brachial plexus injury of her left arm after thoracoscopic sympathicotomy for axillary hyperhidrosis. The lesion involved the whole arm. All nerves of the brachial plexus except the axillary nerve recovered quickly. An axillary nerve type lesion was observed for 7 weeks, until the patient fully recovered all functions of her arm. The mechanism is believed not to be caused by the procedure itself, but by dorsal overextension of the abducted arm during the operation. PMID:17277662

  11. The efficacy of adding dexamethasone, midazolam, or epinephrine to 0.5% bupivacaine in supraclavicular brachial plexus block

    PubMed Central

    El-Baradey, Ghada F.; Elshmaa, Nagat S.

    2014-01-01

    Aims: The aim was to assess the effectiveness of adding either dexamethasone or midazolam in comparison with epinephrine addition to 0.5% bupivacaine in supraclavicular brachial plexus block. Settings and Design: This is a prospective randomized controlled observer-blinded study. Subjects and Methods: This study was carried out in Tanta University Hospital on 60 patients of both sexes; American Society of Anesthesiologists physical Status I and II, age range from 18 to 45 years undergo elective surgery to upper limb. All patients were anesthetized with ultrasound guided supraclavicular brachial plexus block and randomly divided into three groups (each group 20 patients) Group E (epinephrine): 30 mL bupivacaine 0.5%with 1:200,000 epinephrine (5 μg/mL). Group D (dexamethasone): 30 mL bupivacaine 0.5% and dexamethasone 8 mg. Group M (midazolam): 30 ml bupivacaine 0.5% and midazolam 50 μg/kg. The primary outcome measures were onset and duration of sensory and motor block and time to first analgesic request. Statistical Analysis Used: The windows version of SPSS 11.0.1 (SPSS Inc., Chicago, IL, USA) was used for statistical analysis. Data were presented in form of mean ± standard deviation multiple analysis of variance (ANOVA) was used to compare the three groups and Scheffe test was used after ANOVA. Power of significance P < 0.05 was considered to be statistically significant. Results: Onset of sensory and motor block was significantly rapid (P < 0.05) in Groups D and M in comparison with Group E. Time of administration of rescue analgesic, duration of sensory and motor block showed significant increase (P < 0.05) in Group D in comparison with Group M which showed significant increase (P < 0.05) in comparison with Group E. Conclusions: In comparison with epinephrine and midazolam addition of dexamethasone to bupivacaine had rapid onset of block and longer time to first analgesic request with fewer side-effects. PMID:25538528

  12. Endovascular Treatment of Infected Brachial Pseudoaneurysm in an Intravenous Drug Abuser: A Case Report.

    PubMed

    Boieru, Raluca; Georg, Yannick; Ramlugun, Dharmesh; Martinot, Martin; Camin, Amelie; Matysiak, Lucien; Kretz, Benjamin

    2015-10-01

    We report the case of a 36-year-old male, admitted in the emergency room with a nonruptured brachial pseudoaneurysm after buprenorphine injection, with no signs of distal acute ischemia. After endovascular treatment with a nitinol covered stent associated with adapted antibiotherapy and 35 days of hospitalizations, the patient was discharged with good short results but stent need to be removed at 6 months for thrombosis and partial exposure through the wound. PMID:26142880

  13. Perspectives on glenohumeral joint contractures and shoulder dysfunction in children with perinatal brachial plexus palsy.

    PubMed

    Gharbaoui, Idris S; Gogola, Gloria R; Aaron, Dorit H; Kozin, Scott H

    2015-01-01

    Shoulder joint deformities continue to be a challenging aspect of treating upper plexus lesions in children with perinatal brachial plexus palsy (PBPP). It is increasingly recognized that PBPP affects the glenohumeral joint specifically, and that abnormal scapulothoracic movements are a compensatory development. The pathophysiology and assessment of glenohumeral joint contractures, the progression of scapular dyskinesia and skeletal dysplasia, and current shoulder imaging techniques are reviewed. PMID:25835253

  14. Combined Intrauterine Vascular Insufficiency and Brachial Plexus Palsy: A Case Report

    PubMed Central

    Sinclair, Catherine; Terkonda, Sarvam P.

    2007-01-01

    A unique case of combined intrauterine vascular insufficiency and complete brachial plexus palsy is described in a newborn delivered by cesarean section. Intrauterine vascular insufficiency resulted in a right below elbow amputation at 3 weeks of age. Amputation length was preserved after a pedicled thoracoabdominal flap. Function of the C5, C6, and C7 nerve roots returned to normal by 3 months of age. PMID:18780089

  15. Body vectoring technique with Radiesse® for tightening of the abdomen, thighs, and brachial zone

    PubMed Central

    Cogorno Wasylkowski, Valeria

    2015-01-01

    Background The objective of this study was to investigate the efficacy, safety, and subject satisfaction of the calcium hydroxylapatite-based dermal filler Radiesse® in a novel body vectoring technique to correct skin flaccidity in the thighs, abdomen, and brachial zones. Methods Female subjects with self-evaluated flaccidity scores ≥3 on a 6-point scale (0, no flaccidity; 5, very severe flaccidity) in the zones of interest were included. Radiesse was injected according to predesigned vector maps (3 mL per thigh, 1.5 mL per hemiabdomen or brachial zone). Clinical assessments (skin density and thickness) were made by an independent reviewer at an exact position before and 5 weeks after treatment using a cutometer and an ultrascan. Subjects rated skin flaccidity before and 5 weeks after treatment on the 6-point scale and performed a pinch test to self-assess changes in skin thickness. All adverse events were recorded. Results Twenty females (aged 28–67 years) were enrolled, contributing 36 treatment zones. Across all zones, 78% of flaccidity measurements improved after treatment. Improvements in skin flaccidity were most common in the thighs (82% of cases). An improvement in skin density versus baseline was observed in the majority across all zones, most frequently in the abdomen (88% of cases). Skin thickness in each zone also improved versus baseline for the majority, most frequently in the thighs (88% of cases). Mean self-assessed flaccidity scores at baseline were 3.6 (thighs), 3.7 (abdomen), and 3.8 (brachial zone), and 2.6, 2.7, and 3.0, respectively, posttreatment. All subjects reported a positive pinch test. In total, 47.0% of subjects had bruising after treatment, which resolved within a week. No serious adverse events were reported. Conclusion Using this novel technique, Radiesse had notable results on skin flaccidity, density and thickness in the thighs, abdomen, and brachial zones, and was well tolerated. PMID:26056483

  16. Radiation-induced brachial plexopathy in patients with nasopharyngeal carcinoma: a retrospective study

    PubMed Central

    Fu, Ruying; Rong, Xiaoming; Wu, Rong; Cheng, Jinping; Huang, Xiaolong; Luo, Jinjun; Tang, Yamei

    2016-01-01

    Radiation-induced brachial plexopathy (RIBP) is one of the late complications in nasopharyngeal carcinoma (NPC) patients who received radiotherapy. We conducted a retrospective study to investigate its clinical characteristics and risk factors. Thirty-onepatients with RIBP after radiotherapy for NPC were enrolled. Clinical manifestations of RIBP, electrophysiologic data, magnetic resonance imaging (MRI), and the correlation between irradiation strategy and incidence of RIBP were evaluated. The mean latency at the onset of RIBP was 4.26 years. Of the symptoms, paraesthesia usually presented first (51.6%), followed by pain (22.6%) and weakness (22.6%). The major symptoms included paraesthesia (90.3%), pain (54.8%), weakness (48.4%), fasciculation (19.3%) and muscle atrophy (9.7%). Nerve conduction velocity (NCV) and electromyography (EMG) disclosed that pathological changes of brachial plexus involved predominantly in the upper and middle trunks in distribution. MRI of the brachial plexus showed hyper-intensity on T1, T2, post-contrast T1 and diffusion weighted whole body imaging with background body signal suppression (DWIBS) images in lower cervical nerves. Radiotherapy with Gross Tumor volume (GTVnd) and therapeutic dose (mean 66.8±2.8Gy) for patients with lower cervical lymph node metastasis was related to a significantly higher incidence of RIBP (P<0.001). Thus, RIBP is a severe and progressive complication of NPC after radiotherapy. The clinical symptoms are predominantly involved in upper and middle trunk of the brachial plexus in distribution. Lower cervical lymph node metastasis and corresponding radiotherapy might cause a significant increase of the RIBP incidence. PMID:26934119

  17. Automated edge detection versus manual edge measurement in analysis of brachial artery reactivity: a comparison study.

    PubMed

    Williamson, Eric B; Bronas, Ulf G; Dengel, Donald R

    2008-09-01

    High resolution ultrasound, combined with computer imaging technology, is commonly used to measure changes in brachial artery diameter for the determination of endothelial-dependent vasodilation (EDD) and endothelial independent-vasodilation (EID). Currently, two methods of computerized edge-detection systems are in use to measure changes in artery diameter. One system involves the sonographer manually tracking the artery walls while the second system involves a computer automated edge-detection system that automatically tracks the artery wall. The purpose of this study was to compare the two types of computerized edge-detection systems for measuring vascular function and structure. One hundred fifty (female = 70, male = 80) participants agreed to participate. Baseline brachial diameter, carotid intima-medial thickness (cIMT), EDD and EID were measured by the two computerized edge-detection systems utilizing the same ultrasound B-mode image. Mean values (+/-standard error) for baseline diameter, cIMT, EDD and EID were 3.53 (+/-0.10) mm, 0.43 (+/-0.01) mm, 5.72 (+/-0.20)% and 22.17 (+/-0.60)%, respectively for the manual edge-detection software system. Mean values for baseline diameter, cIMT, EDD and EID were 3.59 (+/-0.10) mm, 0.44 (+/-0.01) mm, 7.33 (+/-0.30)% and 25.77 (+/-0.60)%, respectively for the automated edge-detection software system. Bland-Altman plots displayed large variations between the two edge-detection methods for assessing cIMT and changes in artery diameter following brachial EDD and EID. The results of the study demonstrate that manual and automated computerized edge-detection systems track dynamic changes in brachial artery diameter and cIMT measures differently. Therefore, caution should be used when comparing research utilizing different computerized edge-detection systems for measuring vascular function and structure.

  18. A Case of Suspected Breast Cancer Metastasis to Brachial Plexus Detected by Magnetic Resonance Neurography

    PubMed Central

    Mizuma, Atsushi; Kijima, Chikage; Nagata, Eiichiro; Takizawa, Shunya

    2016-01-01

    Metastasis of breast cancer is often detected through a long-term course and difficult to diagnose. We report a case of brachial plexopathy suspected to be the initial lesion of breast cancer metastasis, which was only detected by magnetic resonance (MR) neurography. A 61-year-old woman was admitted to our hospital within 2 years after operation for breast cancer because of progressive dysesthesia and motor weakness initially in the upper limb on the affected side and subsequently on the contralateral side. Enhanced computed tomography, axillary lymph node echo, gallium scintigraphy, and short tau inversion recovery MR images showed no abnormalities. MR neurography revealed a swollen region in the left brachial plexus. We suspected neuralgic amyotrophy and initiated treatment with intravenous immunoglobulin therapy and steroid therapy. However, there was no improvement, and the progression of motor weakness in the bilateral lower limbs appeared over 4 years. Concomitant elevation of carbohydrate antigen 15-3 level (58.9 U/ml) led us to suspect breast cancer metastasis, which was associated with the worsening of neurological findings, although gallium scintigraphy and bone scintigraphy showed no inflammatory and metastatic lesions. Swelling of the cauda equina in enhanced lumbar MR imaging and abnormal accumulation at the brachial plexus and cervical spinal cord in positron-emission tomography were newly detected contrary to the normal findings on the gallium scintigraphy, which suggested cerebrospinal fluid seeding. We suspected breast cancer metastasis about the initial brachial plexopathy based on the clinical course. MR neurography may be a helpful tool to detect metastatic lesion, especially in nerve roots. PMID:27721757

  19. Sensory Evaluation of the Hands in Children with Brachial Plexus Birth Injury

    ERIC Educational Resources Information Center

    Palmgren, Tove; Peltonen, Jari; Linder, Tove; Rautakorpi, Sanna; Nietosvaara, Yrjana

    2007-01-01

    The aim of this study was to examine sensory changes of the hand in brachial plexus birth injury (BPBI). Ninety-five patients (43 females, 52 males) comprising two age groups, 6 to 8 years (mean age 7y 6mo) and 12 to 14 years (mean age 13y 2mo), were included. Sixty-four had upper (cervical [C] 5-6), 19 upper and middle (C5-7), and 12 had total…

  20. Theoretical basis for operational ensemble forecasting of coronal mass ejections

    NASA Astrophysics Data System (ADS)

    Pizzo, V. J.; Koning, C.; Cash, M.; Millward, G.; Biesecker, D. A.; Puga, L.; Codrescu, M.; Odstrcil, D.

    2015-10-01

    We lay out the theoretical underpinnings for the application of the Wang-Sheeley-Arge-Enlil modeling system to ensemble forecasting of coronal mass ejections (CMEs) in an operational environment. In such models, there is no magnetic cloud component, so our results pertain only to CME front properties, such as transit time to Earth. Within this framework, we find no evidence that the propagation is chaotic, and therefore, CME forecasting calls for different tactics than employed for terrestrial weather or hurricane forecasting. We explore a broad range of CME cone inputs and ambient states to flesh out differing CME evolutionary behavior in the various dynamical domains (e.g., large, fast CMEs launched into a slow ambient, and the converse; plus numerous permutations in between). CME propagation in both uniform and highly structured ambient flows is considered to assess how much the solar wind background affects the CME front properties at 1 AU. Graphical and analytic tools pertinent to an ensemble approach are developed to enable uncertainties in forecasting CME impact at Earth to be realistically estimated. We discuss how uncertainties in CME pointing relative to the Sun-Earth line affects the reliability of a forecast and how glancing blows become an issue for CME off-points greater than about the half width of the estimated input CME. While the basic results appear consistent with established impressions of CME behavior, the next step is to use existing records of well-observed CMEs at both Sun and Earth to verify that real events appear to follow the systematic tendencies presented in this study.

  1. Reconstructing the Morphology of an Evolving Coronal Mass Ejection

    NASA Astrophysics Data System (ADS)

    Wood, B. E.; Howard, R. A.; Socker, D. G.

    2010-06-01

    Using imaging data from the Solar TErrestrial RElations Observatory (STEREO) mission, we empirically reconstruct the time-dependent three-dimensional morphology of a coronal mass ejection (CME) from 2008 June 1, which exhibits significant variation in shape as it travels from the Sun to 1 AU, requiring us to abandon the assumption of self-similar expansion. We model the CME as a flux rope that is rather fat relative to its longitudinal extent close to the Sun, but which becomes thinner and flatter on top as the flux rope moves outward. We find best agreement with the STEREO images when the flux rope's west leg is assumed to be rotated 35° below the ecliptic plane. This orientation is consistent with previously published inferences about this CME's orientation from an analysis of in situ observations of the event from June 6 to June 7, when the CME hits STEREO-B. The agreement between these two very different kinds of analysis is encouraging. Close to 1 AU, the CME not only hits STEREO-B but also strikes a comet (Comet C/2007 W1 Boattini), which provides an additional constraint for our reconstruction efforts. Finally, we find that this CME is very instructive for assessing different methods of extracting kinematic information from measurements of elongation angles from the Sun, which is a complicated issue for measurements far from the Sun. The "fixed-phi" assumption that we have used successfully in the past does not work well here, and we discuss the implications for extracting reliable kinematic information from heliospheric imaging.

  2. SYMPATHETIC MAGNETIC BREAKOUT CORONAL MASS EJECTIONS FROM PSEUDOSTREAMERS

    SciTech Connect

    Lynch, B. J.; Edmondson, J. K. E-mail: jkedmond@umich.edu

    2013-02-10

    We present high-resolution 2.5D MHD simulation results of magnetic breakout-initiated coronal mass ejections (CMEs) originating from a coronal pseudostreamer configuration. The coronal null point in the magnetic topology of pseudostreamers means that the initiation of consecutive sympathetic eruptions is a natural consequence of the system's evolution. A generic source region energization process-ideal footpoint shearing parallel to the pseudostreamer arcade polarity inversion lines-is all that is necessary to store sufficient magnetic energy to power consecutive CME eruptions given that the pseudostreamer topology enables the breakout initiation mechanism. The second CME occurs because the eruptive flare reconnection of the first CME simultaneously acts as the overlying pre-eruption breakout reconnection for the sympathetic eruption. We examine the details of the magnetic and kinetic energy evolution and the signatures of the overlying null point distortion, current sheet formation, and magnetic breakout reconnection giving rise to the runaway expansion that drives the flare reconnection below the erupting sheared field core. The numerical simulation's spatial resolution and output cadence are sufficient to resolve the formation of magnetic islands during the reconnection process in both the breakout and eruptive flare current sheets. We quantify the flux transfer between the pseudostreamer arcades and show that the eruptive flare reconnection processes flux {approx}10 times faster than the pre-eruption breakout reconnection. We show that the breakout reconnection jets cause bursty, intermittent upflows along the pseudostreamer stalk, as well as downflows in the adjacent pseudostreamer arcade, both of which may be observable as pre-eruption signatures. Finally, we examine the flux rope CME trajectories and show that the breakout current sheet provides a path of least resistance as an imbalance in the surrounding magnetic energy density and results in a non

  3. A STUDY OF FAST FLARELESS CORONAL MASS EJECTIONS

    SciTech Connect

    Song, H. Q.; Chen, Y.; Ye, D. D.; Han, G. Q.; Du, G. H.; Li, G.; Zhang, J.; Hu, Q.

    2013-08-20

    Two major processes have been proposed to convert coronal magnetic energy into the kinetic energy of a coronal mass ejection (CME): resistive magnetic reconnection and the ideal macroscopic magnetohydrodynamic instability of a magnetic flux rope. However, it remains elusive whether both processes play a comparable role or one of them prevails during a particular eruption. To shed light on this issue, we carefully studied energetic but flareless CMEs, i.e., fast CMEs not accompanied by any flares. Through searching the Coordinated Data Analysis Workshops database of CMEs observed in Solar Cycle 23, we found 13 such events with speeds larger than 1000 km s{sup -1}. Other common observational features of these events are: (1) none of them originated in active regions, they were associated with eruptions of well-developed long filaments in quiet-Sun regions; (2) no apparent enhancement of flare emissions was present in soft X-ray, EUV, and microwave data. Further studies of two events reveal that (1) the reconnection electric fields, as inferred from the product of the separation speed of post-eruption ribbons and the photospheric magnetic field measurement, were generally weak; (2) the period with a measurable reconnection electric field is considerably shorter than the total filament-CME acceleration time. These observations indicate that for these fast CMEs, the magnetic energy was released mainly via the ideal flux-rope instability through the work done by the large-scale Lorentz force acting on the rope currents rather than via magnetic reconnections. We also suggest that reconnections play a less important role in accelerating CMEs in quiet-Sun regions of weak magnetic field than those in active regions of strong magnetic field.

  4. EUV Coronal Dimming and its Relationship to Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Mason, James

    2016-05-01

    As a coronal mass ejection (CME) departs from the inner solar atmosphere, it leaves behind a void. This region of depleted plasma results in a corresponding decrease in coronal emissions that can be observed by instruments tuned to measure the extreme ultraviolet (EUV) part of the electromagnetic spectrum. These coronal dimmings can be observed with EUV imagers and EUV spectral irradiance instruments. Onboard the Solar Dynamics Observatory (SDO), the EUV Variability Experiment (EVE) and Atmospheric Imaging Assembly (AIA) provide complementary observations; together they can be used to obtain high spatial and spectral resolution. AIA provides information about the location, extent, and spatial evolution of the dimming while EVE data are important to understand plasma temperature evolution. Concurrent processes with similar timescales to mass-loss dimming also impact the observations, which makes a deconvolution method necessary for the irradiance time series in order to have a “clean” mass-loss dimming light curve that can be parameterized and compared with CME kinematics. This presentation will first provide background on these various physical processes and the deconvolution method developed. Two case studies will then be presented, followed by a semi-statistical study (~30 events) to establish a correlation between dimming and CME parameters. In particular, the slope of the deconvolved irradiance dimming light curve is representative of the CME speed, and the irradiance dimming depth can serve as a proxy for CME mass. Finally, plans and early results from a more complete statistical study of all dimmings in the SDO era, based on an automated detection routine using EVE data, will be described and compared with independently derived dimmings automatically detected with AIA data.

