Summary
We prospectively observed 36 haematological patients with mucormycosis from nine hospitals of St. Petersburg during 2004–2013. The most frequent underlying diseases were acute leukaemia ...(64%), and main risk factors were prolonged neutropenia (92%) and lymphocytopenia (86%). In 50% of the patients, mucormycosis was diagnosed 1–65 days after invasive aspergillosis. Main clinical form of mucormycosis was pulmonary (64%), while two or more organ involvement was noted in 50% of the cases. The most frequent aetiological agents of mucormycosis were Rhizopus spp. (48%). Twelve‐week survival rate was 50%. Combination therapy (echinocandins + amphotericin B forms) and recovery from the underlying disease significantly improved the survival rate.
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•Effective approach to improve cold flow properties of hydrocracking products proposed;•Combination of USY and ZSM-23 ensures good conversion of n-alkanes and ...isoalkanes;•Appropriately selected combination of USY and ZSM-23 maintains activity and selectivity;•Cold flow properties improved without compromising the selectivity to target products.
The effect of the combined use of three-dimensional large-pore USY zeolite and one-dimensional medium-pore ZSM-23 zeolite to enhance the cold flow properties of hydrocracking products was studied. Based on the results of monozeolite catalysts testing in hexadecane hydroconversion, the compositions of bizeolite catalysts for vacuum gas oil hydrocracking were selected. The catalyst compositions were selected, considering that both zeolite components operate in a similar temperature range and contribute to hexadecane conversion. It has been shown that due to an appropriately selected combination of USY and ZSM-23 zeolites in the catalyst, both zeolites perform together, complementing each other, which ensures good conversion of both n-alkanes and isoalkanes during vacuum gas oil hydrocracking. As a result, it is possible to significantly improve the cold flow properties of the obtained hydrocracking products while maintaining the activity and selectivity for the target products of Pt/USY-ZSM-23 catalyst at the level of conventional Pt/USY catalyst. The cold filter plugging point of the diesel fraction decreases from −10 to less than −44 °C and the pour point from −17 to less than −50 °C. The pour point of lube base oil decreases from 23 to less than −27 °C. The improvement of the cold flow properties is accompanied by only a slight worsening of the other important product characteristics, such as diesel fraction cetane index and lube base oil viscosity index.
Background. In the expanding population of immunocompromised patients rare fungi have emerged as important pathogens, causing invasive infections associated with high morbidity and mortality. The ...number of publications on the invasive fungal diseases caused by rare pathogens (rare IFD) after hematopoietic stem cell transplantation (HSCT) and chemotherapy is limited.
Patients and methods. We design the retrospective study in order to investigate the epidemiology of rare IFD in large cohort of patients after HSCT and chemotherapy for 11-year period. From 2008 to 2018 in R. Gorbacheva Memorial Institute of Children Oncology, Hematology and Transplantation (CIC725) were performed 3209 HSCT including 2118 allogeneic (allo-HSCT) and 1037 autologous HSCT (auto-HSCT). During the observation period 41 probable and proven rare IFD (EORTC/MSG 2008 criteria) cases were diagnosed in children and adults with hematological malignances and non-malignant hematological diseases after allo-HSCT (n=30), auto-HSCT (n=2), and chemotherapy (n=9). The median age was 24 (2-59) y.o., males - 61%(n=25). The median follow up time for rare IFD cases was 3 months; for survivors - 30 months.
Results. Incidence of rare IFD in HSCT recipients was 1,3%, it was higher after allo-HSCT (1,4%) than auto-HSCT (0,2%) (p<0,002). In nine patients, this complication developed after CT and four of them proceed to allo-HSCT. The most frequent underlying diseases were acute lymphoblastic leukemia (32%) and acute myeloid leukemia (29%). The median time of onset of rare IFD after allo-HSCT was 104 (21-1057) days, auto-HSCT - 138 (60-216), after start of CT - 161 (79-189). Etiology of rare IFD was identified by culture in 61% cases: Rhizopus spp. - 44%, Paecilomyces spp. - 16%, Fuzarium spp. - 8%, Malassezia furfur - 8%, Trichosporon asahii - 4%, Scedosporium apiosperium - 4%, Scopulariopsis gracilis - 4%, Rhizomucor pusillus - 4%, mix rare IFD with Rhizopus spp. + Paecilomyces spp. - 4%, Paecilomyces spp. + Fuzarium spp. - 4%. 35% cases (mucormycosis) were diagnosed with microscopy. In 44% cases rare IFD developed after or in combination with invasive aspergillosis, and 2 patients had both preexisting invasive aspergillosis and co-infection with mucormycosis. The main site of infection were lungs (82%), the main clinical symptom - fever (95%). All patients were treated with antifungals: lipid amphotericin B - 32%, lipid amphotericin B + caspofungin - 23%, voriconazole - 15%, posaconazole - 12,5%, lipid amphotericin B + posaconazole - 10%, and echinocandins - 7,5%. Surgery was used in 10% patients. Overall survival at 12 weeks from the diagnosis of rare IFD was 51,2%. The 12-weeks overall survival was better in patients after CT and auto-HSCT (81%) than allo-HSCT (40%), p=0,025.
