bluuebunny/crossref_metadata_2025 huggingface dataset:
Responses to circulatory pressures, and conduction velocity, of pulmocutaneous baroreceptors in Bufo marinus.
Authors: Van Vliet B N , West N H
Published: January 2015

1. Baroreceptor activity was recorded within the recurrent laryngeal branch of the toad vagus in forty‐four preparations. The receptive fields of the receptors were located in the pulmocutaneous artery (p.c.a.), generally within 5 mm of its separation from the truncus. However, the most easily recorded afferents in this nerve were mechanoreceptors which responded to punctate stimulation of the lip of the glottis. 2. The conduction velocities of p.c.a. baroreceptor and mechanoreceptive glottal afferents recorded in the recurrent laryngeal nerve ranged from 0.3‐0.7 (0.5 +/‐ 0.1) m s‐1 and 2.2‐14.0 (6.8 +/‐ 0.8) m s‐1 respectively, which suggests that baroreceptor afferent fibres are non‐myelinated and that glottal afferent fibres are myelinated. 3. The p.c.a. baroreceptor discharge was largely confined to a period of systole in which systemic and p.c.a. arterial pressure profiles were identical. The maximum discharge frequency, number of spikes per cycle, and the duration of discharge increased, and the discharge latency decreased, as p.c.a. pressures were elevated. The latency of the discharge was pronounced at low p.c.a. pressures, and could be partially accounted for by the conduction time of the baroreceptor afferents to the electrodes (up to 100 ms). 4. Carotid and aortic arterial baroreceptor and pharyngeal afferents were recorded in two pharyngeal branches of the vagus nerve which were closely associated with the carotid and aortic arterial arches. 5. It is suggested that baroreceptor populations with their receptive fields in the third‐ (carotid) and sixth‐ (p.c.a. or pulmonary) arch arteries should be considered homologous in anurans and mammals, but that those of the fourth‐ (aorta) arch artery should not, since the vagal branches in which their afferents are carried do not appear to be equivalent in anurans and mammals.
The half‐life of endothelium‐derived relaxing factor released from bovine aortic endothelial cells in culture.
Authors: Angus J A , Cocks T M
Published: January 2015

1. The half‐life of endothelium‐derived relaxing factor (EDRF) in Krebs solution was determined by bioassay in vitro. 2. A column of bovine aortic endothelial cells grown on microcarrier beads in suspension culture was perfused with Krebs solution. EDRF was released from these cells by sequential treatment with increasing concentrations of bradykinin (0.01‐100 nM). EDRF was detected by the relaxation of an endothelium‐denuded ring segment of dog coronary artery. 3. Complete bradykinin concentration‐relaxation curves were determined in the absence or presence of coils of tubing that increased the transit time (delay) between the cell column and the assay tissue. An estimate of the falls in concentration, and hence of the half‐life of EDRF, was obtained from the shift of the bradykinin concentration‐relaxation curves. 4. Mass‐action equations were used to model the relationship between the indirectly acting agonist bradykinin and the relaxation via EDRF. The modelling adequately predicted the consequences of different transit delay times (0‐4 half‐lives). 5. This new analysis of half‐life of an active intermediate emphasizes the measurement of changes in concentration with increasing transit time rather than a fall in tissue response. 6. The half‐life of EDRF in Krebs solution is 41 s.
Inhibitory connections of ipsilateral semicircular canal afferents onto Renshaw cells in the lumbar spinal cord of the cat.
Authors: Ross H G , Thewissen M
Published: January 2015

1. In intercollicularly decerebrate cats, the excitability of lumbar spinal Renshaw cells (tested by single shocks to ventral roots and deafferented muscle nerves) decreased for 600‐1000 ms after conditioning electrical stimulation of ipsilateral semicircular canal nerves. 2. Conditioning stimulation of posterior canal afferents and combined stimulation of anterior and lateral canal afferents were equally effective in causing inhibition of Renshaw cells. No significant differences were observed for Renshaw cells excitable from hind‐limb flexor or extensor nerves. 3. Inhibition appeared when one to five stimuli were applied to the canal afferents and arrived at the spinal segmental level 11‐15 ms after the onset of conditioning stimulation. 4. Evidence is adduced to suggest that the inhibitory effects on Renshaw cells following stimulation of semicircular canal afferents were mediated directly, i.e. they were not caused by alterations of motoneurone activity. 5. Excitation of Renshaw cells due to stimulation of the canal afferents was rarely observed; it could not be excluded that it was secondary to motoneurone discharges. 6. It is suggested that vestibular inhibition of Renshaw cells ensure a high gain of hind‐limb alpha‐motoneurones during postural adjustments following a massive disturbance of body equilibrium.
Push‐pull effect of surround illumination on excitatory and inhibitory inputs to mudpuppy retinal ganglion cells.
Authors: Belgum J H , Dvorak D R , McReynolds J S , Miyachi E
Published: January 2015