  5. Effect of Basic Residue on the Kinetics of Peptide Fragmentation Examined Using Surface-Induced Dissociation Combined with Resonant Ejection

    SciTech Connect

    Laskin, Julia

    2015-11-30

    In this work, resonant ejection coupled with surface-induced dissociation (SID) in a Fourier transform ion cyclotron resonance mass spectrometer is used to examine fragmentation kinetics of two singly protonated hexapeptides, RYGGFL and KYGGFL, containing the basic arginine residue and less basic lysine residue at the N-terminus. The kinetics of individual reaction channels at different collision energies are probed by applying a short ejection pulse (1 ms) in resonance with the cyclotron frequency of a selected fragment ion and varying the delay time between ion-surface collision and resonant ejection while keeping total reaction delay time constant. Rice-Ramsperger-Kassel-Marcus (RRKM) modeling of the experimental data provides accurate threshold energies and activation entropies of individual reaction channels. Substitution of arginine with less basic lysine has a pronounced effect on the observed fragmentation kinetics of several pathways, including the b2 ion formation, but has little or no effect on formation of the b5+H2O fragment ion. The combination of resonant ejection SID, time- and collision energy-resolved SID, and RRKM modeling of both types of experimental data provides a detailed mechanistic understanding of the primary dissociation pathways of complex gaseous ions.

  6. [Transradial percutaneous approach for cardiac catheterization in patients with previous brachial artery cutdown].

    PubMed

    Magariños, Eduardo; Solioz, Germán; Cermesoni, Gabriel; Koretzky, Martín; Carnevalini, Mariana; González, Daniel

    2013-01-01

    The percutaneous punction of the radial artery for catheterization procedures has gained acceptance lately. This was a consequence of achieving results similar to the femoral approach, with the benefits of a lower rate of complications and increased comfort for the patients post procedure. Recently it has gained an additional impulse with the better prognosis obtained in acute coronary syndromes. In this trial we have evaluated if the feasibility, results and advantages related with the use of the radial artery percutaneous approach to perform catheterization procedures, continues when used in patients who have had a previous brachial artery cutdown. Out of a total of 1356 percutaneous radial accesses, 53 were in patients with previous brachial artery cutdown. Through this access 71 catheterization procedures were performed, achieving access success in 96.2% (51/53) of the punctions. Once the access success was obtained, 93.6% (44/47) of the diagnostic procedures and 100% (24/24) of the therapeutics procedures were successful. During hospitalization, in this group of patients, no major adverse cardiac events occurred and there was a 1.4% (1/71) rate of minor events. At seven days follow up, no new complications were recorded. Although this is a small group, we believe that it is enough to show that percutaneous punctions of the radial artery to perform catheterization procedures, in patients with previous brachial artery cutdown, are feasible, allowing high access and procedure success rates, with a low frequency of complications.

  7. Gross anatomy of the brachial plexus in the giant Anteater (Myrmecophaga tridactyla).

    PubMed

    Souza, P R; Cardoso, J R; Araujo, L B M; Moreira, P C; Cruz, V S; Araujo, E G

    2014-10-01

    Ten forelimbs of five Myrmecophaga tridactyla were examined to study the anatomy of the brachial plexus. The brachial plexuses of the M. tridactyla observed in the present study were formed by the ventral rami of the last four cervical spinal nerves, C5 through C8, and the first thoracic spinal nerve, T1. These primary roots joined to form two trunks: a cranial trunk comprising ventral rami from C5-C7 and a caudal trunk receiving ventral rami from C8-T1. The nerves originated from these trunks and their most constant arrangement were as follows: suprascapular (C5-C7), subscapular (C5-C7), cranial pectoral (C5-C8), caudal pectoral (C8-T1), axillary (C5-C7), musculocutaneous (C5-C7), radial (C5-T1), median (C5-T1), ulnar (C5-T1), thoracodorsal (C5-C8), lateral thoracic (C7-T1) and long thoracic (C6-C7). In general, the brachial plexus in the M. tridactyla is similar to the plexuses in mammals, but the number of rami contributing to the formation of each nerve in the M. tridactyla was found to be larger than those of most mammals. This feature may be related to the very distinctive anatomical specializations of the forelimb of the anteaters.

  8. 49 CFR 571.226 - Standard No. 226; Ejection Mitigation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... (within the meaning of 49 CFR 567.7). S3. Definitions. Ejection impactor means a device specified in S7.1... three or fewer carlines, as that term is defined in 49 CFR 583.4, in the United States during a... of 49 CFR 567.7) before September 1, 2018, after having been previously certified in accordance...

  9. 49 CFR 571.226 - Standard No. 226; Ejection Mitigation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... (within the meaning of 49 CFR 567.7). S3. Definitions. Ejection impactor means a device specified in S7.1... three or fewer carlines, as that term is defined in 49 CFR 583.4, in the United States during a... of 49 CFR 567.7) before September 1, 2018, after having been previously certified in accordance...

  10. Dynamo-driven plasmoid ejections above a spherical surface

    NASA Astrophysics Data System (ADS)

    Warnecke, J.; Brandenburg, A.; Mitra, D.

    2011-10-01

    Aims: We extend earlier models of turbulent dynamos with an upper, nearly force-free exterior to spherical geometry, and study how flux emerges from lower layers to the upper ones without being driven by magnetic buoyancy. We also study how this affects the possibility of plasmoid ejection. Methods: A spherical wedge is used that includes northern and southern hemispheres up to mid-latitudes and a certain range in longitude of the Sun. In radius, we cover both the region that corresponds to the convection zone in the Sun and the immediate exterior up to twice the radius of the Sun. Turbulence is driven with a helical forcing function in the interior, where the sign changes at the equator between the two hemispheres. Results: An oscillatory large-scale dynamo with equatorward migration is found to operate in the turbulence zone. Plasmoid ejections occur in regular intervals, similar to what is seen in earlier Cartesian models. These plasmoid ejections are tentatively associated with coronal mass ejections (CMEs). The magnetic helicity is found to change sign outside the turbulence zone, which is in agreement with recent findings for the solar wind. Movie is available in electronic form at http://www.aanda.org

  11. Certain optimal parameters of high-velocity Venturi ejection tubes

    NASA Astrophysics Data System (ADS)

    Stark, S. B.; Reznichenko, I. G.; Pavlenko, Y. P.

    1984-11-01

    The influence of the geometrical characteristics of centrifugal nozzles in high velocity Venturi ejection tubes for atomizing liquid in gas cleaning plant is analyzed. An optimal value of the nozzle geometrical characteristic, which is a function of the degree of filling of the nozzle outlet opening by the liquid, is given, at which the throat length is independent of water pressure before the nozzle.

  12. 49 CFR 571.226 - Standard No. 226; Ejection Mitigation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... (within the meaning of 49 CFR 567.7). S3. Definitions. Ejection impactor means a device specified in S7.1... three or fewer carlines, as that term is defined in 49 CFR 583.4, in the United States during a... of 49 CFR 567.7) before September 1, 2018, after having been previously certified in accordance...

  13. Central blood pressure estimation by using N-point moving average method in the brachial pulse wave.

    PubMed

    Sugawara, Rie; Horinaka, Shigeo; Yagi, Hiroshi; Ishimura, Kimihiko; Honda, Takeharu

    2015-05-01

    Recently, a method of estimating the central systolic blood pressure (C-SBP) using an N-point moving average method in the radial or brachial artery waveform has been reported. Then, we investigated the relationship between the C-SBP estimated from the brachial artery pressure waveform using the N-point moving average method and the C-SBP measured invasively using a catheter. C-SBP using a N/6 moving average method from the scaled right brachial artery pressure waveforms using VaSera VS-1500 was calculated. This estimated C-SBP was compared with the invasively measured C-SBP within a few minutes. In 41 patients who underwent cardiac catheterization (mean age: 65 years), invasively measured C-SBP was significantly lower than right cuff-based brachial BP (138.2 ± 26.3 vs 141.0 ± 24.9 mm Hg, difference -2.78 ± 1.36 mm Hg, P = 0.048). The cuff-based SBP was significantly higher than invasive measured C-SBP in subjects with younger than 60 years old. However, the estimated C-SBP using a N/6 moving average method from the scaled right brachial artery pressure waveforms and the invasively measured C-SBP did not significantly differ (137.8 ± 24.2 vs 138.2 ± 26.3 mm Hg, difference -0.49 ± 1.39, P = 0.73). N/6-point moving average method using the non-invasively acquired brachial artery waveform calibrated by the cuff-based brachial SBP was an accurate, convenient and useful method for estimating C-SBP. Thus, C-SBP can be estimated simply by applying a regular arm cuff, which is greatly feasible in the practical medicine.

  14. New Publicly Available EEGGL Tool for Simulating Coronal Mass Ejections.

    NASA Astrophysics Data System (ADS)

    Sokolov, I.; Manchester, W.; van der Holst, B.; Gombosi, T. I.; Jin, M.; Mullinix, R.; Taktakishvili, A.; Chulaki, A.; Toth, G.

    2015-12-01

    We present and demonstrate a new tool, EEGGL (Eruptive Event Generator using Gibson-Low configuration) for simulating CMEs (Coronal Mass Ejections). CMEs are among the most significant space weather events, producing the radiation hazards (via the diffuse shock acceleration of the Solar Energetic Particles - SEPs), the interplanetary shock waves as well as the geomagnetic activity due to the drastic changes of the interplanetary magnetic field within the "magnetic clouds" ("flux ropes"). Some of this effects may be efficiently simulated using the "cone model", which is employed in the real-time simulations of the ongoing CMEs at the NASA-Goddard Space Flight Center. The cone model provides a capability to predict the location, time, width and shape of the hydrodynamic perturbation in the upper solar corona (at ~0.1 AU), which can be used to drive the heliospheric simulation (with the ENLIL code, for example). At the same time the magnetic field orientation in this perturbation is uncertain within the cone model, which limits the capability of the geomagnetic activity forecast. The new EEGGL tool http://ccmc.gsfc.nasa.gov/analysis/EEGGL/recently developed at the Goddard Space Flight Center in collaboration with the University of Michigan provides a new capability for both evaluating the magnetic field configuration resulting from the CME and tracing the CME through the solar corona. In this way not only the capability to simulate the magnetic field evolution at 1 AU may be achieved, but also the more extensive comparison with the CME observations in the solar corona may be achieved. Based on the magnetogram and evaluation of the CME initial location and speed, the user may choose the active region from which the CME originates and then the EEGGL tools provides the parameters of the Gibson-Low magnetic configuration to parameterize the CME. The recommended parameters may be used then to drive the simulation of CME propagation from the low solar corona to 1 AU using

  15. Ankle-Brachial Index and cardiovascular events in atrial fibrillation. The ARAPACIS Study.

    PubMed

    Violi, Francesco; Davì, Giovanni; Proietti, Marco; Pastori, Daniele; Hiatt, William R; Corazza, Gino Roberto; Perticone, Francesco; Pignatelli, Pasquale; Farcomeni, Alessio; Vestri, Anna Rita; Lip, Gregory Y H; Basili, Stefania

    2016-04-01

    Atrial fibrillation (AF) patients are at high risk for thrombotic and vascular events related to their cardiac arrhythmia and underlying systemic atherosclerosis. Ankle-Brachial Index (ABI) is a non-invasive tool in evaluating systemic atherosclerosis, useful in predicting cardiovascular events in general population; no data are available in AF patients. ARAPACIS is a prospective multicentre observational study performed by the Italian Society of Internal Medicine, analysing association between low ABI (≤ 0.90) and vascular events in NVAF out- or in-patients, enrolled in 136 Italian centres. A total of 2,027 non-valvular AF (NVAF) patients aged > 18 years from both sexes followed for a median time of 34.7 (interquartile range: 22.0-36.0) months, yielding a total of 4,614 patient-years of observation. Mean age was 73 ± 10 years old with 55 % male patients. A total of 176 patients (8.7 %) experienced a vascular event, with a cumulative incidence of 3.81 %/patient-year. ABI≤ 0.90 was more prevalent in patients with a vascular event compared with patients free of vascular events (32.2 vs 20.2 %, p< 0.05). On Cox proportional hazard analysis, ABI≤ 0.90 was an independent predictor of vascular events (hazard ratio (HR): 1.394, 95 % confidence interval (CI): 1.042-1.866; p=0.02), vascular death (HR: 2.047, 95 % CI: 1.255-3.338; p=0.004) and MI (HR: 2.709, 95 % CI: 1.485-5.083; p=0.001). This latter association was also confirmed after excluding patients with previous MI (HR: 2.901, 95 % CI: 1.408-5.990, p=0.004). No association was observed between low ABI and stroke/transient ischaemic attack (p=0.91). In conclusion, low ABI is useful to predict MI and vascular death in NVAF patients and may independently facilitate cardiovascular risk assessment in NVAF patients.

  16. Simulation of 'pathologic' changes in ICG waveforms resulting from superposition of the 'preejection' and ejection waves induced by left ventricular contraction

    NASA Astrophysics Data System (ADS)

    Ermishkin, V. V.; Kolesnikov, V. A.; Lukoshkova, E. V.; Sonina, R. S.

    2013-04-01

    The impedance cardiography (ICG) is widely used for beat-to-beat noninvasive evaluation of the left ventricular stroke volume and contractility. It implies the correct determination of the ejection start and end points and the amplitudes of certain peaks in the differentiated impedance cardiogram. An accurate identification of ejection onset by ICG is often problematic, especially in the cardiologic patients, due to peculiar waveforms. Using a simple theoretical model, we tested the hypothesis that two major processes are responsible for the formation of impedance systolic wave: (1) the changes in the heart geometry and surrounding vessels produced by ventricular contraction, which occur during the isovolumic phase and precede ejection, and (2) expansion of aorta and adjacent arteries during the ejection phase. The former process initiates the preejection wave WpE and the latter triggers the ejection wave WEj. The model predicts a potential mechanism of generating the abnormal shapes of dZ/dt due to the presence of preejection waves and explains the related errors in ICG time and amplitude parameters. An appropriate decomposition method is a promising way to avoid the masking effects of these waves and a further step to correct determination of the onset of ejection and the corresponding peak amplitudes from 'pathologically shaped' ICG signals.

  17. Multiple Plasma Ejections and Intermittent Nature of Magnetic Reconnection in Solar Chromospheric Anemone Jets

    NASA Astrophysics Data System (ADS)

    Singh, K. A. P.; Isobe, H.; Nishizuka, N.; Nishida, K.; Shibata, K.

    2012-11-01

    The recent discovery of chromospheric anemone jets with the Solar Optical Telescope (SOT) on board Hinode has shown an indirect evidence of magnetic reconnection in the solar chromosphere. However, the basic nature of magnetic reconnection in chromosphere is still unclear. We studied nine chromospheric anemone jets from SOT/Hinode using Ca II H filtergrams, and we found multiple bright, plasma ejections along the jets. In most cases, the major intensity enhancements (larger than 30% relative to the background intensity) of the loop correspond to the timing of the plasma ejections. The typical lifetime and size of the plasma ejecta are about 20-60 s and 0.3-1.5 Mm, respectively. The height-time plot of jet shows many sub-structures (or individual jets) and the typical lifetime of the individual jet is about one to five minutes. Before the onset of the jet activity, a loop appears in Ca II H and gradually increases in size, and after few minutes several jets are launched from the loop. Once the jet activity starts and several individual jets are launched, the loop starts shrinking with a speed of ~4 km s-1. In some events, a downward moving blob with a speed of ~35 km s-1 was observed, associated with the upward moving plasma along one of the legs of the loop hosting the jets. The upward moving plasma gradually developed into jets. Multiple plasma ejections in chromospheric anemone jet show the strongly time-dependent as well as intermittent nature of magnetic reconnection in the solar chromosphere.

  18. MULTIPLE PLASMA EJECTIONS AND INTERMITTENT NATURE OF MAGNETIC RECONNECTION IN SOLAR CHROMOSPHERIC ANEMONE JETS

    SciTech Connect

    Singh, K. A. P.; Nishida, K.; Shibata, K.; Isobe, H.; Nishizuka, N. E-mail: nishida@kwasan.kyoto-u.ac.jp E-mail: isobe@kwasan.kyoto-u.ac.jp

    2012-11-01

    The recent discovery of chromospheric anemone jets with the Solar Optical Telescope (SOT) on board Hinode has shown an indirect evidence of magnetic reconnection in the solar chromosphere. However, the basic nature of magnetic reconnection in chromosphere is still unclear. We studied nine chromospheric anemone jets from SOT/Hinode using Ca II H filtergrams, and we found multiple bright, plasma ejections along the jets. In most cases, the major intensity enhancements (larger than 30% relative to the background intensity) of the loop correspond to the timing of the plasma ejections. The typical lifetime and size of the plasma ejecta are about 20-60 s and 0.3-1.5 Mm, respectively. The height-time plot of jet shows many sub-structures (or individual jets) and the typical lifetime of the individual jet is about one to five minutes. Before the onset of the jet activity, a loop appears in Ca II H and gradually increases in size, and after few minutes several jets are launched from the loop. Once the jet activity starts and several individual jets are launched, the loop starts shrinking with a speed of {approx}4 km s{sup -1}. In some events, a downward moving blob with a speed of {approx}35 km s{sup -1} was observed, associated with the upward moving plasma along one of the legs of the loop hosting the jets. The upward moving plasma gradually developed into jets. Multiple plasma ejections in chromospheric anemone jet show the strongly time-dependent as well as intermittent nature of magnetic reconnection in the solar chromosphere.

  19. Quantification of the Interrelationship between Brachial-Ankle and Carotid-Femoral Pulse Wave Velocity in a Workplace Population

    PubMed Central

    Cheng, Yi-Bang; Li, Yan; Sheng, Chang-Sheng; Huang, Qi-Fang; Wang, Ji-Guang

    2016-01-01

    Background Brachial-ankle pulse wave velocity (PWV) is increasingly used for the measurement of arterial stiffness. In the present study, we quantified the interrelationship between brachial-ankle and carotid-femoral PWV in a workplace population, and investigated the associations with cardiovascular risk factors and carotid intima-media thickness (IMT). Methods Brachial-ankle and carotid-femoral PWV were measured using the Omron-Colin VP1000 and SphygmoCor devices, respectively. We investigated the interrelationship by the Pearson's correlation analysis and Bland-Altman plot, and performed sensitivity and specificity analyses. Results The 954 participants (mean ± standard deviation age 42.6 ± 14.2 years) included 630 (66.0%) men and 203 (21.3%) hypertensive patients. Brachial-ankle (13.4 ± 2.7 m/s) and carotid-femoral PWV (7.3 ± 1.6 m/s) were significantly correlated in all subjects (r = 0.75) as well as in men (r = 0.72) and women (r = 0.80) separately. For arterial stiffness defined as a carotid-femoral PWV of 10 m/s or higher, the sensitivity and specificity of brachial-ankle PWV of 16.7 m/s or higher were 72 and 94%, respectively. The area under the receiver operating characteristic curve was 0.953. In multiple stepwise regression, brachial-ankle and carotid-femoral PWV were significantly (p < 0.001) associated with age (partial r = 0.33 and 0.34, respectively) and systolic blood pressure (partial r = 0.71 and 0.66, respectively). In addition, brachial-ankle and carotid-femoral PWV were significantly (p < 0.001) associated with carotid IMT (r = 0.57 and 0.55, respectively) in unadjusted analysis, but not in analysis adjusted for cardiovascular risk factors (p ≥ 0.08). Conclusions Brachial-ankle and carotid-femoral PWV were closely correlated, and had similar determinants. Brachial-ankle PWV can behave as an ease-of-use alternative measure of arterial stiffness for assessing cardiovascular risk. PMID:27195246

  20. Blockade of the brachial plexus abolishes activation of specific brain regions by electroacupuncture at LI4: a functional MRI study

    PubMed Central

    Gu, Weidong; Jiang, Wei; He, Jingwei; Liu, Songbin; Wang, Zhaoxin

    2015-01-01

    Objective Our aim was to test the hypothesis that electroacupuncture (EA) at acupuncture point LI4 activates specific brain regions by nerve stimulation that is mediatied through a pathway involving the brachial plexus. Methods Twelve acupuncture naive right-handed volunteers were allocated to receive three sessions of EA at LI4 in a random different order (crossover): (1) EA alone (EA); EA after injection of local anaesthetics into the deltoid muscle (EA+LA); and (3) EA after blockade of the brachial plexus (EA+NB). During each session, participants were imaged in a 3 T MRI scanner. Brain regions showing change in blood oxygen level-dependent (BOLD) signal (activation) were identified. Subjective acupuncture sensation was quantified after functional MRI scanning was completed. Results were compared between the three sessions for each individual, and averaged. Results Blockade of the brachial plexus inhibited acupuncture sensation during EA. EA and EA+LA activated the bilateral thalamus, basal ganglia, cerebellum and left putamen, whilst no significant activation was observed during EA+NB. The BOLD signal of the thalamus correlated significantly with acupuncture sensation score during EA. Conclusions Blockade of the brachial plexus completely abolishes patterns of brain activation induced by EA at LI4. The results suggest that EA activates specific brain regions through stimulation of the local nerves supplying the tissues at LI4, which transmit sensory information via the brachial plexus. Trial registration number ChiCTR-OO-13003389. PMID:26464415

  1. A demonstration experiment of steam-driven, high-pressure melt ejection

    SciTech Connect

    Allen, M.D.; Pitch, M. ); Nichols, R.T. )

    1990-08-01

    A steam blowdown test was performed at the Surtsey Direct Heating Test Facility to test the steam supply system and burst diaphragm arrangement that will be used in subsequent Surtsey Direct Containment Heating (DCH) experiments. Following successful completion of the steam blowdown test, the HIPS-10S (High-Pressure Melt Streaming) experiment was conducted to demonstrate that the technology to perform steam-driven, high-pressure melt ejection (HPME) experiments has been successfully developed. In addition, the HIPS-10S experiment was used to assess techniques and instrumentation design to create the proper timing of events in HPME experiments. This document discusses the results of this test.

