DENSE GAS IN NEARBY GALAXIES .9. A SURVEY FOR HNC

Ten detections and five tentative detections of hydrogen isocyanide (HNC) J=1-0 emission are reported from a survey including sixteen galaxies. Full maps are presented for the nuclear regions of NGC 253 and IC 342, partial maps for Maffei 2, M 82, and M 83. Toward IC 342, the HNC and HCO+ distributions differ from those observed in 12CO, 13CO, HCN, CS, and NH3. This is likely a consequence of the density structure. Relative HNC abundances are with 10(-10)-10(-9) much smaller than those measured in nearby dark clouds and appear to be slightly smaller than those in regions of massive star formation of the Galactic disk. This is consistent with the presence of dense warm gas or a frequent occurrence of shocks in the nuclear regions of the galaxies observed. As in prominent Galactic star forming regions, 3 mm HNC line emission tends to be weaker than the corresponding emission from HCN and HCO+. Toward Arp 220, however, the 3 mm HNC/HCN line intensity ratio is > 1. HNC/HCO+, HNC/CO, and HNC to 20 cm radio continuum luminosity ratios are also particularly large. A possible interpretation is the presence of cool quiescent gas outside the central region which contains the starburst. In the other ultraluminous galaxy observed, NGC 6240, X(HNC) 10 smaller than in Arp 220, demonstrating that the molecular composition in ultraluminous galaxies is far from being uniform.

Emission lines of Fe XI in the 257-407 A wavelength region observed in solar spectra from EIS/Hinode and SERTS

Theoretical emission-line ratios involving Fe xi transitions in the 257-407 A wavelength range are derived using fully relativistic calculations of radiative rates and electron impact excitation cross-sections. These are subsequently compared with both long wavelength channel Extreme-Ultraviolet Imaging Spectrometer (EIS) spectra from the Hinode satellite (covering 245-291 A) and first-order observations (similar to 235-449 A) obtained by the Solar Extreme-ultraviolet Research Telescope and Spectrograph (SERTS). The 266.39, 266.60 and 276.36 A lines of Fe xi are detected in two EIS spectra, confirming earlier identifications of these features, and 276.36 A is found to provide an electron density (N-e) diagnostic when ratioed against the 257.55 A transition. Agreement between theory and observation is found to be generally good for the SERTS data sets, with discrepancies normally being due to known line blends, while the 257.55 A feature is detected for the first time in SERTS spectra. The most useful Fe xi electron density diagnostic is found to be the 308.54/352.67 intensity ratio, which varies by a factor of 8.4 between N-e = 108 and 1011 cm-3, while showing little temperature sensitivity. However, the 349.04/352.67 ratio potentially provides a superior diagnostic, as it involves lines which are closer in wavelength, and varies by a factor of 14.7 between N-e = 108 and 1011 cm-3. Unfortunately, the 349.04 A line is relatively weak, and also blended with the second-order Fe x 174.52 A feature, unless the first-order instrument response is enhanced.

Microflare Activity Driven By Forced Magnetic Reconnection.

High cadence, multiwavelength, optical observations of a solar active region, obtained with the Swedish Solar Telescope, are presented. Two magnetic bright points are seen to separate in opposite directions at a constant velocity of 2.8 km s(-1). After a separation distance of approximate to 4400 km is reached, multiple Ellerman bombs are observed in both Ha and Ca-K images. As a result of the Ellerman bombs, periodic velocity perturbations in the vicinity of the magnetic neutral line, derived from simultaneous Michelson Doppler Imager data, are generated with amplitude +/-6 km s(-1) and wavelength approximate to 1000 km. The velocity oscillations are followed by an impulsive brightening visible in Ha and Ca-K, with a peak intensity enhancement of 63%. We interpret these velocity perturbations as the magnetic field deformation necessary to trigger forced reconnection. A time delay of approximate to 3 minutes between the Ha-wing and Ca-K observations indicates that the observed magnetic reconnection occurs at a height of similar to 200 km above the solar surface. These observations are consistent with theoretical predictions and provide the first observational evidence of microflare activity driven by forced magnetic reconnection.

Optimization of double pulse pumping for Ni-like Sm x-ray lasers

We report a systematic study of double pulse pumping of the Ni-like Sm x-ray laser at 73 Angstrom, currently the shortest wavelength saturated x-ray laser. It is found that the Sm x-ray laser output can change by orders of magnitude when the intensity ratio of the pumping pulses and their relative delay are varied. Optimum pumping conditions are found and interpreted in terms of a simple model. (C) 1999 American Institute of Physics. [S0021-8979(99)07102-9].

