Performance of a cryo-cooled crystal monochromator illuminated by hard X-rays with MHz repetition rate at the European X-ray Free-Electron Laser.

Due to the high intensity and MHz repetition rate of photon pulses generated by the European X-ray Free-Electron Laser, the heat load on silicon crystal monochromators can become large and prevent ideal transmission in Bragg diffraction geometry due to crystal deformation. Here, we present experimental data illustrating how heat load affects the performance of a cryogenically cooled monochromator under such conditions. The measurements are in good agreement with a depth-uniform model of X-ray dynamical diffraction taking beam absorption and heat deformation of the crystals into account.

Materials Imaging and Dynamics (MID) instrument at the European X-ray Free-Electron Laser Facility.

The Materials Imaging and Dynamics (MID) instrument at the European X-ray Free-Electron Laser (EuXFEL) facility is described. EuXFEL is the first hard X-ray free-electron laser operating in the MHz repetition range which provides novel science opportunities. The aim of MID is to enable studies of nano-structured materials, liquids, and soft- and hard-condensed matter using the bright X-ray beams generated by EuXFEL. Particular emphasis is on studies of structure and dynamics in materials by coherent scattering and imaging using hard X-rays. Commission of MID started at the end of 2018 and first experiments were performed in 2019.

[Blood supply as a factor regulating pacemaker activity of the rat uterine horn].

Effect of ischemia of the uterine artery supplying with blood the main rhythmogenic zone (the ovarian region) of the uterine horn on parameters of activity both of this locus and of all subsequent pacemaker areas up to the uterine cervix was studied in non-pregnant rats. The most pronounced changes in characteristics of the activity (amplitude, frequency, and burst genesis duration) were revealed in the ovarian horn end. The uterine corpus and the horn cervical end were less affected by ischemia. Meanwhile, under these conditions, amplitude of the slow-wave oscillations rose more than 1.5 times. The obtained data allow us to conclude about the presence of a certain connection between the horn ovarian end and the uterine cervix. Morphological studies have revealed strong vascularization of the upper part of uterine horn.

[Role of acetylcholine in coordination od spontaneous electrical activity of various areas of the rat uterus].

Spontaneous electrical activity of myometrium was studied in areas of the uterine corpus, zone of its connection with uterine tube and cervix at intravenous administration of various acetylcholine concentrations. Under these conditions, changes of the frequency and amplitude characteristics of rhythmogenesis were studied both separately and in their combined active state. The presence of 10(-3) M acetylcholine in the animal blood creates the most optimal conditions for synchronization and coordination of activities of all studied uterus areas.

[Role of oxytocin in activation of spontaneous electrical activity of uterine body and uterine tubes in non-pregnant rats].

The work studies effects of various doses of oxytocin (0.01, 0.1, 1 and 10 microg/kg) on duration of discharges of spontaneous electrical activity and frequency of spikes in various parts of uterine tubes and of uterine body of non-pregnant rats. Under these conditions, changes in these parameters for ovarian parts of the uterine tubes had similar character unlike those in cervical parts of the tubes and in the middle part of the uterine body, so the latter parts can be grouped together owing to peculiarities of their changes. The longest duration of genesis of electric discharges has been shown for the ovarian part of uterine tubes at a concentration of 10 microg/kg of oxytocin. Morphological experiments revealed that among all studies areas the ovarian parts of uterine tubes were characterized by the highest amount of atypical cells that have the maximally pronounced functional activity.

[The role of histamine in regulation of spontaneous electrical activity of the rat ureter and bordering to bladder area].

The nature of the influence of histamine on the slow wave and spike spontaneous activity of both perirenal and peribladder bordering areas of the bladder zone has been studied. It is shown that under these conditions of activated renal section of the organ, in the distal part, the decrease in frequency of the slow waves occurred. The histamine effect also contributes to improvement of the conduction of the excitation wave propagating to the bladder, which destroys the coordination of spike activity of the latter with slow waves of ureteral bordering zone.

[Effect of nifedipine on electrophysiological properties of rat ureter spontaneous activity].

The work studied effect of various concentrations of nifedipine on the slow and fast spontaneous activities evoked in the perivesical and perirenal areas of the rat ureter. Whereas in the proximal zone of the organ at the low dose of nifedipine (0.06 and 0.12 mg/kg), inhibition is revealed both of slow waves and of their corresponding spikes, in the perivesical part the opposite effect is observed. Besides, with further increase of the nifedipine dose to 0.15 and 0.2 mg/kg, in the ureter area adjacent to the urinary bladder, alongside with acceleration of slow pacemaker oscillations, the appearance of the antiperistaltically directed action potentials is also possible.

[Effect of oxytocin on activation of spontaneous electrical activities registered from uterine corpus and uterine tubes in rats].

The effects if different concentrations of oxytocin (10(-2), 10(-1), 1 and 10 microg/kg) on burst duration and spikes frequency of spontaneous electrical activity in various parts of uterine horns and uterine corpus in non-pregnant rats have been shown. The changes in given parameters for ovarian parts of horns had similar characters unlike cervical parts of horns and middle part of uterine corpus under these conditions, so the last mentioned areas could be grouped together by the reason of similar changes in their parameters. Oxytocin in a concentration of 10(-1) microg/kg promoted the longest duration of spike electrical activity genesis in ovarian parts of horns. Morphological experiments showed that ovarian parts of horns had a great amount of atypical cells with strongly expressed functional activities.

[Effect of acetylcholine on coordination of spontaneous activities registered from different areas of uterus in rats].

