Direct 3D printing of zero valent iron@polylactic acid catalyst for tetracycline degradation with magnetically inducing active persulfate.

Catalyst stability has become a challenging issue for advanced oxidation processes (AOPs). Herein, we report an alternative method based on 3D printing technology to obtain zero-valent iron polylactic acid prototypes (ZVI@PLA) in a single step and without post etching treatment. ZVI@PLA was used to activate persulfate (PS) for the removal of Tetracycline (TC) in recirculating mode under two different heating methodologies, thermal bath and contactless heating promoted by magnetic induction (MIH). The effect of both heating methodologies was systematically analysed by comparing the kinetic constant of the degradation processes. It was demonstrated that the non-contact heating of ZVI by MIH reactivates the surface of the catalyst, renewing the surface iron content exposed to the pollutant solution, which makes the ZVI@PLA catalyst reusable up to 10 cycles with no efficiency reduction. In contrast, by using a conventional thermal bath, the kinetic constant gradually decreases over the 10 cycles, because of the superficial iron consumption, being the kinetic constant 5 times lower in the 10th run compared to MIH experiment. X-ray diffraction and Mössbauer spectroscopy confirmed the presence of metallic iron embedded in the ZVI@PLA prototype, whose crystalline structure remained unchanged for 10th cycles of MIH. Moreover, it was proven that with no contact heating technology at low magnetic fields (12.2 mT), the solution temperature does not increase, but only the surface of the catalyst does. Under these superficial heated conditions, kinetic rate is increased up to 0.016 min-1 compared to the value of 0.0086 min-1 obtained for conventional heating at 20 °C. This increase is explained not only by PS activation by iron leaching but also by the contribution of ZVI in the heterogeneous activation of persulfate.

Formation of biomineral iron oxides compounds in a Fe hyperaccumulator plant: Imperata cylindrica (L.) P. Beauv.

We report a detailed work of composition and location of naturally formed iron biominerals in plant cells tissues grown in iron rich environments as Imperata cylindrica. This perennial grass grows on the Tinto River banks (Iberian Pyritic Belt) in an extreme acidic ecosystem (pH∼2.3) with high concentration of dissolved iron, sulphate and heavy metals. Iron biominerals were found at the cellular level in tissues of root, stem and leaf both in collected and laboratory-cultivated plants. Iron accumulated in this plant as a mix of iron compounds (mainly as jarosite, ferrihydrite, hematite and spinel phases) was characterized by X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), Mössbauer spectroscopy (MS), magnetometry (SQUID), electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX; TEM-EDX; HRSTEM). A low fraction of phosphorous was detected in this iron hyperaccumulator plant. Root and rhizomes tissues present a high proportion of ferromagnetic iron oxide compounds. Iron oxides-rich zones are localized in electron dense intra and inter-cellular aggregates that appear as dark deposits covering the inner membrane and organelles of the cell. This study aims to contribute to a better understanding of the mechanisms of accumulation, transport, distribution of iron in Imperata cylindrica.

Profilaxis preexposición al VIH. Una controversia no demorable / No disponible

No disponible

Synthesis and characterization of CoFe2O4 ferrite nanoparticles obtained by an electrochemical method.

Uniform size cobalt ferrite nanoparticles have been synthesized in one step using an electrochemical technique. Synthesis parameters such as the current density, temperature and stirring were optimized to produce pure cobalt ferrite. The nanoparticles have been investigated by means of magnetic measurements, Mössbauer spectroscopy, x-ray powder diffraction and transmission electron microscopy. The average size of the electrosynthesized samples was controlled by the synthesis parameters and this showed a rather narrow size distribution. The x-ray analysis shows that the CoFe(2)O(4) obtained presents a totally inverse spinel structure. The magnetic properties of the stoichiometric nanoparticles show ferromagnetic behavior at room temperature with a coercivity up to 6386 Oe and a saturation magnetization of 85 emu g(-1).

X-ray absorption and Mössbauer spectroscopies characterization of iron nanoclusters prepared by the gas aggregation technique.

Partially oxidized iron nanoclusters have been prepared by the gas-phase aggregation technique with typical sizes of 2-3 nm. This preparation technique has been reported to obtain clusters with interesting magnetic properties such as very large exchange bias. In this paper, a sample composition study carried out by Mössbauer and X-ray absorption spectroscopies is reported. The information reached by these techniques, which is based on the iron short range order, results to be an ideal way to have a characterization of the whole sample since the obtained data are an average over a very large amount of the clusters. In addition, our results indicate the presence of ferrihydrite, which is a compound typically ignored when studying this type of systems.

