Erosion Wear of Axial Flow Impellersin a Solid-liquid Suspension

A study was made of the erosion wear of the blades of pitched blade impellers in a suspension of waste gypsum from a thermal power station (vol. concentration CV=18.3 %, particle mean diameter d=0.1 mm, degree of hardness “2.5”) and silicious sand (CV=10 %, d=0.4 mm, degree of hardness “7.5”) in water under a turbulent flow regime of agitated charge when complete homogeneity of the suspension was achieved. Experiments were carried out on pilot plant mixing equipment made of stainless steel (diameter of cylindrical vessel T=390 mm, diameter of impeller D=100 mm, impeller off-bottom clearance h=100 mm) equipped with four wall radial baffles (width b=39 mm) and an impeller with four inclined plane blades (pitch angle α =20°, 30°, 45°, relative blade width W/D=0.2) made either of rolled brass (Brinell hardness 40–50 BH) or of structural steel (Brinell hardness 100–120 BH) always pumping the liquid downwards towards the flat vessel bottom. Two erosion process mechanisms appear, depending on the hardness of the solid particles in the suspension: while the particles of gypsum (lower hardness) generate a uniform sheet erosion over the whole surface of the impeller blade, the particles of silicious sand (higher hardness) generate wear of the leading edge of the impeller blades, together with a reduction of the surface of the worn blade. The hardness of the impeller blade also affects the rate of the erosion process: the higher the hardness of the impeller blade, the lower the wear rate of the blade. This study consists of a description of the kinetics of the erosion process of both mechanisms in dependence on the pitch angle of the tested impellers. While the wear of the leading edge of the blade exhibits a monotonous dependence on the pitch angle, the sheet erosion exhibits the maximum rate within the interval of the pitch angles tested α ϵ <20°; 45°>.However, generally the pitch angle α =45° seems to be the most convenient angle of blade inclination when both investigated mechanisms of the blade erosion process are considered at their minimum rate

Developing speed-related safety performance indicators from floating car data

In the road traffic safety domain there is a need for using proactive (non-crash-based) indicators, known as safety performance indicators (SPIs). Traffic speed based on big data (floating car data [FCD]) could help develop network-wide SPIs, but related knowledge and experience are insufficient so far. The authors attempted to fill this gap by using nationwide Italian FCD to develop speed-related SPIs and validating their relationship to crashes to see their potential explanatory value. The authors calculated the coefficient of variance (CV), congestion index (CI), and the number of incidents as candidate SPIs. For validation, the authors used linear correlation, crash frequency model, and ranking consistency. Incidents turned out to be the best SPI, especially for motorways

C. elegans LIN-28 controls temporal cell fate progression by regulating LIN-46 expression via the 5\u27 UTR of lin-46 mRNA

Lin28/LIN-28 is a conserved RNA-binding protein that promotes proliferation and pluripotency and can be oncogenic in mammals. Mammalian Lin28 and C. elegans LIN-28 have been shown to inhibit biogenesis of the conserved cellular differentiation-promoting microRNA let-7 by directly binding to unprocessed let-7 transcripts. Lin28/LIN-28 also bind and regulate many mRNAs in diverse cell types. However, the determinants and consequences of LIN-28-mRNA interactions are not well understood. Here, we report that C. elegans LIN-28 represses the expression of LIN-46, a downstream protein in the heterochronic pathway. We find that lin-28 and sequences within the lin-46 5\u27 UTR are required to prevent LIN-46 expression at early larval stages. Moreover, we find that precocious LIN-46 expression caused by mutations in the lin-46 5\u27 UTR is sufficient to cause precocious heterochronic defects similar to those of lin-28(lf) animals. Thus, our findings demonstrate the biological importance of the regulation of individual target mRNAs by LIN-28

