An integrated ion trap for the photon-ion spectrometer at PETRA III.

We have added a multipole ion trap to the existing photon-ion spectrometer at PETRA III (PIPE). Its hybrid structure combines a ring-electrode trap with a segmented 16-pole trap. The interaction of gases and ions with extreme ultraviolet radiation from the beamline P04 is planned to be investigated with the newly installed multipole trap. The research focus lies on radiation-induced chemical reactions that take place in the interstellar medium or in the atmospheres of planets, including natural as well as man-made processes that are important in the Earth's atmosphere. In order to determine the mass-to-charge ratio of the stored ions as efficiently as possible, we are using an ion time-of-flight spectrometer. With this technique, all stored ions can be detected simultaneously. To demonstrate the possibilities of the trap setup, two experiments have been carried out: The photoionization of xenon and the ion-impact ionization of norbornadiene. This type of ion-impact ionization can, in principle, also take place in planetary atmospheres. In addition to ionization by photon or ion impact, chemical reactions of the trapped ions with neutral atoms or molecules in the gas phase have been observed. The operation of the trap enables us to simulate conditions similar to those in the ionosphere.

Towards the geometric structure of small supported Au9 clusters on Si.

Ultra-small clusters containing few atoms are of high interest in both fundamental research and applications due to their specific functional, magnetic or chemical properties which depend on size and composition. The experimental results of the morphology of the size-selected clusters, consisting of few atoms can be an ideal benchmark for sophisticated theoretical models. With this motivation we have investigated the geometrical structure of mass-selected Au9 clusters deposited on a silicon substrate prepared by soft-landing conditions. We present results obtained experimentally by Grazing-Incidence Small-Angle X-ray Scattering (GISAXS). Considering the ultra-small size of the clusters and small quantities of material on the surface, we combined advanced techniques which allowed us to investigate the surface structure of the sample. The resulting structural sizes are in concordance with cluster theory. Using a model-based approach, the advanced X-ray techniques allow for understanding how to resolve the possible cluster structure, identify optimal experimental conditions and obtain the probable morphological information which is challenging to be obtained otherwise.

New experimental perspectives for soft x-ray absorption spectroscopies at ultra-low temperatures below 50 mK and in high magnetic fields up to 7 T.

A new ultra-low temperature experiment including a superconducting vector magnet has been developed for soft x-ray absorption spectroscopy experiments at third generation synchrotron light sources. The sample is cooled below 50 mK by a cryogen free (3)He-(4)He dilution refrigerator. At the same time, magnetic fields of up to ±7 T in the horizontal direction and ±0.5 T in the vertical direction can be applied by a superconducting vector magnet. The setup allows to study ex situ and in situ prepared samples, offered by an attached UHV preparation chamber with load lock. The transfer of the prepared samples between the preparation section and the dilution refrigerator is carried out under cryogenic temperatures. First commissioning studies have been carried out at the Variable Polarization XUV Beamline P04 at PETRA III and the influence of the incident photon beam to the sample temperature has been studied.

[The microhemodynamics and lymph flow in the small intestine under the action of histamine against a background of water loading and hyperthermia in dogs]. / Mikrogemodinamika i limfotok v tonkoi kishke pri deistvii gistamina na fone vodnoi nagruzke i gipertermii u sobak.

In anesthetized dogs, an increase of the lymph flow and the transcapillary fluid transfer, under the effect of histamine, was due to elevation of capillary hydrostatic pressure and capillary filtration coefficient in the small intestine. Against the background of water load and hyperthermia, histamine induced less obvious shifts of the microhemodynamic parameters and lymph flow in the small intestine.

[The dependence of changes in the microhemodynamics and lymph formation in the liver on the level of the arterial and portal blood flows]. / Zavisimost' izmenenii mikrogemodinamiki i limfoobrazovaniia v pecheni ot urovnia arterial'nogo i portal'nogo krovotokov.