Impacto de los márgenes quirúrgicos positivos en pacientes post-prostatectomía radical / Positive surgical margins impact in patients after radical prostatectomy

Introducción: Debido a la relativa frecuencia de márgenes quirúrgicos positivos (MP) en las piezas de prostatectomías radicales, es importante para el urólogo entender la etiología e implicancias de estos hallazgos. Se define como un MP a la presencia de tejido tumoral que llega hasta la superficie prostática pintada con "tinta china". Objetivo: Mostrar el impacto de los MP en los pacientes sometidos a prostatectomía radical. Pacientes y Métodos: Se realizó un estudio retrospectivo, descriptivo y comparativo, analizando los datos de 106 pacientes sometidos a prostatectomía radical entre mayo de 1994 y octubre del 2005. Los criterios de exclusión fueron estadios pT3c, pT4 y/o N1. Se evaluaron variables de estadificación clínica: Gleason y antígeno prostático específico (PSA) pretratamiento, tacto rectal y volumen prostático por ecografía transrectal; variables del estudio patológico: Gleason de la pieza y T patológico; y variables evolutivas: recaída bioquímica (punto de corte de PSA mayor de 0,04 ng/ml y 0,2 ng/ml).Resultados: Fueron excluidos 18 pacientes; 22 pacientes presentaron MP (20,7 por ciento) y 66 márgenes negativos (MN) (62 por ciento). No hubo diferencias significativas en cuanto a las variables clínicas analizadas: PSA promedio 9,7 vs 11,16, Gleason pretratamiento menor7 57 por ciento vs 45 por ciento, tacto positivo 48 por ciento vs 38 por ciento, volumen prostático por ecografía transrectal: 54,7 cc vs 50,6 cc, para el grupo de MP y MN respectivamente. Al analizar las variables patológicas, no encontramos una diferencia estadísticamente significativa entre los MP y los MN en cuanto a la recaída bioquímica: Gleason menor 7 ( MN 28 ptes. 42 por ciento, MP 5 ptes. 23 por ciento) vs Gleason mayor o igual a 7 (MN 37ptes. 58 por ciento, MP 17ptes 77 por ciento) (pigual0,1). Estadío patológico del tumor: pT2 (MN 56 ptes. 85 por ciento, MP 19ptes: 86 por ciento) vs pT3a (MN 10 ptes.: 15 por ciento, MP 3 ptes.14 por ciento). Al realizar el análisis de l...

Impacto de los márgenes quirúrgicos positivos en pacientes post-prostatectomía radical / Positive surgical margins impact in patients after radical prostatectomy

Introducción: Debido a la relativa frecuencia de márgenes quirúrgicos positivos (MP) en las piezas de prostatectomías radicales, es importante para el urólogo entender la etiología e implicancias de estos hallazgos. Se define como un MP a la presencia de tejido tumoral que llega hasta la superficie prostática pintada con "tinta china". Objetivo: Mostrar el impacto de los MP en los pacientes sometidos a prostatectomía radical. Pacientes y Métodos: Se realizó un estudio retrospectivo, descriptivo y comparativo, analizando los datos de 106 pacientes sometidos a prostatectomía radical entre mayo de 1994 y octubre del 2005. Los criterios de exclusión fueron estadios pT3c, pT4 y/o N1. Se evaluaron variables de estadificación clínica: Gleason y antígeno prostático específico (PSA) pretratamiento, tacto rectal y volumen prostático por ecografía transrectal; variables del estudio patológico: Gleason de la pieza y T patológico; y variables evolutivas: recaída bioquímica (punto de corte de PSA mayor de 0,04 ng/ml y 0,2 ng/ml).Resultados: Fueron excluidos 18 pacientes; 22 pacientes presentaron MP (20,7 por ciento) y 66 márgenes negativos (MN) (62 por ciento). No hubo diferencias significativas en cuanto a las variables clínicas analizadas: PSA promedio 9,7 vs 11,16, Gleason pretratamiento menor7 57 por ciento vs 45 por ciento, tacto positivo 48 por ciento vs 38 por ciento, volumen prostático por ecografía transrectal: 54,7 cc vs 50,6 cc, para el grupo de MP y MN respectivamente. Al analizar las variables patológicas, no encontramos una diferencia estadísticamente significativa entre los MP y los MN en cuanto a la recaída bioquímica: Gleason menor 7 ( MN 28 ptes. 42 por ciento, MP 5 ptes. 23 por ciento) vs Gleason mayor o igual a 7 (MN 37ptes. 58 por ciento, MP 17ptes 77 por ciento) (pigual0,1). Estadío patológico del tumor: pT2 (MN 56 ptes. 85 por ciento, MP 19ptes: 86 por ciento) vs pT3a (MN 10 ptes.: 15 por ciento, MP 3 ptes.14 por ciento). Al realizar el análisis de l...(AU)