Spontaneous electrical activities of uterine corpus, periuterine part of horn and uterine cervix in response to intravenous injections of different concentrations of acetylcholine were observed. The changes of frequency and amplitude characteristics of rhythmogenesis in these conditions, both separately and with their co-active state were analysed. Acetylcholine in concentration of 10(-3) M in the blood of the animal creates the optimal conditions for synchronization and coordination of electrical activities in the above areas of the uterus.

[Autonomy of spontaneous rhythmogenesis of perivesicular area of cat ureter].

The work present data indicating no dependence of the pacemaker activity located in the zone of junction of cat ureter with urinary bladder on genesis of the main perirenal pacemaker. Data are presented on effect of clamping the renal artery supplying with blood flow the renal area on rhythmogenesis of the ureter perivesicular area. An inhibition of the pacemaker activity of the pyeloureteral anasomosis is observed. At the same time, no marked effect on automatism of the low organ area is revealed. Data of morphological studies of the vascular bed providing blood supply of various ureter areas are presented.

[Analysis of electrical activities of the junction region of the ureter with bladder and surrounding zones in rats].

Spontaneous electrical activity of the rat ureters per bladder zone was studied. In area of ureter connection with bladder, slow-wave activity was revealed. In bladder bordering ureter zone, rapid spike activity was found that was fully correlated with the genesis of upper located fluctuation processes.

[Study of volatile fatty acids in the blood of patients with periodic disease].

Microecological "failures" are an important pathogenetic factor of different diseases and, in the authors' opinion, periodic disease (PD) is one of them. PD is a recessive disease characterized by fever attacks and neutrophil-mediated serous inflammation. A genetic factor has been established to be responsible for half the cases of PD, the influence of non-hereditary factors, particularly a role of the host automicroflora in the genesis of an inflammatory process, has been little studied. The authors' early studies indicate that there are changes in the qualitative and quantitative composition of microbial molecules in the blood of patients with PD. The anaerobic bacterial metabolites that are volatile fatty acids (VFAs) represent biologically active substances that affect the growth of the microflora, on the one hand, and the host's immunological responsiveness, on the other. Out of VFAs, only is acetic acid detectable in small quantities in the blood of healthy individuals. The other VFAs, namely propionic, valeric, butyric, and caproic acids and their isomers, are absent. Gas chromatography was used for qualiitative and quantitative determination of the metabolites of anaerobic microorganisms in the blood of patients with PD (n = 13) during an attack and remission and in that of healthy volunteers (Armenians) (n = 5) of a control group from one Yerevan region. The blood samples from all the patients with PD displayed a significantly higher concentration of caproic acid while the latter was absent in the blood of the controls. This finding suggests that there is a specific shift in the structure of the microbiocenosis in patients with PD. It is conceivable that caproic acid plays a certain role in the pathogenesis of the disease under study. Further studies will deal with the association of some microbial molecules with the manifestation of an attack of PD, which may provide the key to the goal-oriented regulation of detected homeostatic disorders and to the management of the frequency of its attacks.

[Pacemaker activity in distal parts of the cat ureter].

Existence of two types of uncoordinated spontaneous activities of the cat ureterbladder area was shown: spikes and slow waves. The oscillation frequency of this area is two-fold lesser than the rhythm of renal waves. The activity concordance of these pacemakers occurs under conditions of ureter dissection in the middle. Normally pacemakers of this area seem to be a reserve mechanism of urine pushing through.

[Effect of histamine on spontaneous rhythmogenesis of the guinea pig ureter]. / Osobennosti vozdeistviia gistamina na spontannyi ritmogenez mochetochnika morskoi svinki.

Histamine changed characteristics of the perinephric spontaneous spike activity and of the spreading electrical wave. It was shown that histamine could activate latent pacemakers of the ureter's middle area. Morphological picture of the histamine effect was also shown.

[The differentiation of rhythmogenic characteristics of the ureter's different regions in guinea pigs]. / Differentsiatsiia ritmogennykh svoistv razlichnykh oblastei mochetochnika morskoi svinki.

Characteristics of rhythmogenic pacemakers of the ureter's perirenal middle and peribladder region morphologically and electrophysiologically are analysed in guinea pigs both in presence of spreading activity and breach of conductivity. It was shown that the action potential's amplitude of the middle region is the highest and duration of the spike activities from perirenal zone is maximal and all three regions are characterised by different functional conditions.

[Activation of latent pacemakers in the guinea pig ureter]. / Aktivatsiia latentnykh peismeikerov mochetochnika morskoi svinki.

Guinea pig's ureter rhythmogenic autonomous latent pacemaker was shown to generate a significantly higher-frequency rhythm than the pericystic pacemaker. The latent pacemakers of the ureter middle portion can be activated with a breach of electrical conductivity across the organ or with chemical agents (noradrenaline, histamine).

[Electrophysiological pacemaking properties of the ureter peribladder area in cats and rats]. / Analiz élektrofiziologicheskikh ritmogennykh svoistv okolopuzyrnoi oblasti mochetochnika u koshek i krys.

The rhythm generated by the peribladder area was found to be slower than that generated by the basis perirenal pacemaker in cats and rats. The antiperistaltic waves' frequency of the peribladder area was the lowest within the range of all the recorded rhythms.

[Effect of dimedrol on the regulation by histamine of the pacemaker activity of the cat ureter]. / Vliianie dimedrola na reguliatsiiu gistaminom peismekernoi aktivnosti mochetochnika koshki.

A certain concentration of Dimedrol (0.5 x 10(-6) mol/l) turned out to be capable of neutralising the histamine regulation of the slow-wave activity. The histamine H1-receptors were shown to modulate the cat general pace-maker's activity as well as the Na+ mechanism of the slow wave genesis.