  2. The asymmetric scent: ringtailed lemurs (Lemur catta) have distinct chemical signatures in left and right brachial glands.

    PubMed

    Dapporto, Leonardo

    2008-10-01

    Distinctive cues are predicted to evolve when the benefits obtained by the recognition process overcome its costs. When individual recognition is particularly beneficial for both senders and receivers, the expression of strongly distinctive signals is predicted to evolve. On the other hand, it could be predicted that each individual should show a very stable individual signature. In the same perspective, a great stability of the individual signatures could be expected. Lemur catta is the first non-human primate in which olfactory individual recognition has been demonstrated on the basis of the specialized brachial gland secretions. In this paper, I performed gas chromatograph analyses of right and left gland samples collected in two different periods (breeding and non-breeding seasons) from seven males. The aim was to verify if a diversification in such cues, already demonstrated at the inter-individual level, also occurs at the intra-individual level between left and right glands. I verified, by discriminant analysis and chemical distance comparisons, that each gland of each lemur has its particular signature that is maintained through time. Moreover, such diversification resulted so marked to make the overall intra-individual chemical differences similar to/as strong as the inter-individual ones. Since in rodents several odors from different glands may be integrated in individual recognition, I suggest that bilateral diversification in L. catta scents may offer an enhanced distinctiveness that could provide benefits in mate choice and social relationships.

  3. The asymmetric scent: ringtailed lemurs ( Lemur catta) have distinct chemical signatures in left and right brachial glands

    NASA Astrophysics Data System (ADS)

    Dapporto, Leonardo

    2008-10-01

    Distinctive cues are predicted to evolve when the benefits obtained by the recognition process overcome its costs. When individual recognition is particularly beneficial for both senders and receivers, the expression of strongly distinctive signals is predicted to evolve. On the other hand, it could be predicted that each individual should show a very stable individual signature. In the same perspective, a great stability of the individual signatures could be expected. Lemur catta is the first non-human primate in which olfactory individual recognition has been demonstrated on the basis of the specialized brachial gland secretions. In this paper, I performed gas chromatograph analyses of right and left gland samples collected in two different periods (breeding and non-breeding seasons) from seven males. The aim was to verify if a diversification in such cues, already demonstrated at the inter-individual level, also occurs at the intra-individual level between left and right glands. I verified, by discriminant analysis and chemical distance comparisons, that each gland of each lemur has its particular signature that is maintained through time. Moreover, such diversification resulted so marked to make the overall intra-individual chemical differences similar to/as strong as the inter-individual ones. Since in rodents several odors from different glands may be integrated in individual recognition, I suggest that bilateral diversification in L. catta scents may offer an enhanced distinctiveness that could provide benefits in mate choice and social relationships.

  4. [Brachial artery endothelial function in teenagers with obesity depending on severity of clinical, trophological and metabolic disorders].

    PubMed

    Maskova, G S; Chernaia, N L; Nagornova, E Iu; Fomina, O V; Byteva, T A

    2014-01-01

    We carried out complex examination of 68 adolescents aged 11-17 years with primary obesity which in addition to assessment of clinical-anamnestic, laboratory data and functional parameters of cardiovascular system included registration of reaction of brachial artery endothelium to reactive hyperemia. Vascular endothelial dysfunction (VED) was found in 66% of obese teenagers. Obesity in adolescents with VED was characterized by aggravated course with higher fat mass index (36.8 +/- 4.39%) and prevalence of hypothalamic (42%) and metabolic (8.8%) syndromes. Stable arterial hypertension (AH) found in 37% of examined adolescents was 1.5 times more often registered in those with VED. We distinguished 4 groups of adolescents with various degree of risk of development of cardiovascular disorders: with stable AH and VED (group I), with stable AH and normal function of vascular endothelium (group II), with normal or labile arterial pressure with VED (group III), with normal or labile arterial pressure with normal function of vascular endothelium. It is expedient to supplement examination of obese adolescents with assessment of the state of vascular endothelium aiming at determination of degree of risk of development of atherosclerosis and/or stable AH.

  5. MUSCLE TRANSFER FROM TRICEPS TO BICEPS IN PATIENTS WITH CHRONIC INJURY OF THE UPPER TRUNK OF THE BRACHIAL PLEXUS

    PubMed Central

    Souza, Fabiano Inúcio de; Saito, Mateus; Kimura, Luiz Koiti; Júnior, Rames Mattar; Zumiotti, Arnaldo Valdir

    2015-01-01

    Objective: To evaluate the results from transposition of the triceps for elbow flexion in patients with chronic and complete injury to the upper trunk of the brachial plexus. Methods: This was a retrospective study, including only patients who had biceps grade 0 and triceps grade 5, who underwent anterior transfer of the triceps muscle, performed between 1998 and 2005. The affected side, sex, type of accident, strength of elbow flexion, complications and patient satisfaction were investigated in 11 cases. Results: 10 patients were male; the age range was from 24 to 49 years, with a mean of 33.7 years. The minimum time between injury and surgery was 21 months (range 21-74 months). The left side was affected in eight cases, and the right only in three. Good results were obtained in 10 patients, who acquired elbow flexion strength of grade 3 (two cases) and grade 4 (eight cases), while one evolved unfavorably with grade 2 strength. Two cases had complications (initial compartment syndrome and insufficient tensioning). All the patients said that they were satisfied with the procedure. Conclusion: Anterior transposition of the triceps muscle provided patient satisfaction in all cases except one, attaining strength grade 4 in eight cases, grade 3 in two cases and grade 2 in one case. PMID:27022572

  6. Coronal Mass Ejections and Non-recurrent Forbush Decreases

    NASA Astrophysics Data System (ADS)

    Belov, A.; Abunin, A.; Abunina, M.; Eroshenko, E.; Oleneva, V.; Yanke, V.; Papaioannou, A.; Mavromichalaki, H.; Gopalswamy, N.; Yashiro, S.

    2014-10-01

    Coronal mass ejections (CMEs) and their interplanetary counterparts (interplanetary coronal mass ejections, ICMEs) are responsible for large solar energetic particle events and severe geomagnetic storms. They can modulate the intensity of Galactic cosmic rays, resulting in non-recurrent Forbush decreases (FDs). We investigate the connection between CME manifestations and FDs. We used specially processed data from the worldwide neutron monitor network to pinpoint the characteristics of the recorded FDs together with CME-related data from the detailed online catalog based upon the Solar and Heliospheric Observatory (SOHO)/ Large Angle and Spectrometric Coronagraph (LASCO) data. We report on the correlations of the FD magnitude to the CME initial speed, the ICME transit speed, and the maximum solar wind speed. Comparisons between the features of CMEs (mass, width, velocity) and the characteristics of FDs are also discussed. FD features for halo, partial halo, and non-halo CMEs are presented and discussed.

  7. Radiation dose distributions due to sudden ejection of cobalt device.

    PubMed

    Abdelhady, Amr

    2016-09-01

    The evaluation of the radiation dose during accident in a nuclear reactor is of great concern from the viewpoint of safety. One of important accident must be analyzed and may be occurred in open pool type reactor is the rejection of cobalt device. The study is evaluating the dose rate levels resulting from upset withdrawal of co device especially the radiation dose received by the operator in the control room. Study of indirect radiation exposure to the environment due to skyshine effect is also taken into consideration in order to evaluate the radiation dose levels around the reactor during the ejection trip. Microshield, SHLDUTIL, and MCSky codes were used in this study to calculate the radiation dose profiles during cobalt device ejection trip inside and outside the reactor building.

  8. Radiation dose distributions due to sudden ejection of cobalt device.

    PubMed

    Abdelhady, Amr

    2016-09-01

    The evaluation of the radiation dose during accident in a nuclear reactor is of great concern from the viewpoint of safety. One of important accident must be analyzed and may be occurred in open pool type reactor is the rejection of cobalt device. The study is evaluating the dose rate levels resulting from upset withdrawal of co device especially the radiation dose received by the operator in the control room. Study of indirect radiation exposure to the environment due to skyshine effect is also taken into consideration in order to evaluate the radiation dose levels around the reactor during the ejection trip. Microshield, SHLDUTIL, and MCSky codes were used in this study to calculate the radiation dose profiles during cobalt device ejection trip inside and outside the reactor building. PMID:27423021

  9. Light-induced ejection of calcium atoms from polymer surfaces

    NASA Astrophysics Data System (ADS)

    Mango, F.; Maccioni, E.

    2008-12-01

    Laser-induced fluorescence (LIF) of calcium atoms at room temperature has been observed in a polydimethylsiloxane (PDMS) coated cell when the walls are illuminated with non resonant visible light. Ca atomic density in the gas phase, monitored by the LIF, is much higher than normal room-temperature vapour pressure of calcium. In past years photon-stimulated desorption (PSD) was observed for several alkali metals that adsorbed to solid films of PDMS polymers. High yields of photo-desorbed atoms (and molecules in the case of sodium) can be induced, at room temperature and below, by weak intensity radiation. The desorption is characterised by a frequency threshold, whereas any power threshold is undetectable. The calcium photo-ejection is characterised both by a frequency threshold (about 18 500 cm-1) and by an observable power threshold (whose value becomes lower when the photo-ejecting light wavelength decreases).

  10. The impact ejection of living organisms into space

    NASA Technical Reports Server (NTRS)

    Melosh, H. J.

    1985-01-01

    The possibility of natural processes to blast living organisms into space was examined. It is suggested that rocks ejected from the Earth by a giant meteorite or comet impact can carry microorganisms into space. Such microscopic Earth life would have an opportunity to colonize the other planets if it can survive the rigors of space until it falls into the atmosphere of a hospitable planet.

  11. Determining the full halo coronal mass ejection characteristics

    NASA Astrophysics Data System (ADS)

    Fainshtein, V. G.

    2009-03-01

    In this paper we determined the parameters of 45 full halo coronal mass ejections (HCMEs) for various modifications of their cone forms (“ice cream cone models”). We show that the CME determined characteristics depend significantly on the CME chosen form. We show that, regardless of the CME chosen form, the trajectory of practically all the considered HCMEs deviate from the radial direction to the Sun-to-Earth axis at the initial stage of their movement.

  12. Evolving Magnetic Structures and Their Relation to Coronal Mass Ejections

    NASA Technical Reports Server (NTRS)

    Feynman, J.

    1996-01-01

    Solar activity regions are frequently concentrated into cluster which persist for many solar rotations. These activity complexes are associated with weak dispersed magnetic fields which are most apparent after the activity itself has ceased. We call this combination of persistent activity and dispersed Evolving Magnetic Structures (EMS). Here we show examples of EMSs and describe the evolution of an EMS associated with major Coronal Mass Ejections (CME) and other solar and magnetic disturbances.

  13. Associations between coronal mass ejections and interplanetary shocks

    NASA Technical Reports Server (NTRS)

    Sheeley, N. R., Jr.; Howard, R. A.; Koomen, M. J.; Michels, D. J.; Schwenn, R.; Muhlhauser, K. H.; Rosenbauer, H.

    1983-01-01

    Nearly continuous complementary coronal observations and interplanetary plasma measurements for the years 1979-1982 are compared. It is shown that almost all low latitude high speed coronal mass ejections (CME's) were associated with shocks at HELIOS 1. Some suitably directed low speed CME's were clearly associated with shocks while others may have been associated with disturbed plasma (such as NCDE's) without shocks. A few opposite hemisphere CME's associated with great flares seem to be associated with shocks at HELIOS.

  14. Dynamics of bacteriophage genome ejection in vitro and in vivo

    NASA Astrophysics Data System (ADS)

    Panja, Debabrata; Molineux, Ian J.

    2010-12-01

    Bacteriophages, phages for short, are viruses of bacteria. The majority of phages contain a double-stranded DNA genome packaged in a capsid at a density of ~500 mg ml-1. This high density requires substantial compression of the normal B-form helix, leading to the conjecture that DNA in mature phage virions is under significant pressure, and that pressure is used to eject the DNA during infection. A large number of theoretical, computer simulation and in vitro experimental studies surrounding this conjecture have revealed many—though often isolated and/or contradictory—aspects of packaged DNA. This prompts us to present a unified view of the statistical physics and thermodynamics of DNA packaged in phage capsids. We argue that the DNA in a mature phage is in a (meta)stable state, wherein electrostatic self-repulsion is balanced by curvature stress due to confinement in the capsid. We show that in addition to the osmotic pressure associated with the packaged DNA and its counterions, there are four different pressures within the capsid: pressure on the DNA, hydrostatic pressure, the pressure experienced by the capsid and the pressure associated with the chemical potential of DNA ejection. Significantly, we analyze the mechanism of force transmission in the packaged DNA and demonstrate that the pressure on DNA is not important for ejection. We derive equations showing a strong hydrostatic pressure difference across the capsid shell. We propose that when a phage is triggered to eject by interaction with its receptor in vitro, the (thermodynamic) incentive of water molecules to enter the phage capsid flushes the DNA out of the capsid. In vivo, the difference between the osmotic pressures in the bacterial cell cytoplasm and the culture medium similarly results in a water flow that drags the DNA out of the capsid and into the bacterial cell.

  15. Ejection behavior characteristics in experimental cratering in sandstone targets

    NASA Astrophysics Data System (ADS)

    Sommer, Frank; Reiser, Fiona; Dufresne, Anja; Poelchau, Michael H.; Hoerth, Tobias; Deutsch, Alex; Kenkmann, Thomas; Thoma, Klaus

    2013-01-01

    Within the frame of the MEMIN research unit (Multidisciplinary Experimental and Numerical Impact Research Network), impact experiments on sandstone targets were carried out to systematically study the influence of projectile mass, velocity, and target water saturation on the cratering and ejection processes. The projectiles were accelerated with two-stage light-gas guns (Ernst-Mach-Institute) onto fine-grained targets (Seeberger sandstone) with about 23% porosity. Collection of the ejecta on custom-designed catchers allowed determination of particle shape, size distribution, ejection angle, and microstructures. Mapping of the ejecta imprints on the catcher surface enabled linking of the different patterns to ejection stages observed on high-speed videos. The increase in projectile mass from 0.067 to 7.1 g correlates with an increase in the total ejected mass; ejecta angles, however, are similar in range for all experiments. The increase in projectile velocity from 2.5 to 5.1 km s-1 correlates with a total ejecta mass increase as well as in an increase in comminution efficiency, and a widening of the ejecta cone. A higher degree of water saturation of the target yields an increase in total ejecta mass up to 400% with respect to dry targets, higher ejecta velocity, and a steeper cone. These data, in turn, suggest that the reduced impedance contrast between the quartz grains of the target and the pores plays a primary role in the ejecta mass increase, while vaporization of water determines the ejecta behavior concerning ejecta velocity and particle distribution.

  16. Multinucleon Ejection Model for Two Body Current Neutrino Interactions

    SciTech Connect

    Sobczyk, Jan T.; /Fermilab

    2012-06-01

    A model is proposed to describe nucleons ejected from a nucleus as a result of two-body-current neutrino interactions. The model can be easily implemented in Monte Carlo neutrino event generators. Various possibilities to measure the two-body-current contribution are discussed. The model can help identify genuine charge current quasielastic events and allow for a better determination of the systematic error on neutrino energy reconstruction in neutrino oscillation experiments.

  17. r-PROCESS NUCLEOSYNTHESIS IN DYNAMICALLY EJECTED MATTER OF NEUTRON STAR MERGERS

    SciTech Connect

    Goriely, Stephane; Bauswein, Andreas; Janka, Hans-Thomas

    2011-09-10

    Although the rapid neutron-capture process, or r-process, is fundamentally important for explaining the origin of approximately half of the stable nuclei with A > 60, the astrophysical site of this process has not been identified yet. Here we study r-process nucleosynthesis in material that is dynamically ejected by tidal and pressure forces during the merging of binary neutron stars (NSs) and within milliseconds afterward. For the first time we make use of relativistic hydrodynamical simulations of such events, defining consistently the conditions that determine the nucleosynthesis, i.e., neutron enrichment, entropy, early density evolution and thus expansion timescale, and ejecta mass. We find that 10{sup -3}-10{sup -2} M{sub sun} are ejected, which is enough for mergers to be the main source of heavy (A {approx}> 140) galactic r-nuclei for merger rates of some 10{sup -5} yr{sup -1}. While asymmetric mergers eject 2-3 times more mass than symmetric ones, the exact amount depends weakly on whether the NSs have radii of {approx}15 km for a 'stiff' nuclear equation of state (EOS) or {approx}12 km for a 'soft' EOS. r-process nucleosynthesis during the decompression becomes largely insensitive to the detailed conditions because of efficient fission recycling, producing a composition that closely follows the solar r-abundance distribution for nuclei with mass numbers A > 140. Estimating the light curve powered by the radioactive decay heating of r-process nuclei with an approximative model, we expect high emission in the B-V-R bands for 1-2 days with potentially observable longer duration in the case of asymmetric mergers because of the larger ejecta mass.

  18. ON SUN-TO-EARTH PROPAGATION OF CORONAL MASS EJECTIONS

    SciTech Connect

    Liu, Ying D.; Luhmann, Janet G.; Moestl, Christian; Bale, Stuart D.; Lin, Robert P.; Lugaz, Noe; Davies, Jackie A.

    2013-05-20

    We investigate how coronal mass ejections (CMEs) propagate through, and interact with, the inner heliosphere between the Sun and Earth, a key question in CME research and space weather forecasting. CME Sun-to-Earth kinematics are constrained by combining wide-angle heliospheric imaging observations, interplanetary radio type II bursts, and in situ measurements from multiple vantage points. We select three events for this study, the 2012 January 19, 23, and March 7 CMEs. Different from previous event studies, this work attempts to create a general picture for CME Sun-to-Earth propagation and compare different techniques for determining CME interplanetary kinematics. Key results are obtained concerning CME Sun-to-Earth propagation: (1) the Sun-to-Earth propagation of fast CMEs can be approximately formulated into three phases: an impulsive acceleration, then a rapid deceleration, and finally a nearly constant speed propagation (or gradual deceleration); (2) the CMEs studied here are still accelerating even after the flare maximum, so energy must be continuously fed into the CME even after the time of the maximum heating and radiation has elapsed in the corona; (3) the rapid deceleration, presumably due to interactions with the ambient medium, mainly occurs over a relatively short timescale following the acceleration phase; and (4) CME-CME interactions seem a common phenomenon close to solar maximum. Our comparison between different techniques (and data sets) has important implications for CME observations and their interpretations: (1) for the current cases, triangulation assuming a compact CME geometry is more reliable than triangulation assuming a spherical front attached to the Sun for distances below 50-70 solar radii from the Sun, but beyond about 100 solar radii we would trust the latter more; (2) a proper treatment of CME geometry must be performed in determining CME Sun-to-Earth kinematics, especially when the CME propagation direction is far away from the

  19. A Historic View of Solar Coronal Mass Ejections (CMEs)

    NASA Technical Reports Server (NTRS)

    SaintCyr, Orville C.

    2010-01-01

    We present a historic overview of CME observations, ending with concepts for future measurement capabilities. One of the first detections of what we now call a CME was provided by instrumentation on OSO-7 and reported by Tousey (1973); but the phrase "corona) mass ejection" was coined after the Skylab/ATM coronagraph detected dozens of the transients over its nine month observing run (e.g., Munro et al., 1979). Pre-discovery identification of likely CMEs were then reported in historic eclipse photographs and drawings (e.g., Eddy, 1974; Cliver, 1989). Multi-year observations followed with groundbased MLSO MK3/4 coronagraph (1980-present), and spacebased missions: Solwind (1979-1985), SMM (1980-1989), SOHO LASCO/EIT (1996-present), SMEI (2003-present), and STEREO SECCHI (2006-present). The Spartan 201 coronagraph flew in space multiple times. The influential Gosling (1993) "solar flare myth" manuscript identified CMEs as the cause of the most severe geomagnetic storms, thus cementing their importance in Sun-Earth connection studies. A new window into CMEs was opened with the launch of SOHO in 1995 when the UVCS spectrometer began returning plasma diagnostics of a significant number of events (e.g., Ciaravella et al., 2006). What about the future for CME research? Statistical properties of the UVCS CME observations are forthcoming; the STEREO mission should continue to return views of CMEs from unique vantage points; and the recent launch of SDO should provide new insights into the small spatial scale dynamics of activity associated with CMEs. Several new observing techniques have been demonstrated at total eclipses, and inclusion on spacebased platforms in the future could also prove valuable for understanding CMEs. A common element of several recent proposals is to image the white-light corona with extremely high spatial resolution. The momentary glimpses of the corona during total solar eclipses have shown fine structure that is not captured by global models, and

  20. Investigation of a clamshell roll-out ejection concept

    NASA Technical Reports Server (NTRS)

    Hatakeyama, L. F.