Bacteriological study in acute surgical infections in children

Catedra de chirurgie, ortopedie și anesteziologie pediatrică, USMF ,,Nicolae Testemițanu”, Centrul Național Științifico-Practic de Chirurgie Pediatrică ,,Natalia Gheorghiu”, Institutul Mamei și Copilului, Chișinău, Republica Moldova, Conferința stiințifică „Nicolae Anestiadi – nume etern al chirurgiei basarabene” consacrată centenarului de la nașterea profesorului Nicolae Anestiadi 26 august 2016Introducere. La momentul actual numeroase intervenţii chirurgicale sunt efectuate pentru diferite procese patologice, provocate de agenţi infecţioşi. Deci, este de neînchipuit chirurgia fără procese infecţioase. Iată de ce este important de a cunoaște flora patologică care predomină în patologiile chirurgicale în special în contingentul pediatric. Scopul. Scopul acestei lucrări este de a prezenta rolul florei microbiene pentru aprecierea tacticii optime medicochirurgicale în tratamentul afecțiunilor septico-purulente la copil. Studiul bacteriologic a fost efectuat la 107 copii cu afecțiuni septico - purulente acute, ca material servind sângele, punctatul pulmonar, exudatul pleural, peritoneal și osos. Rezultatele. Peritonitele acute generalizate erau preponderent de origine stafilococică (45%), locul doi fiind ocupat de Escherichia Coli (25%). La 28,5% din pacienții cu peritonite s-au depistat asocieri microbiene (E.coli + Enterococcus, E.Coli+S.Aureus). În etiologia osteomielitei acute hematogene predomină S. Aureus (48%) iar flora patogenă mixtă (S.Aureus+Pseudomonas Aerogenosa+S. Epidermidis, (S.Spp+Proteus Vulgaris) a fost prezentă 26,3 % din pacienți. Supurațiile pleuro-pulmonare acute erau determinate de germenii gram-negativi (Proteus Vulgaris 28%, Pseudomonas Aerogenosa 14%), de asocieri microbiene (S.Spp + Proteus Vulgaris). (S.Spp + Pseudomonas Aerogenosa 14%). În cele mai grave sindroame septice (sepsis, sepsis sever,sindromul MODS, șoc septic ) erau prezente infecții cu germeni gram-negativi și asocieri microbiene. Evoluția infecțiilor cu bacterii gram-pozitivi era mai favorabilă iar afecțiunea limitându-se la stadiile SIRS fără generalizarea procesului. Concluzie. Cercetarea efectuată a evidențiat și o multitudine de tulburări biochimice ce corelau cu cele microbiene, fiind potențiali factori de risc în instalarea complicațiilor și principalii promotori ai sepsisului chirurgical, dar și devin ținte vulnerabile pentru prevenția și tratamentul complicațiilor.Introduction. Currently many surgeries are performed for different pathological processes caused by infectious agents. So it is unimaginable to have surgeries without infectious processes. That is why it is important to know pathological flora prevailing in surgical pathologies especially in the pediatric contingent. The purpose. of this paper is to present the role of microbial flora to assess optimal surgical tactics in treatment of septic-purulent diseases in children.This bacteriological study was performed in 107 children with acute septic conditions, serving as material blood, pulmonary punches, pleural, peritoneal and bone exudate.Results. Acute generalized peritonitis were predominantly staphylococcal origin (45%), second place is occupied by Escherichia coli (25%). In 28.5% of patients with peritonitis were detected microbial associations (Enterococcus +E. coli, E. coli + S.aureus). The etiology of acute osteomyelitis marrow predominant S. aureus (48%) and mixed pathogenic flora (S. aureus+ Pseudomonas Aerogenosa + S.epidermidis),(S.Spp + Proteus vulgaris) was present in 26.3% patients. Pleural acute lung abscesses and necrotizing were caused by gram-negative (28% Proteus vulgaris, Pseudomonas Aerogenosa 14%) of microbial associations (S.Spp + Proteus vulgaris). (S.Spp + Pseudomonas Aerogenosa 14%). In the most severe septic syndromes (sepsis, severe sepsis, MODS syndrome, septic shock) were presented Gram-negative infections and microbial associations. Development of infections with gram-positive bacteria was more favorable and affection being focused on limited stages without SIRS. Conclusion. Research carried out revealed a multitude of disorders and correlated with biochemical microbial the potential risks and complications in installing the main promoters of surgical sepsis, but also become vulnerable targets for the prevention and treatment of complications

