ABSTRACT
Liposomes containing magnetic nanoparticles (magnetoliposomes) have been extensively explored for targeted drug delivery. However, the magnetic effect of nanoparticles movement is also an attractive choice for the conduction of signals in communication systems at the nanoscale level because of the simple manipulation and efficient control. Here, we propose a model for the transmission of electrical and luminous signals taking advantage of magnetophoresis. The study involved three steps. Firstly, magnetite was synthesized and incorporated into fusogenic large unilamellar vesicles (LUVs) previously associated with a fluorescent label. Secondly, the fluorescent magnetite-containing LUVs delivered their contents to the giant unilamellar vesicles (GUVs), which were corroborated by magnetophoresis and fluorescence microscopy. In the third step, magnetophoresis of magnetic vesicles was used for the conduction of the luminous signal from a capillary to an optical fibre connected to a fluorescence detector. Also, the magnetophoresis effects on subsequent transmission of the electrochemical signal were demonstrated using magnetite associated with CTAB micelles modified with ferrocene. We glimpse that these magnetic supramolecular systems can be applied in micro- and nanoscale communication systems.
ABSTRACT
BACKGROUND: This study evaluated the morphology of the rat liver when hyperbaric oxygen (HBO) was used at various stages of ischemia and reperfusion. METHODS: Thirty-two male Wistar rats, subjected to 30 minutes of hepatic ischemia and 30 minutes of reperfusion, were randomly assigned as follows: GIR (n = 8), control without HBO; GHBO/I (n = 8), in which HBO was applied only during ischemia; GHBO/R (n = 8), HBO only during reperfusion; and GHBO/IR (n = 8), HBO during both ischemia and reperfusion. Feasibility scores of hepatocytes were determined by assessing 8 items related to liver injury. RESULTS: The histologic injury score of the hepatic specimens was significantly lower in the GHBO/I group (79.0 ± 0.1) compared with the GIR group (135.0 ± 0.1). HBO was not effective when applied during reperfusion (GHBO/R, 151.3 ± 0.1) or during the ischemia plus reperfusion period (GHBO/IR, 131.0 ± 0.1). The sum was significantly higher (P < .05) in HBO-treated animals during the reperfusion period (ie, in the GHBO/R group compared with any of the other groups). CONCLUSIONS: A favorable effect was obtained when HBO was administered early during ischemia. HBO given in later periods of reperfusion was associated with a more severe sum index percentage of liver damage.
Subject(s)
Hyperbaric Oxygenation/methods , Liver Diseases/therapy , Liver/blood supply , Oxygen/metabolism , Reperfusion Injury/therapy , Animals , Disease Models, Animal , Ischemic Preconditioning , Liver/pathology , Liver Diseases/metabolism , Liver Diseases/pathology , Male , Rats , Rats, Wistar , Reperfusion Injury/metabolism , Reperfusion Injury/pathologySubject(s)
Bioprosthesis , Blood Pressure , Heart Valve Prosthesis , Adolescent , Adult , Aortic Valve , Evaluation Studies as Topic , Female , Hemodynamics , Humans , Male , Middle Aged , Mitral Valve , Physical ExertionABSTRACT
Sao apresentados os resultados do estudo hemodinamico em 16 pacientes portadores de 18 proteses Biocor (porcina, com orificio modificado, preservadas em glutaraldeido).Em 4 casos, o debito cardiaco e os gradientes foram medidos antes e apos exercicio. Em 8 pacientes com protese mitrais, a pressao venocapilar media caiu de 28,9 +/- 6,1 mmHg para 13,3 +/- 4,2 mmHg pos - operatorio e as proteses apresentaram um gradiente final diastolico medio de 0,8 mmgH. Seis pacientes tinham proteses aorticas, com gradiente medio de 6 mmgH. Dois pacientes com dupla protese, apresentaram bons resultados em relacao a valvula mitral e gradientes de 29 e 48 mmHg nas valvulas aorticas (ambas numero 23). Conclui-se que as valvulas Biocor apresentaram bom desempenho hemodinamico, com ausencia de gradientes na maioria dos pacientes estudados, boa abertura dos folhetos, sem refluxos significativos