1. Changes in membrane potential and conductance were measured in on‐centre and off‐centre ganglion cells during the responses to illumination of different portions of the receptive field. 2. In on‐centre ganglion cells the sustained depolarizing response to steady illumination of the receptive field centre was associated with a net increase in conductance. In the presence of centre illumination, stimulation of the surround with an annulus of light caused a hyperpolarization and a net decrease in conductance, and the reversal potential of the light‐evoked response was shifted in a negative direction. In the absence of centre illumination the same annular stimulus caused a hyperpolarization and a net increase in conductance. 3. In off‐centre ganglion cells the sustained hyperpolarizing response to centre illumination was associated with a net increase in conductance. In the presence of centre illumination, stimulation of the surround with an annulus caused a depolarization and a net decrease in conductance, and the reversal potential of the light‐evoked response was shifted in a positive direction. In the absence of centre illumination the same annulus caused a depolarization and a net increase in conductance. 4. The results indicate that illumination of the receptive field surround can affect both the excitatory and inhibitory sustained inputs to a given ganglion cell in a 'push‐pull' manner, by decreasing the synaptic input that was increased by centre illumination and increasing the synaptic input of opposite sign. The relative effect of a given surround illumination on these two inputs, and hence the sign and magnitude of the net conductance change, varied with the amount of centre illumination.
The regulation of intracellular pH by identified glial cells and neurones in the central nervous system of the leech.
Authors: Deitmer J W , Schlue W R
Published: January 2015

1. Double‐barrelled, neutral‐carrier pH‐sensitive micro‐electrodes were used to measure the intracellular pH (pHi) and the pHi regulation of neuropile glial (n.g.) cells and of identified neurones of the leech Hirudo medicinalis. 2. The distribution of H+ in the n.g. cells and in the neurones was found not to be in electrical equilibrium. The mean pHi of the n.g. cells was 6.87 +/‐ 0.13 (mean +/‐ S.D. of mean here and for all following data n = 27) in HEPES‐buffered leech saline (pHo = 7.4) and 7.18 +/‐ 0.19 (n = 13) in 2% CO2‐11 mM‐HCO3(‐)‐saline. The mean pHi was 7.28 +/‐ 0.1 (n = 20) in Retzius neurones and 7.32 +/‐ 0.15 (n = 12) in noxious neurones in HEPES‐buffered leech saline, and 7.20 +/‐ 0.15 (n = 10) and 7.27 +/‐ 0.16 (n = 6) in 2% CO2‐11 mM‐HCO3(‐)‐buffered saline in these two types of neurones, respectively. 3. The cytoplasmic buffering power, as calculated by the change in pHi following the change from 2% CO2‐11 mM‐HCO3‐ to 5% CO2‐22 mM‐HCO3‐ in the leech saline, was 20‐30 mM/pH unit in the n.g. cells and between 12 and 33 mM/pH unit in the neurones. 4. The recovery of pHi in n.g. cells from an experimentally induced acidification (addition and removal of 20 mM‐NH4Cl) was dependent on the presence of external Na+. Independent of the buffer system used, pHi recovery was inhibited when external Na+ was exchanged by N‐methyl‐D‐glucamine. Amiloride (2‐3 mM) reduced the rate of pHi recovery by about 50% in these n.g. cells. 5. In CO2‐HCO3(‐)‐free saline, or in the presence of the anion exchange blocker 4‐acetamido‐4'‐isothiocyanostilbene‐2, 2'‐disulphonic acid (SITS, 0.5 mM), pHi recovery from an acid load was often slowed by up to 50% in n.g. cells. This suggests that there is a significant contribution of a HCO3(‐)‐dependent membrane transport to pHi regulation in n.g. cells. 6. When a HEPES‐buffered saline was exchanged by a 2% CO2‐11 mM‐HCO3(‐)‐buffered saline, the pHi of n.g. cells increased by 0.31 pH units. This alkaline shift was reversible upon removal of the CO2‐HCO3‐ and was absent in the Na+‐free saline. It was not inhibited by 1 mM‐furosemide or by 0.5 mM‐SITS.(ABSTRACT TRUNCATED AT 400 WORDS)
Control of end‐plate channel properties by neurotrophic effects and by muscle activity in rat.
Authors: Brenner H R , Lømo T , Williamson R
Published: January 2015

1. The formation of ectopic neuromuscular synapses was induced in rat soleus muscle by implantation of the fibular nerve into the proximal part of the muscle and subsequent sectioning of the soleus nerve. The gating properties of acetylcholine (ACh) receptors at the newly formed end‐plates were examined by analysis of acetylcholine‐induced membrane current fluctuations. 2. In agreement with earlier studies, the apparent mean open time of end‐plate channels decreased during synaptic development from about 4 ms to about 1 ms (‐60 mV membrane potential, 22 degrees C) within 7‐18 days after the soleus nerve had been cut. 3. When the fibular nerve was cut at an early stage of end‐plate development, fast‐gating channels with apparent mean open times of 1 ms characteristic of mature end‐plates did not develop within the next 10‐14 days. 4. When the fibular nerve was cut at an early stage of end‐plate development and the soleus muscle was then stimulated chronically via implanted electrodes, fast‐gating channels did develop in the absence of the nerve terminals within 4‐6 days. 5. When impulse conduction in the transplanted fibular nerve was blocked chronically at the time of soleus nerve section such that ectopic end‐plates formed in inactive muscle, fast‐gating channels developed within 12‐14 days. 6. The results show that motoneurones control the conversion from slow‐gating fetal to fast‐gating adult‐type ACh receptor channels at ectopic end‐plates in rat soleus muscles. The conversion occurs in the absence of impulse activity provided the nerve continues to be present. However, it also occurs in the absence of the nerve provided the muscle is active and had received an early priming influence from the nerve. Thus, nerve‐evoked muscle activity and nerve‐released trophic influences complement each other in controlling the gating properties of junctional ACh receptor channels.
Selectivity and patch measurements of A‐current channels in Helix aspersa neurones.
Authors: Taylor P S
Published: January 2015

