Improvement of photocatalytic activity in the degradation of 4-chlorophenol and phenol in aqueous medium using tin-modified TiO2 photocatalysts.

In this work, we present the synthesis of TiO2 photocatalysts modified with different % mol of tin using the sol-gel method. The materials were characterized using different analytical techniques. The Rietveld refinement, XPS, Raman and UV-Vis techniques confirm the substitution of tin in the TiO2 structural lattice due to changes in crystal lattice parameters, the low-energy shift of the Sn 3d5/2 orbital, generation of oxygen vacancies and the decreased band gap and increased BET surface area. The material with 1 mol% tin shows superior catalytic activity compared to the references for the degradation of 40 ppm 4-chlorophenol (3 hours of reaction) and 50 ppm phenol (6 hours of reaction). Reactions fit pseudo first order kinetics in both instances. The increase in photodegradation efficiency was attributed to the generation of energy levels below the TiO2 conduction band caused by the incorporation of 1% mol of tin, oxygen vacancies, and the heterojunction formed between the brookite-anatase-rutile, causing inhibition of the recombination of the electron (e-) and hole (h+) photogenerated species. The easy synthesis, low cost and increased photodegradation efficiency of the photocatalyst with 1 mol% tin have the potential to favor the remediation of recalcitrant compounds in water.

Photodegradation of 2,4-D (dichlorophenoxyacetic acid) with Rh/TiO2; comparative study with other noble metals (Ru, Pt, and Au).

In this work the effect of noble metal on the photodegradation of 2,4-dichlorophenoxyacetic acid herbicide using TiO2 as support was studied. The metals and concentration were: Rh, Ru, Pt and Au and 1, 0.98, 1.89, and 1.91 wt% respectively. Rhodium was taken as reference for this experiment. The samples were characterized by X-Ray Diffraction (XRD), UV-vis absorption spectra, N2 physisorption (BET Specific Surface Area), High Annular Angle Analysis Darkfield (HAADF) and Transmission Electron Microscopy Scanning (STEM), H2 chemisorption, optical emission spectroscopy with inductive coupling plasma analysis (ICP-OES), solid fluorescence, X-ray Photoelectron Spectroscopy (XPS) and OH quantification. The presence of the anatase crystalline phase was mostly confirmed in all samples. The band gap decreased with the presence of metal (from 3.24 to 2.92 eV). The specific area was a function of the metal particle size. The metal particle diameter showed the following sequence Pt > Ru > Au > Rh. By XPS, TiO2 does not manifest changes in oxidation states, but when impregnated with metals, only Pt shows the highest abundance of any oxidized state (Pt2+). The presence of metal reveals less electron-hole recombination compared with titanium oxide. The results of photocatalytic activity showed that Pt and Rh are the two metals with the highest mineralization (99.0 and 98.3%, respectively).

2-Chlorophenol degradation by catalytic wet air oxidation using copper supported on TiO2-CeO2-ZrO2.

In this work, we describe the morphological, electronic and catalytic properties of support TiO2-CeO2-ZrO2, prepared by sol-gel method, which was impregnated with copper at 5 and 10% by weight, in order to obtain efficient catalysts in the catalytic wet air oxidation (CWAO) of 2-cp. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM-EDS), UV-Vis diffuse reflectance spectroscopy (DRS) and nitrogen physisorption by the Brunauer-Emmett-Teller (BET) method. The activity of the materials used in this study revealed that without the presence of Cu, the SCO2 is low and with a content of 10% this metal shows the best catalytic behaviour; conversely, a reaction mechanism is proposed that describes the complete oxidation of 2-cp in this case.

Molecular comparison of natural hybrids of Phytophthora nicotianae and P. cactorum infecting loquat trees in Peru and Taiwan.

Natural Phytophthora hybrids (P. nicotianae x P. cactorum) infecting loquat in Peru and Taiwan were characterized with AFLP (amplified fragment length polymorphism) markers, the internal transcribed spacer (ITS) region and the phenol acid carboxylase gene (Pheca) and inheritance of the mitochondrial cytochrome oxidase I gene (coxI). AFLP profiles of two Taiwanese isolates recovered in 1995 were polymorphic in approximately 50% of the fragments whereas five Peruvian isolates, recovered 2002-2003 and 2007, showed no genotypic variation. Sequencing analysis of the cloned ITS region resulted in the identification of sequences with high homology to either P. nicotianae (99%) or P. cactorum (97%). Direct sequence analysis of the Pheca gene revealed 13 heterozygous sites suggesting the presence of both P. nicotianae and P. cactorum genes in P. hybrids isolates. Melting analyses of coxI suggested that all seven Phytophthora hybrids inherited the mitochondrial DNA from P. nicotianae. Our results suggest that Phytophthora hybrids from Peru might have originated from a single hybridization event and that the two isolates from Taiwan might have originated through different hybridization events. The Peruvian hybrids appear to have persisted at least 3 y at three locations. Possible factors influencing the population structure of Phytophthora hybrids infecting loquat are discussed.