A time-resolved spectroscopy study of the resonance-line emission in the Ge XXIII XUV laser

A comparison is presented of the temporally resolved resonance-line emission from the Ne-like Ge XUV laser (pumped with nanosecond pulses) with the predictions for the same emission from the hydro-atomic code EHYBRID. The specific lines chosen were the two 3s-2p Ne-like lines at 10.01 and 9.762 Angstrom, and the 3s-2p F-like group of lines in the 9.4-9.6 Angstrom region. Modification of the code to include 112 excited levels of the F-like ion facilitated a direct comparison between experiment and model of (i) the temporal variation of the emissions and (ii) the variation of the peak intensity ratios of the F-like to Ne-like emissions with irradiance on target.

A novel dual-fluorescence strategy for functionally validating microRNA targets in 3-prime untranslated regions: regulation of the inward rectifier potassium channel Kir2.1 by miR-212.

Gene targeting by microRNAs is important in health and disease. We developed a functional assay for identifying microRNA targets and applied it to the K+ channel Kir2.1 (KCNJ2) which is dysregulated in cardiac and vascular disorders. The 3'UTR was inserted downstream of the mCherry red fluorescent protein coding sequence in a mammalian expression plasmid. MicroRNA sequences were inserted into the pSM30 expression vector which provides enhanced green fluorescent protein as an indicator of microRNA expression. HEK293 cells were co-transfected with the mCherry-3'UTR plasmid and a pSM30-based plasmid with a microRNA insert. The principle of the assay is that functional targeting of the 3'UTR by the microRNA results in a decrease in the red/green fluorescence intensity ratio as determined by automated image analysis. The method was validated with miR-1, a known downregulator of Kir2.1 expression, and was used to investigate targeting of the Kir2.1 3'UTR by miR-212. Red/green ratio was lower in miR-212-expressing cells compared to non-targeting controls, an effect that was attenuated by mutating the predicted target site. MiR-212 also reduced inward rectifier current and Kir2.1 protein in HeLa cells. This novel assay has several advantages over traditional luciferase-based assays including larger sample size, amenability to time course studies and adaptability to high-throughput screening.

Map Width Enhancement Technique for a Turbocharger Compressor

This paper presents an investigation of map width enhancement and the performance improvement of a turbocharger compressor using a series of static vanes in the annular cavity of a classical bleed slot system. The investigation has been carried out using both experimental and numerical analysis. The compressor stage used for this study is from a turbocharger unit used in heavy duty diesel engines of approximately 300 kW. Two types of vanes were designed and added to the annular cavity of the baseline classical bleed slot system. The purpose of the annular cavity vane technique is to remove some of the swirl that can be carried through the bleed slot system, which would influence the pressure
ratio. In addition to this, the series of cavity vanes provides a better guidance to the slot recirculating flow before it mixes with the impeller main inlet flow. Better guidance of the flow improves the mixing at the inducer inlet in the circumferential direction. As a consequence, the stability of the compressor is improved at lower flow rates and a wider map can be achieved. The impact of two cavity vane designs on the map width and performance of the compressor was highlighted through a detailed analysis of the impeller flow field. The numerical and experimental study revealed that an effective vane design can improve the map width and pressure ratio characteristic without an efficiency penalty compared to the classical bleed slot system without vanes. The comparison study between the cavity vane and noncavity vane configurations presented in this paper showed that the map width was improved by 14.3% due to a significant reduction in surge flow and the peak pressure ratio was improved by 2.25% with the addition of a series of cavity vanes in the annular cavity of the bleed slot system.

A comparative pharmacokinetic study of conventional propranolol and long acting preparation of propranolol in patients with cirrhosis and normal controls