In cats, when perfusing hemodynamically isolated liver with a constant blood volume, an increasing of arterial as well as portal blood flows was shown to increase hydrostatic pressure in sinusoids and lymph production in the liver, whereas decreasing of the flows decreased these parameters. The above changes of the blood flows entailed various shifts of sinusoidal hydrostatic pressure and postsinusoidal resistance. When the volume blood flow in the liver artery increased, the coefficient of sinusoidal filtration increased too, whereas an increment of the blood flow in portal vein led to its diminishing. The resistance of liver artery and portal vein changed very little both in case of increasing and diminishing of the blood flow in these vessels.

[Changes in the transsinusoidal fluid transfer in the cat liver during noradrenaline infusion]. / Izmenenie transsinusoidal'nogo peremeshcheniia zhidkosti v pecheni koshek pri infuzii noradrenalina.

The blood microcirculation and the lymph flow were studied in the cat hemodynamically isolated liver perfused under conditions of a regulated venous outflow and i.a. and intraportal administration of noradrenaline. An increase in the fluid transsinusoidal transfer revealed by the lymph flow acceleration in the liver, was determined by an increased hydrostatic pressure in the sinusoids at practically unaltered level of sinusoidal filtration. The above shifts were observed against the background of constriction of arterial, portal, venous and lymphatic vessels and of a decrease in capacitance of the liver vessels which were due to alpha-adrenocereptors excitation by noradrenaline.

[Dependence of the parameters of microcirculation and lymph flow in the liver on the value of venous pressure]. / Zavisimost' parametrov mikrogemotsirkuliatsii i limfotoka v pecheni ot velichiny venoznogo davleniia.

In experiments on cats the perfusion (at a constant flow and controlled venous outflow) of haemodynamic isolated liver was carried out. It was shown that at the levels of venous pressure in the liver 0, 2, and 4 mm Hg, the lymph flow (22.8 +/- 3.5, 41.8 +/- 5.7 and 57.6 +/- 8.6 mkl.min-1.100 g-1, respectively) was depended on the value of hydrostatic pressures in the sinusoids (1.4 +/- 0.1, 3.3 +/- 0.1, and 5.4 +/- 0.1 mm Hg, respectively) and did not depend on the value of sinusoidal filtration coefficient (0.421 +/- 0.029, 0.473 +/- 0.036, and 0.474 +/- 0.034 ml.min-1.mm Hg-1.100 g-1, respectively).

[The relation of lymph flow and microcirculation in the cat liver under the effect of serotonin and bradykinin]. / Sootnoshenie limfotoka i mikrogemotsirkuliatsii v pecheni koshek pri deistvii serotonina i bradikinina.

In experiments on cats with hemodynamically isolated and perfused wider constant flow liver it was shown that intraarterial or intraportal infusion of serotonin and bradykinin increased a transinusoidal fluid fransher and lymph formation in the region. The elevated franshes walls of maintained mainly by an increase on the permeability of the walls of exchange microvessels. Differences were revealed in the achions of serofouri and bradykinin upon liver's arterial and portal vessels, the sensitivity of portal vein to the drugs being which lesser than of the live artery.

[Lympho- and hemodynamic reactions during the contraction of the skeletal musculature of the hindlimb in dogs]. / Limfo- i gemodinamicheskie reaktsii pri sokrashchenii skeletnoi muskulatury zadnikh konechnostei sobaki.

Alterations in arterial pressure (AP) values, blood and perfusate flow from the thoracic duct, lymph and perfusate flow from the femoral lymphatic vessel during femoral muscle contractions induced by electrical stimulation applied for 1.5 and 3.0 min, were studied: the AP values were decreased by 10-15 mm Hg, the blood flow increased to 293.5 +/- 21.7%, the lymph flow increased to 525.4 +/- 29.8%, the perfusate flow from the thoracic duct raised to 81.8 +/- 4.7%, and the perfusate flow from the lymphatic vessel increased to 650.0 +/- 28.2%. The increase in the lymph flow during 1.5 min stimulation seems to be due to squeezing of lymph out of the lymphatic channel, whereas during 3 min stimulation it was due to enhanced lymph production.

