Solar-assisted photodegradation of isoproturon over easily recoverable titania catalysts.

An easily recoverable homemade TiO2 catalyst (GICA-1) has been evaluated during the overall photodegradation process, understood as photocatalytic efficiency and catalyst recovery step, in the solar light-assisted photodegradation of isoproturon and its reuse in two consecutive cycles. The global feasibility has been compared to the commercial TiO2 P25. The homemade GICA-1 catalyst presented better sedimentation efficiency than TiO2 P25 at all studied pHs, which could be explained by its higher average hydrodynamic particle size (3 µm) and other physicochemical surface properties. The evaluation of the overall process (isoproturon photo-oxidation + catalyst recovery) revealed GICA-1 homemade titania catalyst strengths: total removal of isoproturon in less than 60 min, easy recovery by sedimentation, and reusability in two consecutive cycles, without any loss of photocatalytic efficiency. Therefore, considering the whole photocatalytic cycle (good performance in photodegradation plus catalyst recovery step), the homemade GICA-1 photocatalyst resulted in more affordability than commercial TiO2 P25. Graphical abstract.

Open ISEmeter: An open hardware high-impedance interface for potentiometric detection.

In this work, a new open hardware interface based on Arduino to read electromotive force (emf) from potentiometric detectors is presented. The interface has been fully designed with the open code philosophy and all documentation will be accessible on web. The paper describes a comprehensive project including the electronic design, the firmware loaded on Arduino, and the Java-coded graphical user interface to load data in a computer (PC or Mac) for processing. The prototype was tested by measuring the calibration curve of a detector. As detection element, an active poly(vinyl chloride)-based membrane was used, doped with cetyltrimethylammonium dodecylsulphate (CTA(+)-DS(-)). The experimental measures of emf indicate Nernstian behaviour with the CTA(+) content of test solutions, as it was described in the literature, proving the validity of the developed prototype. A comparative analysis of performance was made by using the same chemical detector but changing the measurement instrumentation.

Optimisation of the Fischer-Tropsch process using zeolites for tail gas separation.

This work is aimed at optimizing a Fischer-Tropsch Gas To Liquid (GTL) process by recycling compounds of the expelled gas mixture using zeolites for the separation. To that end, we have performed a computational study on four structures widely used in industry. A range of Si/Al ratios have been explored and the effects of their distribution assessed. The ability of the considered force fields and molecular models to reproduce experimental results has been widely proved in previously reported studies. Since this tail gas is formed by a five-component mixture, namely carbon dioxide, methane, carbon monoxide, nitrogen and hydrogen, molecular simulations present clear advantages over experiments. In addition, the viability of the Ideal Adsorption Solution Theory (IAST) has been evaluated to easily handle further separation steps. On the basis of the obtained results, we provide a separation scheme to perform sequentially the separation of CO2, CH4, CO, N2 and H2.

The use of digital simulation to improve the cyclic voltammetric determination of rate constants for homogeneous chemical reactions following charge transfers.

Cyclic voltammetry (CV) is a very useful electrochemical tool used to study reaction systems that include chemical steps that are coupled to electron transfers. This type of system generally involves the chemical reaction of an electrochemically generated free radical. Published methods exist that are used to determine the kinetics of electrochemically initiated chemical reactions from the measurements of the peak current ratio (i(pa)/i(pc)) of a cyclic voltammogram. The published method requires working curves to relate a kinetic parameter to the peak current ratio. In the presented work, a digital simulation package was used to obtain improved working curves for specific working conditions. The curves were compared with the published results for the first- and second-order chemical reactions following the charge transfer step mechanisms. According to the presented results, the previously published working curve is reliable for a mechanism with a first-order chemical reaction; however, a change in the switching potential requires a recalculation of the curve. In the case of mechanisms with a second-order step (dimerisation and disproportionation), several different views exist on how the second-order chemical term should be expressed so that different values of the constant are obtained. Parameters such as electrode type, electrode area, electroactive species concentration, switching potential, scan rate and method for peak current ratio calculation modify the working curves and must always be specified. We propose a standardised method to obtain the most reliable kinetic constant values. The results of this work will permit researchers who handle simulation software to construct their own working curves. Additionally, those who do not have the simulation software could use the working curves described here. The revelations of the presented experiments may be useful to a broad chemistry audience because this study presents a simple and low-cost procedure for the study of free radicals that otherwise should be studied with more sophisticated and expensive techniques, such as ESR or pulse radiolysis.