1. The ionic selectivity of A‐current K+ channels has been measured in single Helix aspersa neurones by recording the reversal potential shift in test solutions containing various monovalent cations. 2. The A‐current channel is permeable to Tl+, K+, Rb+, NH4+ and Cs+. The channels may also be sparingly permeable to Na+ and Li+. Organic cations have an apparent small permeability as judged from their reversal potentials, but this may be an artifact of K+ accumulation. 3. A large patch electrode (3 microns tip) isolated a region that appeared to contain only A‐current channels. This may indicate that A‐current channels are found in the membrane as rafts of at least 3 microns in diameter. 4. The single‐channel conductance calculated from single‐channel current steps was 14 pS.
Absence of a relationship between arterial pH and pancreatic bicarbonate secretion in the isolated perfused cat pancreas.
Authors: Ammar E M , Hutson D , Scratcherd T
Published: January 2015

1. The secretion rate of bicarbonate by the isolated saline‐perfused cat pancreas was linearly related to the bicarbonate concentration of the arterial inflow at constant PCO2 and at high volume rates of secretion. 2. Pancreatic bicarbonate secretion was independent of arterial inflow pH at constant bicarbonate concentrations when the pH was manipulated by alterations in the PCO2 at high volume rates of secretion. 3. A small but statistically significant linear relationship existed between the pH of the arterial inflow and bicarbonate secretion at constant PCO2 after inhibition of carbonic anhydrase by acetazolamide. Under the same conditions no relationship was found between bicarbonate secretion and arterial inflow pH when the perfusate bicarbonate concentration was kept constant and the PCO2 varied. 4. When the volume rate of secretion was reduced by about 60‐70% of maximum no relationship was found to exist between arterial inflow pH and bicarbonate secretion at constant bicarbonate concentration in the perfusate. There was also no relationship between inflow pH and bicarbonate secretion at constant PCO2 down to a pH of 7.3 until the bicarbonate concentration of the perfusate was reduced below 10 mM, when the secretion rate fell off rapidly. 5. A linear relationship was found to exist between the volume rate of secretion and the PCO2 of the pancreatic juice and the output of lactate both in the isolated saline‐perfused gland and the blood‐perfused pancreas in situ. 6. At high rates of secretion the PCO2 of the pancreatic juice was always higher than that of either the arterial inflow or the venous outflow. There is therefore no gradient for the passive movement of carbon dioxide between the arterial inflow and the pancreatic juice. 7. Inhibition of secretion with acetazolamide caused a fall in the PCO2 of pancreatic juice and increased the output of lactate. The secretion of lactate was not due to hypoxia as it also occurred in the blood‐perfused gland in situ which had normal haemoglobin concentrations and oxygen saturation. 8. It is concluded that the secretion of bicarbonate is independent of arterial pH but critically dependent upon the arterial concentration of the bicarbonate ion. These experiments do not support the concept that the secretion of protons over the basolateral membrane is the major primary event in pancreatic secretion of bicarbonate.
Suppression of calcium current by an endogenous neuropeptide in neurones of Aplysia californica.
Authors: Brezina V , Eckert R , Erxleben C
Published: January 2015

1. Actions of the neuropeptide FMRFamide (Phe‐Met‐Arg‐Phe‐NH2) and its derivative YGG‐FMRFamide (Tyr‐Gly‐Gly‐Phe‐Met‐Arg‐Phe‐NH2) on Ca2+ current were examined in identified, voltage‐clamped neurones in the abdominal ganglion of Aplysia californica. 2. 'Puffed' application of either peptide at concentrations of 1‐50 microM was followed by a transient partial suppression of pharmacologically isolated inward Ca2+ current elicited by a depolarizing step. At 20 degrees C, suppression was maximal 10‐25 s following the brief puff of peptide, and lasted up to 90 s. Bath application of peptide had a steady suppressing effect, showing little if any desensitization. 3. Alternative sources of inward current suppression were ruled out, indicating that application of FMRFamide or YGG‐FMRFamide produces a true decrease in Ca2+ current, rather than enhancement of possible contaminating outward (K+, H+ or Cl‐) currents. 4. FMRFamide and YGG‐FMRFamide were equally effective in suppressing Ca2+ current (apparent dissociation constant, KD* approximately 10 microM). However, only 30‐50% of the total Ca2+ current elicited by voltage steps to above +10 mV appeared to be susceptible to suppression by even saturating concentrations of peptide. This, as well as a reduced effect of the peptides on Ca2+ current which was observed at potentials below +10 mV, may perhaps result from the presence of more than one class of Ca2+ channels, only one of which is sensitive to FMRFamide. 5. FMRFamide eliminated a constant fraction of Ca2+ current at all potentials above +10 mV, and had no direct effect on activation or inactivation of the remaining current. This behaviour is consistent with reduction in the number of functional Ca2+ channels by the peptide. 6. Suppression of Ca2+ current produced a concomitant depression of Ca2+‐dependent K+ current, which was shown previously to be insensitive to FMRFamide when activated by direct ionophoretic injection of Ca2+ into the cell. 7. The effect of FMRFamide on Ca2+ current was normal following interference with or activation of known second‐messenger systems, those involving adenosine 3',5'‐cyclic monophosphate (cyclic AMP), cyclic GMP, Ca2+, inositol trisphosphate and protein kinase C. 8. Suppression of Ca2+ current by FMRFamide appeared to be mediated by the same receptor as enhancement by the peptide of K+ current resembling IK(S) (K+ current suppressed by serotonin), an effect seen in most of the same cells. Both effects of FMRFamide were mimicked by injection of guanosine 5'‐O‐(3‐thiotriphosphate) (GTP‐gamma‐S) into the cell, suggesting that the peptide may exert its effects by activating a guanosine 5'‐triphosphate (GTP)‐binding protein
Presynaptic actions of curare and atropine on quantal acetylcholine release at a central synapse of Aplysia.
Authors: Baux G , Tauc L
Published: January 2015