[Lymph-blood microcirculatory shifts in the intestines during histamine action]. / Limfo-mikrogemotsirkuliatornye sdvigi v kishechnike pri deistvii gistamina.

The infusion of histamine increased the lymph flow in the cat innervated intestine due to squeezing off of the lymph from lymphatic vessels under motor activation of the intestine, followed by an increase in the lymph production because of accelerated transcapillary transfer of fluid from the blood into interstitium. The increase in the water hemato-lymphatic transition was maintained by an augmentation of the capillary filtration coefficient against the background of both a decrease and an increase tin capillary hydrostatic pressure occurring simultaneously with a drop of the perfusion pressure under the effect of histamine. After decentralization of the intestine histamine led to a drop of capillary hydrostatic pressure, leaving the shifts of other parameters the same.

[Lymph flow, micro- and macrohemocirculation in the intestine of cats during infusion of serotonin]. / Limfotok, mikro- i makrogemotsirkuliatsiia v kishechnike koshek pri infuzii serotonina.

In the cat isolated small intestine perfused with a constant flow, i. a. serotonin (0.1--10.0 mu.min-1.kg-1) increased transcapillary fluid transfer against the background of decreasing capillary hydrostatic pressure and increasing capillary filtration coefficient. The reactions of arteries, veins and lymphatic ducts of the small intestine to serotonin were similar: they dilated at low and constricted at high-doses of the amine.

[Coupled functions of vessels and lymph outflow in the cat small intestine during stimulation of the sympathetic nerves]. / Soopriazhennye funktsii sosudov i limfoottok v tonkoi kishke koshek pri vozbuzhdenii simpaticheskikh nervov.

Experiments in cats with the constant blood volume perfusion of the small intestine vessels revealed constrictor responses of arterial, venous and lymphatic vessels to electrical stimulation of sympathetic nerves, the responses being most obvious at the 8, 10 and 10-20 Hz frequency of stimulation. Activation of sympathetic nerves augmented the pre- and postcapillary resistance of the vessels, the resistance being the greatest at 8 and 10 Hz. Stretching ability of venous vessels decreased. The capillary hydrostatic pressure increased, its shift being maximal at 10 Hz. The capillary filtration coefficient increased, the increment being maximal at 1 Hz. The lymph production and outflow enhanced. The motor activity of the intestine was suppressed. Analysis of the conjugated shifts in macro- and microhemodynamic parameters as well as in lymph flow revealed a transcapillary transition of intravascular fluid into the extravascular space due to the increase in the capillary hydrostatic pressure followed with a resorption into the roots of the intestine lymphatic system.

[Relation of lymph and microcirculation dynamics in the extremities of cats as affected by bradykinin and histamine]. / Sootnoshenie limfo- i mikrogemodinamiki v konechnosti koshhi pri deistvii bradikinina i gistamina.

In perfused with constant flow isolated cat hindlimbs, i.a. infusion of 0.1-1.0 micrograms.min-1.kg-1 histamine and bradykinin caused a dilatation of arteries and veins and an increase of the capillary filtration coefficient. Histamine elevated capillary hydrostatic pressure and dilated lymphatic ducts with no alteration in the lymph formation process in the hindlimb. Bradykinin decreased capillary hydrostatic pressure and activated formation of lymph. The elevation of transcapillary fluid movement under the effect of bradykinin seems to be the result of a disturbance in colloid osmotic (oncotic) pressures on both sides of the capillary wall.

[Macro- and micro-hemocirculatory shifts in the small intestine during pressor reflexes]. / Makro- i mikrogemotsirkuliatornye sdvigi v tonkom kishechnike pri pressornykh refleksakh.

