Morphological determinants for the local hemostatic effect of exogenous fibrin monomer in its systemic administration after injury with inhibition of platelet aggregation in the experiment

Background. In our previously published studies, we demonstrated a high hemostatic activity of a low dose of exogenous fibrin monomer during its systemic administration in a model of dosed liver injury with preliminary inhibition of platelet aggregation. However, the analysis of platelet involvement in the mechanisms of local fibrin formation has not been analyzed. The aim of the study. To conduct a comparative analysis of the cellular composition of venous and wound blood, as well as blood in the wound vessels to assess the contribution of platelets to the hemostatic effect of exogenously administered fibrin monomers in dosed liver injury under conditions of pharmacologically determined thrombocytopathy. Methods. In a model of dosed liver injury in rabbits after inhibition of platelet aggregation by  acetylsalicylic acid in combination with clopidogrel, the effect of the administration of fibrin monomer was evaluated in comparison with the use of tranexamic acid. We studied the number of platelets in venous and wound blood smears, as well as in the contents of wound vessels. Results. It has been established that with the systemic administration of exogenous fibrin monomer, the number of platelets in wound blood smears decreases by 17.2 % in comparison with free circulating venous blood. Platelets in wound blood form aggregates and are in an activated state. In the wound vessels, the number of these cells was maximum (150 per lower field) compared with the number of platelets in the placebo and tranexamic acid groups (55 and 84 per lower field, respectively). Also in the wound blood, erythrocytes with altered forms (echinocytes, schistocytes, stomatocytes and ovalocytes) were found. Conclusion. Systemic administration of exogenous fibrin monomer affects the redistribution of platelets between the systemic circulation, wound vessels and wound blood, determining its hemostatic effect and local wound fibrin formation in dosed liver injury. The presence of receptor-mediated platelets recruitment due to fibrin monomer in the wound vessels with the  participation of damaged erythrocytes is assumed

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

Model of the turboprop engine reduction gear tooth harmonic spectral component

The width of spectral components in rotary machines is determined by the frequency modulation of the carrier from the rotor speed deviation in the stationary operation mode. It was shown that, for the tooth spectral component, it is not enough to take into account this factor only. The analysis of publications and the studies performed show that it is also determined by the effect of many other factors: process-related ones (errors in manufacturing and assembly of gear wheels), operation mode parameters (rpm, temperature, transmitted load); design-related factors (flexibility of drive parts; modification of the tooth face), as well as uneven wear of tooth flanks. Using the planetary gearbox of a turboprop engine as an example, the structure of the tooth spectral component width in function of the analyzed influencing factors was considered. Based on the vibration statistics for eighteen gearboxes in overhauled engines, the choice of a ratio for the spectral component width of a frequency modulated process was justified. This choice showed readings closest to the corresponding experimental data. For the vibration of ten gearboxes with different degrees of tooth flank wear, the corresponding dependence of the width on the wear is presented. A mathematical model for the tooth spectral component width in overhauled and newly manufactured gearboxes as the product of the constant coefficient with the deviation dispersion sum from the considered factors was proposed. The same dependence was also given for gearboxes with wear when adding the dispersion from wear to the dispersion sum. It was demonstrated that, for the presented case of the maximum wear, its fraction in the total width was about 50%, whereas the fraction of the frequency modulation from the operating system of adjusting relative rotor speed constancy in the stationary engine operation mode was equal to half of all the other factors