1. In a cholinergic synaptic couple in the buccal ganglion of Aplysia california, where the synaptic areas are situated close to the somata (500 micron), we were able to control transmitter release by stimulating the cell body of the presynaptic neurone with long depolarizing pulses in the presence of tetrodotoxin (TTX). 2. Statistical analysis of noise occurring at the peak of the long‐depolarization‐induced post‐synaptic current (p.s.c.) responses allowed us to calculate the amplitude and the decay time of the miniature post‐synaptic currents (m.p.s.c.s). These data were used to calculate the quantal content of the responses. 3. Bath‐applied tubocurarine reduced the amplitude of the long‐depolarization‐induced p.s.c. more than that of the m.p.s.c.s, indicating that tubocurarine exerts a depressive presynaptic action on the quantal content of the post‐synaptic responses. 4. Tubocurarine injected into the presynaptic neurone blocked synaptic transmission without decreasing the size of the m.p.s.c.s probably by acting on the mechanism of transmitter release. 5. Bath‐applied atropine (10(‐6) and 10(‐5) M) caused a slight decrease of the m.p.s.c.s but the long‐depolarization‐induced p.s.c.s increased, as did the quantal content. Higher concentrations of atropine depressed strongly both the m.p.s.c. and the quantal content. 6. Injection of atropine into the presynaptic neurone had the same effect as its bath application, probably due to the leakage of the drug into the synaptic cleft; the effect depended on the concentration reached in the cleft, i.e. on the quantity of injected drug. The synapses of the neighbouring cholinergic neurone were also affected by this leak of atropine. 7. The presence of nicotinic presynaptic receptors blocked by tubocurarine, and muscarinic presynaptic receptors blocked by atropine, which regulate synaptic transmission by facilitating and depressing the ACh release respectively, is discussed.
Experimental characterization of adsorbed protein orientation, conformation, and bioactivity
Authors: Thyparambil Aby A. , Wei Yang , Latour Robert A.
Published: January 2015

Protein adsorption on material surfaces is a common phenomenon that is of critical importance in many biotechnological applications. The structure and function of adsorbed proteins are tightly interrelated and play a key role in the communication and interaction of the adsorbed proteins with the surrounding environment. Because the bioactive state of a protein on a surface is a function of the orientation, conformation, and accessibility of its bioactive site(s), the isolated determination of just one or two of these factors will typically not be sufficient to understand the structure–function relationships of the adsorbed layer. Rather a combination of methods is needed to address each of these factors in a synergistic manner to provide a complementary dataset to characterize and understand the bioactive state of adsorbed protein. Over the past several years, the authors have focused on the development of such a set of complementary methods to address this need. These methods include adsorbed-state circular dichroism spectropolarimetry to determine adsorption-induced changes in protein secondary structure, amino-acid labeling/mass spectrometry to assess adsorbed protein orientation and tertiary structure by monitoring adsorption-induced changes in residue solvent accessibility, and bioactivity assays to assess adsorption-induced changes in protein bioactivity. In this paper, the authors describe the methods that they have developed and/or adapted for each of these assays. The authors then provide an example of their application to characterize how adsorption-induced changes in protein structure influence the enzymatic activity of hen egg-white lysozyme on fused silica glass, high density polyethylene, and poly(methyl-methacrylate) as a set of model systems.
Design and fabrication of a SAW device with Ta filled microcavities inserted into its delay path for improved power transfer
Authors: Richardson Mandek , Cheemalapati Surya , Everly Richard , Sankaranarayanan Subramanian K. R. S. , Pyayt Anna , Bhethanabotla Venkat R.
Published: January 2015

The authors report the design and fabrication of a surface acoustic wave (SAW) device with improved power transfer due to modification of its delay path. Typically, SAW delay-line devices suffer from relatively high insertion loss (IL) (∼10–30 dB). Our approach is to incorporate an array of microcavities, having square cross-sectional area (λ/2 × λ/2) and filled with tantalum, within the delay path to maximize acoustic confinement to the surface and reduce IL. To determine the effectiveness of the cavities without expending too many resources and to explain trends found in actual devices, a finite element model of a SAW device with tantalum filled cavities having various depths was utilized. For each depth simulated, IL was decreased compared to a standard SAW device. Microcavities 2.5 μm deep filled with tantalum showed the best performance (ΔIL = 17.93 dB). To validate simulated results, the authors fabricated a SAW device on ST 90°-X quartz with microcavities etched into its delay path using deep reactive ion etching and filled with tantalum. Measurement of fabricated devices showed inclusion of tantalum filled microcavities increased power transfer compared to a device without cavities.
Improvement of negative-bias-illumination-stress stability in all-transparent double-gate InGaZnO thin-film transistors
Authors: Jeon Da-Bin , Ryu Min-Ki , Byun Chun-Won , Yang Jong-Heon , Hwang Chi-Sun , Yoon Sung-Min
Published: January 2015

Fully transparent amorphous-InGaZnO thin-film transistors (TFTs) with double-gate (DG) configuration were fabricated. Both top-gate and bottom-gate (BG) TFT fabricated with a single gate-stack structure were found to exhibit sound device characteristics with μsat of 17.0 and 18.1 cm2 V−1 s−1, respectively. Confirmed benefits of DG configuration include improved current drivability and threshold voltage tunability. Further, controlling the fixed voltage bias to the BG was observed to enhance device stability under negative-bias-illumination-stress conditions.
Improved dosimetry for targeted radionuclide therapy using nonrigid registration on sequential SPECT images
Authors: Ao Edwin C. I. , Wu Nien‐Yun , Wang Shyh‐Jen , Song Na , Mok Greta S. P.
Published: January 2015

Purpose:

Voxel‐level and patient‐specific 3D dosimetry for targeted radionuclide therapy (TRT) typically involves serial nuclear medicine scans. Misalignment of the images can result in reduced dosimetric accuracy. Since the scans are typically performed over a period of several days, there will be patient movement between scans and possible nonrigid organ deformation. This work aims to implement and evaluate the use of nonrigid image registration on a series of quantitative SPECT (QSPECT) images for TRT dosimetry.

