Doped nanostructured zinc oxide films grown by electrodeposition.

ZnO thin films doped with either In or Al are n-type oxide materials of interest for application in electronic devices and thin-film solar cells. In this work, the doped ZnO films were electrodeposited at 80 degrees C from an aqueous solution on polycrystalline conductive Indium Tin Oxide covered glass substrates. The incorporation of the dopants into the ZnO film has been verified by energy dispersive X-ray spectrum, X-Ray diffraction and optical transmission analysis. The optical and surface structure properties of the ZnO doped films are strongly affected by the In and Al concentrations in the electrodeposition solution as evidenced by optical transmission and reflection measurements, and scanning electron microscopy.

Determinación del péptido natriurético cerebral en pacientes sometidos a diferentes técnicas de hemodiafiltración / No disponible

El péptido natriurético cerebral (BNP) es una hormona que se libera a la circulación en respuesta de dilatación ventricular. Sus niveles se correlacionan con la masa del ventrículo izquierdo y con la disfunción ventricular. Los pacientes en diálisis presentan valores elevados a consecuencia de la situación de expansión de volumen y la reducción de su aclaramiento. Objetivo: analizar los niveles de BNP en pacientes sometidos a diferentes técnicas de hemodiafiltración: on-line diaria (HDFOLd), on-line (HDFOL) y con bajo volumen convectivo (HDF). Se determinaron las concentraciones séricas pre y posdiálisis de 15 pacientes (cinco de cada grupo) durante ocho semanas. Se efectuaron dos determinaciones, una a principio de semana (período largo) y otra al final de semana (período corto), con el fin de determinar si existían diferencias significativas entre técnicas y entre períodos. Al comparar los valores globales de BNP prehemodiálisis entre el período corto (BNPpreC) y el largo (BNP pre-L), se objetivaron diferencias significativas. Igualmente, se apreciaron diferencias entre el BNPpos del período corto y del largo. Asimismo, entre el BNP preC vs. BNPpos-C y entre BNPpre-L vs. BNPpos-L. El estudio comparativo entre técnicas mostró diferencias significativas en el período corto entre el BNPpre-C y BNPpos-C de HDFOLd con respecto a las mismas determinaciones en HDF y HDFOL. Conclusión: aunque la determinación del BNP tiene un potencial limitado para la evaluación del estado de hidratación en los pacientes en hemodiálisis, en este trabajo hemos comprobado que tras la sesión de diálisis se produce un descenso significativo del BNP, tanto en el período corto como en el largo, y que de manera significativa los pacientes del grupo de diaria presentan concentraciones inferiores de BNP, lo que se explicaría por la menor ganancia de peso interdiálisis y la mejor tolerancia hemodinámica a la técnica (AU)

IB-type natriuretic peptide is a cardíac neurohormone secreted by the cardíac ventricules in response to ventricular dilatation soplasma BNP level correlate with left ventricular mass and dysfunction. Dialysis patients have much greater levels of BNP due to the volume overload and because of reduced renal clearance. The aim of this study was to mesure and compare the BNP levels in three groups of patients who received different hemodia filtration techniques: Daily on-line hemodiafiltration (HDFOLd),on-line hemodiafiltration (HDFOL) and low convective volume hemodiafiltration (HDF). Fifteen patients were included, five ineach group. Pre and postdialysis BNP leves were measured during 8 weeks. The measure was done at the beginning of the week (long period), and at the end (short period), in order to study if there were significative differences between techniques and periods. We found significative differences between predialysis BNP levels in the short period (BNPpreC) and the long period (BNPpre-L). We also found significative differences with the posdialysis BNP in both periods; BNPpre-L vs. BNPpos-L(1069±1031 vs. 612 ± 540). After comparing the three techniques the study showed significative differences between BNPpreC in HDF and HDFOL compared with HDFOld. And also after dialysis between BNPpos-C in HDFOLd compared with the other techniques. Conclusion: Although previous papers have shown thatBNP levels have limited potential for assessment of hydration in hemodialysis patients, in this study our data demonstrate thatafter dialysis BNP levels decline in a significative way in the long and short period and we have found that patients on daily hemodialysis show lower BNP levels, and maybe this could be explained because daily on-line haemodiafiltration patients had lower weight rise between dialysis sessions and also better haemodynamic tolerance (AU)

Repeated pancreatitis in peritoneal dialysis patient

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[Kinetic of calcium, phosphate, magnesium and PTH variations during hemodiafiltration]. / Cinéica del calcio, fósforo, magnesio y variaciones de la parathormona (PTH) en pacientes en hemodiafiltracion.