Combination of steam explosion and laccase-mediator treatments prior to Eucalyptus globulus kraft pulping.

The effect of a pretreatment consisting of steam explosion (SE) followed by a laccase mediator system (LMS) stage on Eucalyptus globulus kraft pulping has been evaluated and compared with fungal pretreatments. Pretreatment with SE and LMS was more efficient than pretreatments using Pycnoporus sanguineus and Trametes sp. I-62. Steam explosion not only improved the enzyme penetration into the wood chips and shortened the pulping process by 60%, but also extracted around 50% of the hemicelluloses which could be converted into value-added products. The optimal conditions for the LMS treatment were 3h, 3UA/g and 40°C. Compared to SE, the SE/LMS treatment yielded an increase in delignification of 13.9% without affecting pulp properties, provided a similar screened kraft yield, and reduced consumption of chemical reagents Na(2)S and NaOH by 11.5% and 6.3%, respectively. Therefore, SE/LMS is a promising pretreatment for converting the pulp mill into a forest bio-refinery.

Coagulation-Fenton coupled treatment for ecotoxicity reduction in highly polluted industrial wastewater.

A coupled coagulation-Fenton process was applied for the treatment of cosmetic industry effluents. In a first step, FeSO(4) was used as coagulant and the non-precipitated Fe(2+) remaining in dissolution was used as catalyst in the further Fenton process. In the coagulation process a huge decrease in total organic carbon (TOC) was achieved, but the high concentration of phenol derivatives was not diminished. The decrease in TOC in the coagulation step significantly reduces the amount of H(2)O(2) required in the Fenton process for phenol depletion. The coupled process, using a H(2)O(2) dose of only 2 g l(-1), reduced TOC and total phenol to values lower than 40 and 0.10 mg l(-1), respectively. The short reaction period (less than 15 min) in TOC and phenol degradation bodes well for improving treatment in a continuous regime. The combination of both processes significantly reduced the ecotoxicity of raw effluent and markedly increased its biodegradability, thus allowing easier treatment by the conventional biological units in conventional sewage treatment plants (STPs).

Kraft pulp biobleaching using an extracellular enzymatic fluid produced by Pycnoporus sanguineus.

The aim of this work was to obtain a LMS pre-treatment applicable to industrial TCF bleaching. Kraft pulp from Eucalyptus globulus was treated at 40 degrees C/pH 3 and 60 degrees C/pH 5 for 1h using an extracellular fluid enriched in laccase produced by Pycnoporus sanguineus and acetosyringone as mediator (HBT was used as a control mediator) (L). Alkaline extraction (E) and hydrogen peroxide (P) stages were then assayed. The LEP alternative was an efficient sequence to bleach kraft pulp since the enzymatic pre-treatment boosted the subsequent chemical bleaching. The best L pre-treatment was obtained with laccase-acetosyringone at 40 degrees C/pH 3. It reduces kappa number and hexenuronic acids, increases pulp viscosity, lowers hydrogen peroxide consumption down to an 87.4% (94.0% without L) and enhances brightness up to a 59% ISO (51% ISO without L).

Bioremediation of lignosulphonates by lignin-degrading basidiomycetous fungi.

