Computational Study of Two-Phase Flow Morphology in a Nozzle

Multiphase flow meters are widely used in nuclear, petroleum and chemical industries. Here the flow rate is defined indirectly by the differential pressure measurement over the device. An additional measurement is required to estimate average density of the phase mixture. This could be done by means of the gamma-ray, electromagnetic or acoustic tomography. The accuracy of the technique is dependent on flow morphology. The present paper reports the results of CFD-modelling of the gas-liquid flow through the vertical flow meter accompanied by a flow conditioner. The model is used to consider the morphology for three different combinations of liquid and gas flow rates. The model demonstrates high non-uniformities of the flow field at the entrance of the flow meter and generally confirms the agreement of flow morphology with previous experimental observations for vertical pipes.

Physical research of microgravity influence on physical phenomenon in cryogenic liquids and general-purpose onboard cryogenic facility for realization of this researchaboard International Space Station

The united research plan named "Boiling" is created on the basis of several cryogenic research projects developed by experts in Russia and Ukraine for International Space Station. The "Boiling" plan includes 8 first experiments aimed at investigating the influence of microgravity on boiling processes, heat transfer and hydrodynamics in liquid helium being either under normal or superfluid conditions. The experiments are supposed to be carried out with individual cells collected inside a single cryogenic onboard experimental facility. The international research program experiments are characterized by the following features: utilization of several artificially simulated microgravity levels, owing to rotation of the experimental helium cryostat; visualization of the processes that occur in liquid helium; research of boiling and hydrodynamics both in a large volume of stationary liquid, and in a liquid flow running through a channel. Upon completion of the "Boiling" research plan, the cryogenic onboard facility created for International Space Station would be able to find its application in further scientific and experimental researches with helium

Non-immunogenic recombinant staphylokinase versus alteplase for patients with acute ischaemic stroke 4·5 h after symptom onset in Russia (FRIDA): a randomised, open label, multicentre, parallel-group, non-inferiority trial

Background: Non-immunogenic staphylokinase is modified recombinant staphylokinase with low immunogenicity, high thrombolytic activity, and selectivity to fibrin. We aimed to assess the safety and efficacy of a single intravenous bolus of non-immunogenic staphylokinase compared with alteplase in patients with acute ischaemic stroke within 4·5 h after symptom onset. Methods: We did a randomised, open-label, multicentre, parallel-group, non-inferiority trial in 18 clinical sites in Russia. We included patients aged 18 years and older with a diagnosis of acute ischaemic stroke (up to 25 points on the National Institutes of Health Stroke Scale). The study drug had to be administered within 4·5 h after the onset of symptoms. Patients were randomly assigned to receive either non-immunogenic staphylokinase (10 mg) or alteplase (0·9 mg/kg, maximum 90 mg), both administered intravenously. The randomisation sequence was created by an independent biostatistician using computer-generated random numbers. 84 blocks (block size of four) of opaque sealed envelopes were numbered sequentially from 1 to 336 and were opened in numerical order. Patients were unaware of their assigned treatment and were assessed by the study investigators who were also unaware of the treatment assignment on all trial days. Emergency department staff, who administered the assigned drug and opened the envelopes, were not masked to treatment. The primary efficacy endpoint was a favourable outcome, defined as a modified Rankin scale (mRS) score of 0–1 on day 90. The margin of non-inferiority was established as 16% for the difference in mRS score of 0–1 on day 90. Non-inferiority was tested using Welch's t-test for the primary outcome only. Endpoints were analysed in the per-protocol population, which comprised all randomly assigned patients who completed treatment without any protocol violations; this population was identical to the intention-to-treat population. This trial is completed and registered at ClinicalTrials.gov, NCT03151993. Findings: Of 385 patients recruited from March 18, 2017, to March 23, 2019, 336 (87%) were included in the trial. 168 (50%) patients were randomly assigned to receive non-immunogenic staphylokinase and 168 (50%) to receive alteplase. The median duration of follow-up was 89 days (IQR 89–89). 84 (50%) of 168 patients in the non-immunogenic staphylokinase group had a favourable outcome at day 90 compared with 68 (40%) of 168 patients in the alteplase group (odds ratio [OR] 1·47, 95% CI 0·93 to 2·32; p=0·10). The difference in the rate of favourable outcome at day 90 was 9·5% (95% CI –1·7 to 20·7) and the lower limit did not cross the margin of non-inferiority (pnon-inferiority <0·0001). Symptomatic intracranial haemorrhage occurred in five (3%) patients in the non-immunogenic staphylokinase group and in 13 (8%) patients in the alteplase group (p=0·087). On day 90, 17 (10%) patients in the non-immunogenic staphylokinase group and 24 (14%) patients in the alteplase group had died (p=0·32). 22 (13%) patients in the non-immunogenic staphylokinase group had serious adverse events, compared with 37 (22%) patients in the alteplase group (p=0·044). Interpretation: Non-immunogenic staphylokinase was non-inferior to alteplase for patients with acute ischaemic stroke. Mortality, symptomatic intracranial haemorrhage, and serious adverse events did not differ significantly between groups. Future studies are needed to continue to assess the safety and efficacy of non-immunogenic staphylokinase in patients with acute ischaemic stroke within the 4·5 h time window, and to assess the drug in patients with acute ischaemic stroke outside this time window with reperfusion CT or magnetic resonance angiography followed by thrombectomy if necessary. Funding: The Russian Academy of Sciences. © 2021 Elsevier Lt