    1971-01-01

    The equations for the motion, forces, and couples generated by clamshells released from spinning sounding rockets in accordance with a roll-out ejection concept are presented. The application of these equations to a study of a system for the Javelin rocket vehicle is discussed. The roll-out ejection concept advocated requires that each deploying clamshell be pivoted about an axis at its trailing edge located in the system sectioning plane. Clamshell despinning is a consequence of this deployment since the pivotal rate is in opposition to the rocket vehicle spin. The energy required by the deployment is derived largely from the rotational energy of the clamshell. Thus, the rocket vehicle will not be significantly despun by this kind of clamshell deployment. This ejection concept also permits a system design which makes it possible to limit clamshell angular motion to rotation about that one of its centroidal principal axes which is brought into parallelism with the rocket vehicle longitudinal axis. Also, by equalizing the moments of inertia about the other centroidal principal axes, the roll-out motion can be decoupled from any extraneous angular motion about these axes.

  1. The Formation of Brown Dwarfs as Ejected Stellar Embryos

    NASA Astrophysics Data System (ADS)

    Reipurth, Bo; Clarke, Cathie

    2001-07-01

    We conjecture that brown dwarfs are substellar objects because they have been ejected from small newborn multiple systems that have decayed in dynamical interactions. In this view, brown dwarfs are stellar embryos for which the star formation process was aborted before the hydrostatic cores could build up enough mass to eventually start hydrogen burning. The disintegration of a small multiple system is a stochastic process, which can be described only in terms of the half-life of the decay. A stellar embryo competes with its siblings in order to accrete infalling matter, and the one that grows slowest is most likely to be ejected. With better luck, a brown dwarf would therefore have become a normal star. This interpretation of brown dwarfs readily explains the rarity of brown dwarfs as close companions to normal stars, the absence of wide brown dwarf binaries, and the flattening of the low-mass end of the initial mass function. Possible observational tests of this scenario include statistics of brown dwarfs near Class 0 sources and the kinematics of brown dwarfs in star-forming regions, while they still retain a kinematic signature of their expulsion. Because the ejection process limits the amount of gas brought along in a disk, it is predicted that substellar equivalents to the classical T Tauri stars should be rather short-lived.

  2. Brachial-ankle pulse wave velocity as a predictor of mortality in elderly Chinese.

    PubMed

    Sheng, Chang-Sheng; Li, Yan; Li, Li-Hua; Huang, Qi-Fang; Zeng, Wei-Fang; Kang, Yuan-Yuan; Zhang, Lu; Liu, Ming; Wei, Fang-Fei; Li, Ge-Le; Song, Jie; Wang, Shuai; Wang, Ji-Guang

    2014-11-01

    Pulse wave velocity (PWV) is a measure of arterial stiffness and predicts cardiovascular events and mortality in the general population and various patient populations. In the present study, we investigated the predictive value of brachial-ankle PWV for mortality in an elderly Chinese population. Our study subjects were older (≥60 years) persons living in a suburban town of Shanghai. We measured brachial-ankle PWV using an automated cuff device at baseline and collected vital information till June 30, 2013, during follow-up. The 3876 participants (1713 [44.2%] men; mean [±SD] age, 68.1±7.3 years) included 2292 (59.1%) hypertensive patients. PWV was on average 17.8 (±4.0) m/s and was significantly (P<0.0001) associated with age (r=0.48) and in unadjusted analysis with all-cause (n=316), cardiovascular (n=148), stroke (n=46), and noncardiovascular mortality (n=168) during a median follow-up of 5.9 years. In further adjusted analysis, we studied the risk of mortality according to the decile distributions of PWV. Only the subjects in the top decile (23.3-39.3 m/s) had a significantly (P≤0.003) higher risk of all-cause mortality (hazard ratio relative to the whole study population, 1.56; 95% confidence interval, 1.16-2.08), especially in hypertensive patients (hazard ratio, 1.86; 95% confidence interval, 1.31-2.64; P=0.02 for the interaction between PWV and hypertension). Similar trends were observed for cardiovascular, stroke, and noncardiovascular mortality, although statistical significance was not reached (P≥0.08). In conclusion, brachial-ankle PWV predicts mortality in elderly Chinese on the conditions of markedly increased PWV and hypertension.

  3. Brachial plexus block using lidocaine/epinephrine or lidocaine/xylazine in fat-tailed sheep.

    PubMed

    Ghadirian, Safoura; Vesal, Nasser

    2013-01-01

    This blinded, randomized experimental study was designed to evaluate the analgesic effects of adding epinephrine or xylazine to lidocaine solution for brachial plexus block (BPB) in sheep. Nine healthy, fat-tailed female lambs (26.6 ± 1.5 kg) were randomly allocated into three groups: lidocaine 2%, 5 mg kg(-1) (LID, n = 6), lidocaine (5 mg kg(-1)) with epinephrine 5 µg mL(-1) (LIDEP, n = 6) or lidocaine (5 mg kg(-1)) with xylazine 0.05 mg kg(-1) (LIDXY, n = 6). Each animal was tested twice. The sheep received a total volume of 0.25 mL kg(-1) for BPB. A nerve stimulator was used to locate the nerves of the brachial plexus. Onset and duration of analgesia of the forelimb were evaluated using superficial and deep pin prick and pinching of skin with a hemostat clamp. Heart and respiratory rates, and rectal temperature were recorded before and at predetermined intervals following the completion of the block. Brachial administration of LID, LIDEP or LIDXY produced forelimb analgesia within 11.3, 11.0 and 7.0 minutes, respectively. The mean duration of analgesia was 100.0 min in LID and 133.2 min in LIDEP group. The mean duration of analgesia in LIDXY group (186.8 min) was significantly longer compared with LID group. In LIDEP group a significant increase in heart rate occurred 5 min after drug administration. Heart rate decreased from 35 to 80 min in sheep received LIDXY. In conclusion, the addition of xylazine to lidocaine solution for BBP provided a prolonged duration of action without any adverse effects in fat-tailed sheep. PMID:25653791

  4. Brachial plexus block using lidocaine/epinephrine or lidocaine/xylazine in fat-tailed sheep.

    PubMed

    Ghadirian, Safoura; Vesal, Nasser

    2013-01-01

    This blinded, randomized experimental study was designed to evaluate the analgesic effects of adding epinephrine or xylazine to lidocaine solution for brachial plexus block (BPB) in sheep. Nine healthy, fat-tailed female lambs (26.6 ± 1.5 kg) were randomly allocated into three groups: lidocaine 2%, 5 mg kg(-1) (LID, n = 6), lidocaine (5 mg kg(-1)) with epinephrine 5 µg mL(-1) (LIDEP, n = 6) or lidocaine (5 mg kg(-1)) with xylazine 0.05 mg kg(-1) (LIDXY, n = 6). Each animal was tested twice. The sheep received a total volume of 0.25 mL kg(-1) for BPB. A nerve stimulator was used to locate the nerves of the brachial plexus. Onset and duration of analgesia of the forelimb were evaluated using superficial and deep pin prick and pinching of skin with a hemostat clamp. Heart and respiratory rates, and rectal temperature were recorded before and at predetermined intervals following the completion of the block. Brachial administration of LID, LIDEP or LIDXY produced forelimb analgesia within 11.3, 11.0 and 7.0 minutes, respectively. The mean duration of analgesia was 100.0 min in LID and 133.2 min in LIDEP group. The mean duration of analgesia in LIDXY group (186.8 min) was significantly longer compared with LID group. In LIDEP group a significant increase in heart rate occurred 5 min after drug administration. Heart rate decreased from 35 to 80 min in sheep received LIDXY. In conclusion, the addition of xylazine to lidocaine solution for BBP provided a prolonged duration of action without any adverse effects in fat-tailed sheep.

  5. Range of motion and strength after surgery for brachial plexus birth palsy

    PubMed Central

    2011-01-01

    Background There is little information about the range of motion (ROM) and strength of the affected upper limbs of patients with permanent brachial plexus birth palsy. Patients and methods 107 patients who had brachial plexus surgery in Finland between 1971 and 1998 were investigated in this population-based, cross-sectional, 12-year follow-up study. During the follow-up, 59 patients underwent secondary procedures. ROM and isometric strength of the shoulders, elbows, wrists, and thumbs were measured. Ratios for ROM and strength between the affected and unaffected sides were calculated. Results 61 patients (57%) had no active shoulder external rotation (median 0° (-75–90)). Median active abduction was 90° (1–170). Shoulder external rotation strength of the affected side was diminished (median ratio 28% (0–83)). Active elbow extension deficiency was recorded in 82 patients (median 25° (5–80)). Elbow flexion strength of the affected side was uniformly impaired (median ratio 43% (0–79)). Median active extension of the wrist was 55° (-70–90). The median ratio of grip strength for the affected side vs. the unaffected side was 68% (0–121). Patients with total injury had poorer ROM and strength than those with C5–6 injury. Incongruity of the radiohumeral joint and avulsion were associated with poor strength values. Interpretation ROM and strength of affected upper limbs of patients with surgically treated brachial plexus birth palsy were reduced. Patients with avulsion injuries and/or consequent joint deformities fared worst. PMID:21142823

  6. Décompression chirurgicale du syndrome de défilé thoraco-brachial

    PubMed Central

    Lukulunga, Loubet Unyendje; Moussa, Abdou Kadri; Mahfoud, Mustapha; Ismael, Farid; Berrada, Mohamed Saleh; El Yaacoubi, Moradh

    2014-01-01

    Le syndrome de défilé thoraco-brachial est une pathologie souvent méconnue à cause de diagnostic difficile par manque des signes pathognomoniques conduisant souvent à des errances. Les manifestations cliniques dépendent selon qu'il s'agit d'une compression nerveuse, vasculaire ou vasculo-nerveuse. Le but de cette étude est de décrire certains aspects cliniques particuliers et évaluer le résultat fonctionnel après la décompression chirurgicale du paquet vasculo-nerveux. Notre étude rétrospective a porté sur l'analyse des données cliniques, radiologiques, IRM et EMG sur les patients opérés entre janvier 2010 et juillet 2013 du syndrome de défilé thoraco-brachial dans le service de traumatologie orthopédie de l'hôpital Ibn Sina de Rabat. 15 cas ont été colligés: 12 cas post traumatiques (fracture de la clavicule) et 3 cas d'origines congénitales, dont l’âge moyen était 35 ans (20 à 50 ans) avec 9 femmes et 6 hommes. A la fin du traitement, le score de Dash est passé de 109 (46% Normal=0) à 70 (20%), et le stress test de Roos était de 70/100 à 80/100. Le résultat était excellent dans 12 cas soit (80%) et moins bon dans dans 3 cas (20%). En définitive, la résection de malformations osseuses, l'excision des brides et la neurolyse du plexus brachial suivie de la rééducation a donné une bonne évolution fonctionnelle. PMID:25709735

  7. Estimation of central aortic pressure waveform features derived from the brachial cuff volume displacement waveform.

    PubMed

    Butlin, Mark; Qasem, Ahmad; Avolio, Alberto P

    2012-01-01

    There is increasing interest in non-invasive estimation of central aortic waveform parameters in the clinical setting. However, controversy has arisen around radial tonometric based systems due to the requirement of a trained operator or lack of ease of use, especially in the clinical environment. A recently developed device utilizes a novel algorithm for brachial cuff based assessment of aortic pressure values and waveform (SphygmoCor XCEL, AtCor Medical). The cuff was inflated to 10 mmHg below an individual's diastolic blood pressure and the brachial volume displacement waveform recorded. The aortic waveform was derived using proprietary digital signal processing and transfer function applied to the recorded waveform. The aortic waveform was also estimated using a validated technique (radial tonometry based assessment, SphygmoCor, AtCor Medical). Measurements were taken in triplicate with each device in 30 people (17 female) aged 22 to 79 years of age. An average for each device for each individual was calculated, and the results from the two devices were compared using regression and Bland-Altman analysis. A high correlation was found between the devices for measures of aortic systolic (R(2)=0.99) and diastolic (R(2)=0.98) pressure. Augmentation index and subendocardial viability ratio both had a between device R(2) value of 0.82. The difference between devices for measured aortic systolic pressure was 0.5±1.8 mmHg, and for augmentation index, 1.8±7.0%. The brachial cuff based approach, with an individualized sub-diastolic cuff pressure, provides an operator independent method of assessing not only systolic pressure, but also aortic waveform features, comparable to existing validated tonometric-based methods.

  8. Feline left ventricular oxygen consumption is not affected by volume expansion, ejection or redevelopment of pressure during relaxation.

    PubMed

    Duwel, C M; Westerhof, N

    1988-09-01

    We studied the dependency of myocardial oxygen consumption on the mechanical events during left ventricular relaxation in isolated supported cat hearts. The volume of the left ventricle was controlled by means of a balloon connected to a membrane pump. Oxygen consumption (MVO2 in cm3.min-1.100 g-1) for three protocols (PROT) performed at peak isovolumic pressure, was studied: (1) rapid ejection to zero pressure, (2) partial rapid ejection followed by redevelopment of pressure, (3) volume expansion during relaxation, and compared with oxygen consumption of isovolumic (ISOV) beats. We found (mean +/- SD): (table; see text) In the protocols 1 and 3 the differences were not significant (paired Student's t-test, p greater than 0.05). In protocols 1 and 2 left ventricular volume was decreased up to 2.15 cm3 (i.e. stroke volume, SV) during the pressure release. We studied the specific effect of ejection (i.e., wall muscle shortening) in a fourth protocol in which the ventricle ejected up to 2.7 cm3 under nearly zero pressure load (isobaric contraction). There was a small amount of oxygen consumption associable with this unloaded ejection i.e. MVO2 = 3.38 (+/- 0.47) + 0.30 (+/- 0.16) SV, but it was too small to compensate for a decrease in MVO2 expected from the pressure release according to the tension time index. These findings suggest that oxygen consumption does not depend on the mechanical events during ventricular relaxation. PMID:3174398

  9. Humeral rotational osteotomy for shoulder deformity in obstetric brachial plexus palsy: which direction should I rotate?

    PubMed

    Abdelgawad, Amr A; Pirela-Cruz, Miguel A

    2014-01-01

    Shoulder internal rotation contracture is the most common deformity affecting the shoulder in patients with Obstetric Brachial Plexus Palsy. With progression of the deformity, the glenohumeral joint starts to subluxate and then dislocates. This is accompanied with bony changes of both the humerus and the glenoid. Two opposite direction humeral osteotomies have been proposed for this condition (internal rotation osteotomy (IRO) and external rotation osteotomy (ERO)). This fact of different direction osteotomies has not adequately been explained in the literature. Most orthopedic surgeons may not be able to fully differentiate between these two osteotomies regarding the indications, outcomes and effects on the joint. This review explains these differences in details.

  10. Dorsal root entry zone lesions (Nashold's procedure) for pain relief following brachial plexus avulsion.

    PubMed Central

    Thomas, D G; Sheehy, J P

    1983-01-01

    Brachial plexus avulsion is an important cause of severe intractable pain, particularly in young motor cyclists. The pain usually develops soon after the injury. In a minority of cases severe pain persists and is refractory to management. Nineteen patients are reviewed in whom dorsal root entry zone lesions have been produced for pain relief. The operative technique is described. Early post-operative motor or sensory disturbance in the ipsilateral leg have been temporary side effects, with mild persisting deficits in a minority. Sixteen cases have had significant persisting pain relief. The maximum follow-up period is 2 1/2 years. Images PMID:6644316

  11. Arthroscopic Release of Adhesive Capsulitis of the Shoulder Complicated With Shoulder Dislocation and Brachial Plexus Injury.

    PubMed

    Nunez, Fiesky A; Papadonikolakis, Anastasios; Li, Zhongyu

    2016-01-01

    The incidence of brachial plexus injury after shoulder dislocation or arthroscopic shoulder surgery is low. Complex regional pain syndrome (CRPS) is an uncommon but painful condition that can develop after nerve injury. Historically, CRPS has been difficult to treat and therapeutic efforts are sometimes limited to ameliorating symptoms. However, if a dystrophic focus can be identified, the condition can be addressed with surgical exploration for potential neurolysis or nerve repair. The present article reports on a case of type II CRPS that developed in the postoperative setting of arthroscopic shoulder surgery complicated with simple shoulder dislocation. PMID:27518297

  12. Brachial artery injury due to closed posterior elbow dislocation: case report☆

    PubMed Central

    Miyazaki, Alberto Naoki; Fregoneze, Marcelo; Santos, Pedro Doneux; do Val Sella, Guilherme; Checchia, Caio Santos; Checchia, Sergio Luiz

    2016-01-01

    An association between closed posterior elbow dislocation and traumatic brachial artery injury is rare. Absence of radial pulse on palpation is an important warning sign and arteriography is the gold-standard diagnostic test. Early diagnosis is essential for appropriate treatment to be provided. This consists of joint reduction and immobilization, along with urgent surgical restoration of arterial flow. Here, a case (novel to the Brazilian literature) of an association between these injuries (and the treatment implemented) in a 27-year-old male patient is reported. These injuries were sustained through physical assault. PMID:27069896

  13. The use of the phrenic nerve communicating branch to the fifth cervical root for nerve transfer to the suprascapular nerve in infants with obstetric brachial plexus palsy.

    PubMed

    Al-Qattan, M M; El-Sayed, A A F

    2014-01-01

    Traditionally, suprascapular nerve reconstruction in obstetric brachial plexus palsy is done using either the proximal C5 root stump or the spinal accessory nerve. This paper introduces another potential donor nerve for neurotizing the suprascapular nerve: the phrenic nerve communicating branch to the C5 root. The prevalence of this communicating branch ranges from 23% to 62% in various anatomical dissections. Over the last two decades, the phrenic communicating branch was used to reconstruct the suprascapular nerve in 15 infants. Another 15 infants in whom the accessory nerve was used to reconstruct the suprascapular nerve were selected to match the former 15 cases with regard to age at the time of surgery, type of palsy, and number of avulsed roots. The results showed that there is no significant difference between the two groups with regard to recovery of external rotation of the shoulder. It was concluded that the phrenic nerve communicating branch may be considered as another option to neurotize the suprascapular nerve.

  14. Thrombin Injection for Treatment of Brachial Artery Pseudoaneurysm at the Site of a Hemodialysis Fistula: Report of Two Patients

    SciTech Connect

    Clark, Timothy W.I.; Abraham, Robert J.

    2000-09-15

    We report two patients with arteriovenous hemodialysis fistulas that were complicated by brachial artery pseudoaneurysms. Each pseudoanerysm was percutaneously thrombosed with an injection of thrombin, using techniques to prevent escape of thrombin into the native brachial artery. In one patient, an angioplasty balloon was inflated across the neck of the aneurysm during thrombin injection. In the second patient, thrombin was injected during ultrasound-guided compression of the neck of the pseudoaneurysm. Complete thrombosis of each pseudoaneurysm was achieved within 30 sec. No ischemic or embolic events occurred. This technique may be useful in treating pseudoaneurysms of smaller peripheral arteries.

  15. Brachial blood pressure-independent relations between radial late systolic shoulder-derived aortic pressures and target organ changes.

    PubMed

    Norton, Gavin R; Majane, Olebogeng H I; Maseko, Muzi J; Libhaber, Carlos; Redelinghuys, Michelle; Kruger, Deirdre; Veller, Martin; Sareli, Pinhas; Woodiwiss, Angela J

    2012-04-01

    Central aortic blood pressure (BP; BPc) predicts outcomes beyond brachial BP. In this regard, the application of a generalized transfer function (GTF) to radial pulse waves for the derivation of BPc is an easy and reproducible measurement technique. However, the use of the GTF may not be appropriate in all circumstances. Although the peak of the second shoulder of the radial waveform (P2) is closely associated with BPc, and, hence, BPc may be assessed without the need for a GTF, whether P2-derived BPc is associated with adverse cardiovascular changes independent of brachial BP is uncertain. Thus, P2- and GTF-derived aortic BPs were assessed using applanation tonometry and SphygmoCor software. Left ventricular mass was indexed for height(1.7) (n=678) and carotid intima-media thickness (IMT; n=462) was determined using echocardiography and vascular ultrasound. With adjustments for nurse-derived brachial pulse pressure (PP), P2-derived central PP was independently associated with left ventricular mass indexed for height(1.7) (partial r=0.18; P<0.0001) and IMT (partial r=0.40; P<0.0001). These relations were similar to nurse-derived brachial PP-independent relations between GTF-derived central PP and target organ changes (left ventricular mass indexed for height(1.7): partial r=0.17, P<0.0001; IMT: partial r=0.37, P<0.0001). In contrast, with adjustments for central PP, nurse-derived brachial PP-target organ relations were eliminated (partial r=-0.21 to 0.05). Twenty-four-hour, day, and night PP-target organ relations did not survive adjustments for nurse-derived brachial BP. In conclusion, central PP derived from P2, which does not require a GTF, is associated with cardiovascular target organ changes independent of brachial BP. Thus, when assessing adverse cardiovascular effects of aortic BP independent of brachial BP, P2-derived measures may complement GTF-derived measures of aortic BP.

