Homogeneous Ziegler-Natta polymerisation: A kinetic approach .2. Transient-state kinetics

An integrated view is presented of several possible mechanisms applicable to the interpretation of homogeneous Ziegler-Natta polymerisation. In this paper, the transient aspects related to the kinetics of Ziegler-Natta polymerisation are investigated. Extensive data are used to construct kinetic profiles (rM vs. t) from a theoretical approach. Special attention is given to the duration of the transient period as a function of the different kinetic parameters. The kinetic models developed are fitted to experimental data, either directly obtained by the authors or published in the literature. These general models have a broad range of application.info:eu-repo/semantics/publishedVersio

A kinetic approach to homogeneous Ziegler type polymerization. Transient state

In this paper we present a kinetic approach to the analysis of transient-state homogeneous Ziegler-Natta polymerization activity data. The main features of the experimental data are discussed and fitted to transient kinetic models.info:eu-repo/semantics/publishedVersio

Cristo, misterio de la alianza, en la teología de Jean Daniélou

La presente investigación se centra en los escritos de Jean Daniélou sobre Jesucristo. En ella se analizan categorías centrales que Daniélou tomó de los Padres, como economía de la salvación (Justino), recapitulación de todas las cosas en Cristo (Ireneo de Lyon) y concatenación (akoulouthía) de todo hacia y desde Jesucristo (Gregorio de Nisa). La perspectiva bíblica de Daniélou, siendo patrística, es esencialmente tipológica. Los estudios de exégesis tipológica conducen a una idea central en la Sagrada Escritura, la noción de alianza, que es la que domina nuestra investigación. La reflexión de Daniélou sobre Jesucristo presenta una cristología de la alianza, y el misterio de la unión hipostática como el momento en el que se consuman todas las alianzas de Dios. En esta línea, llaman la atención algunas peculiaridades en la presentación que el teólogo francés hace de la Pascua de Cristo: la salvación vista desde su universalidad; la contemplación del misterio pascual, y muy especialmente de la pasión y de la muerte de Jesús, desde la perspectiva de su ministerio profético; las consideraciones en torno a la cólera de Dios como manifestación de la vida intensa que hay en Dios y que justamente en el Calvario se abraza con el amor; la solución para el drama de la existencia humana vista como liberación; la donación del Espíritu Santo al Cristo resucitado en cuanto Cabeza de la Iglesia; el tiempo de la Iglesia como continuación de la historia de la salvación guiada por el Kyrios resucitado y sentado a la derecha del Padre

CARACTERIZAÇÃO MORFOPEDOLÓGICA E CAPACIDADE DE USO DA TERRA NO MUNICÍPIO DE MINAÇU-GO.

O objetivo deste estudo é apresentar uma avaliação da capacidade de uso da terra e da suscetibilidade a erosão por compartimentos morfopedológicos. O estudo foi aplicado no município de Minaçu-GO e os resultados apresentam três grupos de compartimentos: Um grupo onde a suscetibilidade erosão é alta mas o uso é compatível; outro em que a suscetibilidade é moderada e com problemas simples de conservação e um terceiro grupo com alta suscetibilidade, com problemas complexos de conservação

A comparative study of lesions caused by different parasitic stages of Boophilus Microplus (Canestrini) in the skins of naturally infested taurine and zebuine hosts. The correlation of tick resistence with mast cell counts in the host's skin

