Collinear Laser Spectroscopy of 2

Transition frequencies and fine-structure splittings of the 2 ^{3}S_{1}→2 ^{3}P_{J} transitions in helium-like ^{12}C^{4+} were measured by collinear laser spectroscopy on a 1-ppb level. Accuracy is increased by more than 3 orders of magnitude with respect to previous measurements, enabling tests of recent nonrelativistic (NR) QED calculations including terms up to mα^{7}. Deviations between the theoretical and experimental values are within theoretical uncertainties and are ascribed to mα^{8} and higher-order contributions in the series expansion of the NR QED calculations. Finally, prospects for an all-optical charge radius determination of light isotopes are evaluated.

Improved Limit on Tensor Currents in the Weak Interaction from

The electroweak interaction in the standard model is described by a pure vector-axial-vector structure, though any Lorentz-invariant component could contribute. In this Letter, we present the most precise measurement of tensor currents in the low-energy regime by examining the ß-ν[over ¯] correlation of trapped ^{8}Li ions with the Beta-decay Paul Trap. We find a_{ßν}=-0.3325±0.0013_{stat}±0.0019_{syst} at 1σ for the case of coupling to right-handed neutrinos (C_{T}=-C_{T}^{'}), which is consistent with the standard model prediction.

A new Collinear Apparatus for Laser Spectroscopy and Applied Science (COALA).

We present a new collinear laser spectroscopy setup that has been designed to overcome systematic uncertainty limits arising from high-voltage and frequency measurements, beam superposition, and collisions with residual gas that are present in other installations utilizing this technique. The applied methods and experimental realizations are described, including an active stabilization of the ion-source potential, new types of ion sources that have not been used for collinear laser spectroscopy so far, dedicated installations for pump-and-probe measurements, and a versatile laser system referenced to a frequency comb. The advanced setup enables us to routinely determine transition frequencies, which was so far demonstrated only for a few cases and with lower accuracy at other facilities. It has also been designed to perform accurate high-voltage measurements for metrological applications. Demonstration and performance measurements were carried out with Ca+ and In+ ions.

Laser Spectroscopy of Neutron-Rich Tin Isotopes: A Discontinuity in Charge Radii across the N=82 Shell Closure.

The change in mean-square nuclear charge radii δ⟨r^{2}⟩ along the even-A tin isotopic chain ^{108-134}Sn has been investigated by means of collinear laser spectroscopy at ISOLDE/CERN using the atomic transitions 5p^{2} ^{1}S_{0}→5p6 s^{1}P_{1} and 5p^{2} ^{3}P_{0}→5p6s ^{3}P_{1}. With the determination of the charge radius of ^{134}Sn and corrected values for some of the neutron-rich isotopes, the evolution of the charge radii across the N=82 shell closure is established. A clear kink at the doubly magic ^{132}Sn is revealed, similar to what has been observed at N=82 in other isotopic chains with larger proton numbers, and at the N=126 shell closure in doubly magic ^{208}Pb. While most standard nuclear density functional calculations struggle with a consistent explanation of these discontinuities, we demonstrate that a recently developed Fayans energy density functional provides a coherent description of the kinks at both doubly magic nuclei, ^{132}Sn and ^{208}Pb, without sacrificing the overall performance. A multiple correlation analysis leads to the conclusion that both kinks are related to pairing and surface effects.

Charge Radii of Neutron Deficient

Bunched-beam collinear laser spectroscopy is performed on neutron deficient ^{52,53}Fe prepared through in-flight separation followed by a gas stopping. This novel scheme is a major step to reach nuclides far from the stability line in laser spectroscopy. Differential mean-square charge radii δ⟨r^{2}⟩ of ^{52,53}Fe are determined relative to stable ^{56}Fe as δ⟨r^{2}⟩^{56,52}=-0.034(13) fm^{2} and δ⟨r^{2}⟩^{56,53}=-0.218(13) fm^{2}, respectively, from the isotope shift of atomic hyperfine structures. The multiconfiguration Dirac-Fock method is used to calculate atomic factors to deduce δ⟨r^{2}⟩. The values of δ⟨r^{2}⟩ exhibit a minimum at the N=28 neutron shell closure. The nuclear density functional theory with Fayans and Skyrme energy density functionals is used to interpret the data. The trend of δ⟨r^{2}⟩ along the Fe isotopic chain results from an interplay between single-particle shell structure, pairing, and polarization effects and provides important data for understanding the intricate trend in the δ⟨r^{2}⟩ of closed-shell Ca isotopes.

Geographical patterns of genetic variation in two species of Stylosanthes Sw. using amplified fragment length polymorphism.