Impacto de los márgenes quirúrgicos positivos en pacientes post-prostatectomía radical / Positive surgical margins impact in patients after radical prostatectomy

Introducción: Debido a la relativa frecuencia de márgenes quirúrgicos positivos (MP) en las piezas de prostatectomías radicales, es importante para el urólogo entender la etiología e implicancias de estos hallazgos. Se define como un MP a la presencia de tejido tumoral que llega hasta la superficie prostática pintada con "tinta china". Objetivo: Mostrar el impacto de los MP en los pacientes sometidos a prostatectomía radical. Pacientes y Métodos: Se realizó un estudio retrospectivo, descriptivo y comparativo, analizando los datos de 106 pacientes sometidos a prostatectomía radical entre mayo de 1994 y octubre del 2005. Los criterios de exclusión fueron estadios pT3c, pT4 y/o N1. Se evaluaron variables de estadificación clínica: Gleason y antígeno prostático específico (PSA) pretratamiento, tacto rectal y volumen prostático por ecografía transrectal; variables del estudio patológico: Gleason de la pieza y T patológico; y variables evolutivas: recaída bioquímica (punto de corte de PSA mayor de 0,04 ng/ml y 0,2 ng/ml).Resultados: Fueron excluidos 18 pacientes; 22 pacientes presentaron MP (20,7 por ciento) y 66 márgenes negativos (MN) (62 por ciento). No hubo diferencias significativas en cuanto a las variables clínicas analizadas: PSA promedio 9,7 vs 11,16, Gleason pretratamiento menor7 57 por ciento vs 45 por ciento, tacto positivo 48 por ciento vs 38 por ciento, volumen prostático por ecografía transrectal: 54,7 cc vs 50,6 cc, para el grupo de MP y MN respectivamente. Al analizar las variables patológicas, no encontramos una diferencia estadísticamente significativa entre los MP y los MN en cuanto a la recaída bioquímica: Gleason menor 7 ( MN 28 ptes. 42 por ciento, MP 5 ptes. 23 por ciento) vs Gleason mayor o igual a 7 (MN 37ptes. 58 por ciento, MP 17ptes 77 por ciento) (pigual0,1). Estadío patológico del tumor: pT2 (MN 56 ptes. 85 por ciento, MP 19ptes: 86 por ciento) vs pT3a (MN 10 ptes.: 15 por ciento, MP 3 ptes.14 por ciento). Al realizar el análisis de l...(AU)

Cerebral and conjunctival haemorrhages associated with von Willebrand factor deficiency and canine angiostrongylosis.

A case of angiostrongylosis is described in a 14-month-old golden retriever bitch. Conjunctival haemorrhage and neurological signs, referable to a space-occupying cerebral lesion, were associated with defective primary haemostasis caused by low levels of von Willebrand factor. Full clinical recovery followed treatment with desmopressin, fresh whole blood transfusion, fenbendazole and supportive care. The magnetic resonance image of the suspected organising haematoma is described. Similarities to the human condition, acquired von Willebrand syndrome, and a possible role for aberrant larval migration in haematoma formation are suggested.

Internal iron biomineralization in Imperata cylindrica, a perennial grass: chemical composition, speciation and plant localization.

* The analysis of metal distribution in Imperata cylindrica, a perennial grass isolated from the banks of Tinto River (Iberian Pyritic Belt), an extreme acidic environment with high content in metals, has shown a remarkable accumulation of iron. This property has been used to study iron speciation and its distribution among different tissues and structures of the plant. * Mossbauer (MS) and X-ray diffraction (XRD) were used to determine the iron species, scanning electron microscopy (SEM) to locate iron biominerals among plant tissue structures, and energy-dispersive X-ray microanalysis (EDAX), X-ray fluorescence (TXRF) and inductively coupled plasma emission spectroscopy (ICP-MS) to confirm their elemental composition. * The MS spectral analysis indicated that iron accumulated in this plant mainly as jarosite and ferritin. The presence of jarosite was confirmed by XRD and the distribution of both minerals in structures of different tissues was ascertained by SEM-EDAX analysis. * The convergent results obtained by complementary techniques suggest a complex iron management system in I. cylindrica, probably as a consequence of the environmental conditions of its habitat.