Hemodiafiltration (HDF) is a technique resulting from coupling of diffusive and convective transport and thereby increase the elimination of small and middle molecules. However, may induce a convective loss from others substances such as calcium and magnesium. The aim of this study was to evaluate the effects of Ultrafiltration on the kinetics of calcium, phosphate, magnesium and parathyroid hormone. A total of thirteen patients (7 males and 6 females) on hemodialysis, were studied. Each patient was randomly dialyzed with the same dialysate calcium concentration and three different ultrafiltration rate. Schedule A: High flux hemodialysis, schedule B: HDF with 10% of weight body and schedule C: HDF with 20% of weight body. The others parameters were kept identical. Total Ultrafiltration was 2,6+/-0,9 L (9,78+/-3,78 ml/min) in A, 9,3+/-1,7 L (34,54+/-6,22 ml/min) in B and 16,3+/-3,3 L (60,94+/-12,63 ml/min) in C. Replacement fluid during dialysis was 6,85+/-1,42 and 13,65+/-2,9 L. in C and C respectively. Postdialysis total,ionized calcium and magnesium were significantly lower in schedules B and C versus A. PTH levels did not differ significantly. However, PTH changes during dialysis was -36.6+/-38.6%, 6.3+/-69.8% and 32.2+/-63.2% in A, B and C, respectively (p<0.05 A vs. C). A significant inverse correlation was found between total Ultrafiltration and postdialysis levels of total calcium (r:-0.56, p<0.001), ionized calcium (r:-0.65, p<0.001) and magnesium (r:-0.47, p<0.01). No differences were observed in pre and postdialysis phosphate levels, neither mass transfer and clearance of phosphate. We concluded that high ultrafiltration flow rates and substitution fluid without divalent cations induces a negative calcium and magnesium balance. These changes may stimulate PTH secretion during HDF. This technique did not resulted in a higher clearance or phosphate removal.

[Oxidative stress analysis in patients on hemodiafiltration on-line]. / Análisis del estrés oxidativo en pacientes en hemodiafiltración en línea.

Patients with chronic renal disease have a very high mortality due to cardiovascular disease. However, the traditional risk factors are not the only one explanation. Nowadays, there are new risk factors becoming, and one of these is the oxidative stress. Besides today we know that when these patients receive haemodialysis are being exposed to an additional oxidative stress. The aim of this study was to measure and to compare the degree of oxidative stress in two groups of patients on different dialysis techniques: a) On-Line Haemodiafiltration three times / week (OL-HDF). b) Daily Om-Line haemodiafiltration ( six times / week ) ( dOL-HDF) We studied 9 patients with chronic renal disease stage 5 on hemodialysis. They all were men, with a medium age of 72,5 +/- 6 years. Five patients were on dOL-HDFand four on tOL-HDF. Glutathione (GSH) concentration of patients on dOL-HDF before dialysis was 742+/- 153 nmol/ml and post-dialysis de 878+/- 223. Blood GSSG concentration before and after dialysis was 34+/- 14 nmol/ml y 137+/- 74 nmol/ml (p< 0,03). GSSG/GSH ratio pre-dialysis was 58+/-10 and post-dialysis 169+/-65 ( p < 0,03). In OL-HDF group GSSG concentration and the ratio GSSG/GSH also increased in a significative way from 99+/-45 nmol/ml to 179+/-66 nmol/ml, and from 161+/- 99 to 337+/-143 ( p<0,05). We also found differences in pCR concentrations between both groups; 3+/-1,4 g/l in dOL-HDF and 8,75+/-5,8 g/l in HDF OL. (p< 0,05). We did not find differences between xatine-oxidase activity before and after hemodialysis and between groups. In conclusion, patient with terminal chronic renal disease on OL-HDF receive an additional load of oxidative stress, as the increase in GSSG/GSH ratio in both groups shows. However patients on dHDF-OL shows low ratios GSSG/GSH post-hemodialysis and low pCR concentrations, and maybe this could be explained because daily on line haemodiafiltration improves purification of inflammatory mediators. Clue words: Hemodialysis, oxidative stress, glutathione, gssg/gsh ratio, xantine oxidasa.