  16. Homage to Bob Brodkey at 85: ejections, sweeps and the genesis and extensions of quadrant analysis

    NASA Astrophysics Data System (ADS)

    Wallace, James

    2013-11-01

    Almost 50 years ago Bob Brodkey and his student, Corino, conceived and carried out a visualization experiment for the very near wall region of a turbulent pipe flow (JFM 37) that, together with the turbulent boundary layer visualization of Kline et al. (JFM 30), excited the turbulence community. Using a high speed movie camera mounted on a lathe bed that recorded magnified images in a moving frame of reference, they observed the motions of small particles in the sub- and buffer-layers. Surprisingly, these motion were not nearly so locally random as was the general view of turbulence at the time. Rather, connected regions of the near wall flow decelerated and then erupted away from the wall in what they called ``ejections.'' These decelerated motions were followed by larger scale connected motions toward the wall from above that they called ``sweeps.'' Brodkey and Corino estimated that ejections accounted for 70 % the Reynolds shear stress at Red = 20 , 000 while only occurring about 18 % of the time. Wallace et al. (JFM 54) attempted to quantify these visual observations by conceiving of and carrying out a quadrant analyisis in a turbulent oil channel flow. This paper will trace this history and describe the expanding use of these ideas in turbulence research today.

  17. OBSERVATION OF HEATING BY FLARE-ACCELERATED ELECTRONS IN A SOLAR CORONAL MASS EJECTION

    SciTech Connect

    Glesener, Lindsay; Bain, Hazel M.; Krucker, Säm; Lin, Robert P.

    2013-12-20

    We report a Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) observation of flare-accelerated electrons in the core of a coronal mass ejection (CME) and examine their role in heating the CME. Previous CME observations have revealed remarkably high thermal energies that can far surpass the CME's kinetic energy. A joint observation by RHESSI and the Atmospheric Imaging Assembly of a partly occulted flare on 2010 November 3 allows us to test the hypothesis that this excess energy is collisionally deposited by flare-accelerated electrons. Extreme ultraviolet (EUV) images show an ejection forming the CME core and sheath, with isothermal multifilter analysis revealing temperatures of ∼11 MK in the core. RHESSI images reveal a large (∼100 × 50 arcsec{sup 2}) hard X-ray (HXR) source matching the location, shape, and evolution of the EUV plasma, indicating that the emerging CME is filled with flare-accelerated electrons. The time derivative of the EUV emission matches the HXR light curve (similar to the Neupert effect observed in soft and HXR time profiles), directly linking the CME temperature increase with the nonthermal electron energy loss, while HXR spectroscopy demonstrates that the nonthermal electrons contain enough energy to heat the CME. This is the most direct observation to date of flare-accelerated electrons heating a CME, emphasizing the close relationship of the two in solar eruptive events.

  18. Deflections of Fast Coronal Mass Ejections and the Properties of Associated Solar Energetic Particle Events

    NASA Technical Reports Server (NTRS)

    Kahler, S. W.; Akiyama, S.; Gopalswamy, N.

    2012-01-01

    The onset times and peak intensities of solar energetic particle (SEP) events at Earth have long been thought to be influenced by the open magnetic fields of coronal holes (CHs). The original idea was that a CH lying between the solar SEP source region and the magnetic footpoint of the 1 AU observer would result in a delay in onset and/or a decrease in the peak intensity of that SEP event. Recently, Gopalswamy et al. showed that CHs near coronal mass ejection (CME) source regions can deflect fast CMEs from their expected trajectories in space, explaining the appearance of driverless shocks at 1 AU from CMEs ejected near solar central meridian (CM). This suggests that SEP events originating in CME-driven shocks may show variations attributable to CH deflections of the CME trajectories. Here, we use a CH magnetic force parameter to examine possible effects of CHs on the timing and intensities of 41 observed gradual E approx 20 MeV SEP events with CME source regions within 20 deg. of CM. We find no systematic CH effects on SEP event intensity profiles. Furthermore, we find no correlation between the CME leading-edge measured position angles and SEP event properties, suggesting that the widths of CME-driven shock sources of the SEPs are much larger than the CMEs. Independently of the SEP event properties, we do find evidence for significant CME deflections by CH fields in these events

  19. Use of Sudden Ionospheric Disturbance Monitors to Detect Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Campagna, A.; Amador, J.; Marchese, A. K.; Espinosa, M.

    2015-12-01

    The purpose of this research is to study the effect of Earth directed coronal mass ejections (CMEs) on the ionosphere in 2011, and to see if sudden ionospheric disturbance (SID) monitors could be used to predict whether a CME was geoeffective. A CME is a cloud of highly energized particles ejected from the Sun. It is hypothesized that a strong CME will affect the ionosphere, and this might be observed in certain data sets. Data was taken from two SID monitors in Vienna receiving transmissions from Norway and France from February through July, 2011. This data was then analyzed relative to the kinetic energy of Earth directed CMEs that occurred during the same time period. The Earth directed CME data was taken from the Large Angle and Spectrometric Coronagraph (LASCO) device on NASA's Solar and Heliospheric Observatory (SOHO). A correlation was found between CME kinetic energy and SID energy, with the maximum correlation at a 6 day lag of the SID data. The 6 day delay accounts for the travel time for the CME to reach Earth. Though the impact of the CME on the ionosphere was observed retrospectively, the research indicates that CMEs may be identified using SID monitors alone.

  20. A model of the gastric gland ejection cycle: low ejection fractions require reduction of the glandular dead space.

    PubMed

    Kurbel, S; Kurbel, B; Dmitrović, B; Vcev, A

    2001-06-01

    This paper was inspired by the reported results of authors from Uppsala and Lund that gastric glands in rats rhythmically contract 3-7 cycles per minute and develop luminal pressures more than 10 mmHg. To ensure that pepsinogen is not retained in the acid-rich section of the gland, ejection fractions would need to be more than 50% of the gland volume. We have tried to calculate the ejection fraction of such contractions. Dimensions of human gastric glands were measured on the fresh frozen samples of macroscopically and histologically normal gastric mucosa. In total, 18 specimens (from nine persons) were measured under the microscope. The density of glands was 135 +/- 11 (mean +/- S.D.) glands per mm( 2) of gastric mucosa. A typical gastric gland is a tubular structure 1.2 +/- 0.22 mm long and 0.03-0.05 mm wide. We have used 1 mm for length and 0.03 mm for the gland diameter to calculate that each gland approximates a volume of 707 pl, suggesting that the total glandular volume for 15 million glands reaches 10.6 ml. Further calculations based on one to five contractions per minute on an average and on the total volume of gastric glands of 10 ml showed that only ejection fractions less than 10% deliver daily volumes less than 3 l. The presented model of the gastric gland activity is based on the idea that the low ejection fractions require a reduction of the glandular dead space. The reduced luminal pressure during the gland relaxation might cause backflux of hydrophobic viscoelastic mucus through the gland aperture. Repeated glandular contractions and relaxations would move the mucus all the way to the gland bottom, filling the gland cavity below the neck with an axial semisolid mucous cylinder. This filling would reduce the gland dead space. During contractions, the gland would eject mainly the peripheral, the more liquid part of its content. The decreasing luminal pressure in the relaxing gland would pull the outlet mucus inside, protecting gland apertures from

  1. Reproducibility of near-infrared spectroscopy parameters measured during brachial artery occlusion and reactive hyperemia in healthy men

    NASA Astrophysics Data System (ADS)

    Lacroix, Sébastien; Gayda, Mathieu; Gremeaux, Vincent; Juneau, Martin; Tardif, Jean-Claude; Nigam, Anil

    2012-07-01

    Near-infrared spectroscopy (NIRS) is a noninvasive technique evaluating microvascular function. The aim of this study was to assess the reproducibility of NIRS parameters during reactive hyperemia induced by a 5 min brachial artery occlusion. Twenty-four healthy young males (mean 34+/-8 years old) had two microvascular function evaluations by NIRS over a 7 to 30-day period (mean 16+/-10 days). Intra-subject and inter-observer reproducibility were evaluated with intraclass correlation coefficient (ICC), coefficient of variation (CV), and standard error of measurement (SEM%) for every parameter. Mean NIRS parameters did not differ between both evaluations. Reproducibility was greatest for muscle oxygen consumption (ICC: 0.84; CV: 6.51% SEM: 7.11%), time to basal O2Hb (ICC: 0.63, CV: 20.04%, SEM 27.22%), time to maximal O2Hb (ICC: 0.71; CV: 15.61% SEM: 19.27%), peak of O2Hb (ICC: 0.63, CV: 6.68%, SEM 8.53%), time to maximal tHb (ICC: 0.73, CV: 19,61%, SEM 24.56%) and area under the O2Hb and tHb curves (ICC: 0.68, CV: 16.15%, SEM 22.93% and ICC: 0.62, CV: 18.59%, SEM 26.64%, respectively). Moreover, inter-observer reproducibility ranged from excellent to perfect (ICC from 0.85 to 1.00) for every parameter. NIRS parameters during reactive hyperemia are highly reproducible which enables their repeated measurement to study microvascular function in healthy subjects.

  2. Hubble Sees Material Ejected From Comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    1995-01-01

    These NASA Hubble Space Telescope pictures of comet Hale-Bopp show a remarkable 'pinwheel' pattern and a blob of free-flying debris near the nucleus. The bright clump of light along the spiral (above the nucleus, which is near the center of the frame) may be a piece of the comet's icy crust that was ejected into space by a combination of ice evaporation and the comet's rotation, and which then disintegrated into a bright cloud of particles.

    Although the 'blob' is about 3.5 times fainter than the brightest portion at the nucleus, the lump appears brighter because it covers a larger area. The debris follows a spiral pattern outward because the solid nucleus is rotating like a lawn sprinkler, completing a single rotation about once per week.

    Ground-based observations conducted over the past two months have documented at least two separate episodes of jet and pinwheel formation and fading. By coincidence, the first Hubble images of Hale-Bopp, taken on September 26, 1995, immediately followed one of these outbursts and allow researchers to examine it at unprecedented detail. For the first time they see a clear separation between the nucleus and some of the debris being shed. By putting together information from the Hubble images and those taken during the recent outburst using the 82 cm telescope of the Teide Observatory (Tenerife, Canary Islands, Spain), astronomers find that the debris is moving away from the nucleus at a speed (projected on the sky) of about 68 miles per hour (109 kilometers per hour).

    The Hubble observations will be used to determine if Hale-Bopp is really a giant comet or rather a more moderate-sized object whose current activity is driven by outgassing from a very volatile ice which will 'burn out' over the next year. Comet Hale-Bopp was discovered on July 23, 1995 by amateur astronomers Alan Hale and Thomas Bopp. Though this comet is still well outside the orbit of Jupiter (almost 600 million miles, or one billion kilometers from Earth

  3. Occult rib fractures and brachial plexus injury following median sternotomy for open-heart operations.

    PubMed

    Baisden, C E; Greenwald, L V; Symbas, P N

    1984-09-01

    The incidence and the sites of rib fractures during open-heart operations through a median sternotomy incision were studied in 36 consecutive patients divided into two groups. In Group 1 (24 patients), a conventional Ankeney retractor was used to expose the heart, and in Group 2 (12 patients), a similar retractor was used but with its uppermost pair of blades removed. Thorough physical examinations and preoperative and postoperative chest roentgenograms were obtained, and postoperative bone scans were done in all patients. No rib fractures were detected on the routine chest roentgenograms in patients in either group. Bone scans, however, showed 44 rib fractures (15 of the first rib, 13 of the second rib, 4 of the third rib, 6 of the fourth rib, 3 of the fifth rib, and 3 of the sixth rib) in 16 patients in Group 1. Six patients in Group 2 had 9 rib fractures (2 of the first rib, 4 of the second rib, and 1 each of the third, fifth, and sixth ribs). None of the patients in Group 2 had brachial plexus injury and neither of the first rib fractures in this group were located posteriorly, whereas 3 patients in Group 1 had both brachial plexus injury and posterior first rib fractures.

  4. Brachial Artery Conductance During Reactive Hyperemia is Increased in Women with Polycystic Ovary Syndrome

    PubMed Central

    Raja-Khan, Nazia; Shuja, Showieb A.; Kunselman, Allen R.; Hogeman, Cynthia S.; Demers, Laurence M.; Gnatuk, Carol L.; Legro, Richard S.

    2010-01-01

    Objective To examine changes in brachial artery conductance (BAC) during reactive hyperemia in women with polycystic ovary syndrome (PCOS) compared to controls. Study Design This is a pilot case-control study performed at a single academic medical center. Changes in BAC during reactive hyperemia were evaluated in 31 women with PCOS and 11 healthy control women. Fasting glucose, insulin, lipids and androgen levels were also determined. A mixed-effects model was used to compare the PCOS curve to the control curve for change in BAC from baseline during reactive hyperemia. Results Body mass index (BMI) and testosterone levels were significantly increased in the PCOS group compared to controls (P < 0.05). In addition, the PCOS group had higher total and LDL cholesterol levels (P = 0.05 and 0.09, respectively). Change in BAC from baseline during reactive hyperemia was significantly increased in the PCOS group compared to controls even after adjusting for age, BMI and LDL cholesterol levels (P < 0.0001). There were no significant differences between the two groups in age, blood pressure, or fasting glucose or insulin levels. Conclusions Brachial artery conductance during reactive hyperemia is significantly increased in women with PCOS compared to controls and may be a novel early indicator of increased cardiovascular risk in women with PCOS. PMID:21112136

  5. Brachial artery Doppler flux parameters before and after hot flush in Mexican postmenopausal women: preliminary report

    PubMed Central

    Rodríguez, Karina Vázquez; Ortiz, Sergio Rosales

    2016-01-01

    Objective To analyse brachial artery flux parameters in postmenopausal women before and after hot flush. Material and methods Two groups of postmenopausal women were studied: Group I, without vasomotor symptoms (n = 10) and Group II, with vasomotor symptoms (n = 10). In all them a brachial artery Doppler ultrasound was done, measuring before and after hyperaemic stimulus of the arterial diameter (AD), the pulsatility index (PI), and the resistive index (RI). In Group I, measurements were done at baseline and five minutes after. In Group II, measurements were at baseline, and one and five minutes after the hot-flush. Comparison between the groups was done with Mann-Whitney U test, and within the groups with Wilcoxon test. Results No differences were found among the groups in Doppler parameters. When comparing each group separately, in Group I, at baseline and at five minutes measurements, the AD was greater after the hyperaemic stimulus than before it. In group II at baseline, the PI was significantly greater after the hyperaemic stimulus than before to it. At the first and fifth minute, the AD was significantly greater after the hyperaemic stimulus than before to it. Conclusions No differences were found between those who did not have and those who had hot flushes. PMID:27095957

  6. [Meningoencephalo-myeloradiculitis due to Flavivirus: bi-brachial paralysis and respiratory insufficiency].

    PubMed

    Kuntzer, T; de Marval, F; Ochsner, F; de Torrenté, A; Kuhn, M; Fitting, J W

    1995-04-01

    3 patients developed rapid onset of fever and nuchal stiffness. Paresis of brachial muscles occurred within 4 days and all patients had respiratory failure that needed mechanical ventilation. At the peak of the disease there were bilateral asymmetrical severe atrophy of brachial, shoulder and neck muscles, cranial nerve pareses and absent or weak deep reflexes in the upper extremities. CSF analyses showed sterile lymphocytic pleocytosis. In 2 cases the patients suffered a tick bite in Switzerland and the third was probably bitten by an insect while opening a package received from Indonesia. Patients had rapid defervescence and serological tests were found to be highly positive for IgM and then IgG ELISA FSME (Frühsommer-Meningoenzephalitis). The patients were ventilated for 2 to 5 weeks before a progressive improvement was seen. However, on follow-up at 12, 18 and 30 months respectively, proximal muscles were still atrophied and quite weak. Our cases underline that: (1) FSME-ELISA results may cross-react with the Japanese and Central European encephalitis virus species; (2) Flaviviruses do induce unusual and preferential long-term paralysis of the upper extremities simulating poliomyelitis; (3) in the 2 patients studied electrophysiologically, there were signs of axonal reinnervation not seen in lower motor neuron syndrome which were important for reinnervation to permit progressive, but late, motor improvement; (4) there is no evidence of extension of the endemic foci of tick-borne encephalitis in Switzerland. PMID:7709179

  7. Ankle Brachial Index: simple non-invasive estimation of peripheral artery disease

    NASA Astrophysics Data System (ADS)

    Pieniak, Marcin; Cieślicki, Krzysztof; Żyliński, Marek; Górski, Piotr; Murgrabia, Agnieszka; Cybulski, Gerard

    2014-11-01

    According to international guidelines, patients with Peripheral Artery Disease (PAD) are burdened with high cardiovascular risk. One of the simplest, non-invasive methods for PAD detection is the ankle-brachial index (ABI) measurement. The ABI is calculated as the ratio of systolic blood pressure at the ankle (pressure in the posterior tibial artery or the dorsal artery) to the systolic pressure in the arm (in the brachial artery) when the body is in a horizontal position. The physiological value of the ABI is assumed to be between 1 and 1.3; however, these limits vary from study to study. A value less than 0.9 indicates PAD. Some authors propose also measuring the ABI on both sides of the body to highlight possible differences in blood pressure between the opposite arterial segments. The aim of this study was to perform a meta-analysis of the ABI diagnostic criteria used in different publications. Additionally, ABI measurements were performed on 19 healthy patients in age ranged from 20 to 63 years. The results showed a slight dependence between age and the differences between the values obtained from left and right sides of the body.

  8. Ejection and Lofting of Dust from Hypervelocity Impacts on the Moon

    NASA Astrophysics Data System (ADS)

    Hermalyn, B.; Schultz, P. H.

    2011-12-01

    Hypervelocity impact events mobilize and redistribute fine-grained regolith dust across the surfaces of planetary bodies. The ejecta mass-velocity distribution controls the location and emplacement of these materials. The current flux of material falling on the moon is dominated by small bolides and should cause frequent impacts that eject dust at high speeds. For example, approximately 25 LCROSS-sized (~20-30m diameter) craters are statistically expected to be formed naturally on the moon during any given earth year. When scaled to lunar conditions, the high-speed component of ejecta from hypervelocity impacts can be lofted for significant periods of time (as evidenced by the LCROSS mission results, c.f., Schultz, et al., 2010, Colaprete, et al., 2010). Even at laboratory scales, ejecta can approach orbital velocities; the higher impact speeds and larger projectiles bombarding the lunar surface may permit a significant portion of material to be launched closer to escape velocity. When these ejecta return to the surface (or encounter local topography), they impact at hundreds of meters per second or faster, thereby "scouring" the surface with low mass oblique impacts. While these high-speed ejecta represent only a small fraction of the total ejected mass, the lofting and subsequent ballistic return of this dust has the highest mobilization potential and will be directly applicable to the upcoming LADEE mission. A suite of hypervelocity impact experiments into granular materials was performed at the NASA Ames Vertical Gun Range (AVGR). This study incorporates both canonical sand targets and air-fall pumice dust to simulate the mechanical properties of lunar regolith. The implementation of a Particle Tracking Velocimetry (PTV) technique permits non-intrusive measurement of the ejecta velocity distribution within the ejecta curtain by following the path of individual ejecta particles. The PTV system developed at the AVGR uses a series of high-speed cameras (ranging

  9. Invasive hemodynamic characterization of heart failure with preserved ejection fraction.

    PubMed

    Andersen, Mads J; Borlaug, Barry A

    2014-07-01

    Recent hemodynamic studies have advanced our understanding of heart failure with preserved ejection fraction (HFpEF). Despite improved pathophysiologic insight, clinical trials have failed to identify an effective treatment for HFpEF. Invasive hemodynamic assessment can diagnose or exclude HFpEF, making it invaluable in understanding the basis of the disease. This article reviews the hemodynamic mechanisms underlying HFpEF and how they manifest clinically, discusses invasive hemodynamic assessment as a diagnostic tool, and explores how invasive hemodynamic profiling may allow understanding of pathophysiological differences and inform the design and entry criteria for future trials.

  10. Flux-Rope Structure of Coronal Mass Ejections

    NASA Technical Reports Server (NTRS)

    Gopalswamy, N.; Nieves-Chinchilla, T.; Hidalgo, M.; Zhang, J.; Riley, P.; van Driel-Gesztelyi, L.; Mandrini, C. H.

