Characterization of Cellulose regenerated from solutions of pine and eucalyptus woods in 1-allyl-3-methilimidazolium chloride.

Cellulose is currently separated from lignocellulosic materials using non-environmentally friendly processes. The development of new methods for treating biomass and separating cellulose remains a challenge and would be very useful in the context of the biorefinery philosophy. In this work, cellulose has been regenerated from solutions of Pinus radiata and Eucalyptus globulus woods in 1-allyl-3-methylimidazolium chloride. Wood dissolution was performed in a microwave oven at 120 °C for 20 min. Cellulose was characterized and compared to the reference material, microcrystalline cellulose (MCC). Regenerated celluloses showed lower crystallinity and thermal stability than MCC, although the ash contents at 400 °C were higher than in MCC. The regenerated celluloses were obtained without lignin and almost free from hemicellulose. Furthermore, cellulose was not significantly degraded in the dissolution process of both woods. The insoluble solids showed higher content of lignin and hemicellulose than the raw materials.

Las recomendaciones de la European Society of Urogenital Radiology sobre uso de medios de contraste y la oportunidad de usar contraste paramagnético en pacientes alérgicos a contrastes yodados tratados mediante endourología / European Society of Urogenital Radiology recommendations of the use of contrast techniques and the opportunity of using paramagnetic contrast in iodine-alergic patients treated with endourology

No disponible

[Blood fractionation based on the extraction of the buffy-coat layer. Analysis of our results]. / Fraccionamiento sanguíneo basado en la extracción de la capa leucoplaquetaria. Análisis de nuestros resultados.

PURPOSE: To compare a procedure of blood processing via a quadruple bag for the preparation of white-cell-poor blood components with the results obtained with triple-bag-system, in order to adopt it as routine in our blood centre. MATERIAL AND METHODS: Blood was collected in 289 quadruple-bag-system containing 63 mL of CPD as anticoagulant and 100 mL of SAG M solution as additive for the red cells. We used 237 standard quadruple-bags supplied by Fenwal (195) and NPBI (42), and 52 of the top-and-bottom system supplied by Fenwal. Blood separation was made automatically by CompomatR (NPBI) and platelet concentrates were prepared from the buffy-coat fraction. Standard bags were processing as follows: After the first centrifugation of the whole blood (28,800 g), the plasma was transferred into the 300-mL bag until the interface of red cells and plasma was detected; then approximately 80 mL of plasma and buffy-coat (BC) were collected into the 100-mL satellite bag. Top-and-bottom bags were centrifuged at 43,500 g., the red-cells were transferred into the bottom-bag containing SAGM, and plasma was transferred into the top-bag. The buffy-coat fraction remains in the original bag. In both procedures, platelet concentrates were prepared from buffy-coat fraction. After the centrifugation of this fraction (1,400 g and 1,600 g), the supernatant (concentrated platelets in plasma) was transferred into a 300-mL bag and the bag with the residual buffy-coat was then discarded. 287 triple-bags were separated in the traditional way, using platelet-rich plasma (PRP) as a source for the preparation of platelet concentrate (PC). Volumes were measured by weigh and specificity gravity. Platelet, leukocytes and red-cells were counted in the Coulter-Counter (STKR.Izasa). T-Student test and Chi2 test were used for statistical analysis and p < 0.05 was taken as a significant difference between samples. RESULTS: The three kinds of quadruple-bags showed results very homogeneous with little differences. For all brand of bags packed-red-cells showed a volume of 300 +/- 2.9 mL, EVF of 51.9 +/- 0.7%. The recovery of red cells into the packed red cells and of platelets into the platelet concentrate was 90 +/- 0.4 percent and 69 +/- 2 percent respectively, of the original value. White cells in the packed red cells were 9.7 +/- 03 x 10(9) with recovery of 30.1 +/- 1.4 percent of the original value; statistical difference was found in comparison with triple bags PRC (p < 0.001). The PC volumes averaged 71 +/- 1 mL and the overall mean platelet concentration was 77 +/- 2 x 10(9). Eighty three percent of PC contained more than 55 x 10(9). White cells contamination of platelet concentrates was 0.283 +/- 0.039 x 10(9), with a recovery of 9.5 +/- 1.5 percent of the leukocytes present in the whole blood. This value is below the threshold that prevents febrile reactions and microaggregate formation. The plasma yield in the quadruple-bag system was much greater than that in the triple-bag system (p < 0.001). With this process we removed about 77 +/- 0.5 percent of the plasma present in the original unit in comparison with 56 +/- 1 percent removed in that of the triple-bag system. CONCLUSION: With this procedure leukocyte-poor blood components are obtained in which more of 90 percent original white cells have been removed, with a red-cell recovery of 90 percent. Moreover, the plasma yield is also excellent.

[Study of relations between the peripheral organ of olfaction and the olfactory bulb using anterograde and retrograde axon transport of horseradish peroxidase (HRP)]. / Estudio de las relaciones entre el órgano periférico de la olfación y el bulbo olfatorio, utilizando el transporte axónico anterógrado y retrógrado de la peroxidasa de rábano (HRP).

Utilizing 26 Wistar albino rats, an anterograde and retrograde study has been performed on the connections between the first neuron of the olfactory pathway located in the olfactory epithelium and the second neuron in the glomeruli of the bulb. In the experiment we used horse radish peroxidase (HRP) in free form and combined with wheat lectin. In anterograde transport (epithelium-bulb), the HRP is deposited in preestablished sites in the olfactory epithelium of the nasal fossa. In retrograde transport (bulb-epithelium), HRP combined with wheat lectin is injected by means of a Hamilton microsyringe, glass micropipette and stereotaxic apparatus, in foreseen sites of the glomerular layer of the bulb.