Understanding the extent and distribution of genetic diversity within a species is essential for the development of effective conservation strategies. The objective of this study was to assess genetic variation using amplified fragment length polymorphisms (AFLP) in two species of the tropical legume genus Stylosanthes Sw. Annual, S. humilis (2n = 20) and perennial, S. viscosa (2n = 20) are found throughout tropical America, and are sympatric for much of their range of distribution. One hundred and eleven accessions, covering a wide geographical range, were selected for AFLP analysis. Binary data matrices derived from DNA banding patterns were analysed using the software programs NTSYS-PC and ARLEQUIN. Several accessions were found to be misidentified. Of the S. humilis accessions, the overall average similarity value was (0.72) slightly higher than the value obtained for S. viscosa (0.67). Cluster analysis and principal coordinate analysis grouped accessions from both species by geographical origin, with a few exceptions. Analysis of molecular variance (AMOVA) in S. humilis revealed 59.4% of the variation among groups formed from the cluster analysis. This was highly significant (P < 0.001). For S. viscosa AMOVA also revealed more variation among than within groups (66.5%). This was also highly significant (P < 0.001). The majority of accessions of both species conserved ex situ are of Brazilian and Venezuelan origin. This study has identified areas in Central America and Mexico for which novel genetic variation may be found and where conservation activities should be focused.

Coronary thrombolysis with Desmodus salivary plasminogen activator in dogs. Fast and persistent recanalization by intravenous bolus administration.

BACKGROUND: DSPA (Desmodus salivary plasminogen activator) is a new thrombolytic agent corresponding to a natural plasminogen activator discovered in the saliva of the vampire bat Desmodus rotundus. Compared with tissue plasminogen activator (TPA), DSPA, produced in a recombinant cell line, is more fibrin cofactor dependent than TPA. METHODS AND RESULTS: The thrombolytic properties of DSPA and TPA were compared in a canine model of copper coil-induced coronary thrombosis. All dogs received heparin 200 IU/kg IV and SC. Whereas controls did not reperfuse within 180 minutes (none of six), intravenous bolus administration of DSPA at 25, 50, and 100 micrograms/kg resulted in a 100% incidence (6 of 6) of recanalization within 37, 23, and 18 minutes, respectively. TPA at 63 and 125 micrograms/kg reopened the coronaries in 33% (two of six) and 50% (three of six) of cases within 40 minutes. Eighty-three percent (5 of 6) of the arteries were still patent 3 hours after 50 and 100 micrograms/kg DSPA, whereas only 20% (one of five) of all coronaries originally recanalized with both doses of TPA were still open at 3 hours. Plasma levels of alpha 2-antiplasmin decreased significantly only with 125 micrograms/kg TPA. The clearance of DSPA (2.3 to 3.5 mL.min-1.kg-1) was lower compared with TPA (11.4 to 20 mL.min-1.kg-1) due to a prolonged terminal half-life. CONCLUSIONS: In a canine coronary thrombosis model, DSPA exhibited higher potency and recanalized coronary arteries faster and with a lower incidence of reocclusion than TPA. Its properties may translate into a higher efficacy in patients compared with available thrombolytic agents. The long half-life of DSPA may allow for single bolus administration in the treatment of acute myocardial infarction.

[Laboratory diagnostic monitoring of blood gas parameters in children during bronchologic studies]. / Labordiagnostische Uberwachung der Blutgasparameter bei Kindern während bronchologischer Untersuchungen.

Changes in PaO2 and parameters of acid-base-status during bronchological investigations were studied. 20 patients of both sexes with chronic nonspecific respiratory diseases have been investigated. The most important results were a respiratory acidosis after intubation and simultaneous hyperoxigenation during controlled (manual) ventilation. A respiratory acidosis with a small metabolic part was observed during extubation and change to normal respiration. In some cases acidosis was decomposated. These changes were found to be more extensive after bronchography than after bronchoscopy. Acidosis was normalized latest 60 minutes after extubation in all cases. The used method of bronchological examination has caused a favourable influence on the conditions of ventilation.

[The effect of bronchologic studies on blood gases and hemodynamics in children]. / Der Einfluss bronchologischer Untersuchungen auf Blutgase und Hämodynamik bei Kindern.

During 78 bronchological examinations in children of all age groups out of 6 centers of children bronchology of the GDR PaO2, PaCO2 and pH were registered, in a part of them additionally pulse, systolic and diastolic blood pressure. Following to the intubation--under ventilation with 100% oxygen or a halothane-NO2-oxygen mixture--there was a marked rise of PaO2, which normalized after extubation quickly. After extubation a slight hypoxemia occurred for a short period, a quick rise of PaCO2 and a slight acidosis, too. Besides, the hearth rate, systolic and diastolic blood pressure elevated following to the intubation and diminished after extubation.

Pharmacological profile of a new potent 5-hydroxytryptamine (5-HT2) alpha 1-receptor antagonist.