    2013-01-01

    This Topical Issue (TI) of Solar Physics, devoted to the study of flux-rope structure in coronal mass ejections (CMEs), is based on two Coordinated Data Analysis Workshops (CDAWs) held in 2010 (20-23 September in Dan Diego, California, USA) and 2011 (5-9 September in Alcala, Spain). The primary purpose of the CDAWs was to address the question whether all CMEs have a flux rope structure. Each CDAW was attended by about 50 scientists interested in the origin, propagation, and interplanetary manifestation of CME phenomena.

  11. The Expansion and Radial Speeds of Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Gopalswamy, N.; Dal Lago, A.; Yashiro, S.; Akiyama, S.

    We show the relation between radial (V_{rad}) and expansion (V_{exp}) speeds of coronal mass ejections (CMEs) depends on the CME width. As CME width increases, {V_{rad}/V_{exp}} decreases from a value >1 to <1. For widths approaching 180°, the ratio approaches 0 if the cone has a flat base, while it approaches 0.5 if the base has a bulge (ice cream cone). The speed difference between the limb and disk halos and the spherical expansion of super fast CMEs can be explained by the width dependence.

  12. An efficient, selective collisional ejection mechanism for inner-shell population inversion in laser-driven plasmas

    SciTech Connect

    SCHROEDER,W. ANDREAS; NELSON,THOMAS R.; BORISOV,A.B.; LONGWORTH,J.W.; BOYER,K.; RHODES,C.K.

    2000-06-07

    A theoretical analysis of laser-driven collisional ejection of inner-shell electrons is presented to explain the previously observed anomalous kilovolt L-shell x-ray emission spectra from atomic Xe cluster targets excited by intense sub-picosecond 248nrn ultraviolet radiation. For incident ponderomotively-driven electrons photoionized by strong above threshold ionization, the collisional ejection mechanism is shown to be highly l-state and significantly n-state (i.e. radially) selective for time periods shorter than the collisional dephasing time of the photoionized electronic wavefunction. The resulting preference for the collisional ejection of 2p electrons by an ionized 4p state produces the measured anomalous Xe(L) emission which contains direct evidence for (i) the generation of Xe{sup 27+}(2p{sup 5}3d{sup 10}) and Xe{sup 28+}(2p{sup 5}3d{sup 9}) ions exhibiting inner-shell population inversion and (ii) a coherent correlated electron state collision responsible for the production of double 2p vacancies. For longer time periods, the selectivity of this coherent impact ionization mechanism is rapidly reduced by the combined effects of intrinsic quantum mechanical spreading and dephasing--in agreement with the experimentally observed and extremely strong {minus}{lambda}{sup {minus}6} pump-laser wavelength dependence of the efficiency of inner-shell (2p) vacancy production in Xe clusters excited in underdense plasmas.

  13. Ejection Regimes in Picosecond Laser-Induced Forward Transfer of Metals

    NASA Astrophysics Data System (ADS)

    Pohl, Ralph; Visser, Claas Willem; Römer, Gert-Willem; Lohse, Detlef; Sun, Chao; Huis in't Veld, Bert

    2015-02-01

    Laser-induced forward transfer (LIFT) is a 3D direct-write method suitable for precision printing of various materials, including pure metals. To understand the ejection mechanism and thereby improve deposition, here we present visualizations of ejection events at high-spatial (submicrometer) and high-temporal resolutions, for picosecond LIFT of copper and gold films with a thickness 50 nm ≤d ≤400 nm . For increasing fluences, these visualizations reveals the fluence threshold below which no ejection is observed, followed by the release of a metal cap (i.e., a hemisphere-shaped droplet), the formation of an elongated jet, and the release of a metal spray. For each ejection regime, the driving mechanisms are analyzed, aided by a two-temperature model. Cap ejection is driven by relaxation of thermal stresses induced by laser-induced heating, whereas jet and spray ejections are vapor driven (as the metal film is partly vaporized). We introduce energy balances that provide the ejection velocity in qualitative agreement with our velocity measurements. The threshold fluences separating the ejection regimes are determined. In addition, the fluence threshold below which no ejection is observed is quantitatively described using a balance between the surface energy and the inertia of the (locally melted) film. In conclusion, the ejection type can now be controlled, which allows for improved deposition of pure metal droplets and sprays.

  14. PARTICLE ACCELERATION IN PLASMOID EJECTIONS DERIVED FROM RADIO DRIFTING PULSATING STRUCTURES

    SciTech Connect

    Nishizuka, N.; Karlický, M.; Bárta, M.; Janvier, M.

    2015-02-01

    We report observations of slowly drifting pulsating structures (DPSs) in the 0.8-4.5 GHz frequency range of the RT4 and RT5 radio spectrographs at Ondřejov Observatory, between 2002 and 2012. We found 106 events of DPSs, which we classified into four cases: (I) single events with a constant frequency drift (12 events), (II) multiple events occurring in the same flare with constant frequency drifts (11 events), (III) single or multiple events with increasing or decreasing frequency drift rates (52 events), and (IV) complex events containing multiple events occurring at the same time in a different frequency range (31 events). Many DPSs are associated with hard X-ray (HXR) bursts (15-25 keV) and soft X-ray (SXR) gradient peaks, as they typically occurred at the beginning of HXR peaks. This indicates that DPS events are related to the processes of fast energy release and particle acceleration. Furthermore, interpreting DPSs as signatures of plasmoids, we measured their ejection velocity, their width, and their height from the DPS spectra, from which we also estimated the reconnection rate and the plasma beta. In this interpretation, constant frequency drift indicates a constant velocity of a plasmoid, and an increasing/decreasing frequency drift indicates a deceleration/acceleration of a plasmoid ejection. The reconnection rate shows a good positive correlation with the plasmoid velocity. Finally we confirmed that some DPS events show plasmoid counterparts in Solar Dynamics Observatory/Atmospheric Imaging Assembly images.

  15. Solar Radio Emission as a Prediction Technique for Coronal Mass Ejections' registration

    NASA Astrophysics Data System (ADS)

    Sheiner, Olga; Fridman, Vladimir

    2016-07-01

    The concept of solar Coronal Mass Ejections (CMEs) as global phenomenon of solar activity caused by the global magnetohydrodynamic processes is considered commonly accepted. These processes occur in different ranges of emission, primarily in the optical and the microwave emission being generated near the surface of the sun from a total of several thousand kilometers. The usage of radio-astronomical data for CMEs prediction is convenient and promising. Actually, spectral measurements of solar radio emission cover all heights of solar atmosphere, sensitivity and accuracy of measurements make it possible to record even small energy changes. Registration of the radio emission is provided by virtually all-weather ground-based observations, and there is the relative cheapness to obtain the corresponding information due to a developed system of monitoring observations. On the large statistical material there are established regularities of the existence of sporadic radio emission at the initial stage of CMEs' formation and propagation in the lower layers of the solar atmosphere during the time interval from 2-3 days to 2 hours before registration of CMEs on coronagraph. In this report we present the prediction algorithm and scheme of short-term forecasting developed on the base of statistical analysis regularities of solar radio emission data prior to "isolated" solar Coronal Mass Ejections registered in 1998, 2003, 2009-2013.

  16. On the autonomous detection of coronal mass ejections in heliospheric imager data

    NASA Astrophysics Data System (ADS)

    Tappin, S. J.; Howard, T. A.; Hampson, M. M.; Thompson, R. N.; Burns, C. E.

    2012-05-01

    We report on the development of an Automatic Coronal Mass Ejection (CME) Detection tool (AICMED) for the Solar Mass Ejection Imager (SMEI). CMEs observed with heliospheric imagers are much more difficult to detect than those observed by coronagraphs as they have a lower contrast compared with the background light, have a larger range of intensity variation and are easily confused with other transient activity. CMEs appear in SMEI images as very faint often-fragmented arcs amongst a much brighter and often variable background. AICMED operates along the same lines as Computer Aided CME Tracking (CACTus), using the Hough Transform on elongation-time J-maps to extract straight lines from the data set. We compare AICMED results with manually measured CMEs on almost three years of data from early in SMEI operations. AICMED identified 83 verifiable events. Of these 46 could be matched with manually identified events, the majority of the non-detections can be explained. The remaining 37 AICMED events were newly discovered CMEs. The proportion of false identification was high, at 71% of the autonomously detected events. We find that AICMED is very effective as a region of interest highlighter, and is a promising first step in autonomous heliospheric imager CME detection, but the SMEI data are too noisy for the tool to be completely automated.

  17. Coronal Mass Ejections: a Summary of Recent Results

    NASA Technical Reports Server (NTRS)

    Gopalswamy, Nat; Davila, J. M.

    2010-01-01

    Coronal mass ejections (CMEs) have been recognized as the most energetic phenomenon in the heliosphere, deriving their energy from the stressed magnetic fields on the Sun. This paper highlights some of the recent results on CMEs obtained from the Solar and Heliospheric Observatory (SOHO) and the Solar Terrestrial Relations Observatory (STEREO) missions. The summary of the talk follows. SOHO observations revealed that the CME rate is almost a factor of two larger than previously thought and varied with the solar activity cycle in a complex way (e.g., high-latitude CMEs occurred in great abundance during the solar maximum years). CMEs were found to interact with other CMEs as well as with other large-scale structures (coronal holes), resulting in deflections and additional particle acceleration. STEREO observations have confirmed the three-dimensional nature of CMEs and the shocks surrounding them. The EUV signatures (flare arcades, corona) dimming, filament eruption, and EUV waves) associated with CMEs have become vital in the identification of solar sources from which CMEs erupt. CMEs with speeds exceeding the characteristic speeds of the corona and the interplanetary medium drive shocks, which produce type II radio bursts. The wavelength range of type II bursts depends on the CME kinetic energy: type II bursts with emission components at all wavelengths (metric to kilometric) are due to CMEs of the highest kinetic energy. Some CMEs, as fast as 1600 km/s do not produce type II bursts, while slow CMEs (400 km/s) occasionally produce type II bursts. These observations can be explained as the variation in the ambient flow speed (solar wind) and the Alfven speed. Not all CME-driven shocks produce type II bursts because either they are subcritical or do not have the appropriate geometry. The same shocks that produce type II bursts also produce solar energetic particles (SEPs), whose release near the Sun seems to be delayed with respect to the onset of type II bursts

  18. Corona Mass Ejections: a Summary of Recent Results

    NASA Astrophysics Data System (ADS)

    Gopalswamy, N.

    2010-12-01

    Corona mass ejections (CMEs) have been Recognized as the most energetic phenomenon in the heliosphere, deriving their energy from the stressed magnetic fields on the Sun. This paper highlights some of the recent results obtained on CMEs from the Solar and Heliospheric Observatory (SOHO) and the Solar Terrestrial Relations Observatory (STEREO) missions. The summary of follows the talk. SOHO observations revealed that the CME rate is almost a factor of: Two larger than previously thought and varied with the solar activity cycle in a complex way (eg, high-latitude CMEs occurred in great abundance during the solar years maximum). CMEs were found to interact with other CMEs as well as with other large-scale structures (corona holes), Resulting in deflections and additional particle acceleration. STEREO observations have confirmed the three-dimensional nature of CMEs and shocks the surrounding them. The EUV signatures (flare arcades, Corona dimming, filament Eruption, and EUV waves) associated with CMEs have become vital in the identification of sources from Which solar CMEs erupt. CMEs with speeds exceeding the characteristic speeds of the corona and the interplanetary medium drive shocks, which produce type II radio bursts. The wavelength range of type II bursts depends on the CME kinetic energy: type II bursts with emission components at all wavelengths (metric to kilometric) due to CMEs are of the highest kinetic energy. Some CMEs, as fast as 1600 km / s do not produce type II bursts, while slow CMEs (400 km / s) occasionally produce type II bursts. These observations can be explained as the variation in the ambient flow speed (solar wind) speed and the Alfvén. Not all CME-driven shocks produce type II bursts because they are either subcritical Or do not have the appropriate geometry. The same shocks that produce type II bursts also produce solar energetic particles (SEPS), Whose release near the Sun seems to be delayed with respect to the onset of type II bursts

  19. Group A Streptococcal Suppurative Arthritis and Osteomyelitis of the Shoulder With Brachial Plexus Palsy in a Newborn.

    PubMed

    Dierig, Alexa; Ritz, Nicole; Tacke, Uta; Heininger, Ulrich

    2016-10-01

    Osteoarticular infections in the newborn period are rare. A serious complication is paralysis of the affected extremity resulting from either pain or direct involvement of the nerve. We report a newborn with combined osteomyelitis and suppurative arthritis caused by Streptococcus pyogenes presenting with right brachial plexus palsy. PMID:27622687

  20. [Self-mutilation of the hand in a girl with total, persistent obstetric brachial plexus palsy--case report].

    PubMed

    Sibiński, Marcin; Dorman, Tomsz; Synder, Marek

    2008-01-01

    A case of hand self-mutilation in six years old girl with totals persistent obstetric brachial plexus palsy was presented. Self-mutilation involved biting the tips of the digits what lead to removal of nail of IV finger and partial V finger distal phalanx amputation. Furthermore, possible etiology, mechanism, evaluation of this behavior and literature was discussed in the text. PMID:18847017

  1. Endogenous testosterone and brachial artery endothelial function in middle-aged men with symptoms of late-onset hypogonadism.

    PubMed

    Mäkinen, Juuso I; Perheentupa, Antti; Irjala, Kerttu; Pöllänen, Pasi; Mäkinen, Juha; Huhtaniemi, Ilpo; Raitakari, Olli T

    2011-12-01

    In aging men, serum endogenous testosterone is inversely associated with common carotid intima-media thickness (IMT) and directly with beneficial plasma lipid levels; however, the relationship to endothelial function is poorly characterized. We examined the association between serum testosterone and endothelium-dependent brachial artery flow-mediated dilatation (FMD) in middle-aged to elderly men. A group of 83 men aged 40?69 years (mean 55.9 ± 7.5 [SD]) with andropausal symptoms were studied. We measured their serum lipids, testosterone, luteinizing hormone, mean carotid IMT and brachial artery FMD by high resolution B-mode ultrasound. Brachial FMD correlated inversely with vessel diameter (r = -0.38, p = 0.0004), alcohol consumption (r = -0.22, p = 0.047) and serum testosterone (r = -0.27, p = 0.01), but not with luteinizing hormone. In multivariate analysis, FMD was explained by testosterone (β = -0.17, p = 0.0226), high density lipoprotein cholesterol (β = 4.17, p = 0.0312) and vessel diameter (β = -4.37, p < 0.0001) when adjusted for age, body mass index, triglycerides, blood pressure, carotid IMT, smoking, alcohol consumption, cardiovascular diseases and use of lipid lowering medication (HMG-CoA reductase inhibitors). In middle-aged to elderly men, there is an inverse correlation between serum testosterone and brachial FMD. These data suggest that testosterone may have an adverse effect on systemic endothelial function.

  2. Evaluation of ejection murmurs by pulsed Doppler echocardiography.

    PubMed Central

    Kawabori, I; Stevenson, J G; Dooley, T K; Guntheroth, W G

    1980-01-01

    A common problem is a soft basal ejection murmur in an asymptomatic child with a normal electrocardiogram and chest x-ray films. If the diagnosis is aortic stenosis, there is a need for prophylaxis for subacute bacterial endocarditis and concern about development of calcific aortic stenosis. In 40 consecutive children referred for this differential diagnosis, aortic stenosis was diagnosed in 30, based on an ejection murmur at the second right interspace (not necessarily louder than at the second left), which transmitted well to the neck, accompanied by a normal second heart sound. Pulsed Doppler echocardiography confirmed turbulence at the aortic valve in 26. In the 10 children diagnosed clinically as having an innocent murmur, three had evidence on pulsed Doppler echocardiography for an abnormal aortic valve. The conventional echocardiographic findings of an eccentric aortic orifice were present in only 21 of 29 patients with aortic turbulence. Though our current clinical criteria are reasonably specific (87%), they are not as sensitive (70%). Pulsed Doppler echocardiography provides powerful non-invasive assistance for this important differential diagnosis. Images PMID:7426143

  3. Initiation of Coronal Mass Ejections by Tether-Cutting Reconnection

    NASA Technical Reports Server (NTRS)

    Moore, Ronald L.; Sterling, Alphonse C.; Falconer, David A.; Six, N. Frank (Technical Monitor)

    2002-01-01

    We present and interpret examples of the eruptive motion and flare brightening observed in the onset of magnetic explosions that produce coronal mass ejections. The observations are photospheric magnetograms and sequences of coronal and/or chromospheric images. In our examples, the explosion is apparently driven by the ejective eruption of a sigmoidal sheared-field flux rope from the core of an initially closed bipole. This eruption is initiated (triggered and unleashed) by reconnection located either (1) internally, low in the sheared core field, or (2) externally, at a magnetic null above the closed bipole. The internal reconnection is commonly called 'tether-cutting" reconnection, and the external reconnection is commonly called "break-out' reconnection. We point out that break-out reconnection amounts to external tether cutting. In one example, the eruptive motion of the sheared core field starts several minutes prior to any detectable brightening in the coronal images. We suggest that in this case the eruption is triggered by internal tether-cutting reconnection that at first is too slow and/or too localized to produce detectable heating in the coronal images. This work is supported by NASA's Office of Space Science through its Solar & Heliospheric Physics Supporting Research & Technology program and its Sun-Earth Connection Guest Investigator program.

  4. The initiation of coronal mass ejections by magnetic flux emergence

    NASA Astrophysics Data System (ADS)

    Dubey, G.; van der Holst, B.; Poedts, S.

    2006-12-01

    Aims.The initiation of solar Coronal Mass Ejections (CMEs) is studied in the framework of computational Magneto-Hydro-Dynamics (MHD). Methods: .The initial configuration includes a magnetic flux rope that is embedded in a gravitationally stratified solar atmosphere with a background dipole magnetic field in spherical, axi-symmetric geometry. The flux rope is in equilibrium due to an image current below the photosphere. An emerging magnetic flux triggering mechanism is used to make this equilibrium configuration unstable. Results: . When the magnetic flux emerges within the filament below the flux rope this results in a catastrophic behavior similar to earlier, more simple models. As a result, the flux rope rises and a current sheet forms below it. It is shown that the magnetic reconnection in the current sheet below the flux rope in combination with the outward curvature forces results in a fast ejection of the flux rope as observed for solar CMEs. We have done a parameter study of the effect of the flux emergence rate on the velocity and the acceleration of the resulting CMEs.

  5. Simulating the Fate of an Ionospheric Mass Ejection

    NASA Astrophysics Data System (ADS)

    Moore, T. E.; Fok, M. H.; Delcourt, D. C.; Slinker, S. P.; Fedder, J. A.

    2008-12-01

    We report global ion kinetic (GIK) simulations of the 24-25 Sep 1998 storm, with all relevant ionospheric outflows including polar, auroral, and plasmaspheric winds. This storm included substantial periods of northward interplanetary magnetic field, but did develop a Dst of -200 nT at its peak. The solar disturbance resulted form a coronal mass ejection that reached a peak dynamic pressure at the magnetosphere of 6.2 nPa, and produced a substantial enhancement of auroral wind oxygen outflow from the dayside, which has been termed an "ionospheric mass ejection" in an earlier observational paper. We use the LFM global simulation model to produce electric and magnetic fields in the outer magnetosphere, the Strangeway-Zheng outflow scalings with Delcourt ion trajectories to include ionospheric outflows, and the Fok-Ober inner magnetospheric model for the plasmaspheric and ring current response to all particle populations. We assess the combined contributions of heliospheric and geospheric plasmas to the ring current for this event.

  6. Forbush decreases associated to Stealth Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Heber, B.; Wallmann, C.; Galsdorf, D.; Herbst K.; Kühl, P.; Dumbovic, M.; Vršnak, B.; Veronig, A.; Temmer, M.; Möstl, C.; Dalla, S.

    Interplanetary coronal mass ejections (ICMEs) are structures in the solar wind that are the counterparts of coronal mass ejections (CMEs) at the Sun. It is commonly believed that enhanced magnetic fields in interplanetary shocks and solar ejecta as well as the increased turbulence in the solar wind sheath region are the cause of Forbush decreases (FDs) representing decreases of galactic cosmic ray (GCR) intensities. Recently, stealth CMEs i.e.~CMEs with no apparent solar surface association have become a subject in recent studies of solar activity. Whether all of such stealth CMEs can drive a FD is difficult to investigate on the basis of neutron monitor NM measurements because these measurements not only reflect the GCR intensity variation in interplanetary space but also the variation of the geomagnetic field as well as the conditions in the Earth atmosphere. Single detector counter from spacecraft instrumentation, here SOHO and Chandra EPHIN, exceed counting statistic of NMs allowing to determine intensity variation of less than 1 permil in interplanetary space on the basis of 30 minute count rate averages. Here we present the ongoing analysis of eleven stealth CMEs.