Sospechas de reacciones adversas asociadas a los glucocorticoides inhalados / No disponible

Las notificaciones de sospechas de reacciones adversas enviadas por los profesionales sanitarios y la industria farmacéutica se codifican, evalúan y registran en la base de datos FEDRA. Los corticoides inhalados constituyen el tratamiento inicial de elección para controlar la evolución de la inflamación en el asma bronquial, pero su uso puede no estar exento de efectos adversos. En este trabajo hemos revisado y comparado los sospechas de reacciones adversas para budesonida, fluticasona y beclometasona, registradas en FEDRA hasta abril de 2004, clasificándolas según localización, gravedad y conocimiento previo y analizando la distribución por órgano y sistema para cada principio activo. Se localizaron un total de 307 notificaciones, que incluían 519 sospechas de reacciones adversas. De ellas, 38% eran locales, 93% no graves y sólo un 7% desconocidas. El análisis comparativo de la distribución por principio activo mostró una mayor frecuencia de reacciones cutáneas para budesonida, del sistema nervioso central para fluticasona y digestivas, cardiovasculares y urinarias para beclometasona. Este perfil de reacciones adversas concuerda con la toxicidad conocida para estos principios activos, excepto las reacciones cardiovasculares y urinarias para beclometasona, que podrían estar magnificadas, debido al menor número de notificaciones asociadas a este principio activo (AU)

No disponible

Vascular hamartoma within the flexor muscles of the left carpus in a dog.

A three-year-old male bearded collie was presented with a history of left thoracic limb lameness and a fluctuant non-painful swelling within the flexor tendons of the left carpus. Investigations included ultrasonography, laboratory analysis of fluid aspirated from the lesion and positive contrast radiography. Treatment involved surgical resection of the lesion from the local flexor muscles of the carpus. Histologically, the resected tissue was considered to represent a vascular hamartoma associated with the pronator quadratus muscle.

Concurrent torsion of the right cranial and right middle lung lobes in a whippet.

A four-year-old, entire male whippet was presented with a three-day history of lethargy, inappetence, occasional retching, a soft cough and intermittent episodes of haemoptysis. Clinical and laboratory findings, and thoracic radiographic and ultrasonographic studies suggested a diagnosis of lung lobe torsion. A concurrent lung lobe torsion of the right cranial and right middle lung lobes was confirmed at exploratory thoracotomy. Management included resection of both the affected lung lobes. No obvious underlying aetiology for the condition was apparent. The dog made a full recovery from the procedure and at the time of writing (11 months postoperatively) was reported to be well, exercising normally and showing no breathing abnormalities.

Taurine release evoked by NMDA receptor activation is largely dependent on calcium mobilization from intracellular stores.

It is known that the activation of N-methyl-D-aspartate (NMDA) receptors leads to an increase in extracellular taurine concentration in different brain regions. The mechanism that mediates this effect is not totally understood. In this study, rat hippocampal slices were used to determine the dependence of NMDA-induced taurine release on extracellular calcium and/or on calcium mobilization from intracellular stores. NMDA was administered through a microdialysis probe inserted into the slice, at the level of CA1 stratum radiatum, which was also used to collect amino acids from the extracellular space. Field potentials evoked by stimulation of the Schaffer collaterals and recorded in the stratum pyramidale of CA1 were used as a control of NMDA receptor activation. NMDA induced a marked increase in extracellular taurine levels and a decrease in field potential amplitude, and both effects were suppressed in the presence of MK-801, a blocker of the NMDA receptor-linked channel. Dantrolene, an inhibitor of calcium release from intracellular stores, partially inhibited the extracellular taurine increase, while 2-nitro-4-carboxyphenyl-N,N-diphenyl carbamate (NCDC), an inhibitor of phosphatidylinositol-specific phospholipase C activation, had no effect. Removal of extracellular calcium diminished, but did not abolish, the extracellular taurine increase caused by NMDA. The remaining taurine response was totally suppressed by dantrolene, and also by NCDC. These results demonstrate that the release of taurine induced by NMDA receptor activation is triggered by the increase in cytoplasmic calcium concentration. We suggest that, under physiological conditions, calcium influx provides the signal for NMDA-induced taurine release, which is amplified by calcium-dependent calcium mobilization from intracellular stores.(ABSTRACT TRUNCATED AT 250 WORDS)

Nicotinamide adenine dinucleotides mimic adenosine inhibition on synaptic transmission by decreasing glutamate release in rat hippocampal slices.