First Report of Phytophthora nicotianae Causing Asparagus Spear and Root Rot in Peru.

During 2006, spears, roots, and crowns of asparagus (Asparagus officinalis) exhibiting brown necrotic lesions with water soaking were collected from several sites across Peru (Ica, Lima, and Trujillo). Small infected tissue sections were washed thoroughly with tap and sterile distilled water and transferred to corn meal agar plates (CMA) amended with PARP (100 ppm of pimaricin, 100 ppm of ampicillin, 30 ppm of rifampicin, and 100 ppm of pentachloronitrobenzene) and incubated for five days at 25°C. Hyphal tips were subcultured from actively expanding mycelium. Sporangia produced on CMA were papillate and averaged 38 µm long × 29 µm wide. Chlamydospores were terminal or intercalary and averaged 35 µm in diameter. Isolates incubated in the dark for more than 3 weeks did not produce oospores in single culture. Mating with Phytophthora capsici tester isolates CBS 121656 = A1 and CBS 121657 = A2 indicate that all five isolates were A2. For pathogenicity tests, inoculum was generated by incubating 300 g of autoclaved wheat seeds with four agar plugs (7 mm) of expanding mycelium in polyethylene bags for 1 month at 25°C. Nine-week-old asparagus plants (UC151 F1) were transferred into pots containing autoclaved substrate (1 part sand, 1 part potting soil, and 1 part peat). Inoculum was added as 1 g of inoculum per kilogram of substrate. Plants were maintained in the greenhouse at 23°C and watered daily. Decline symptoms as well as root and spear rot were observed after 7 days and a Phytophthora sp. was reisolated from infected tissue. No symptoms were observed on asparagus plants inoculated with sterile inoculum. DNA was isolated from two representative isolates, and the nuclear ribosomal internal transcribed spacer (ITS) region was amplified with ITS4 and ITS6 primers and sequenced. ITS sequence was submitted for a BLAST search in the NCBI database, showing Phytophthora nicotianae strain UQ848 Accession No AF266776 as the closest match with 99% sequence similarity (1). The consensus ITS sequence was deposited in NCBI (Accession No. EU433396). These results, together with the morphological characteristics, indicate that the Phytophthora sp. isolated from asparagus in Peru is P. nicotianae (Breda de Haan) (2). To our knowledge, this is the first report of P. nicotianae infecting asparagus and represents a new threat for asparagus growers in Peru. Control methods such as moderate watering and metalaxyl application are being applied to reduce Phytophthora outbreaks. References: (1) D. E. Cooke et al. Fungal Genet. Biol. 30:17, 2000. (2) D. C. Erwin and O. K. Ribeiro. Phytophthora Diseases Worldwide. The American Phytopathological Society. St Paul, MN, 1996.

Initial poor function in the age of old donors: prognostic factors.

INTRODUCTION: The current donor selection criteria have changed from the past years. Primary nonfunction is a serious complication after liver transplantation, but initial poor function (IPF), which occurs from 2% to 23%, also has an increased morbidity and mortality. We analyzed prognostic factors associated with IPF. MATERIALS AND METHOD: This retrospective study of 551 liver transplants performed from January 2000 to December 2005 excluded retransplantations and transplants by classic surgery. The study cohort was attentified according to the presence or the absence of IPF. The variables included were (1) donor age, gender, cause of death, length of stay in Critical Care Medicine, noradrenaline use, sodium levels, and cardiorespiratory arrest, (2) from the standpoint of surgery: we included ischemia time (IT), intervention time, units of packet red cells (PRC), volume of blood autotransfusion (VBA), postreperfusion syndrome (PRS), and vasoactive drugs within the surgery procedure (VAD); (3) from the recipient's: view we examined age, gender, etiology, functional state, and covermittant pathology; (4) During the postoperative period we noted the presence of postoperative hemorrhage. Statistical analysis used chi-square test, Student t test, multiple logistic regression with significance set at P < .05. RESULTS: Differences were found in IT (P = .001), VBA (P = .001), PRS (P = .012), VAD (P = .03), fulminant hepatic failure as the cause the transplantation (P = .002), and chronic obstructive pulmonary disease (P = .007). A regression model retained the following variables: IT, VBA, PRS, fulminant hepatic failure, and chronic obstructive pulmonary disease. CONCLUSIONS: The prognostic factors for IPF need to be modified together with donor selection criteria in liver transplantation.