Methods:

A population of 4D extended cardiac torso phantoms, comprised of three In‐111 Zevalin biokinetics models and three anatomical variations, was generated based on the patient data. The authors simulated QSPECT acquisitions at five time points. At each time point, individual organ and whole‐body deformation between scans were modeled by translating/rotating organs and the body up to 5°/voxels, keeping ≤5% difference in organ volume. An analytical projector was used to generate realistic noisy projections for a medium energy general purpose collimator. Projections were reconstructed using OS‐EM algorithm with geometric collimator detector response, attenuation, and scatter corrections. The QSPECT images were registered using organ‐based nonrigid image registration method. The cumulative activity in each voxel was obtained by integrating the activity over time. Dose distribution images were obtained by convolving the cumulative activity images with a Y‐90 dose kernel. Dose volume histograms (DVHs) for organs‐of‐interest were analyzed.

Results:

After nonrigid registration, the mean differences in organ doses compared to the case without misalignment were improved from (−15.50 ± 5.59)% to (−2.12 ± 1.05)% and (−7.28 ± 2.30)% to (−0.23 ± 0.71)% for the spleen and liver, respectively. For all organs, the cumulative DVHs showed improvement after nonrigid registration and the normalized absolute error of differential DVHs ranged from 6.79% to 22.70% for liver and 26.00% to 39.70% for spleen with different segmentation methods.

Conclusions:

These results demonstrated that nonrigid registration of sequential QSPECT images is feasible for TRT and improves the accuracy of 3D dosimetry.
Characterization of cardiac quiescence from retrospective cardiac computed tomography using a correlation‐based phase‐to‐phase deviation measure
Authors: Wick Carson A. , McClellan James H. , Arepalli Chesnal D. , Auffermann William F. , Henry Travis S. , Khosa Faisal , Coy Adam M. , Tridandapani Srini
Published: January 2015

Purpose:

Accurate knowledge of cardiac quiescence is crucial to the performance of many cardiac imaging modalities, including computed tomography coronary angiography (CTCA). To accurately quantify quiescence, a method for detecting the quiescent periods of the heart from retrospective cardiac computed tomography (CT) using a correlation‐based, phase‐to‐phase deviation measure was developed.

Methods:

Retrospective cardiac CT data were obtained from 20 patients (11 male, 9 female, 33–74 yr) and the left main, left anterior descending, left circumflex, right coronary artery (RCA), and interventricular septum (IVS) were segmented for each phase using a semiautomated technique. Cardiac motion of individual coronary vessels as well as the IVS was calculated using phase‐to‐phase deviation. As an easily identifiable feature, the IVS was analyzed to assess how well it predicts vessel quiescence. Finally, the diagnostic quality of the reconstructed volumes from the quiescent phases determined using the deviation measure from the vessels in aggregate and the IVS was compared to that from quiescent phases calculated by the CT scanner. Three board‐certified radiologists, fellowship‐trained in cardiothoracic imaging, graded the diagnostic quality of the reconstructions using a Likert response format: 1 = excellent, 2 = good, 3 = adequate, 4 = nondiagnostic.

Results:

Systolic and diastolic quiescent periods were identified for each subject from the vessel motion calculated using the phase‐to‐phase deviation measure. The motion of the IVS was found to be similar to the aggregate vessel (AGG) motion. The diagnostic quality of the coronary vessels for the quiescent phases calculated from the aggregate vessel (PAGG) and IVS (PIV S) deviation signal using the proposed methods was comparable to the quiescent phases calculated by the CT scanner (PCT). The one exception was the RCA, which improved for PAGG for 18 of the 20 subjects when compared to PCT (PCT = 2.48; PAGG = 2.07, p = 0.001).

Conclusions:

A method for quantifying the motion of specific coronary vessels using a correlation‐based, phase‐to‐phase deviation measure was developed and tested on 20 patients receiving cardiac CT exams. The IVS was found to be a suitable predictor of vessel quiescence. The diagnostic quality of the quiescent phases detected by the proposed methods was comparable to those calculated by the CT scanner. The ability to quantify coronary vessel quiescence from the motion of the IVS can be used to develop new CTCA gating techniques and quantify the resulting potential improvement in CTCA image quality.
Accelerated acquisition of tagged MRI for cardiac motion correction in simultaneous PET‐MR: Phantom and patient studies
Authors: Huang Chuan , Petibon Yoann , Ouyang Jinsong , Reese Timothy G. , Ahlman Mark A. , Bluemke David A. , El Fakhri Georges
Published: January 2015

Purpose:

Degradation of image quality caused by cardiac and respiratory motions hampers the diagnostic quality of cardiac PET. It has been shown that improved diagnostic accuracy of myocardial defect can be achieved by tagged MR (tMR) based PET motion correction using simultaneous PET‐MR. However, one major hurdle for the adoption of tMR‐based PET motion correction in the PET‐MR routine is the long acquisition time needed for the collection of fully sampled tMR data. In this work, the authors propose an accelerated tMR acquisition strategy using parallel imaging and/or compressed sensing and assess the impact on the tMR‐based motion corrected PET using phantom and patient data.