Interleukin 10 marker of inflammation in acute appendicitis in children

Catedra de chirurgie, ortopedie și anesteziologie pediatrică, USMF ,,Nicolae Testemițanu”, Centrul Național Științifico-Practic de Chirurgie Pediatrică ,,Natalia Gheorghiu”, Institutul Mamei și Copilului, Chișinău, Republica Moldova, Conferința stiințifică „Nicolae Anestiadi – nume etern al chirurgiei basarabene” consacrată centenarului de la nașterea profesorului Nicolae Anestiadi 26 august 2016Introducere. Apendicita acută este o patologie des întâlnită la copii între 6- 10 ani. Sugari și copiii mici au o rată crescută de perforație a apendicelui modificat (50-90%). Varietatea formelor clinice ale apendicitei a cuprins toate vârstele copilului, creând o paletă semiotică vastă. Apendicita acută prin evoluția sa a inflamației permite o explorare paraclinică în permanentă actualizare. Evaluarea markerilor inflamatori în apendicita acută permite de ai cuantifica cu formele clinice evolutive, de a prognoza complicațiile și exodul bolii. Lucrarea de față monitorizează valorile markerilor de inflamație, de tipul Interleukinei 10, la etape clinico-evolutive al apendicitei acute la copil. Material și metode. În studiu au fost incluși 80 de pacienți cu vârsta cuprinsă între 0-18 ani cu diferite forme și stadii clinico-evolutive ale apendicitei acute. A fost studiată dinamica concentrației Interleukinei 10 în 7 etape clinico-evolutive: la internarea pacientului, intraoperator, în prima zi postoperator și respectiv în 3,5,8 zi și la externare și la pacienții la care s-au asociat complicații s-a evaluat concentrația interleukinei10 și la 10 zi. Rezultatele. Studiul denotă reducerea concentrației interleukinei 10 în loturile pacienților care au prezentat forma clinico-evolutivă a apendicitei acute flegmonoase, atât la internare cât și prima zi postoperator, urmată de creșterea lentă la etapele de cercetare atingând valorile normale la a 10 zi postoperator. În peritonita apendiculară acută în cele 3 faze clinico-evolutive ale ei s-a înregistrat o reducere a valorilor IL-10 cu 28% (p 0,05) la internare, I zi postoperator și o creștere la externare. La unii pacienți cu apendicită acută flegmonoasă și peritonită, faza reactivă s-au înregistrat valorile Il-10 mai jos de limitele normei cu - 30% și la internare cu -20% ce poate fi explicat prin reactivitatea scăzută a organismului copilului la răspunsul inflamator sistemic. Concluzii. Conchidem, la importanța evaluării IL-10 în apendicita acută la copil și rolul ei în certificarea concordanței cu formele histologice, clinice și evolutive.Acute appendicitis is the most frequently encountered pathology in children between 6- 10 years. Infants and young children have an increased rate of perforation of the changed appendix (50-90%). The variety of clinical appendicitis covered all ages in children, creating a vast semiotics palette. Acute appendicitis in its developments of inflammation allows an paraclinical constantly updated exploration. Evaluation of inflammatory markers in acute appendicitis allows to quantify evolutionary clinical forms, to forecast complications.This paper monitors the markers of inflammation, such as Interleukin 10, in clinical stage course of acute appendicitis in children. Material and Methods. The study included 80 patients aged 0-18 years with various forms and stages of clinical course of acute appendicitis. It studied the dynamics of Interleukin 10 in 7 stages of concentration in the clinical course: the admission of the patient, intraoperative, postoperative first day ,in the 3,5,8 days and at discharge. Patients who have associated complications were measures the concentration of interleukin10 in 10th day also. Results. The study shows low concentration of interleukin 10 in lots of patients who showed clinical and evolutionary forms of phlegmonous acute appendicitis, both at admission and the first postoperative day, followed by slow growth to the research reaching normal values at the 10th postoperative day.The cecal acute peritonitis in 3 phases of its clinical course was recorded a decrease in IL-10 by 28% (p≥0,05) at admission, I postoperative day and increased by discharge. In some patients with acute phlegmonous appendicitis and peritonitis, there were reactive phase Il-10 values below the normal limits of - 30% and -20% on admission that could be explained by the low reactivity of the child's body systemic inflammatory response . Conclusions. We conclude, the importance of evaluating IL-10 in acute appendicitis in children and its role in certifying the compliance with histological, clinical and evolutionary forms