  7. Analysis of bolus formation from the micropipette ejection systems

    NASA Astrophysics Data System (ADS)

    Meng, Diwen; Mirbod, Parisa

    2013-11-01

    Ejection of drugs from micropipettes has significant applications in biomedical research and clinical studies, however little is known about the dynamics of the process involved. The experimental results show that micropipette ejection systems operate in a tip Reynolds number (Ret). A series of experiments was performed from a micropipette to visualize the shape of the droplet. The observations led to the following conclusions: a) A nearly spherical bolus, closely corresponding to Sampson flow through a circular orifice, could be achieved provided at Ret <0.05 b) Pear-like bolus distortions are observed at a Ret as small as 0.1. (d) Large distortions are observed at Ret = 0.5 and (e) for Ret > 1 an axial jet develops. Consequently, the transition point between the flow domains represents an important operating point. In this research, laminar is demarcated from turbulent regime by studying the influence of the various material and process parameters on the transition point. Three-dimensional numerical simulations on bolus formation and growth with different tip diameter were investigated and the results were validated with the experimental observations. Effects of fluid physical properties, operation conditions and tip exit size on bolus behavior were also analyzed.

  8. Biomarkers in heart failure with preserved ejection fraction.

    PubMed

    Meijers, W C; van der Velde, A R; de Boer, R A

    2016-04-01

    Biomarkers are widely used and studied in heart failure. Most studies have described the utility and performance of biomarkers in sub-studies of randomised clinical trials, where the vast majority of the patients suffered from heart failure with reduced ejection fraction (HFrEF), and not with preserved ejection fraction (HFpEF). As a result, there is a scarcity of data describing the levels, dynamics, clinical and biochemical correlates, and biology of biomarkers in patients suffering from HFpEF, whereas HFpEF is in fact a very frequent clinical entity. This article discusses the value of different biomarkers in HFpEF. We describe various aspects of natriuretic peptide measurements in HFpEF patients, with a focus on diagnosis, prognosis and the risk prediction of developing heart failure. Further, we will discuss several emerging biomarkers such as galectin-3 and suppression of tumorigenicity 2, and recently discovered ones such as growth differentiation factor-15 and syndecan-1. PMID:26942916

  9. The interval ejection fraction: a cineangiographic and radionuclide study

    SciTech Connect

    Kemper, A.J.; Bianco, J.A.; Shulman, R.M.; Folland, E.D.; Parisi, A.F.; Tow, D.E.

    1982-06-01

    To evaluate the clinical usefulness of the first-third ejection fraction (1/3 EF) for detecting patients with coronary artery disease (CAD), resting contrast ventriculography and first-pass radionuclide angiography with a high-count-rate, multicrystal camera system were performed in 47 subjects: 22 normal controls and 25 patients with clinically stable angina pectoris and severe CAD without and with resting wall motion abnormalities. By contrast angiography, only group 3 had depressed global EF or 1/3 EF compared with control. Whereas 11 of 25 CAD patients had global EF outside the normal range, only two of 25 had depressed 1/3 EF. Both had left ventricular asynergy and a depressed global EF. Studies performed using first-pass radionuclide angiography revealed similar results. A wide range of 1/3 EF values was found in normal subjects by both techniques. Thus, the ejection fraction during the first third of systole at rest is of limited value for detecting patients with CAD.

  10. Manifestation of Coronal Mass Ejections near Earth: A review

    NASA Astrophysics Data System (ADS)

    Dasso, Sergio; Rodriguez, Luciano; Demoulin, Pascal; Masías-Meza, Jimmy J.; Janvier, Miho

    2016-07-01

    Coronal Mass Ejections (CMEs) are launched from the Sun, as a result of magnetic instabilities, carrying away a huge amount of magnetic flux and helicity. Interplanetary CMEs (ICMEs) are their manifestation observed further away in the heliosphere. ICMEs produce important changes of plasma and magnetic field properties in the interplanetary medium, with respect to the ones of the ambient solar wind. From the large number of observed ICMEs, in the past years we significantly increased our kwnoledge on several of their properties, such as: the identification of the composing sub-structures and their local properties, their global 3D shape, the amount of magnetohydrodynamical quantities transported in the heliosphere by the associated flux ropes, as well as how the plasma and magnetic field are distributed inside them. In the present talk we will present a general review of these aspects of ICMEs. In particular we will focuss on the total amount of magnetic flux and helicity ejected by CMEs from the Sun along a solar cycle, and on plasma and magnetic properties of their shock-sheath-flux_rope-wake. These results can help to understand their interaction with the ambient solar wind and with planetary magnetic environments. They are particularly crucial for a better understanding of the Sun-Earth coupling.

  11. New Approach for Studying Slow Fragmentation Kinetics in FT-ICR: Surface-Induced Dissociation Combined with Resonant Ejection

    SciTech Connect

    Laskin, Julia; Futrell, Jean H.

    2015-02-01

    We introduce a new approach for studying the kinetics of large ion fragmentation in the gas phase by coupling surface-induced dissociation (SID) in a Fourier transform ion cyclotron resonance mass spectrometer with resonant ejection of selected fragment ions using a relatively short (5 ms) ejection pulse. The approach is demonstrated for singly protonated angiotensin III ions excited by collisions with a self-assembled monolayer of alkylthiol on gold (HSAM). The overall decomposition rate and rate constants of individual reaction channels are controlled by varying the kinetic energy of the precursor ion in a range of 65–95 eV. The kinetics of peptide fragmentation are probed by varying the delay time between resonant ejection and fragment ion detection at a constant total reaction time. RRKM modeling indicates that the shape of the kinetics plots is strongly affected by the shape and position of the energy deposition function (EDF) describing the internal energy distribution of the ion following ion-surface collision. Modeling of the kinetics data provides detailed information on the shape of the EDF and energy and entropy effects of individual reaction channels.

  12. Low-Sodium DASH Diet Improves Diastolic Function and Ventricular-Arterial Coupling in Hypertensive Heart Failure with Preserved Ejection Fraction

    PubMed Central

    Hummel, Scott L.; Seymour, E. Mitchell; Brook, Robert D.; Sheth, Samar S.; Ghosh, Erina; Zhu, Simeng; Weder, Alan B.; Kovács, Sándor J.; Kolias, Theodore J.

    2014-01-01

    Background Heart failure with preserved ejection fraction (HFPEF) involves failure of cardiovascular reserve in multiple domains. In HFPEF animal models, dietary sodium restriction improves ventricular and vascular stiffness and function. We hypothesized that the sodium-restricted Dietary Approaches to Stop Hypertension diet (DASH/SRD) would improve left ventricular diastolic function, arterial elastance, and ventricular-arterial (V-A) coupling in hypertensive HFPEF. Methods and Results Thirteen patients with treated hypertension and compensated HFPEF consumed the DASH/SRD (target sodium 50 mmol/2100 kcal) for 21 days. We measured baseline and post-DASH/SRD brachial and central BP (via radial arterial tonometry), and cardiovascular function with echocardiographic measures (all previously invasively validated). Diastolic function was quantified via the Parametrized Diastolic Filling formalism, which yields relaxation/viscoelastic (c) and passive/stiffness (k) constants through analysis of Doppler mitral inflow velocity (E-wave) contours. Effective arterial elastance (Ea) end-systolic elastance (Ees), and V-A coupling (defined as the ratio Ees:Ea) were determined using previously published techniques. Wilcoxon matched-pairs tests were used for pre-post comparisons. The DASH/SRD reduced clinic and 24-hour brachial systolic pressure (155±35 to 138±30 and 130±16 to 123±18 mmHg, both p=.02) and central end-systolic pressure trended lower (116±18 to 111±16 mmHg, p=.12). In conjunction, diastolic function improved (c, 24.3±5.3 to 22.7±8.1 s−1;p=.03; k, 252±115 to 170±37 s−1;p=.03), Ea decreased (2.0±0.4 to 1.7±0.4 mmHg/ml;p=.007), and V-A coupling improved (Ees:Ea, 1.5±0.3 to 1.7±0.4;p=.04). Conclusions In hypertensive HFPEF patients, the sodium-restricted DASH diet was associated with favorable changes in ventricular diastolic function, arterial elastance, and V-A coupling. PMID:23985432

  13. Measurements of the Gegenschein brightness from the Solar Mass Ejection Imager (SMEI)

    NASA Astrophysics Data System (ADS)

    Buffington, A.; Bisi, M. M.; Clover, J. M.; Hick, P.; Jackson, B. V.

    2008-12-01

    The Gegenschein is a faint diffuse component of the zodiacal light centered upon the antisolar point; this has now been viewed by the Solar Mass Ejection Imager (SMEI) for over 5 years. SMEI provides unprecedented near-full-sky photometric maps each 102-minute orbit, using data from 3 unfiltered CCD cameras. Its 0.1% photometric precision enables observation over long periods of time, of heliospheric structures having surface brightness down to several S10's (an S10 is the equivalent brightness of a 10th magnitude star spread over one square degree). When individual bright stars are removed from the maps and an empirical sidereal background subtracted, the residue is dominated by the zodiacal light. The sky coverage and duration of these measurements enables a definitive characterization. We describe the analysis method for these data, characterize the average Gegenschein brightness distribution, present empirical formulae describing its shape, and discuss its variation with time.

  14. Evaluation of ejection safety for the joint helmet-mounted cueing system

    NASA Astrophysics Data System (ADS)

    Barnaba, James M.; Kirk, William K.

    1999-07-01

    Aircrew safety is paramount in the design of a helmet-mounted display (HMD). For the tactical aircrew, ensuring a successful ejection presents significant design challenges. The Joint Helmet Mounted Cueing System (JHMCS) Integrated Product Team (IPT) has been evaluating Vision Systems International's HMD design for aircrew protection in this environment. The JHMCS IPT has developed a set of test objectives in concert with acquisition reform to demonstrate ejection compatibility of the JHMCS. This testing series will be discussed, and will include windblast, ejection tower, and sled and in-flight ejection testing, findings and design impacts. JHMCS performance parameters evaluated include structural integrity, facial and head protection, neck tensile loads, ejection seat and crew equipment compatibility, and mechanical functionality. The design environment for the JHMCS currently is both small and large, male and female aircrew withstanding a successful 450-knot ejection in any of four current USAF & USN tactical aircraft platforms.

  15. Case report: chronic sub-dural hematoma following high-speed ejection.

    PubMed

    Warburton, R

    1993-06-01

    This paper reports a case of chronic sub-dural hematoma occurring in a pilot after a high-speed ejection that was within the survival envelope of the Mark 10 Martin Baker ejection seat. The events leading up to the ejection, his subsequent hospitalization for treatment of immediate injuries and late development of neurological signs, 6 weeks after the ejection, are presented. (A thorough search of literature has failed to reveal any previously published account of chronic sub-dural hematoma as a post-ejection complication.) His surgical treatment, recovery, and final assessment are discussed together with the possible causes of his sub-dural hematoma. Flight surgeons should take careful note of the events in this case. Sub-dural hematoma is frequently difficult to diagnose but it should not be discounted as a potential late complication from an ejection which is within the parameters of survivability and which yields, initially, only signs of relatively minor injury. PMID:8338501

  16. CMEs FROM AR 10365: MORPHOLOGY AND PHYSICAL PARAMETERS OF THE EJECTIONS AND OF THE ASSOCIATED CURRENT SHEET

    SciTech Connect

    Schettino, G.; Romoli, M.; Poletto, G.

    2010-01-10

    We study the evolution and physical parameters of three consecutive coronal mass ejections (CMEs) that occurred at the west limb of the Sun on 2003 June 2 at 00:30, 08:54, 16:08 UT, respectively. The Large Angle and Spectrometric Coronagraph Experiment (LASCO) CME catalog shows that the CMEs entered the C2 field of view with position angles within a 5 deg. interval. This suggests a common origin for the ejections, to be identified with the magnetic system associated with the active region that lies below the CMEs. The close proximity in time and source location of the events prompted us to analyze LASCO white light data and Ultraviolet Coronagraph Spectrometer (UVCS) spectra with the aim of identifying similarities and differences among the three CMEs. It turns out that two of them display the typical three-part structure, while no conclusion can be drawn about the morphology of the third ejection. The CMEs plasma is 'cool', i.e., electron temperatures in the CMEs front are of the order of 2 x 10{sup 5} K, with no significant variation between different events. However, ejection speeds vary by a factor of approx1.5 between consecutive events and electron densities (more precisely emission measures) by a factor of approx6 between the first CME and the second and third CMEs. In the aftermath of all events, we found evidence of current sheets (CSs) both in LASCO and UVCS. We give here the CS physical parameters (electron temperature, density, and kinetic temperature) and follow, in one of the events, their temporal evolution over a 6 hr time interval. A discussion of our results, in the framework of previous findings, concludes the paper.

  17. The ejection of shells in the stellar wind of P CYG - The most plausible explanation of the Balmer-line radial velocity variations

    NASA Astrophysics Data System (ADS)

    Markova, N.

    1986-07-01

    Our new data of the Balmer line radial velocities in the P Cygni spectrum are compared to the measurments published by de Groot (1969), Kolka (1983) and Markova (1986). The observed variations are analysed in terms of a model proposed by Kolka (1983) which implies a multiple ejection of shells in the stellar wind of P Cygni. It is shown that all data agree to an ejection time scale of about 200 days. The estimated accelerations for the three data groups are very close which supposes a stability of the ejection mechanism over an interval of about 40 yr. The radial velocities of nalmer and the FeII and FeIII (far UV) lines are compared. The identity of the Balmer and the FeII and FeIII shells is discussed.

  18. Recovery from exercise at varying work loads - Time course of responses of heart rate and systolic intervals

    NASA Technical Reports Server (NTRS)

    Nandi, P. S.; Spodick, D. H.

    1977-01-01

    The time course of the recovery period was characterized by noninvasive measurements after 4 minute bicycle exercise at 3 separate work loads in volunteers with normal peak responses. Most responses started immediately to return toward resting control values. Left ventricular ejection time and stroke volume change are discussed. Changes in pre-ejection period were determined by changes in isovolume contraction time, and factors affecting the degree and rate of return are considered. The rates of change in the ejection time index and in the ratio pre-ejection period/left ventricular ejection time were virtually independent of load throughout most of recovery.

  19. The ejection experience of the Royal Australian Air Force: 1951-92.

    PubMed

    Newman, D G

    1995-01-01

    This paper reviews the ejection experience of the Royal Australian Air Force (RAAF) between 1951 and 1992. During this period 84 aircrew ejected from their aircraft, with 77 survivors and 7 fatalities. The causes of these ejections were examined, and the injuries received by the ejectees were classified into four categories: fatal, major, minor, and no injuries. Vertebral fractures were the most common type of major injury (35%). Most ejectees received at least one minor injury. There were 7 reported cases in which the ejectee received no injuries. The RAAF ejection experience was found to be comparable with other international series, both in terms of survival rates and injury patterns. PMID:7695551

  20. Ejection fraction response to exercise in patients with chest pain and normal coronary arteriograms

    SciTech Connect

    Gibbons, R.L.; Lee, K.L.; Cobb, F.; Jones, R.H.

    1981-11-01

    In this study we describe the ejection fraction response to upright exercise using first-pass radionuclide angiocardiography in a group of 60 patients with chest pain, normal coronary ateriograms and normal resting ventricular function. A wide range of resting function (heart rate and ejection fraction) and exercise function (heart rate, ejection fraction, peak work load and estimated peak oxygen uptake) were measured. The ejection fraction response to exercise demonstrated wide variation, ranging from a decrease of 23% to an increase of 24%. Six of 22 clinical and radionuclide angiocardiographic variables (resting ejection fraction, peak work load, age, sex, body surface area and the change in end-diastolic volume index with exercise) were significant univariate predictors of the ejection fraction response to exercise. Multivariable analysis identified resting ejection fraction, the change in end-diastolic volume index with exercise and either sex or peak work load as variables that provided significant independent predictive information. These observations indicate that the ejection fraction response to exercise is a complex response that is influenced by multiple physiologic variables. The wide variation in this population suggests that the ejection fraction response to exercise is not a reliable test for the diagnosis of coronary artery disease because of its low specificity.

  1. Isosorbide Mononitrate in Heart Failure with Preserved Ejection Fraction

    PubMed Central

    Redfield, Margaret M.; Anstrom, Kevin J.; Levine, James A.; Koepp, Gabe A.; Borlaug, Barry A.; Chen, Horng H.; LeWinter, Martin M.; Joseph, Susan M.; Shah, Sanjiv J.; Semigran, Marc J.; Felker, G. Michael; Cole, Robert T.; Reeves, Gordon R.; Tedford, Ryan J.; Tang, W.H. Wilson; McNulty, Steven E.; Velazquez, Eric J.; Shah, Monica R.; Braunwald, Eugene

    2015-01-01

    BACKGROUND Nitrates are commonly prescribed to enhance activity tolerance in patients with heart failure and a preserved ejection fraction. We compared the effect of isosorbide mononitrate or placebo on daily activity in such patients. METHODS In this multicenter, double-blind, crossover study, 110 patients with heart failure and a preserved ejection fraction were randomly assigned to a 6-week dose-escalation regimen of isosorbide mononitrate (from 30 mg to 60 mg to 120 mg once daily) or placebo, with subsequent crossover to the other group for 6 weeks. The primary end point was the daily activity level, quantified as the average daily accelerometer units during the 120-mg phase, as assessed by patient-worn accelerometers. Secondary end points included hours of activity per day during the 120-mg phase, daily accelerometer units during all three dose regimens, quality-of-life scores, 6-minute walk distance, and levels of N-terminal pro–brain natriuretic peptide (NT-proBNP). RESULTS In the group receiving the 120-mg dose of isosorbide mononitrate, as compared with the placebo group, there was a nonsignificant trend toward lower daily activity (−381 accelerometer units; 95% confidence interval [CI], −780 to 17; P = 0.06) and a significant decrease in hours of activity per day (−0.30 hours; 95% CI, −0.55 to −0.05; P = 0.02). During all dose regimens, activity in the isosorbide mononitrate group was lower than that in the placebo group (−439 accelerometer units; 95% CI, −792 to −86; P = 0.02). Activity levels decreased progressively and significantly with increased doses of isosorbide mononitrate (but not placebo). There were no significant between-group differences in the 6-minute walk distance, quality-of-life scores, or NT-proBNP levels. CONCLUSIONS Patients with heart failure and a preserved ejection fraction who received isosorbide mononitrate were less active and did not have better quality of life or submaximal exercise capacity than did

  2. Brachial plexopathy

    MedlinePlus

    ... include: Numbness of the shoulder, arm, or hand Shoulder pain Tingling, burning, pain, or abnormal sensations (location depends ... Call your health care provider if you experience pain, numbness, tingling, or weakness in the shoulder, arm, or hand.

  3. INFLUENCE OF THE AMBIENT SOLAR WIND FLOW ON THE PROPAGATION BEHAVIOR OF INTERPLANETARY CORONAL MASS EJECTIONS

    SciTech Connect

    Temmer, Manuela; Rollett, Tanja; Moestl, Christian; Veronig, Astrid M.; Vrsnak, Bojan; Odstrcil, Dusan

    2011-12-20

    We study three coronal mass ejection (CME)/interplanetary coronal mass ejection (ICME) events (2008 June 1-6, 2009 February 13-18, and 2010 April 3-5) tracked from Sun to 1 AU in remote-sensing observations of Solar Terrestrial Relations Observatory Heliospheric Imagers and in situ plasma and magnetic field measurements. We focus on the ICME propagation in interplanetary (IP) space that is governed by two forces: the propelling Lorentz force and the drag force. We address the question: which heliospheric distance range does the drag become dominant and the CME adjust to the solar wind flow. To this end, we analyze speed differences between ICMEs and the ambient solar wind flow as a function of distance. The evolution of the ambient solar wind flow is derived from ENLIL three-dimensional MHD model runs using different solar wind models, namely, Wang-Sheeley-Arge and MHD-Around-A-Sphere. Comparing the measured CME kinematics with the solar wind models, we find that the CME speed becomes adjusted to the solar wind speed at very different heliospheric distances in the three events under study: from below 30 R{sub Sun }, to beyond 1 AU, depending on the CME and ambient solar wind characteristics. ENLIL can be used to derive important information about the overall structure of the background solar wind, providing more reliable results during times of low solar activity than during times of high solar activity. The results from this study enable us to obtain greater insight into the forces acting on CMEs over the IP space distance range, which is an important prerequisite for predicting their 1 AU transit times.

  4. Investigations of the sensitivity of a coronal mass ejection model (ENLIL) to solar input parameters

    NASA Astrophysics Data System (ADS)

    Falkenberg, T. V.; Vršnak, B.; Taktakishvili, A.; Odstrcil, D.; MacNeice, P.; Hesse, M.