In acute experiments on cats, effects of occlusion of common carotid arteries, stimulation of afferent fibers of the brachial plexus, application of acetylcholine to reflexogenous zones of peritoneum and mesentery of the small intestine on macro- and microcirculation of the isolated small intestine perfused under constant flow, were studied. Under effects of occlusion and afferent stimulation, arteries and veins of the small intestine were constricted, whereas in stimulation of abdominal reflexogenous zones their reactions were different. All the reflexes induced augmentation of the capillary hydrostatic pressure, capillary filtration coefficient and post-capillary resistance, whereas decreasing the venous vessels distention.

Reciprocal translocations in germ cells of male mice receiving external gamma-irradiation.

Data reported in the literature up to 1985 on reciprocal translocation induction in male mouse germ cells by external gamma-ray doses ranging from 0.5 to 6.0 Gy delivered at fixed dose rates were analyzed. On the assumption of a non-threshold linear dose response, zero effect at zero dose, and a center of distribution lying on an approximately straight line, calculations were made of linear regression coefficients. These coefficients (b), as a function of the dose rate (P), were well fitted by two straight lines: b = (3.15 +/- 0.59 log P) X 10(-6) for dose rates from 0.01 to 0.1 mGy/min; and b = (7.52 +/- 3.86 log P) X 10(-6) for dose rates ranging from 0.06 to 1.2 X 10(3) mGy/min. The intersection point of these two lines determined the so-called threshold level of the dose rate, namely, 4.6 X 10(-2) mGy/min, at which the effectiveness of external gamma-irradiation is not expected to exceed 2.36 X 10(-6)/mGy. In addition, experiments were undertaken in which yields were recorded of reciprocal translocations in germ cells of male mice exposed to 0.9 Gy of gamma-radiation at dose rates ranging from 6.14 X 10(-3) to 6.14 X 10(2) mGy/min (6 levels); comparisons were made with data published up to 1985 from similar studies using other fixed doses. To do this, translocation yields were expressed as relative yields (F) and their relationship to the dose rate (P) for the individual fixed doses was represented by an equation of the type: F = alpha + beta log P. For most of the equations, the regression coefficients were in good agreement and a single relationship was obtained to represent them. From the analysis performed it follows that, within the 0.6-6.0 Gy dose range, the pattern of the F vs. P relationship is unaffected by the dose. This supports the initial assumption that for the dose range up to 6.0 Gy the dose response for the reciprocal translocation yield is a non-threshold straight-line relationship.

[Relation between changes in macro- and microcirculation and lymph flow in the extremities of the cat after histamine infusion]. / Vzaimootnoshenie sdvigov makro- i mikrotsirkuliatsii s limfotokom v konechnosti koshki pri infuzii gistamina.

In experiments on the cat isolated hindlimb perfused with a constant flow, it was shown that against the background of dilatation of arteries under effect of histamine, venous outflow from the hindlimb increased after 0.05-0.1 microgram X min-1 X kg-1 histamine and decreased after a higher doses. In lower doses of histamine, a decrease of capillary hydrostatic pressure prevailed whereas in higher doses it was increased. The capillary filtration coefficient increased proportionally to the dose of histamine. The transcapillary fluid exchange involved no alteration in lymph formation in the hindlimb, the lymph being stored in lymphatic ducts.

[Effect of space flight factors on bone marrow cells in the rat]. / Deistvie faktorov kosmicheskogo poleta na kostnomozgovye kletki krys.

The effect of space flight factors, weightlessness in particular, on the genetic structures of bone marrow cells of rats flown for 18.5 days on Cosmos-1129 was investigated. Chromosome aberrations were measured on postflight days 6 and 25. The frequency of unstable chromosome aberrations was similar in the flight, synchronous and vivarium rats. Karyotyping of metaphase plates revealed chromosome aberrations in the flight and synchronous rats. Exposure to weightlessness did not influence the mutagenic effect in bone marrow cells of the rats.