Methods:

Fully sampled tMR data were acquired simultaneously with PET list‐mode data on two simultaneous PET‐MR scanners for a cardiac phantom and a patient. Parallel imaging and compressed sensing were retrospectively performed by GRAPPA and kt‐FOCUSS algorithms with various acceleration factors. Motion fields were estimated using nonrigid B‐spline image registration from both the accelerated and fully sampled tMR images. The motion fields were incorporated into a motion corrected ordered subset expectation maximization reconstruction algorithm with motion‐dependent attenuation correction.

Results:

Although tMR acceleration introduced image artifacts into the tMR images for both phantom and patient data, motion corrected PET images yielded similar image quality as those obtained using the fully sampled tMR images for low to moderate acceleration factors (<4). Quantitative analysis of myocardial defect contrast over ten independent noise realizations showed similar results. It was further observed that although the image quality of the motion corrected PET images deteriorates for high acceleration factors, the images were still superior to the images reconstructed without motion correction.

Conclusions:

Accelerated tMR images obtained with more than 4 times acceleration can still provide relatively accurate motion fields and yield tMR‐based motion corrected PET images with similar image quality as those reconstructed using fully sampled tMR data. The reduction of tMR acquisition time makes it more compatible with routine clinical cardiac PET‐MR studies.
Camera selection for real‐time in vivo radiation treatment verification systems using Cherenkov imaging
Authors: Andreozzi Jacqueline M. , Zhang Rongxiao , Glaser Adam K. , Jarvis Lesley A. , Pogue Brian W. , Gladstone David J.
Published: January 2015

Purpose:

To identify achievable camera performance and hardware needs in a clinical Cherenkov imaging system for real‐time, in vivo monitoring of the surface beam profile on patients, as novel visual information, documentation, and possible treatment verification for clinicians.

Methods:

Complementary metal‐oxide‐semiconductor (CMOS), charge‐coupled device (CCD), intensified charge‐coupled device (ICCD), and electron multiplying‐intensified charge coupled device (EM‐ICCD) cameras were investigated to determine Cherenkov imaging performance in a clinical radiotherapy setting, with one emphasis on the maximum supportable frame rate. Where possible, the image intensifier was synchronized using a pulse signal from the Linac in order to image with room lighting conditions comparable to patient treatment scenarios. A solid water phantom irradiated with a 6 MV photon beam was imaged by the cameras to evaluate the maximum frame rate for adequate Cherenkov detection. Adequate detection was defined as an average electron count in the background‐subtracted Cherenkov image region of interest in excess of 0.5% (327 counts) of the 16‐bit maximum electron count value. Additionally, an ICCD and an EM‐ICCD were each used clinically to image two patients undergoing whole‐breast radiotherapy to compare clinical advantages and limitations of each system.

Results:

Intensifier‐coupled cameras were required for imaging Cherenkov emission on the phantom surface with ambient room lighting; standalone CMOS and CCD cameras were not viable. The EM‐ICCD was able to collect images from a single Linac pulse delivering less than 0.05 cGy of dose at 30 frames/s (fps) and pixel resolution of 512 × 512, compared to an ICCD which was limited to 4.7 fps at 1024 × 1024 resolution. An intensifier with higher quantum efficiency at the entrance photocathode in the red wavelengths [30% quantum efficiency (QE) vs previous 19%] promises at least 8.6 fps at a resolution of 1024 × 1024 and lower monetary cost than the EM‐ICCD.

Conclusions:

The ICCD with an intensifier better optimized for red wavelengths was found to provide the best potential for real‐time display (at least 8.6 fps) of radiation dose on the skin during treatment at a resolution of 1024 × 1024.
Patient feature based dosimetric Pareto front prediction in esophageal cancer radiotherapy
Authors: Wang Jiazhou , Jin Xiance , Zhao Kuaike , Peng Jiayuan , Xie Jiang , Chen Junchao , Zhang Zhen , Studenski Matthew , Hu Weigang
Published: January 2015

Purpose:

To investigate the feasibility of the dosimetric Pareto front (PF) prediction based on patient's anatomic and dosimetric parameters for esophageal cancer patients.

Methods:

Eighty esophagus patients in the authors’ institution were enrolled in this study. A total of 2928 intensity‐modulated radiotherapy plans were obtained and used to generate PF for each patient. On average, each patient had 36.6 plans. The anatomic and dosimetric features were extracted from these plans. The mean lung dose (MLD), mean heart dose (MHD), spinal cord max dose, and PTV homogeneity index were recorded for each plan. Principal component analysis was used to extract overlap volume histogram (OVH) features between PTV and other organs at risk. The full dataset was separated into two parts; a training dataset and a validation dataset. The prediction outcomes were the MHD and MLD. The spearman's rank correlation coefficient was used to evaluate the correlation between the anatomical features and dosimetric features. The stepwise multiple regression method was used to fit the PF. The cross validation method was used to evaluate the model.

Results:

With 1000 repetitions, the mean prediction error of the MHD was 469 cGy. The most correlated factor was the first principal components of the OVH between heart and PTV and the overlap between heart and PTV in Z‐axis. The mean prediction error of the MLD was 284 cGy. The most correlated factors were the first principal components of the OVH between heart and PTV and the overlap between lung and PTV in Z‐axis.