The capability of some ligninolytic fungi to degrade lignosulphonates has been studied. Three lignosulphonates concentrations, three culture media and seven different basidiomycetes in solid-cultures have been assayed to select the conditions for further experiments on submerged cultures. The best results of growth and lignosulphonate decolourization in solid-cultures were obtained with Pycnoporus sanguineus, Coriolus pubescens and Trametes sp. I-62 on Kirk's medium and 1% and 2% of lignosulphonate concentrations. In submerged cultures the lignosulphonate decolourization rate was generally higher when it was added on the 6th day, rather than when it was added from the beginning of the incubation and C. pubescens and P. sanguineus showed again the optimum results of decolourization. Extracellular laccase activity increased with lignosulphonate concentration in all assayed fungi, suggesting that lignosulphonate act as inductors of laccase activity.

[Sinonasal mucosal melanoma]. / Melanomas mucosos nasosinusales.

Mucosal melanomas of the nasal cavity and paranasal sinuses are rare and agresive neoplasms and carries a bad prognosis. The diagnosis may require confirmatory immunohistochemical stains (S-100 protein, HMB-45, vimentin and cytokeratine). The clinical records of 6 patients with the diagnosis of sinonasal melanomas between 1991 and 2005 were retrospectively reviewed. The mean age was 70 years (range 51 to 83 years), there were 2 men and 4 women. Surgery was performed in four patients, adjuvant radiation therapy was used in one patient after local recurrence and chemotherapy in three patients. Three of four patients (75%) had a recurrence after previous treatment (surgery). The actuarial disease-free survival for this group of 6 is 33.3% (2 of 6). Mucosal melanoma of the head and neck remains a difficult disease to treat, with high locoregional recurrence rates and poor prognosis.

Melanomas mucosos nasosinusales / Sinonasal mucosal melanoma

Los melanomas mucosos de cavidad nasal y senos paranasales son tumores raros, agresivos y presentan un mal pronóstico. El diagnóstico de sospecha se confirma mediante el estudio inmunohistoquímico con la proteína S-, HMB, vimentina y citoqueratina. Se realiza una revisión retrospectiva de 6 pacientes entre 1991 y 2005, con el diagnóstico de melanoma nasosinusal. Con una edad media de 70 años y un rango variable entre 51 y 83 años, se registran dos varones y cuatros mujeres. Se realizó cirugía en cuatro pacientes, radioterapia después de una recidiva local reintervenidad en una paciente y quimioterapia en tres pacientes. Tres de los cuatro pacientes intervenidos (75%) tuvieron una recurrencia local. En la actualidad la supervivencia libre de esta enfermedad para esta patología es del 33% (2 de 6). Los melanomas mucosos de cabeza y cuello tienen un tratamieto difícil, alta recurrencia local y pobre pronóstico

Mucosal melanomas of the nasal cavity and paranasal sinuses are rare and agresive neoplasms and carries a bad prognosis. The diagnosis may require confirmatory immunohistochemical stains (S-100 protein, HMB-45, vimentin and cytokeratine). The clinical records of 6 patients with the diagnosis of sinonasal melanomas between 1991 and 2005 were retrospectively reviewed. The mean age was 70 years (range 51 to 83 years), there were 2 men and 4 women. Surgery was performed in four patients, adjuvant radiation therapy was used in one patient after local recurrence and chemotherapy in three patients. Three of four patients (75%) had a recurrence after previous treatment (surgery). The actuarial disease-free survival for this group of 6 is 33.3% (2 of 6). Mucosal melanoma of the head and neck remains a difficult disease to treat, with high locoregional recurrence rates and poor prognosis

[Cutaneous melanoma of the head and neck]. / Melanomas cutaneos de cabeza y cuello.

The clinical records of 20 patients with the diagnosis of cutaneous melanoma of the head and neck treated between 1991 and 2005 were retrospectively reviewed. Advances in diagnostic techniques and treatment have had obvious impact on outcomes in cutaneous melanoma. Cutaneous melanoma of the head of neck is treated with complete surgical resection in early stage disease. Resection margins are determined by the size and depth. Evaluation for regional and distant metastatic disease is necessary in advanced stage disease. Adjuvant therapy may be indicated in regional nodal disease.