International approach to eradication and surveillance for foot-and-mouth disease in the Americas.

Foot-and-mouth disease (FMD) was introduced into the Americas in 1870. At that time the disease was described simultaneously in the North coast of the United States of North America, the Province of Buenos Aires in Argentina, the central region of Chile, Uruguay, and South Brazil. At the beginning of the twentieth century the disease spread to the rest of Brazil, Bolivia, Paraguay, and Perú. In 1950 the disease was introduced into Venezuela, and in the same year to Colombia, and from there to Ecuador. The United States of America eradicated an outbreak of FMD in 1929. Outbreaks of FMD were also eradicated from Mexico in 1947 and from Canada in 1952. The last outbreak that occurred in Mexico in 1954 was also eradicated. In 1951 the Americas Animal Health Authorities decided to establish a Pan-American Foot-and-Mouth Disease Center (PANAFTOSA), initially as a special program within the American States Organization (OAS). The center was later transferred to the Pan-American Health Organization (PAHO). In the early 1970s PANAFTOSA developed a proposal for a continental surveillance system for vesicular diseases, which was approved by Agriculture Ministers at an International Meeting for FMD and Zoonoses (RICAZ). Since then, PANAFTOSA dedicated all efforts to collaborate with each country in the implementation of the system and to receive, analyze, and distribute a weekly report of vesicular diseases. The model was elaborated using coordinate grid maps, one for the South American Continent, others for each country in the region. The reports from each country consist of the grid location for any suspicious outbreak of vesicular disease. Using the information gathered during visits to the countries, as well as weekly reports, and by studying the most frequent animal movements within the region, PANAFTOSA developed a proposal for FMD eradication. This plan was approved by the Government of South America and implemented in cooperation with PANAFTOSA. The hemispheric plan for FMD eradication (PHEFA), has been implemented and today Chile and Uruguay are FMD free without vaccination; Argentina, Paraguay, and the states of Rio Grande do Sul and Santa Catarina in Brazil are also recognized by the OIE to be FMD Free, with vaccination. The use of the continental surveillance system is the main strategy for achieving the eradication of FMD in South America. At this time PANAFTOSA is working to improve the system, and to add other diseases indicated by the governments of the Americas.

Meat from small ruminants and public health in the Caribbean.

Small ruminants are very important livestock species in the English-speaking Caribbean. Total populations for the Caribbean region are approximately 677,000 goats and 281,000 sheep. Although the primary purpose of sheep and goats is meat production for local consumption, the animals are also a source of emergency income. Production systems are generally characterised as small-scale and low-input, and few breeding or productivity records are kept. Although intra-regional trade does occur between Caribbean countries, there is insufficient production for extra-regional trade. The Caribbean countries collectively have a very favourable animal health situation, which is maintained by strict import restrictions on livestock. Zoonotic diseases are relatively rare, with the exception of leptospirosis. The most important public health risk relates to the slaughter of small ruminants in small, unregulated butcheries which do not have acceptable standards of hygiene. In addition, meat is often transported or sold under unhygienic conditions. Recommendations are made for the reduction of these risks.

Sistema de información y vigilancia epidemiológica a nivel local

La situación de salud de los pobladores rurales en la mayor parte de América Latina se ve comprometida por la existencia de diferentes enfermedades, cuyo origen en el caso de las zoonosis está dado por la estrecha convivencia con los animales y la carencia de condiciones de higiene básica. En el documento de la Organización Panamericana de la Salud (OPS) "Indicadores Básicos, 1995" (Health situation in the Americas. Basic indicators. Washington, D.C., PAHO, 1995), se informa que en el medio rural la disponibilidad de agua potable es del 48 por ciento y la de servicios de disposición de excretas es del 37 por ciento. El Dr. Carlyle Guerra de Macedo, director de la OPS, en su intervención (A saúde para todos um desafio para o Brasil no final do século. Brasília, OPAS, 1994) durante la inauguración del Seminario sobre "Los Escenarios Sociales, Económicos y Políticos en Brasil para el Final del Siglo", afirmó que: "la idea de desarrollo debe tener una característica de integración, y estar orientada para conseguir el bienestar de todos los ciudadanos de una determinada sociedad". Dentro de este contexto, la estrategia de la OPS de contribuir a mejorar las condiciones de vida de las poblaciones económica y socialmente postergadas ha propuesto a los países el establecimiento de los sistemas locales de salud (SILOS), con lo cual se persigue la participación consciente de toda la comunidad y del personal de salud, a fin de contribuir a una mejora de la salud de la población.