Conclusions:

It is feasible to use patients’ anatomic and dosimetric features to generate a predicted Pareto front. Additional samples and further studies are required improve the prediction model.
Validity of Physical Activity Monitors for Estimating Energy Expenditure During Wheelchair Propulsion
Authors: Conger Scott A. , Scott Stacy N. , Fitzhugh Eugene C. , Thompson Dixie L. , Bassett David R.
Published: January 2015

Background:

It is unknown if activity monitors can detect the increased energy expenditure (EE) of wheelchair propulsion at different speeds or on different surfaces.

Methods:

Individuals who used manual wheelchairs (n = 14) performed 5 wheeling activities: on a level surface at 3 speeds, on a rubberized track at 1 fixed speed and on a sidewalk course at a self-selected speed. EE was measured using a portable indirect calorimetry system and estimated by an Actical (AC) worn on the wrist and a SenseWear (SW) activity monitor worn on the upper arm. Repeated-measures ANOVA was used to compare measured EE to the estimates from the standard AC prediction equation and SW using 2 different equations.

Results:

Repeated-measures ANOVA demonstrated a significant main effect between measured EE and estimated EE. There were no differences between the criterion method and the AC across the 5 activities. The SW overestimated EE when wheeling at 3 speeds on a level surface, and during sidewalk wheeling. The wheelchair-specific SW equation improved the EE prediction during low intensity activities, but error progressively increased during higher intensity activities.

Conclusions:

During manual wheelchair propulsion, the wrist-mounted AC provided valid estimates of EE, whereas the SW tended to overestimate EE.
School Environment and its Effects on Physical Activity
Authors: Chen Ang
Published: February 2015

School is an environment where children and adolescents spend most of their time during the day. The environment is characterized by a sedentary culture necessary for academic learning. In this article, I present research evidence showing the effects of four physical activity opportunities in this environment: school athletics, recess, classroom physical activity breaks, and physical education. Based on an analysis of research evidence on the four opportunities, I propose that the efforts to promote the opportunities should be coordinated into a concerted action to integrate a physical activity-friendly culture in the sedentary environment. Using an example of China's whole-school physical activity promotion strategy, I identify four areas for us to continue to work on: legislature-based policies, physical education as core content, creation and maintenance of physical activity traditions in schools, and integration of physical activity-friendly culture into the sedentary school environment.
Probing Johnson noise and ballistic transport in normal metals with a single-spin qubit
Authors: Kolkowitz S. , Safira A. , High A. A. , Devlin R. C. , Choi S. , Unterreithmeier Q. P. , Patterson D. , Zibrov A. S. , Manucharyan V. E. , Park H. , Lukin M. D.
Published: January 2015

Listen to the quantum art of noise

Electrons in metals are subject to thermally induced noise that can generate tiny magnetic fields. For quantum electronic applications, the noise and magnetic fields can be damaging. Kolkowitz
et al.
show that the spin properties of single defects in diamond can be used to probe the noise. The findings provide insight into how the noise is generated, which could help to mitigate its damaging effects in sensitive quantum electronic circuits.

Science
, this issue p.
1129
Electron-hole diffusion lengths > 175 μm in solution-grown CH
3
NH
3
PbI
3
single crystals
Authors: Dong Qingfeng , Fang Yanjun , Shao Yuchuan , Mulligan Padhraic , Qiu Jie , Cao Lei , Huang Jinsong
Published: January 2015

Balanced carrier diffusion in perovskites

The efficient operation of solar cells based on inorganic-organic perovskites requires balanced transport of positive and negative charge carriers over long distances. Dong
et al.
used a top-seeded solution growth method to obtain millimeter-scale single crystals of the organolead trihalide perovskite CH
3
NH
3
PbI
3
. Under low light illumination, the electron and hole diffusion lengths exceeded 3 mm, and under full sunlight illumination, they exceeded 175 µm.

Science
, this issue p.
967
Complete Genome Sequences of Two Isolates of Human Parvovirus 4 from Patients with Acute Encephalitis Syndrome
Authors: Prakash Shantanu , Jain Amita , Seth Akanksha , Singh Arvind K. , Jain Bhawana
Published: January 2015

Human parvovirus 4 (Parv4) is a relatively new virus. Association of this virus with any human disease is yet to be established. We detected human parvovirus 4 in the cerebrospinal fluid (CSF) of two patients presenting with acute encephalitis syndrome in northern India. This is the first report of the Parv4 genome sequence from northern India.
Complete Genome Sequence of “Candidatus Sulcia muelleri” ML, an Obligate Nutritional Symbiont of Maize Leafhopper (
Dalbulus maidis
)
Authors: Chang Hsing-Hua , Cho Shu-Ting , Canale Maria C. , Mugford Sam T. , Lopes João R. S. , Hogenhout Saskia A. , Kuo Chih-Horng
Published: January 2015

“Candidatus Sulcia muelleri” is a symbiont of sap-feeding insects in the suborder Auchenorrhyncha. The strain “
Ca
. Sulcia muelleri” ML is associated with the maize leafhopper (
Dalbulus maidis
), collected in Brazil, which is a disease vector that affects corn production. Here, we report the complete genome sequence of this bacterium.
Draft Genome Sequence of Paenibacillus Strain P1XP2, a Polysaccharide-Degrading, Thermophilic, Facultative Anaerobic Bacterium Isolated from a Commercial Bioreactor Degrading Food Waste
Authors: Adelskov Joseph , Patel Bharat K. C.
Published: January 2015