In in vitro binding studies ZK 33.839 (4-(3-[3-(4-(4-fluorobenzoyl)-1-piperidinyl)-propoxy]-4-methoxyphenyl)- 2-pyrrolidone) showed highly specific binding affinity for 5-hydroxytryptamine (5-HT2) and alpha 1-receptors. With 2.0 nmol/l and 5.2 nmol/l both Ki-values occur in the same concentration range. The pharmacodynamic profile of ZK 33.839 has been investigated under in vitro and in vivo conditions. In human platelets, in rat vascular smooth muscle and in guinea pig tracheal smooth muscle 5-HT-induced proaggregatory and contractile effects were inhibited dose-dependently with IC50-values ranging from 1.85 x 10(-8) mol/l to 9 x 10(-9) mol/l. 5-HT-induced amplification of the response of rabbit femoral artery to different vasoconstrictors (angiotensin II, histamine, norepinephrine, and prostaglandin F2 alpha) and 5-HT-mediated increase of microvascular permeability in hamster cheek pouch preparation were also inhibited by ZK 33.839. ZK 33.839 was found to be a potent alpha 1-receptor antagonist, the pA2-value in rat aortic strips determined against phenylephrine was 9.16. In blood-perfused hindquarters of anaesthetized rats, pretreated with reserpine, pressor dose-response curves to norepinephrine and 5-HT were shifted to a higher dose range. ZK 33.839 lowered blood pressure in conscious Dahl-S-rats and in anaesthetized rabbits. Decrease of blood pressure was due to a decrease of peripheral vascular resistance. Cardiac output and heart rate were not significantly altered. ZK 33.839 is a potential antihypertensive compound which combines vasodilatatory effects due to selective alpha 1-receptor antagonistic action and platelet antiaggregatory, antivasospastic, and vasoprotective properties due to selective 5-HT2-receptor blockade.

[Assessment of the effect of piracetam (Nootrop) on hydrogen clearance in the inner ear]. / Prüfung der Wirkung von Piracetam (Nootrop) auf die Wasserstoff-Clearance am Innenohr.

The animal experiment described in this report was conducted to study the effect of piracetam on the blood flow of the inner ear. Blood flow was measured indirectly by means of hydrogen clearance using the polarographic microanalysis technique. A group of twelve crossbred male and female guinea pigs were given 400 mg/kg body weight piracetam (2 ml/kg body weight of commercial solution for injection) by intravenous injection, and hydrogen clearance was measured before and after administering the study drug at the round window in the scala media at the base of the cochlea. Twelve animals in an control group were given an equal volume of physiological saline instead of the study drug. The H2 clearance measurements were taken before and after intravenous injection of saline. The operation and clearance measurements were performed under injection anaesthesia with 2.5 mg. diazepam and 25 mg. pentobarbital sodium, each per kg body weight. The guinea pigs were premedicated with atropine (0.5 mg./kg. body weight i.p.) and, after tracheotomy, were relaxed with pancuronium bromide (1 mg./kg. body weight i.v.) and respirated with a pneumatic respiration pump and the parameters blood pressure, pH and blood gases (pO2, pCO2) were continuously recorded. The results show that intravenous injection of piracetam in the above mentioned dose accelerates hydrogen clearance processes at the base of the cochlea from 8.68 +/- 3.48 to 5.37 +/- 2.05 minutes half-life. This effect is statistically significant (p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

[Autoradiography study of the uptake of 3H-2-deoxyglucose in the inner ear in normal and unilaterally sympathectomized albino rats]. / Autoradiographische Studie über den Einbau der 3H-2-Deoxyglukose im Innenohr bei normalen und einseitig sympathektomierten Albinoratten.

Using the autoradiographic technique for water-soluble substances, the uptake of 3H-2-deoxyglucose (2-DG) was measured in the inner ear tissue. The experiments were performed on 26 albino rats (22-27 days). 10 microCi/g b.w. of 2-DG were applied i.v. and the control group was immediately kept in the Camera silens in darkness. The main group was exposed to pink noise (50 Hz - 10 kHz of 60-110 dB). 8 unilaterally sympathectomised animals were exposed to pink noise of different intensity after 24h. The highest uptake of 2-DG independent of the intensity of noise was observed in the cochlear lateral wall (stria vasc., sp. lig., sp. prominentia) in the basal turn and decreased to the apical turn. The uptake in the lateral wall increased from 30-40 dB to 60dB and decreased from 60 to 80 dB exposure. The region of the inner hair cells was clearly marked by 80 dB. With increasing intensity of noise exposure, 2-DG uptake in the spiral ganglion increased continually. Unilateral sympathectomy did not result in any significant difference in the uptake of 2-DG. Therefore, the hypothesis that the decrease of 2-DG uptake in the lateral wall may be due to sympathico-adrenergic vasoconstriction is not verified by our results.

Limitation of myocardial unperfused area and necrotic zone 24 hours and 7 days after coronary artery ligation in rats by the stable prostacyclin analogue iloprost.