1 Six male patients with alcoholic cirrhosis and seven normal control subjects were each given 80 mg twice daily of conventional propranolol for 1 week and 160 mg once daily of a long acting preparation (LA) of propranolol for 1 week. 2 Plasma propranolol levels were measured at regular intervals on the first and seventh days of both weeks and also following an acute intravenous infusion of 10 mg propranolol on a separate occasion. 3 After the single intravenous dose the elimination half-life tended to be prolonged in the cirrhotic group (median 7.15 h) compared with controls (median 2.92 h) (P = 0.055). 4 After multiple oral dosing with 80 mg twice daily of conventional propranolol the steady-state plasma concentration (Css), area under the curve (AUC tau), peak concentration (Cmax) and trough concentration (Cmin) were significantly higher in cirrhotic patients and the peak: trough ratio (Cmax/Cmin) was significantly lower than controls. 5 After multiple oral dosing with 160 mg LA once daily Cmin was significantly higher than Cmax/min significantly lower in cirrhotic patients; Css, AUC and Cmax were higher than controls but not statistically different. 6 Within both subject groups the bioavailability of 80 mg twice daily of conventional propranolol tended to be greater than 160 mg LA once daily. Cmax was significantly higher in both groups and Css higher in the cirrhotic group with conventional propranolol. 7 In the cirrhotic group the mean reduction in supine heart rate in the steady state was 31.8% with conventional 80 mg twice daily propranolol and 23.75% with 160 mg LA once daily.(ABSTRACT TRUNCATED AT 250 WORDS)

Probing spin-orbit-interaction-induced electron dynamics in the carbon atom by multiphoton ionization

We use R-matrix theory with time dependence (RMT) to investigate multiphoton ionization of ground-state atomic carbon with initial orbital magnetic quantum number M_L=0 and M_L=1 at a laser wavelength of 390 nm and peak intensity of 10(14) W/cm(2). Significant differences in ionization yield and ejected-electron momentum distribution are observed between the two values for M_L. We use our theoretical results to model how the spin-orbit interaction affects electron emission along the laser polarization axis. Under the assumption that an initial C atom is prepared at zero time delay with M_L=0, the dynamics with respect to time delay of an ionizing probe pulse modeled by using RMT theory is found to be in good agreement with available experimental data.

INTERPLAY OF CAF2 SUBSTRATE ROUGHENING AND FILM DEPOSITION RATE ON RADIATIVE SCATTERING OF SURFACE-PLASMON POLARITONS FROM AG FILMS

The radiative decay of surface plasmon polaritons has been investigated in an attempt to characterize the surface roughness of Ag films prepared under different conditions. The polaritons were excited by the method of attenuated total reflection of light. The films were deposited on the face of a 60-degrees BK-7 glass prism at a rate that was deliberately fixed in two different ranges (centred on 0.1 and 10 nm s-1) and in some cases a CaF2 underlayer was used to roughen the film surfaces. The intensity of the scattered light emitted from the opposite face of the films was measured as a function of direction for each using the same sensitivity scale and was correlated with the preparation of the film. It was found that on nominally smooth substrates fast-deposited thinner films give out more light and are deduced to have greater short wavelength (300-600 nm) roughness amplitude. There is also evidence for long wavelenth (7 mum) periodic roughness due to the prism substrate itself. On CaF2 roughened surfaces the light output from the films is further increased and the peak intensity is backward directed with respect to the exciting laser beam direction. Here roughness on a lateral scale of 350 nm is responsible. Also, elastic scattering of surface plasmon polaritons at grain boundaries reduces the light output from fast deposited, small grain, films on CaF2 roughened surfaces. Overall, a consistent picture of roughness induced radiative polariton decay emerges for all cases studied.

Fragmentation of CD+ induced by intense ultrashort laser pulses

The fragmentation of CD+ in intense ultrashort laser pulses was investigated using a coincidence three-dimensional momentum imaging technique improved by employing both transverse and longitudinal electric fields. This allowed clear separation of all fragmentation channels and the determination of the kinetic energy release down to nearly zero, for a molecule with significant mass asymmetry. The most probable dissociation pathways for the two lowest dissociation limits, C+ + D and C+ D+, were identified for both 22-fs, 798-nm and 50-fs, 392-nm pulses. Curiously, the charge asymmetric dissociation of CD2+ was not observed for 392-nm photons, even though it was clearly visible for the fundamental 798 nm at the same peak intensity.

SN2014J gamma rays from the 56Ni decay chain

Context. The detection and measurement of gamma-ray lines from the decaychain of 56Ni provides unique information about the explosionin supernovae. SN2014J at 3.3 Mpc is a sufficiently-nearby supernova oftype Ia so that such measurements have been feasible with the gamma-rayspectrometer SPI on ESA's INTEGRAL gamma-ray observatory.