Oxidation of C4-hydroxyphenyl 1,4-dihydropyridines in dimethylsulfoxide and its reactivity towards alkylperoxyl radicals in aqueous medium.

This work reports the electrochemical oxidation of three newly synthesized C4-hydroxyphenyl-substituted 1,4-dihydropyridine derivatives in dimethylsulfoxide. The reactivity of the compounds with ABAP-derived alkylperoxyl radicals in aqueous buffer pH 7.4, was also studied. The oxidation mechanism involves the formation of the unstable dihydropyridyl radical, which was confirmed by controlled-potential electrolysis (CPE) and ESR experiments. The final product of the CPE, that is, pyridine derivative, was identified by GC-MS technique for the three derivatives. A direct reactivity of the synthesized compounds toward ABAP-derived alkylperoxyl radicals was found. The pyridine derivative was identified by GC-MS as the final product of the reaction. Results reveal that this type of 1,4-DHPs significantly reacts with the radicals, even compared with commercial 1,4-DHP drugs with a well-known antioxidant ability.

Melanomas cutáneos de cabeza y cuello / Cutaneous melanoma of the head and neck

Se realiza una revisión retrospectiva de 20 pacientes diagnosticados de melanomas cutáneos de cabeza y cuello tratados entre 1991 y 2005. Los avances en las técnicas diagnósticas y en el tratamiento han tenido un impacto obvio en los resultados de los melanomas cutáneos. En estadios tempranos se realiza una resección quirúrgica completa. Los márgenes de resección están determinados por la extensión superficial y en profundidad. Cuando la enfermedad se diagnostica en un estadio avanzado es necesario el estudio de las metástasis regionales y a distancia. El tratamiento complementario podría estar indicado cuando existe afectación regional

The clinical records of 20 patients with the diagnosis of cutaneous melanoma of the head and neck treated between 1991 and 2005 were retrospectively reviewed. Advances in diagnostic techniques and treatment have had obvious impact on outcomes in cutaneous melanoma. Cutaneous melanoma of the head of neck is treated with complete surgical resection in early stage disease. Resection margins are determined by the size and depth. Evaluation for regional and distant metastatic disease is necessary in advanced stage disease. Adjuvant therapy may be indicated in regional nodal disease

Analyses by GC-MS and GC-MS-MS of the Hantzsch synthesis products using hydroxy- and methoxy-aromatic aldehydes.

EI mass spectra of products of the dihydropyridine Hantzsch synthesis using hydroxy and methoxy aldehydes as starting materials are reported. The reaction products (C-4 hydroxy- and methoxyphenyl-1,4-dihydropyridines and chromeno[3,4,c]-pyridines) were derivatized with N-methyl-N-(trimethylsilyl)-trifluoracetamide to be analyzed by gas chromatographic techniques. Fragmentation pathways for 1,4-dihydropyridines and chromeno-pyridines are proposed. The study provides (mainly through MS-MS technique) useful data for the confirmation of the structure of the compounds and also is a valuable tool for further analytical purposes to follow both photostability and reactivity studies with free radicals for these types of compounds.

[Metastasis to the parotid gland]. / Metastasis en la glandula parótida.

INTRODUCTION: Metastatic disease in the parotid gland has been observed and reported in the literature, and its treatment is controversial. MATERIAL AND METHODS: We review 48 patients with parotid tumors that underwent surgery during 1997-2004. The clinical and histogical features are reviewed. RESULTS: Among these 48, there were 12 cases of metastatic tumors to the parotid (25%). The pathohistological analysis of these tumors revealed that 8 were epidermoid carcinoma (66%), 1 patient was a melanoma (8%), 2 lymphomas below clavicules (16%) and 1 patient with a metastasis of a primary renal cancer. All patients underwent parotidectomy and 10 also cervical neck dissection (6 cases showed cervical metastases). 8 patients received radiotherapy after surgery. CONCLUSIONS: In our study parotid metastases are relatively common in patients submitted for parotid surgery. Often the site of origin of the primary tumor is the facial skin, and the primary tumors most commonly are melanomas or squamous-cell carcinomas, but it is possible distant primary tumors below clavicules.