The analysis of the ~5.8-Mb draft genome sequence of a moderately thermophilic, heterotrophic, facultative anaerobic bacterium, Paenibacillus strain P1XP2, identified genes for enzymes with the potential for degrading complex food wastes, a property consistent with the ecological habitat of the isolate.
Draft Genome Sequences of the Three Pectobacterium-Antagonistic Bacteria Pseudomonas brassicacearum PP1-210F and PA1G7 and Bacillus simplex BA2H3
Authors: Khayi Slimane , Raoul des Essarts Yannick , Mondy Samuel , Moumni Mohieddine , Hélias Valérie , Beury-Cirou Amélie , Faure Denis
Published: January 2015

Pectobacterium spp. are bacterial pathogens causing soft rot diseases on a wide range of plants and crops. We present in this paper the draft genome sequences of three bacterial strains,
Pseudomonas brassicacearum
PP1-210F and PA1G7 and
Bacillus simplex
BA2H3, which exhibit antagonistic activities against the Pectobacterium plant pathogens.
Draft Whole-Genome Sequence of Bacillus altitudinis Strain B-388, a Producer of Extracellular RNase
Authors: Shah Mahmud Raihan , Ulyanova Vera , Malanin Sergey , Dudkina Elena , Vershinina Valentina , Ilinskaya Olga
Published: January 2015

Here, we present a draft genome sequence of
Bacillus altitudinis
strain B-388, including a putative plasmid. The strain was isolated from the intestine of Indian meal moth, a common pest of stored grains, and it is characterized by the production of extracellular RNase, similar to binase, which is of interest for comparative studies and biotechnology.
A diagnostic approach to recurrent myalgia and rhabdomyolysis in children
Authors: Chan Eunice K , Kornberg Andrew J , Ryan Monique M
Published: January 2015

Episodic myalgia is a common complaint in children and young adults. While many cases remain idiopathic even after extensive investigation, myalgia can be the first symptom of an underlying serious neuromuscular condition, and can be associated with an increased risk of such serious complications as rhabdomyolysis and malignant hyperthermia. We review and highlight the metabolic myopathies and other increasingly recognised muscle disorders that may present to paediatricians with episodic myalgia or isolated episodes of rhabdomyolysis, and propose a diagnostic algorithm for investigation of these complaints.
The first North American use of the Pipeline Flex flow diverter
Authors: Duckworth Edward AM , Nickele Christopher , Hoit Daniel , Belayev Andrey , Moran Christopher J , Arthur Adam S
Published: January 2015

Flow diversion for the management of intracranial aneurysms represents a paradigm shift in how aneurysms are managed. The Pipeline embolization device (PED) is, to date, the only flow diverter approved for use in the USA by the Food and Drug Administration. Limitations and complications with new treatment strategies are inevitable, and with the PED there have been reports of complications, most commonly with challenging deployments. Once deployment has been initiated, the device is ‘one-way’; it can only be deployed further or removed. Yet, situations arise in which the ability to recapture or reposition the device would be advantageous. A second-generation Pipeline has been developed that addresses these concerns. We report the first use in North America of this second-generation Pipeline device: the Pipeline Flex. We discuss our rationale for using the device, our impressions of its operation, and the relevant literature concerning the current state of flow diversion.
Choice of plastic or metal stent for patients with jaundice with pancreaticobiliary malignancy using simple clinical tools: a prospective evaluation
Authors: Wilcox C Mel , Kim Hwasoon , Seay Toni , Varadarajulu Shyam
Published: February 2015

Background and aim

Although plastic stents have been recommended for patients with pancreaticobiliary malignancy and an expected survival of less than 6 months, no study has developed criteria to assess survival which could then determine the choice of stent for biliary decompression. The aim of the study was to determine the utility of simple clinical tools in deciding whether to place a plastic or metal stent in patients with malignant obstructive jaundice.

Methods

At presentation for endoscopic retrograde cholangiopancreatography for suspected malignant distal bile duct obstruction, prospectively patients with Karnofsky score of <80 and/or metastatic disease to the liver underwent placement of 10-French plastic stents while patients with a Karnofsky score of ≥80 underwent placement of self-expandable metal stents (SEMS). Long-term stent patency and mortality was determined.

Results

98 patients (mean age 66.5 years; 62.2% male) were enrolled with 67 (68.4%) receiving plastic stents and 31 (31.6%) uncovered SEMS. Overall, patients receiving plastic stents had a median survival of 2.8 months compared with 11.6 months for metallic stents (p<0.0001). Patients with a Karnofsky score <80 or liver metastases had very poor survival of 3.1 and 1.8 months, respectively. The overall reintervention rate was 42% for those receiving plastic stents and 19% for metallic stents.

Conclusions

The decision whether to place a plastic stent or SEMS for patients with distal malignant obstructive jaundice may be based on simple clinical tools resulting in low rates of reintervention.
Naming babies "Baby-of" at birth: A project to encourage earlier naming of infants in Abu Dhabi
Authors: Santos Rodney Jay , Palacios Luena , Amuan Rommel
Published: January 2015

In 2013, Sweihan Healthcare Center, one of several government clinics in Abu Dhabi, catered to 19,349 patients or an average of 52 patients in a day. During the weekdays, close to 80 patients are seen per day, a relatively huge number for a small town clinic. In 2011, the clinic only saw 16,816 patients, which amounts to a 15% increase in two years.

Circumstances called for a search for gaps in the system in order to ease the workflow of a steadily increasing patient influx. The focus was mainly on patient identification due to a considerable number of patients having the same name. Data extraction was simplified by the advent of electronic medical records and, as the names of the patients were filtered, one name stood out: "Baby of".

The goal of this project was to track the patients using the name "Baby of", and change their names in their respective medical records and thus be able to comply with the International Patient Safety Goals (IPSG) of both Joint Commission International [1] and the Health Authority of Abu Dhabi [2].