Protective effects of prostacyclin (PGI2) and Iloprost in experimental cardiac ischemia are reported by several authors. However, the effects of continuous administration on the final outcome of myocardial infarction are not yet known. We investigated the effects of Iloprost on cardiac unperfused area (UA) and necrotic zone (NZ) as assessed by Evans blue perfusion and extraction and nitrobluetetrazolium staining, respectively, using osmotic minipumps for continuous intravenous drug administration. Starting 3-4 hours after left descending coronary artery-ligation (LAD-L) Iloprost was infused at doses of 0.1 microgram and 0.5 microgram X kg-1 X min-1. While the lower dose is below pharmacological effect level, the higher dose in rats slightly lowered blood pressure and effectively inhibited platelet aggregation. LAD-L in control rats resulted in UA and NZ extending to 34.2 and 16.9%, respectively, of total ventricular mass (VM) after 24 hours and 28.3 and 21.3% of VM, respectively, after 7 days. At the dose of 0.1 micrograms X kg-1 X min-1 Iloprost was ineffective in reducing UA 24 hours after LAD-L. However, at 0.5 microgram X kg-1 X min-1 Iloprost with UA and NZ of 16.3 and 8.4% of VM, respectively, after 24 hours and 8.5 and 5.2% of VM, respectively, after 7 days reduced the extension of myocardial infarction by approximately 50% after 24 hours and 70% after 7 days, as compared to controls. As assessed in unperfused ventricular tissue after LAD-L and normal myocardium of sham-operated rats following 24 hours of Iloprost infusion, myocardial tissue concentrations of Iloprost amount to approximately half of the plasma levels irrespective of LAD-L.(ABSTRACT TRUNCATED AT 250 WORDS)

Antifibrillatory action of the stable orally active prostacyclin analogues iloprost and ZK 96 480 in rats after coronary artery ligation.

Iloprost (ILO) and ZK 96 480 (96 480) are stable prostacyclin (PGI2) analogues with platelet aggregation-inhibiting and hypotensive activities equal or superior to PGI2 which in contrast to PGI2 show longlasting pharmacological effects also after oral application. PGI2 as well as ILO and 96 480 with i.v. infusion at equihypotensive doses in rats after coronary artery ligation reduce ventricular ectopic beats, markedly reduce or abolish the periods of ventricular tachycardia and entirely prevent ventricular fibrilloflutter. Even nonhypotensive doses of the prostanoids attenuate postligation arrhythmias. Catecholamine depletion by reserpine pretreatment also markedly reduced the incidence of arrhythmias. As PGI2 and ILO have previously been shown by others to preserve noradrenaline content of sympathetic nerve terminals in ischemic myocardium, prevention of excessive catecholamine loss from hypoxically compromised sympathetic nerve terminals might be involved in the antiarrhythmic action of PGI2, ILO and 96 480.

Effect of pentoxifylline ('Trental') on cochlear blood flow as measured by hydrogen wash-out.

A comparative experimental study was carried out in guinea-pigs to assess the effect of pentoxifylline on inner ear perfusion. Five animals were given a single dose of 30 mg pentoxifylline per 10-minute intravenous infusion and the cochlear blood flow measured by means of the hydrogen-clearance technique before and after administration of the drug. A control group of 11 animals received the solvent only. Compared to controls, a significant increase in inner ear blood flow was observed in the pentoxifylline-treated animals. These data may explain positive clinical findings with pentoxifylline in otological disorders associated with impaired cochlear perfusion.

Hydrogen clearance and cochlear microcirculation at different levels of blood pressure.

To study the autoregulative capabilities of the cochlear vessels, hydrogen clearance (HC) measurements were carried out by means of various blood pressure levels in hemorrhagic hypotension. H2-sensitive platinum--needle electrode were applied and a polarographic microanalysis method was used. The measurements were performed in the scala media of anesthetized cats during measuring of blood pressure and blood gases. The statistical analysis of the experimental data shows that the relationship between the HC and aortic blood pressure represents a regression line. According to the regression line the half-life time of HC was delayed for 0.7 min, when the blood pressure was reduced by 10 mm Hg (40-150 mm Hg blood pressure range). This corresponds to a cochlea flow rate of 0.3 ml/100 g/min. By mean aortic blood pressure of 40 mm Hg, the speed of H2 exchange still remains about 50% of the initial clearance. This indicates that the cochlear vessels have autoregulative capability. This autoregulative capability differs from the saturation curves of most autoregulated blood flow in the brain, heart and kidney vessels. These findings are in accordance with the observations of other authors. As our experimental data show, and as long as an analogy can be drawn between man and cat, it is hardly possible to explain that the fall of the blood pressure alone could lead to a disturbance of the oxygen supply to the inner ear, as often discussed in certain inner-ear dysfunctions.