Aims:The 56Ni freshly produced in the supernova is understood topower the optical light curve, because it emits gamma rays upon itsradioactive decay first to 56Co and then to 56Fe.Gamma-ray lines from 56Co decay are expected to becomedirectly visible through the white dwarf material several weeks afterthe explosion, as they progressively penetrate the overlying material ofthe supernova envelope, which is diluted as it expands. The lines areexpected to be Doppler-shifted or broadened from the kinematics of the56Ni ejecta. We aim to exploit high-resolution gamma-rayspectroscopy with the SPI spectrometer on INTEGRAL toward constrainingthe 56Ni distribution and kinematics in this supernova.

Methods: We use the observations with the SPI spectrometer onINTEGRAL, together with an improved instrumental background method.

Results: We detect the two main lines from 56Co decay at847 and 1238 keV, which are significantly Doppler-broadened, and atintensities (3.65 ± 1.21) × 10-4 and (2.27± 0.69) × 10-4 ph cm-2s-1, respectively, at their brightness maximum. We measuretheir rise toward a maximum after about 60-100 days and a declinethereafter. The intensity ratio of the two lines is found to beconsistent with expectations from 56Co decay (0.62 ±0.28 at brightness maximum, the expected ratio is 0.68). We find thatthe broad lines seen in the late, gamma-ray transparent phase are notrepresentative of the early gamma-ray emission, and notice instead thatthe emission spectrum is complex and irregular until the supernova isfully transparent to gamma rays, with progressive uncovering of the bulkof 56Ni. We infer that the explosion morphology is notspherically symmetric, both in the distribution of 56Ni andin the unburnt material which occults the 56Co emission.After we compare light curves from different plausible models, theresulting 56Ni mass is determined to be 0.49 ± 0.09M⊙.

Raman spectra of SiC nanorods with different excitation wavelengths

With increasing excitation wavelength from 514 to 782 nm, a significant difference in the Raman spectra of SiC nanorods was observed as compared to bulk material. The intensity ratio of the LO mode to that of the IF mode increases with the excitation wavelength increasing. This has been identified as resonant Raman scattering caused by Fröhlich interaction.

Departure of high temperature iron lines from the equilibrium state in flaring solar plasmas

The aim of this study is to clarify if the assumption of ionization equilibrium and a Maxwellian electron energy distribution is valid in flaring solar plasmas. We analyze the 2014 December 20 X1.8 flare, in which the \ion{Fe}{xxi} 187~\AA, \ion{Fe}{xxii} 253~\AA, \ion{Fe}{xxiii} 263~\AA\ and \ion{Fe}{xxiv} 255~\AA\ emission lines were simultaneously observed by the EUV Imaging Spectrometer onboard the Hinode satellite. Intensity ratios among these high temperature Fe lines are compared and departures from isothermal conditions and ionization equilibrium examined. Temperatures derived from intensity ratios involving these four lines show significant discrepancies at the flare footpoints in the impulsive phase, and at the looptop in the gradual phase. Among these, the temperature derived from the \ion{Fe}{xxii}/\ion{Fe}{xxiv} intensity ratio is the lowest, which cannot be explained if we assume a Maxwellian electron distribution and ionization equilibrium, even in the case of a multi-thermal structure. This result suggests that the assumption of ionization equilibrium and/or a Maxwellian electron energy distribution can be violated in evaporating solar plasma around 10MK.

Potential improvements in the therapeutic ratio of prostate cancer irradiation: dose escalation of pathologically identified tumour nodules using intensity modulated radiotherapy.

The potential of intensity modulated radiotherapy (IMRT) to improve the therapeutic ratio in prostate cancer by dose escalation of intraprostatic tumour nodules (IPTNs) was investigated using a simultaneous integrated boost technique. The prostate and organs-at-risk were outlined on CT images from six prostate cancer patients. Positions of IPTNs were transferred onto the CT images from prostate maps derived from sequential large block sections of whole prostatectomy specimens. Inverse planned IMRT dose distributions were created to irradiate the prostate to 70 Gy and all the IPTNs to 90 Gy. A second plan was produced to escalate only the dominant IPTN (DIPTN) to 90 Gy, mimicking current imaging techniques. These plans were compared with homogeneous prostate irradiation to 70 Gy using dose–volume histograms, tumour control probability (TCP) and normal tissue complication probability (NTCP) for the rectum. The mean dose to IPTNs was increased from 69.8 Gy to 89.1 Gy if all the IPTNs were dose escalated (p=0.0003). This corresponded to a mean increase in TCP of 8.7–31.2% depending on the /ß ratio of prostate cancer (p