    2010-06-01

    Understanding space weather is not only important for satellite operations and human exploration of the solar system but also to phenomena here on Earth that may potentially disturb and disrupt electrical signals. Some of the most violent space weather effects are caused by coronal mass ejections (CMEs), but in order to predict the caused effects, we need to be able to model their propagation from their origin in the solar corona to the point of interest, e.g., Earth. Many such models exist, but to understand the models in detail we must understand the primary input parameters. Here we investigate the parameter space of the ENLILv2.5b model using the CME event of 25 July 2004. ENLIL is a time-dependent 3-D MHD model that can simulate the propagation of cone-shaped interplanetary coronal mass ejections (ICMEs) through the solar system. Excepting the cone parameters (radius, position, and initial velocity), all remaining parameters are varied, resulting in more than 20 runs investigated here. The output parameters considered are velocity, density, magnetic field strength, and temperature. We find that the largest effects on the model output are the input parameters of upper limit for ambient solar wind velocity, CME density, and elongation factor, regardless of whether one's main interest is arrival time, signal shape, or signal amplitude of the ICME. We find that though ENLILv2.5b currently does not include the magnetic cloud of the ICME, it replicates the signal at L1 well in the studied event. The arrival time difference between satellite data and the ENLILv2.5b baseline run of this study is less than 30 min.

  5. [Brachial plexus compression from supraclavicular encapsulated fat necrosis. A case report].

    PubMed

    Domínguez-Páez, Miguel; de Miguel-Pueyo, Luis; Marín-Salido, Esteban José; Carrasco-Brenes, Antonio; Martín-Gallego, Alvaro; Arráez-Sánchez, Miguel Ángel

    2014-01-01

    We report the case of a 44-year-old male, lacking clinical history of previous illness, who had surgery at our hospital to treat a mass in the supraclavicular space. The patient presented with a 1-month progressive distal paresis of the left arm. The histo-pathological examination of the mass revealed an encapsulated fat necrosis. Fat necrosis is characterised by cystic architecture, encapsulation with fat necrosis within, and inflammatory infiltration of its walls. Neural structure compression secondary to this tumour mass is very rare. Fat necrosis is more frequent in the lower limbs, in areas exposed to trauma. This article is the first report of brachial plexus compression due to supraclavicular fat necrosis. PMID:24837841

  6. Brachial neuritis or Parsonage-Turner syndrome: A problem of liability. A presentation of 3 cases.

    PubMed

    Rodríguez-Hornillo, M; de la Riva, M C; Ojeda, R

    2016-01-01

    Neuralgic amyotrophy, brachial neuritis or Parsonage-Turner syndrome is a rare neuromuscular involvement of unknown aetiology. When it onsets in connection with a health care act, such as childbirth or surgery, a malpractice argument is often used as a cause of adverse outcome, usually due to an incorrect position of the patient on the operating table, a circumstance which directly involves the anesthesia area. Three cases are presented of Parsonage-Turner syndrome following very different surgery, with different results as regards prognosis. A review and discussion of bibliography is presented on the possibility that such circumstances are the subject of malpractice claims. Special emphasis is placed on the most currently accepted aetiopathogenic theories, and the relationship of this syndrome with the surgical act as a determining medico-legal aspect. Valuation parameters are proposed. PMID:26948383

  7. Axillary artery pseudoaneurysm resulting in brachial plexus injury in a patient taking new oral anticoagulants.

    PubMed

    Monem, Mohammed; Iskandarani, Mohamad Khalid; Gokaraju, Kishan

    2016-01-01

    We discuss the case of an independent 80-year-old Caucasian woman, being treated with new oral anticoagulants for a previous deep vein thrombosis, who had fallen on her right shoulder. She made a delayed presentation to the emergency department with a wrist drop in her right dominant hand. She had right arm bruising with good distal pulses but had a global neurological deficit in the hand. Plain radiographs of the shoulder, humerus, elbow, forearm and wrist demonstrated no fractures. MRI showed a significant right axillary lesion distorting the surrounding soft tissues, including the brachial plexus, and CT with contrast confirmed this to be a large axillary pseudoaneurysm. This was treated with an endovascular stent resulting in slightly improved motor function, but the significant residual deficit required subsequent rehabilitation to improve right upper limb function. PMID:27535738

  8. Brachial neuritis or Parsonage-Turner syndrome: A problem of liability. A presentation of 3 cases.

    PubMed

    Rodríguez-Hornillo, M; de la Riva, M C; Ojeda, R

    2016-01-01

    Neuralgic amyotrophy, brachial neuritis or Parsonage-Turner syndrome is a rare neuromuscular involvement of unknown aetiology. When it onsets in connection with a health care act, such as childbirth or surgery, a malpractice argument is often used as a cause of adverse outcome, usually due to an incorrect position of the patient on the operating table, a circumstance which directly involves the anesthesia area. Three cases are presented of Parsonage-Turner syndrome following very different surgery, with different results as regards prognosis. A review and discussion of bibliography is presented on the possibility that such circumstances are the subject of malpractice claims. Special emphasis is placed on the most currently accepted aetiopathogenic theories, and the relationship of this syndrome with the surgical act as a determining medico-legal aspect. Valuation parameters are proposed.

  9. [Ankle-brachial pressure index as a predictor of future cardiovascular outcomes].

    PubMed

    Topalusić, Iva; Valpotić, Ina; Marković, Asja Stipić

    2012-10-01

    Peripheral arterial occlusive disease is very common in the general population and it is mostly of atherosclerotic origin. About 50%-75% of patients are asymptomatic. Many studies have shown the ankle-brachial pressure index (ABPI) to be a simple and reliable test with high sensitivity (90%) and specificity (98%) in the diagnosis of hemodynamically relevant stenosis of an arterial segment and also in detection of asymptomatic patients. The values of ABPI < 0.90 suggest widespread atherosclerosis, while the ABPI > 1.40 is associated with arterial calcification and wall stiffening. This test is highly specific (92.7%) in predicting future cardiovascular and cerebrovascular risk and could provide a tool for more focused prevention strategies. PMID:23814974

  10. A correlation study between ankle brachial pressure index and the severity of coronary artery disease.

    PubMed

    Benyakorn, Thoetphum; Kuanprasert, Sarun; Rerkasem, Kittipan

    2012-06-01

    Previous studies have shown that there was a correlation between low ankle brachial pressure index (ABPI) and the presence of the coronary artery disease (CAD). However, few studies have investigated the correlation between ABPI and the severity of CAD by using a scoring system. The authors aimed to investigate this correlation by using ABPI and CAD diagnosed by coronary angiography (CAG). A total of 213 consecutive patients awaiting CAG in Maharaj Nakorn Chiang Mai Hospital from July 2009 to November 2009 were enrolled in this study. The ABPI was measured before CAG. The severity of CAD was graded on CAG by using SYNTAX scores. The authors found a significantly negative correlation between ABPI and SYNTAX scores (correlation coefficient = -.172, P = .01). The authors concluded that ABPI appeared to correlate negatively with the severity of CAD in the Thai population. PMID:22561522

  11. The prognostic value of concurrent Horner syndrome in extended Erb obstetric brachial plexus palsy.

    PubMed

    El-Sayed, Amel A F

    2014-10-01

    Horner syndrome may be seen in infants with extended Erb obstetric brachial plexus palsy. However, its prognostic value in these infants has not been previously investigated. A total of 220 infants with extended Erb palsy were included and divided into 2 groups: group I (n = 209) were infants with extended Erb palsy without Horner syndrome, and group II (n = 11) were infants with extended Erb palsy and concurrent Horner syndrome. The rate of good spontaneous recovery of elbow flexion was 59% in group I and 27% in group II, and the difference was significant (P = .038). The rate of good spontaneous recovery of wrist extension was 61% in group I and 0% in group II, and the difference as highly significant (P < .0001). Concurrent Horner syndrome in infants with extended Erb palsy may be considered as a poor prognostic sign for recovery of the sixth and seventh cervical roots.

  12. On the deficit problem of mass and energy of solar coronal mass ejections connected with interplanetary shocks

    NASA Technical Reports Server (NTRS)

    Ivanchuk, V. I.; Pishkalo, N. I.

    1995-01-01

    Mean values of a number of parameters of the most powerful coronal mass ejections (CMEs) and interplanetary shocks generated by these ejections are estimated using an analysis of data obtained by the cosmic coronagraphs and spacecrafts, and geomagnetic storm measurements. It was payed attention that the shock mass and mechanical energy, averaging 5 x 10(exp 16) grm and 2 x 10(exp 32) erg respectively, are nearly 10 times larger than corresponding parameters of the ejections. So, the CME energy deficit problem seems to exist really. To solve this problem one can make an assumption that the process of the mass and energy growth of CMEs during their propagation out of the Sun observed in the solar corona is continued in supercorona too up to distances of 10-30 solar radii. This assumption is confirmed by the data analysis of five events observed using zodiacal light photometers of the HELIOS- I and HELIOS-2 spacecrafts. The mass growth rate is estimated to be equal to (1-7) x 10(exp 11) grm/sec. It is concluded that the CME contribution to mass and energy flows in the solar winds probably, is larger enough than the value of 3-5% adopted usually.

  13. [Echocardiographic evaluation of systolic left ventricular function in heart failure: value of alternative parameters for determination of ejection fraction].

    PubMed

    Dornberger, V; Dittrich, H D; Busch, R

    2015-04-01

    Assessment of the left ventricular ejection fraction plays a key role in the echocardiographic diagnosis of heart failure. The parameter most commonly used is the ejection fraction computed with the biplane disc summation method of Simpson; however, there are numerous limitations to this method, such as the assumption of geometrical symmetry, a substantial intraobserver and interobserver variability, foreshortening of the left ventricle and insufficient image quality for endocardial tracking. Alternative parameters for the evaluation of left ventricular function should be taken into consideration. Speckle tracking echocardiography has proven to be a reliable prognostic factor and a good tool for differentiating cardiomyopathies. Simple measurements, which are also feasible with poor image quality, are mitral annular plane systolic excursion (MAPSE) and the velocity of mitral annular movement (Sm or S'). In mitral regurgitation, left ventricular dP/dt represents the time to build up a certain pressure gradient and is therefore a measure of the contractile force exerted. Three-dimensional echocardiography has proven to be an important tool not only for three-dimensional measurement of the left ventricular ejection fraction but also for multivectoral speckle tracking analysis.

  14. Quantification of Left Ventricular Volumes, Mass and Ejection Fraction using Cine Displacement Encoding with Stimulated Echoes (DENSE) MRI

    PubMed Central

    Haggerty, Christopher M.; Kramer, Sage P.; Skrinjar, Oskar; Binkley, Cassi M.; Powell, David K.; Mattingly, Andrea C.; Epstein, Frederick H.; Fornwalt, Brandon K.

    2014-01-01

    Purpose To test the hypothesis that magnitude images from cine Displacement Encoding with Stimulated Echoes (DENSE) MRI can accurately quantify left ventricular (LV) volumes, mass, and ejection fraction. Materials and Methods Thirteen mice (C57BL/6J) were imaged using a 7T ClinScan MRI. A short-axis stack of cine T2-weighted black blood (BB) images was acquired for calculation of left ventricular volumes, mass, and ejection fraction (EF) using the gold standard sum-of-slices methodology. DENSE images were acquired during the same imaging session in three short-axis (basal, mid, apical) and two long-axis orientations. A custom surface fitting algorithm was applied to epicardial and endocardial borders from the DENSE magnitude images to calculate volumes, mass, and EF. Agreement between the DENSE-derived measures and BB-derived measures was assessed via coefficient of variation (CoV). Results 3D surface reconstruction was completed on the order of seconds from segmented images, and required fewer slices to be segmented. Volumes, mass, and EF from DENSE-derived surfaces matched well with BB data (CoVs ≤11%). Conclusion LV mass, volumes, and ejection fraction in mice can be quantified through sparse (5 slices) sampling with DENSE. This consolidation significantly reduces the time required to assess both mass/volume-based measures of cardiac function and advanced cardiac mechanics. PMID:24923710

  15. Hypervelocity Stars. III. The Space Density and Ejection History of Main-Sequence Stars from the Galactic Center

    NASA Astrophysics Data System (ADS)

    Brown, Warren R.; Geller, Margaret J.; Kenyon, Scott J.; Kurtz, Michael J.; Bromley, Benjamin C.

    2007-12-01

    We report the discovery of three new unbound hypervelocity stars (HVSs), stars traveling with such extreme velocities that dynamical ejection from a massive black hole (MBH) is their only suggested origin. We also detect a population of possibly bound HVSs. The significant asymmetry we observe in the velocity distribution-we find 26 stars with vrf>275 km s-1 and one star with vrf<-275 km s-1-shows that HVSs must be short-lived, probably 3-4 Msolar main-sequence stars. Any population of hypervelocity post-main-sequence stars should contain stars falling back onto the Galaxy, contrary to the observations. The spatial distribution of HVSs also supports the main-sequence interpretation: longer lived 3 Msolar HVSs fill our survey volume; shorter lived 4 Msolar HVSs are missing at faint magnitudes. We infer that there are 96+/-10 HVSs of mass 3-4 Msolar within R<100 kpc, possibly enough HVSs to constrain ejection mechanisms and potential models. Depending on the mass function of HVSs, we predict that SEGUE may find up to 5-15 new HVSs. The travel times of our HVSs favor a continuous ejection process, although a ~120 Myr old burst of HVSs is also allowed.

  16. The 2011 Outburst of Recurrent Nova T Pyx: X-Ray Observations Expose the White Dwarf Mass and Ejection Dynamics

    NASA Technical Reports Server (NTRS)

    Chomiuk, Laura; Nelson, Thomas; Mukai, Koji; Solokoski, J. L.; Rupen, Michael P.; Page, Kim L.; Osborne, Julian P.; Kuulkers, Erik; Mioduszewski, Amy J.; Roy, Nirupam; Weston, Jennifer; Krauss, Miriam I.

    2014-01-01

    The recurrent nova T Pyx underwent its sixth historical outburst in 2011, and became the subject of an intensive multi-wavelength observational campaign.We analyze data from the Swift and Suzaku satellites to produce a detailed X-ray light curve augmented by epochs of spectral information. X-ray observations yield mostly non-detections in the first four months of outburst, but both a super-soft and hard X-ray component rise rapidly after Day 115. The super-soft X-ray component, attributable to the photosphere of the nuclear-burning white dwarf, is relatively cool (approximately 45 electron volts) and implies that the white dwarf in T Pyx is significantly below the Chandrasekhar mass (approximately 1 M). The late turn-on time of the super-soft component yields a large nova ejecta mass (approximately greater than 10(exp -5) solar mass), consistent with estimates at other wavelengths. The hard X-ray component is well fit by a approximately 1 kiloelectron volt thermal plasma, and is attributed to shocks internal to the 2011 nova ejecta. The presence of a strong oxygen line in this thermal plasma on Day 194 requires a significantly super-solar abundance of oxygen and implies that the ejecta are polluted by white dwarf material. The X-ray light curve can be explained by a dual-phase ejection, with a significant delay between the first and second ejection phases, and the second ejection finally released two months after outburst. A delayed ejection is consistent with optical and radio observations of T Pyx, but the physical mechanism producing such a delay remains a mystery.

  17. The 2011 outburst of recurrent nova T Pyx: X-ray observations expose the white dwarf mass and ejection dynamics

    SciTech Connect

    Chomiuk, Laura; Nelson, Thomas; Mukai, Koji; Rupen, Michael P.; Mioduszewski, Amy J.; Krauss, Miriam I.; Page, Kim L.; Osborne, Julian P.; Kuulkers, Erik; Roy, Nirupam

    2014-06-20

    The recurrent nova T Pyx underwent its sixth historical outburst in 2011, and became the subject of an intensive multi-wavelength observational campaign. We analyze data from the Swift and Suzaku satellites to produce a detailed X-ray light curve augmented by epochs of spectral information. X-ray observations yield mostly non-detections in the first four months of outburst, but both a super-soft and hard X-ray component rise rapidly after Day 115. The super-soft X-ray component, attributable to the photosphere of the nuclear-burning white dwarf, is relatively cool (∼45 eV) and implies that the white dwarf in T Pyx is significantly below the Chandrasekhar mass (∼1 M {sub ☉}). The late turn-on time of the super-soft component yields a large nova ejecta mass (≳ 10{sup –5} M {sub ☉}), consistent with estimates at other wavelengths. The hard X-ray component is well fit by a ∼1 keV thermal plasma, and is attributed to shocks internal to the 2011 nova ejecta. The presence of a strong oxygen line in this thermal plasma on Day 194 requires a significantly super-solar abundance of oxygen and implies that the ejecta are polluted by white dwarf material. The X-ray light curve can be explained by a dual-phase ejection, with a significant delay between the first and second ejection phases, and the second ejection finally released two months after outburst. A delayed ejection is consistent with optical and radio observations of T Pyx, but the physical mechanism producing such a delay remains a mystery.

  18. The 2011 Outburst of Recurrent Nova T Pyx: X-ray Observations Expose the White Dwarf Mass and Ejection Dynamics

    NASA Astrophysics Data System (ADS)

    Chomiuk, Laura; Nelson, Thomas; Mukai, Koji; Sokoloski, J. L.; Rupen, Michael P.; Page, Kim L.; Osborne, Julian P.; Kuulkers, Erik; Mioduszewski, Amy J.; Roy, Nirupam; Weston, Jennifer; Krauss, Miriam I.

    2014-06-01

    The recurrent nova T Pyx underwent its sixth historical outburst in 2011, and became the subject of an intensive multi-wavelength observational campaign. We analyze data from the Swift and Suzaku satellites to produce a detailed X-ray light curve augmented by epochs of spectral information. X-ray observations yield mostly non-detections in the first four months of outburst, but both a super-soft and hard X-ray component rise rapidly after Day 115. The super-soft X-ray component, attributable to the photosphere of the nuclear-burning white dwarf, is relatively cool (~45 eV) and implies that the white dwarf in T Pyx is significantly below the Chandrasekhar mass (~1 M ⊙). The late turn-on time of the super-soft component yields a large nova ejecta mass (gsim 10-5 M ⊙), consistent with estimates at other wavelengths. The hard X-ray component is well fit by a ~1 keV thermal plasma, and is attributed to shocks internal to the 2011 nova ejecta. The presence of a strong oxygen line in this thermal plasma on Day 194 requires a significantly super-solar abundance of oxygen and implies that the ejecta are polluted by white dwarf material. The X-ray light curve can be explained by a dual-phase ejection, with a significant delay between the first and second ejection phases, and the second ejection finally released two months after outburst. A delayed ejection is consistent with optical and radio observations of T Pyx, but the physical mechanism producing such a delay remains a mystery.

  19. Accretion and ejection in black-hole X-ray transients

    NASA Astrophysics Data System (ADS)

    Kylafis, N. D.; Belloni, T. M.

    2015-02-01

    Context. A rich phenomenology has been accumulated over the years regarding accretion and ejection in black-hole X-ray transients (BHTs) and it needs an interpretation. Aims: Here we summarize the current observational picture of the outbursts of BHTs, based on the evolution traced in a hardness-luminosity diagram (HLD), and we offer a physical interpretation. Methods: The basic ingredient in our interpretation is the Poynting-Robertson cosmic battery (PRCB), which provides locally the poloidal magnetic field needed for the ejection of the jet. In addition, we make two assumptions, easily justifiable. The first is that the mass-accretion rate to the black hole in a BHT outburst has a generic bell-shaped form, whose characteristic time scale is much longer than the dynamical or the cooling ones. This is guaranteed by the observational fact that all BHTs start their outburst and end it at the quiescent state, i.e., at very low accretion rate, and that state transitions take place over long time scales (hours to days). The second assumption is that at low accretion rates the accretion flow is geometrically thick, ADAF-like, while at high accretion rates it is geometrically thin. Last, but not least, we demonstrate that the previous history of the system is absolutely necessary for the interpretation of the HLD. Results: Both, at the beginning and the end of an outburst, the PRCB establishes a strong poloidal magnetic field in the ADAF-like part of the accretion flow, and this explains naturally why a jet is always present in the right part of the HLD. In the left part of the HLD, the accretion flow is in the form of a thin disk, and such a disk cannot sustain a strong poloidal magnetic filed. Thus, no jet is expected in this part of the HLD. Finally, the counterclockwise traversal of the HLD is explained as follows: all outbursts start from the quiescent state, in which the inner part of the accretion flow is ADAF-like, threaded by a poloidal magnetic field. As the

  20. Systems biology applied to heart failure with normal ejection fraction.

    PubMed

    Mesquita, Evandro Tinoco; Jorge, Antonio Jose Lagoeiro; Souza Junior, Celso Vale de; Cassino, João Paulo Pedroza

    2014-05-01

    Heart failure with normal ejection fraction (HFNEF) is currently the most prevalent clinical phenotype of heart failure. However, the treatments available have shown no reduction in mortality so far. Advances in the omics sciences and techniques of high data processing used in molecular biology have enabled the development of an integrating approach to HFNEF based on systems biology. This study aimed at presenting a systems-biology-based HFNEF model using the bottom-up and top-down approaches. A literature search was conducted for studies published between 1991 and 2013 regarding HFNEF pathophysiology, its biomarkers and systems biology. A conceptual model was developed using bottom-up and top-down approaches of systems biology. The use of systems-biology approaches for HFNEF, a complex clinical syndrome, can be useful to better understand its pathophysiology and to discover new therapeutic targets.