[Otology manifestations of the Anderson-Fabry disease]. / Manifestaciones otológicas en la enfermedad de Fabry-Anderson.

Anderson-Fabry disease in an inherited X-linked metabolic disorder involving glycosphingolipid metabolism. Few data are available regarding cochlear involvement. Clinical manifestations of Fabry disease appeared on the first decade of life. The prognosis of males with Fabry disease is serious and life expectancy is limited; clinical evolution of heterozygous females is clearly better. We report a family with Fabry disease in several members. The mother, already dead, had two child which have been examined in our department; the male, without a risk of ototoxicity, or acoustic trauma, has progressive hearing loss, tinnitus and dizinness sometimes; the daughter, without a history of deafness, shows unilateral hearing loss on high-tone frequencies. It is important to emphasize these data to those physicians expert in children with Fabry disease because early enzyme replacement therapy intervention should offer increased possibilities of regression of the disease.

[Postseptal orbital cellulitis and sinusitis. Descriptive study of 8 cases and literature review]. / Celulitis orbitaria retroseptal y sinusitis. Presentación de 8 casos y revisión de la literatura.

This is a retrospective study of 8 patients with postseptal orbital cellulitis (stages II-V of Chandler) caused by sinusitis during 1999-2003. The variables analyzed in this study included age, sex, delay in diagnosis, aetiology, imaging studies, microbiology specimens collected and treatment. Delays in diagnosis were frecuent. CT was the best radiologic study. Polymicrobial infections were the rule, including anaerobes. 4 patients of 8 needed surgical drainage. A general guideline for the management of periorbital and orbital cellulitis according to the clinical staging of the process is presented.

Manifestaciones otológicas en la enfermedad de Fabry-Anderson / Otology manifestation of the Anderson-Fabry disease

La enfermedad de Fabry-Anderson es un déficit genético ligado al cromosoma X, y se debe a un error del metabolismo de los glucoesfingolípidos. Los síntomas clínicos suelen aparecer a partir de la primera década de la vida y se han descrito pocos casos donde se identifique la afectación coclear. El pronóstico de la enfermedad en los hombres es grave y la expectativa de vida es limitada; el curso clínico de las mujeres heterocigotas es claramente mejor. Presentamos una familia de pacientes con la enfermedad de Fabry. La madre, fallecida, tuvo dos hijos que son el objeto de nuestro estudio; el varón, sin tener factores de riesgo de ototoxidad, ni trauma acústico, refiere una hipoacusia neurosensorial progresiva, acúfenos y ocasionalmente mareos; la hija, aunque no refiere hipoacusia, en la audiometría tonal se aprecia una pérdida auditiva unilateral en frecuencias agudas. Es importante llamar la atención de los especialistas implicados sobre las manifestaciones de la enfermedad de Fabry en el niño, especialmente porque el tratamiento de sustitución enzimática ha demostrado su efectividad para conseguir la regresión de la enfermedad

Anderson-Fabry disease in an inherited X-linked metabolic disorder involving glycosphingolipid metabolism. Few data are available regarding cochlear involvement. Clinical manifestations of Fabry disease appeared on the first decade of life. The prognosis of males with Fabry disease is serious and life expectancy is limited; clinical evolution of heterozygous females is clearly better. We report a family with Fabry disease in several members. The mother, already dead, had two child which have been examined in our department; the male, without a risk of ototoxicity, or acoustic trauma, has progressive hearing loss, tinnitus and dizinness sometimes; the daughter, without a history of deafness, shows unilateral hearing loss on high-tone frequencies. It is important to emphasize these data to those physicians expert in children with Fabry disease because early enzyme replacement therapy intervention should offer increased possibilities of regression of the disease