Biópsias de pele lesada por larvas, ninfas e fêmeas engurgitadas de Boophilus microplus foram colhidas de cinco Bos taurus da raça Holandesa e de cinco Bos indicus da raça Gir, adquiridos na mesma propriedade, com aproximadamente 23 meses de idade, e colocados em convivência no mesmo pasto durante 90 dias que precederam este ensaio. O grau de susceptibilidade ao ácaro foi estimado previamente, sendo os zebuínos cerca de 15 vezes mais resistentes que os taurinos. As biópsias foram colhidas de modo que o parasito ficasse localizado no centro do fragmento de pele. Essas peças foram fixadas em formalina a 10% durante 24 h e processadas pelos métodos usuais em histologia seguindo-se a coloração pela técnica da Hematoxilin-Eosin ou do “tricrômico” de Masson. Não foram constatadas diferenças morfológicas que pudessem ser relacionadas aos diferentes graus de resistência ao parasito entre os taurinos e zebuinos. Biópsias foram colhidas de zonas não lesadas, na região da virilha dos cinco taurinos e dos cinco zebuínos, fixadas em subacetato de chumbo a 1% em solução de etanol 50%, contendo 1% de ácido acético, por 24 h. A seguir os fragmentos foram processados pelas técnicas usuais em histologia e corados pelo método do azul de toluidina 0,1%. Os mastócitos foram contados comparativamente em 80 campos microscópicos, em aumento de 100 vezes. Os resultados mostram que os zebuínos tem mais que o dobro do número de mastócitos dérmicos quando comparado com o encontrado nos taurinos. Esses resultados sugerem que os mastócitos dérmicos possam, pelo menos em parte, participar dos mecanismos de resistência dos bovinos ao Boophilus microplus.Biopsies of skin injuries caused by larvae, nymphs, unengorged and engorged females of Boophilus microplus were collected from five Bos taurus and five Bos indicus steers, which had been bom on the same ranch, aged about 23 months and had been grazing together in the same pasture during the preceding 90 days. Their susceptibilities to the tick had been previously estimated, being the taurine animals around fifteen times as susceptible as the zebuine ones. The biopsies were made in such a manner that the mouth pieces were in the center of the skin fragments. These were immersed for 24 hours in 10% formalin, then processed through usual histopathological techniques and stained either by the haematoxilin-eosin or by Masson’s “trichromic” procedures. No morphological differences were found capable of explaining the higher tick susceptibility observed for the taurine hosts as compared to the zebuine’s. Biopsies from non parasitized skin from the groin region of five B. taurus and five B. indicus steers were fixed in 1% lead subacetate, plus 50% ethanol, plus 1% acetic acid, for 24 hours, which they were histologically processed and stained in 0.1 % toluidin blue. The mast cells were comparatively counted in 80 microscope fields per sample with 100 diameters of magnification and the counts averaged more than twice as high in the zebuine than in the taurine host’s skins. These results strongly suggest that mast cells participate as important elements in the bovine host’s resistance to the cattle tick

The Syntaxin-1A gene single nucleotide polymorphism rs4717806 associates with the risk of ischemic heart disease

Ischemic heart disease (IHD) has a genetic predisposition and a number of cardiovascular risk factors are known to be affected by genetic factors. Development of metabolic syndrome and insulin resistance, strongly influenced by lifestyle and environmental factors, frequently occur in subjects with a genetic susceptibility. The definition of genetic factors influencing disease susceptibility would allow to identify individuals at higher risk and thus needing to be closely monitored.To this end, we focused on a complex of soluble-N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), playing an important role in metabolic syndrome and insulin resistance, involved in endothelial dysfunction and heart disease. We assessed if genetic variants of the SNARE genes are associated with IHD.SNAP25 rs363050, Stx-1A rs4717806, rs2293489, and VAMP2 26bp ins/del genetic polymorphisms were analyzed in a cohort of 100 participants who underwent heart surgery; 56 of them were affected by IHD, while 44 were not. A statistical association of plasma glycemia and insulin resistance, calculated as Triglyceride glucose (TyG) index, was observed in IHD (P<.001 and P=.03, respectively) after binomial logistic stepwise regression analysis, adjusted by age, gender, diabetes positivity, waist circumference, and cholesterol plasma level. Among genetic polymorphisms, rs4717806(A) and rs2293489(T), as well as the rs4717806 - rs2293489 (A-T) haplotype were associated with higher risk for IHD (Pc=.02; Pc=.02; P=.04, respectively). Finally, a statistical association of rs4717806(AA) genotype with higher TyG index in IHD patients (P=.03) was highlighted by multiple regression analysis considering log-transformed biochemical parameters as dependent variable and presence of coronary artery disease, age, gender, waist circumference, presence of diabetes as predictors. These results point to a role of the Stx-1A rs4717806 SNP in IHD, possibly due to its influence on Stx-1A expression and, as a consequence, on insulin secretion and glucose metabolism