Conclusions. The incidence of rare IFD in HSCT recipients was 1,3% and depends on type of transplantation. Rare IFD was a late complication after chemotherapy and HSCT and usually developed after or in combination with invasive aspergillosis. Higher incidence and worst prognosis of rare IFD was observed in allo-HSCT recipients.
Moiseev:MSD: Other: Travel grants; Pfizer: Other: Travel grants; Celgene: Consultancy, Other: Travel grants; BMS: Other: Travel grants; Novartis: Consultancy, Honoraria, Other: Travel grants, Speakers Bureau; Takeda: Other: Travel grants.
Background: Introducing a new antifungals and diagnostic procedures has improved prognosis of the invasive aspergillosis (IA) in hematological patients. The number of patients with IA who are ...candidates for allogeneic hematopoietic stem cell transplantation (allo-HSCT) has increased. The influence of IA on survival and on allo-HSCT related complications has not been investigated in a prospective study.
Aim: to estimate impact of prior proven and probable IA on outcome of allo-HSCT compared to patients without IA.
Methods: In prospective observational single center study 362 allo-HSCT recipients (336 - first and 26 - second allo-HSCT) were included from Jan 2012 to Dec 2014. The median age was 34 y, males - 54%. Most of pts had high-risk acute leukemia (70%). Allo-HSCT with MUD were performed in 57%, MRD - 24%, haplo - 11%, MMUD - 8%, predominantly with RIC (80%). All patients with lesions in CT scan before allo-HSCT have undergone bronchoscopy with BAL microscopy, culture and GM test. EORTC/MSG 2008 criteria were used for the diagnosis of proven and probable IA as well as to evaluate response to therapy. "Active" invasive IA - IA diagnosed just before allo-HSCT. All patients were observed with the median 2 years follow up. We analyze status of pts before HSCT, donor types, source of HSCT, CMV status, conditioning regimens and type of immunosuppression, relapse or progression of IA, relapse of underlying disease, duration of antifungal therapy and prophylaxis, acute and chronic GvHD. The cumulative incidences were determined with cumulative incidence method. Differences between the two cohorts were verified with Gray test. Overall survival after allo-HSCT was estimated with Kaplan-Meier method and cohorts were compared by log-rank test.
Results: Incidence of IA before allo-HSCT was 20% (n=72/362). According to EORTC/MSG 2008 criteria 92% of pts had probable IA and 8% - proven IA. The main sites of IA were lungs - 95%, central nervous system - 3%, and colon - 3%, other sites were observed in a combination with lungs involvement: sinuses - 5%, spleen - 3%, and liver - 3%. The median time from IA to allo-HSCT was 3 months (3 days - 30 months). Antifungal therapy before allo-HSCT was used in 69% pts (voriconazole - 95%, other - 5%) with the median duration of therapy - 2 months. Complete response to antifungal therapy was registered in 19 (26%) patients, partial response or stabilization - 31 (43%), and "active IA" - 22 (31%). After allo-HSCT all patients received antifungal therapy with voriconazole (first line - 31%, continuation of treatment - 43%, and secondary prophylaxis - 26%). Median length of treatment was 166 days (37 - 394) with the median duration to effect 99 days (31 - 217). No toxicity of the antifungal treatment was registered. Cumulative incidence of relapse or progression of IA at 2 year after allo-HSCT was 14% (n=10). "Active" underlying disease before D+100 post transplant was the only risk factor for the relapse or progression of IA after allo-HSCT (6% vs 33%, p=0,007). 100-days OS after allo-HSCT was 77%, 2-year OS after allo-HSCT was 62%. There was no significant difference in OS in patients with or without IA prior to allo-HSCT (57% vs 65%, p=0,3). Duration of antifungal therapy before HSCT (<90 days vs ≥90 days), status of IA at the moment of HSCT ("active" IA vs PR vs CR), relapse/progression of IA after HSCT was not affected on 2-year OS after allo-HSCT in patients with prior IA.
Conclusions: Incidence of proven and probable invasive aspergillosis before allo-HSCT was 20%. Cumulative incidence of relapse or progression of the invasive aspergillosis after allo-HSCT was 14% and "active" underlying disease before D+100 post transplant was the only risk factor. Invasive aspergillosis prior to allo-HSCT did not impair the outcome of the procedure with effective diagnosis and prophylaxis being used.
No relevant conflicts of interest to declare.
The estimation of the most effective length of the working blade of the last stage of a powerful turbine is made in terms of obtaining its maximum efficiency and ensuring reliability in the design ...mode. When solving this problem, a method was used to calculate the axisymmetric steam flow in the flow part of the turbine stage as an inviscid single-phase working fluid was used, and energy losses were calculated according to the semiempirical MPEI method. The characteristics of stages with different lengths of working blades are presented and the results of their calculation on the nominal mode are given.
It is shown that the choice of the maximum length of the working blade is limited not only by its strength characteristics, but also by the growth of wave losses in the gratings due to an increase in the optimal available heat drop H0, or rather the associated increase in supersonic velocities near the meridional contours. So for a high-speed turbine To-1200-6,8/50 the maximum efficiency of the last stage is achieved with a length of 1400 mm, both when the turbine is configured with three two-flow CND, and with four.
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