Diaphragm discharge in liquids: Fundamentals and applications Diaphragm Discharge in Liquids: Fundamentals and Applications

Abstract. Paper describes results of our research on DC diaphragm discharge creation in water solutions of electrolytes from the viewpoint of its principles, properties and applications. The thermal theory of discharge ignition in bubbles of evaporated solution has been confirmed by both high speed camera and sound records. Static current-voltage characteristics revealed a significant dependence of discharge breakdown on the solution conductivity. Determined breakdown parameters lay in the range of 900-1300 V and 40-100 mA, respectively, for NaCl solution conductivity varying from 150 to 1300 µS·cm -1 . Time resolved electrical characteristics showed a simultaneous appearance of current, voltage and sound oscillations as well as a light emission. Plasma diagnostics by optical emission spectroscopy confirmed formation of reactive species (hydroxyl, hydrogen and oxygen radicals) and excitation of metallic atoms presented in the solution. Moreover, rotational temperature was calculated from the obtained OH spectrum. Experiments focused on the diaphragm discharge applications are outlined in the paper. Results of hydrogen peroxide production, organic dye decomposition and treatment of humic acid solutions are compared from the viewpoint of experimental conditions

Prognostic Impact of Peripheral Blood Involvement during Early Time Points of Childhood ALL Treatment.

Abstract Minimal residual disease (MRD) testing performed on bone marrow (BM) samples has become a part of the risk group stratification procedure in several of the most progressive acute lymphoblastic leukemia (ALL) treatment protocols. MRD testing of peripheral blood (PB) instead of BM is not routinely performed, although PB sampling could cause less discomfort especially in children. It is well established that the level of MRD in PB and BM correlates well in T-ALL; the data concerning B-cell precursor (BCP)-ALL remain controversial, with most studies lacking sufficient number of samples taken during the early phase of treatment with quantifiable MRD in both compartments. We simultaneously evaluated MRD in BM and PB using immunoglobulin and T-cell receptor gene-based RQ-PCR. 221 paired samples from 47 children with BCP-ALL treated according to the Berlin-Frankfurt-Muenster (BFM) ALL IC-BFM 2002 protocol were taken at diagnosis (dg, n=47), day 8 (d8, n=39), day 15 (d15, n=44), day 33 (d33, n=34), week 12 (w12, n=31) and at the end of maintenance therapy (post-MT, n=26). As in the BM at d15, patients with lower MRD in PB at d15 were more likely to achieve MRD negativity in BM at d33 in the univariate analysis (p=0.01, Mann Whitney). Patients younger than 10 yrs had lower MRD in PB at d8 and at d15 than other patients (p=0.03 and p=0.01, respectively). Unlike in BM, patients with hyperdiploidy had lower MRD in PB at d15 than other patients excluding TEL/AML1 cases (p=0.05). There were no significant associations with diagnostic white blood cell count (WBC), sex, immunophenotype (cALL/prae-B ALL) or presence of TEL/AML1 fusion at any time point. Patients with MRD&amp;lt;1E-04 in PB at d15 had a 5-year relapse-free survival (RFS) of 100% vs. 62.5±9.9% for those with a higher MRD (p=0.0089). No such threshold could be set for dg, d8 and d33 PB MRD level. Low numbers of MRD-positive results at w12 and post-MT samples precluded statistical analysis. In 125 paired samples MRD was detected in both tissues, in 18 pairs in BM only and in 5 pairs in PB only. MRD levels in PB varied greatly and were a mean of 149-fold lower than in BM (range 0.04–8293). We next examined the prognostic impact of BM/PB MRD ratio. Patients having MRD levels in PB similar to those in BM (BM/PB MRD&amp;lt;10) at d8 and d15 were more likely to relapse (d8: RFS 88.1±6.4% vs. 61.5±13.5%, p=0.04; d15: RFS 89.5±5.7% vs. 54.5±15%, p=0.01). No such relationship was observed for dg or d33. In conclusion, our data show that in childhood BCP-ALL, MRD in PB is not simply proportional to the BM level and provides additional prognostic information. A higher relapse rate in patients with PB MRD level similar to that in BM suggests that leukemic blasts with the propensity for massive escape from BM to PB during the induction treatment have a great potential for giving rise to relapse.</jats:p

Composition of Cellular Subsets by Flow Cytometry Identifies Differences Between MDS Subtypes and Aplastic Anemia but No Differences Are Identified Between Cases with and without Monosomy 7.

Abstract Abstract 3802 Poster Board III-738 Introduction Monosomy 7 or del(7q) are frequent cytogenetic abnormalities in children with myelodysplastic syndrome (MDS) and associates with poor prognosis. MDS globally affects all cellular subsets in bone marrow and in peripheral blood. We asked whether flow cytometry (FC) can separate individual subtypes of MDS from each other and from aplastic anemia (SAA) and whether in individual subtypes of childhood MDS can separate patients with and without monosomy 7. Patients/analyzed parameters In total we analyzed 94 children with centrally analyzed immunophenotype in the reference lab who were diagnosed and treated for MDS or SAA between 1998 and 2009. In total we analyzed 14 patients with refractory cytopenia, 37 patients with advanced forms of MDS (JMML 10, RAEB 25, CMML 2) and 43 patients with SAA. Monosomy 7/del(7q) was present in 17 patients (RC 6, JMML 3, RAEB 8). Analyzed parameters were as follows: B cells, CD10+CD19+, CD19+45dim/neg, CD19+34+, CD19/CD34 ratio, CD34+, CD117 cells, CD34+38dim/neg, CD3+, CD3+4+, CD3+8+, CD3+HLADR+. Statistics We analyzed all parameters using non parametric tests (Mann-Whitney, Kruskal Wallis) and principal component analysis (PCA). Results Principal component analysis of all analyzed patients together clearly separates advanced forms of MDS from RC and SAA, the most contributing factor being the number of CD34 and CD117+ cells. In non parametric statistics following factors significantly differ among MDS subtypes and SAA (Kruskal-Wallis): CD19, CD117, CD34, CD3, CD3+4+, CD8+ and CD3+HLADR+. RC and SAA patients are separated mainly by the number of B cells and the CD34:CD19 ratio. In addition, the following parameters differ between RC and SAA (Mann-Whitney): CD34, CD117 and CD3+HLADR+. Unlike the CD34:CD19 ratio, the number of CD19+34+ precursors does not differ between RC and SAA patients. Patients with monosomy 7 do not differ from the remaining patients when all MDS patients are analyzed together or separately in the respective subgroups (RC, non RC, JMML) by PCA or by non parametric statistics. Conclusion PCA separates advanced MDS forms from RC and SAA. Advanced forms of MDS are characterized by increased percentage of CD34+ and CD117+ cells compared to RC and SAA patients. The global reduction of B cell progenitor compartment is pronounced especially in non-JMML cases of MDS, whereas SAA patients typically present with isolated reduction of cells at early stages (CD19+34+) of B cell development. Patients with monosomy 7 cluster within the respective disease category, they do not form own cluster in PCA. Supported by MSMT VZ MSM0021620813, MZO 00064203 VZ FNM, MZO VFN2005, IGA NR/9531-3, NPV 2B06064. Disclosures: No relevant conflicts of interest to declare. </jats:sec