Infection By Cytomegalovirus In Patients With Neonatal Cholestasis

Background - Neonatal cholestasis syndrome with an intra or extrahepatic origin has been associated to viral infections. The participation of the cytomegalovirus in the etiopathogenesis of neonatal hepatitis has been already known for some time, but only recently there have been indications that this virus may be one of the possible etiological factors for extrahepatic biliary atresia. Aims - To assess the prevalence of infection by cytomegalovirus in patients with intrahepatic cholestasis and extrahepatic cholestasis. To compare the clinical characteristics of the intrahepatic cholestasis and extrahepatic cholestasis groups with the cytomegalovirus serological results. Patients and Methods - This study consisted of 76 patients with neonatal cholestasis who were admitted between January 1980 and January 1999 when they underwent a cytomegalovirus serologic study using the ELISA method. A case note was kept on each patient with the following data: age of patient at admission, serologic result for cytomegalovirus, history of maternal infection, prematurity, fetal distress, birth weight, ponderal gain, choluria and fecal acholia. The final anatomic diagnosis of cholestasis was based on the results of an abdominal ultrasonography, a liver biopsy and its evolution. The patients were then divided into two groups: group I - intrahepatic cholestasis and group II - extrahepatic cholestasis. Each of these groups were then divided into two subgroups: subgroup A - positive serology (IgM) for cytomegalovirus and subgroup B - negative serology (IgM) for cytomegalovirus. Results - The frequency of positive serology (IgM) for cytomegalovirus was 29.4% in children with intrahepatic cholestasis and 28.5% in children with extrahepatic cholestasis. In comparison with group IIB, group IIA presented a higher rate of maternal infection history. The patients in group IIA demonstrated a delayed access to the service in comparison with group IA. The groups did not demonstrate any significant differences regarding the onset age of jaundice, choluria and fecal acholia, birth weight and ponderal gain. Conclusions - The positive (IgM) seroprevalence for cytomegalovirus in children with intrahepatic cholestasis and extrahepatic cholestasis is high. The history of maternal infection was more common in extrahepatic cholestasis patients with positive serology for cytomegalovirus. There was a delay in the referral of these patients which resulted in a late diagnosis and surgical treatment.392132136Balistreri, W.F., Grand, R., Hoofnagle, J.H., Suchy, F.J., Ryckman, F.C., Perlmutter, D.H., Sokol, R.J., Biliary atresia: Current concepts and research directions (1996) Hepatology, 23, pp. 1682-1692Boppana, S.B., Pass, R.F., Britt, W.J., Stagno, S., Alford, C.A., Symptomatic congenital cytomegalovirus infection: Neonatal morbidity and mortality (1992) Pediatr Infect Dis J, 11, pp. 93-99Chang, M.H., Huang, H.H., Huang, E.S., Kao, C.L., Hsu, H.Y., Lee, C.Y., Polymerase chain reaction to detect human cytomegalovirus in livers of infants with neonatal hepatitis (1992) Gastroenterology, 103, pp. 1022-1025Fischler, B., Ehrnst, A., Forsgren, M., Örvell, C., Nemeth, A., The viral association of neonatal cholestasis in Sweden: A possible link between cytomegalovirus infection and extrahepatic biliary atresia (1998) J Pediatr Gastroenterol Nutr, 27, pp. 57-64Fowler, K.B., Stagno, S., Pass, R.F., Maternal age and congenital cytomegalovirus infection: Screening of two diverse newborn populations, 1980-1990 (1993) J Infect Dis, 168, pp. 552-556Griffiths, P.D., Baboonian, C., A prospective study of primary cytomegalovirus infection during pregnancy: Final report (1984) Br J Obstet Gynaecol, 91, pp. 307-315Hanshaw, J.B., Congenital cytomegalovirus infection: A fifteen year perspective (1971) J Infect Dis, 123, pp. 555-561Jevon, G.P., Dimmick, J.E., Biliary atresia and cytomegalovirus infection: A DNA study (1999) Pediatr Dev Pathol, 2, pp. 11-14Kumar, M.L., Nankervis, G.A., Cooper, A.R., Gold, E., Postnatally acquired cytomegalovirus infections in infants of CMV excreting mothers (1984) J Pediatr, 104, pp. 669-673Leinikki, P., Granstrüm, M.L., Santavuori, P., Pettay, O., Epidemiology of cytomegalovirus infections during pregnancy and infancy: A prospective study (1978) Scand J Infect Dis, 10, pp. 165-171Leinikki, P., Heinonen, K., Pettay, O., Incidence of cytomegalovirus infections in early childhood (1972) Scand J Infect Dis, 4, pp. 1-5Levinsohn, E.M., Foy, H.M., Kenny, G.E., Wentworth, B.B., Grayston, J.T., Isolation of cytomegalovirus from a cohort of 100 infant throughout the first year of life (1969) Proc Soc Exp Biol Med, 132, pp. 957-962Machado, C.M., Fink, M.C.D.S., Vilas Boas, L.S., Sumita, L.M., Weinberg, A., Shiguematsu, K., Souza, I.C., Pannuti, C.S., Infecção perinatal pelo citomegalovirus em hospital público do municipio de São Paulo: Estudo prospectivo (1991) Rev Inst Med Trop São Paulo, 33, pp. 159-166Mediaris, D.N., Observations concerning human cytomegalovirus infection and disease (1964) Bull Johns Hopkins, 114, pp. 181-211Nankervis, G.A., Kumar, M.L., Cox, F.E., Gold, E., A prospective study of maternal cytomegalovirus infection and its effect on the fetus (1984) Am J Obstet Gynecol, 149, pp. 435-440Poley, J.R., Syndromes of neonatal cholestasis (1993) Pediatric Gastroenterology and Hepatology. 3. Ed., pp. 566-593. , Gracey M, Burke V, editors. Boston: Blackwell ScientificPrado, E.T.M.L., Araujo, M.F., Campos, J.V.M., Colestase neonatal prolongada: Estudo prospectivo (1999) Arq Gastroenterol, 36, pp. 185-194Reynolds, D.W., Stagno, S., Hosty, T.S., Tiller, M., Alford, C.A., Maternal cytomegalovirus excretion and perinatal infection (1973) N Engl J Med, 289, pp. 1-5Siegel, S., A prova de Kruskal-Wallis e o caso de duas amostras independentes (1975) Estatistica Não-paramétrica, pp. 107-124. , Siegel S, editor. São Paulo: McGraw-HillStagno, S., Pass, R.F., Dworsky, M.E., Henderson, R.E., Moore, E.G., Walton, P.D., Alford, C.A., Congenital cytomegalovirus infection: The relative importance of primary and recurrent maternal infection (1982) N Engl J Med, 306, pp. 945-949Stagno, S., Pass, R.F., Thomas, J.P., Navia, J.M., Dworsky, M.E., Defects of tooth structure in congenital cytomegalovirus infection (1982) Pediatrics, 69, pp. 646-648Stagno, S., Reynolds, D.W., Huang, E.S., Thames, S.D., Smith, R.J., Alford, C.A., Congenital cytomegalovirus infection: Occurrence in immune population (1977) N Engl J Med, 296, pp. 1254-1258Starr, J.G., Bart, R.D., Gold, E., Inapparent congenital cytomegalovirus infection: Clinical and epidemiologic characteristics in early infancy (1970) N Engl J Med, 282, pp. 1075-1078Tarr, P.I., Haas, J.E., Christie, D.L., Biliary atresia, cytomegalovirus and age at referral (1996) Pediatrics, 97, pp. 828-831Yamamoto, A.Y., Figueiredo, L.T.M., Mussi-Pinhata, M.M., Infecção perinatal por citomegalovirus: Muito freqüente mas pouco diagnosticada (1999) J Pediatr (Rio de Janeiro), 75, pp. 126-130Yamamoto, A.Y., Mussi-Pinhata, M.M., Pinto, P.C., Figueiredo, L.T., Jorge, S.M., Congenital cytomegalovirus infection in preterm and full-term newborn infants from a population with a high seroprevalence rate (2001) Pediatr Infect Dis J, 20, pp. 188-19

ArcheoFOSS: passato, presente e prospettive future

Introduction to the XII ArcheoFOSS Workshop Proceedings (Roma, 19-22 febbraio 2018