Mutations in Conserved Residues of the C. elegans microRNA Argonaute ALG-1 Identify Separable Functions in ALG-1 miRISC Loading and Target Repression

microRNAs function in diverse developmental and physiological processes by regulating target gene expression at the post-transcriptional level. ALG-1 is one of two Caenorhabditis elegans Argonautes (ALG-1 and ALG-2) that together are essential for microRNA biogenesis and function. Here, we report the identification of novel antimorphic (anti) alleles of ALG-1 as suppressors of lin-28(lf) precocious developmental phenotypes. The alg-1(anti) mutations broadly impair the function of many microRNAs and cause dosage-dependent phenotypes that are more severe than the complete loss of ALG-1. ALG-1(anti) mutant proteins are competent for promoting Dicer cleavage of microRNA precursors and for associating with and stabilizing microRNAs. However, our results suggest that ALG-1(anti) proteins may sequester microRNAs in immature and functionally deficient microRNA Induced Silencing Complexes (miRISCs), and hence compete with ALG-2 for access to functional microRNAs. Immunoprecipitation experiments show that ALG-1(anti) proteins display an increased association with Dicer and a decreased association with AIN-1/GW182. These findings suggest that alg-1(anti) mutations impair the ability of ALG-1 miRISC to execute a transition from Dicer-associated microRNA processing to AIN-1/GW182 associated effector function, and indicate an active role for ALG/Argonaute in mediating this transition

MicroRNA enrichment among short ‘ultraconserved’ sequences in insects

MicroRNAs are short (∼22 nt) regulatory RNA molecules that play key roles in metazoan development and have been implicated in human disease. First discovered in Caenorhabditis elegans, over 2500 microRNAs have been isolated in metazoans and plants; it has been estimated that there may be more than a thousand microRNA genes in the human genome alone. Motivated by the experimental observation of strong conservation of the microRNA let-7 among nearly all metazoans, we developed a novel methodology to characterize the class of such strongly conserved sequences: we identified a non-redundant set of all sequences 20 to 29 bases in length that are shared among three insects: fly, bee and mosquito. Among the few hundred sequences greater than 20 bases in length are close to 40% of the 78 confirmed fly microRNAs, along with other non-coding RNAs and coding sequence

Segmental chromosomal alterations have prognostic impact in neuroblastoma: a report from the INRG project

Background: In the INRG dataset, the hypothesis that any segmental chromosomal alteration might be of prognostic impact in neuroblastoma without MYCN amplification (MNA) was tested. Methods: The presence of any segmental chromosomal alteration (chromosome 1p deletion, 11q deletion and/or chromosome 17q gain) defined a segmental genomic profile. Only tumours with a confirmed unaltered status for all three chromosome arms were considered as having no segmental chromosomal alterations. Results: Among the 8800 patients in the INRG database, a genomic type could be attributed for 505 patients without MNA: 397 cases had a segmental genomic type, whereas 108 cases had an absence of any segmental alteration. A segmental genomic type was more frequent in patients >18 months and in stage 4 disease (P<0.0001). In univariate analysis, 11q deletion, 17q gain and a segmental genomic type were associated with a poorer event-free survival (EFS) (P<0.0001, P=0.0002 and P<0.0001, respectively). In multivariate analysis modelling EFS, the parameters age, stage and a segmental genomic type were retained in the model, whereas the individual genetic markers were not (P<0.0001 and RR=2.56; P=0.0002 and RR=1.8; P=0.01 and RR=1.7, respectively). Conclusion: A segmental genomic profile, rather than the single genetic markers, adds prognostic information to the clinical markers age and stage in neuroblastoma patients without MNA, underlining the importance of pangenomic studies