To assess the possible inhibitory action of nicotinamide adenine dinucleotides on the synaptic release of glutamate, electrophysiological and biochemical experiments were performed on rat hippocampal slices. Perfusion of adenosine, beta-nicotinamide adenine dinucleotide (NAD) or beta-nicotinamide adenine dinucleotide phosphate (NADP), reversibly inhibited the field excitatory postsynaptic potentials (fEPSP). Dose-response curves for their inhibitory action showed that these three substances had a similar potency in the range of concentrations from 0.1 microM to 100 microM. NADP and adenosine (100 microM) halved the K(+)-induced release of endogenous glutamate and aspartate, leaving gamma-amino-butyric acid (GABA) levels unchanged. 3-Isobutyl-1-methylxanthine (IBMX) 200 microM, an antagonist of the P1-purinoreceptors, antagonized the depressant effects of these coenzymes on both fEPSP and also on amino acid release. Based on these results we propose that nicotinamide adenine dinucleotides, similar to adenosine, inhibit excitatory synaptic transmission in the rat hippocampus by decreasing glutamate release from synaptic terminals.

[Hepatitis B virus markers in alcoholics: clinical importance]. / Marcadores de virus de la hepatitis B en alcohólicos: importancia clínica.

The prevalence of HBV markers is greater in alcoholics, with or without liver disease, than in general population. The high prevalence of HBsAg carriers in alcoholics suggests an inadequate immune response or a different expression of the HBV genome. Some studies suggest that in alcoholics HBsAg carriers, the HBV plays an important role in the progression of the liver disease, while others indicate that continuous alcohol consumption could intensify the liver damage caused by HBV. Active HBV infection has been demonstrated in alcoholics, even in absence of usual serologic markers. Finally, the integration of HBV in the hepatocites is frequent in alcoholics with liver disease; this could have importance in the development of hepatocellular carcinoma.

Role of endogenous taurine on the glutamate analogue-induced neurotoxicity in the rat hippocampus in vivo.

The glutamate analogues N-methyl-D-aspartate (NMDA), kainic acid (KA), and quisqualic acid (QA), prepared in different hypertonic media, were perfused in vivo in the hippocampal CA1 field of rats using a microdialysis technique. Extracellular taurine levels, estimated after analysis of the taurine content of dialysates, increased during perfusion of all three agonists but varied according to the osmolarity of the medium. The NMDA-induced increase in extracellular taurine content was only slightly inhibited by perfusion of 150 and 300 mM sucrose. The KA-evoked increase was partially dependent on extracellular osmolarity, because addition of 50 and 150 mM sucrose caused a dose-dependent inhibition that was not augmented using higher sucrose concentrations. QA caused a taurine increase that was totally abolished by addition of 50 mM sucrose. These results indicate that the rise in extracellular taurine level elicited by QA and part of the increase elicited by KA are probably due to a release caused by the cellular swelling that these substances evoke, a finding substantiating the previously proposed osmoregulatory role of taurine. However, almost all the increase in extracellular taurine content caused by NMDA and all the osmotically insensitive part of the KA-evoked rise cannot be explained as release triggered by cell swelling and may reflect a function of taurine other than osmoregulation.

Weak organic acids induce taurine release through an osmotic-sensitive process in in vivo rat hippocampus.

Isotonic media containing sodium salts from weak organic acids induce cell swelling in several experimental preparations (Grinstein et al., 1984; Jakubovicz et al., 1987). In vivo perfusion of rat dentate gyrus, using a microdialysis probe, with modified Krebs-Ringer bicarbonate solutions in which 50 mM NaCl was isotonically substituted by the sodium salts from organic acids with a pKa value of greater than 2 (acetate, propionate, or pyruvate), induced a reversible increase in the extracellular taurine concentration. By contrast, similar NaCl substitutions with sodium salts from the stronger organic acids isethionate and methane-sulfonate did not change extracellular taurine levels. Extracellular taurine increases evoked by acetate, propionate, or pyruvate were almost completely abolished when the perfusion liquid was made hypertonic by adding sucrose (50 mM). A 30% reduction of the acetate-induced extracellular taurine increase was observed both when amiloride was present or when the [Na+]0 was lowered. Both conditions are known to inhibit Na+/H+ exchange. These results are compatible with the hypothesis that acid load-induced taurine release is stimulated by an osmotic sensitive mechanism, part of which is dependent on activation of the Na+/H+ exchange.