Celulitis orbitaria retroseptal y sinusitis. Presentación de 8 casos y revisión de la literatura / Postseptal orbital cellulitis and sinusitis. Descriptive study of 8 cases and literature review

Se realiza un estudio retrospectivo sobre 8 pacientes con diagnóstico de celulitis orbitaria retrospectal (fase II-V de Chandler), secundaria a sinusitis, diagnosticadas y tratadas en nuestro servicio entre los años 1999 y 2003. En este estudio se analizan las siguientes variables: edad, sexo, retraso en el diagnóstico, etiología, estudios de imagen realizados, estudios microbiológicos y forma de tratamiento. Se constata que los retrasos en el diagnóstico fueron frecuentes, el scanner fue el método diagnóstico de elección y las infecciones polimicrobianas fueron la regla, incluyendo anaerobios. De los 8 pacientes, 4 precisaron drenaje quirúrgico. Se presenta un protocolo para el manejo de la celulitis orbitaria severa asociada a sinusitis

This is a retrospective study of 8 patients with postsepta 1 orbital cellulitis (stages II -V of Chandler) caused by sinusitis during 1999-2003. The variables analyzed in this study included age, sex, delay in diagnosis, aetiology, irnaging studies, microbiology specimens collected and treatment. Delays in diagnosis were frecuent. CT was the best radiologic study. Polymicrobial infections were the rule, including anaerobes. 4 patients of 8 needed surgical drainage. A general guideline for the management of periorbital and orbital cellulitis according to the clinical staging of the process is presented

Metástasis en la glándula parótida / Metastasis to the parotid gland

Introducción: La existencia de metástasis parotídeas ha sido reflejada en la literatura, siendo su tratamiento controvertido. Material y métodos: Se realiza un estudio retrospectivo sobre 48 pacientes sometidos a cirugía de parótida entre los años 1997 y 2004, revisándose aspectos clínicos e histológicos. Resultados: De los 48 pacientes intervenidos, en 12 casos se diagnosticó metástasis parotídea de un tumor primario (25%). El estudio histopatológico identificó: tumor primario en la piel en 9 pacientes (8 carcinomas epidermoides y 1 melanoma), 2 linfomas de localización inicial infraclavicular y un carcinoma renal de células claras. Los 12 pacientes fueron sometidos a parotidectomía, acompañada de vaciamiento ganglionar cervical en 10 pacientes (en 6 de ellos se identificaron metástasis ganglionares); 8 pacientes recibieron tratamiento radioterápico postquirúrgico. Conclusión: En nuestro estudio las metástasis parotídeas son relativamente frecuentes en el global de los pacientes intervenidos por tumores de parótida. En la mayoría de las ocasiones el tumor primario se encuentra en zonas cutáneas próximas (melanomas o carcinomas epidermoides), aunque es posible que el tumor primario se encuentre por debajo de las clavículas

Introduction: Metastatic disease in the parotid gland has been observed and reported in the literature, and its treatment is controversial. Material and methods: We review 48 patients with parotid tumors that underwent surgery during 1997-2004. The clinical and histogical features are reviewed. Results: Among these 48, there were 12 cases of metastatic tumors to the parotid (25%). The pathohistological analysis of these tumors revealed that 8 were epidermoid carcinoma (66%), 1 patient was a melanoma (8%), 2 lymphomas below clavicules (16%) and 1 patient with a metastasis of a primary renal cancer. All patients underwent parotidectomy and 10 also cervical neck dissection (6 cases showed cervical metastases). 8 patients received radiotherapy after surgery. Conclusions: In our study parotid metastases are relatively common in patients submitted for parotid surgery. Often the site of origin of the primary tumor is the facial skin, and the primary tumors most commonly are melanomas or squamous-cell carcinomas, but it is possible distant primary tumors below clavicules