Enfoques de análisis de riesgo para la definición de las estratégias de los programas nacionales

El Centro Panamericano de Fiebre Aftosa (PANAFTOSA-OPS/OMS), como parte de su compromiso de cooperación técnica con los países de la región, ha realizado estudios para definir los posibles riesgos en el comercio de material genético y de carnes. La metodología de análisis de riesgo es valiosa no solo para el comercio internacional, sino también en el comercio nacional, y es una herramienta miy útil para definir las estrategias de acción en los programas de prevención, control y/o erradicación de la fiebre aftosa. La aplicación de esa metodología es útil para la definición de las estratégias de los programas nacionales, pues permite una más detallada caracterización de los riesgos potenciales de la fiebre aftosa, u otra enfermedad que sea estudiada, sea transmitida de un ecosistema a otro. Los estudios realizados por PANAFTOSA permitieron caracterizar a los diferentes ecosistemas de producción y su relación con las condiciones de los ecosistemas y su interrelación, facilitó el ordenamiento inicial de los programas de control, los cuales en varios países ya han consolidado la etapa de erradicación de la fiebre aftosa, o se encuentran en la fase previa.

Effectiveness of repeated gonorrhea cultures in the third trimester.

OBJECTIVE: With the high cost of health care today, the universal prophylactic measures recommended, and the availability of effective treatment should infection occur, the practice of routinely repeating the endocervical gonorrhea (GC) culture in the third trimester of pregnancy may be unwarranted. METHODS: To test this hypothesis, we reviewed charts from patients who had received routine prenatal care during a 2-year period at the Lafayette and Opelousas parish health units. Those charts, which had documented results of both the initial and repeat GC cultures, were then used for retrospective review. The results ofthe initial GC culture were compared with that taken in the third trimester. Other data recorded included age, gravidity, race, and history of gonorrhea, syphilis, or multiple sexual partners. RESULTS: Two hundred fifty charts were available for extraction; 130 of these had documentation of both GC cultures. Of the 130 cultures obtained during the initial prenatal visit, only 6 (4.6%) were positive. Of the repeat cultures taken during the third trimester, none were positive. Thirteen patients (10.0%) had a documented history of GC infection; none of them had positive cultures during the study period. CONCLUSIONS: Screening for GC during pregnancy is important and appropriate. This is commonly accomplished by taking a GC culture during the initial prenatal visit. Based upon the present study, we found that repeating this culture in the third trimester, even in a relatively high-risk population, seems unnecessary, whether the initial culture is negative or not.

Adrenocortical insufficiency with normal serum cortisol levels and hyporeninaemia in a patient with acquired immunodeficiency syndrome (AIDS).

The acquired immunodeficiency syndrome (AIDS) has been associated with abnormalities of adrenocortical function, and hypoaldosteronism due to hyporeninaemic hypoaldosteronism (HHA). We here report the case of a woman with AIDS associated with orthostatic hypotension, persistent hyponatraemia and hyperkalaemia, in whom basal serum cortisol levels were normal and serum renin activity was low. Subsequent post-mortem examination revealed almost complete adrenocortical destruction. A possible explanation of this apparently contradictory combination of findings is discussed, together with the therapeutic implications for similar cases.

Protoporphyrin IX-induced impairment of biliary lipid secretion in the rat.

1. In order to gain information on the effect of protoporphyrin IX on changes in the properties of the canalicular plasma membrane, we studied the release of canalicular membrane constituents, namely phospholipids, cholesterol and 5'-nucleotidase, into bile in anaesthetized rats receiving saline or taurocholate (0.5 mumol min-1 100 g-1 body weight) with or without protoporphyrin IX infusion (10 or 20 micrograms min-1 100 g-1 body weight). 2. Protoporphyrin IX induced an impairment of spontaneous bile flow and of biliary secretion of cholesterol, phospholipids and bile acids. The taurocholate-induced increase in bile acid output was not significantly reduced by protoporphyrin IX at either of the doses used. However, when a cholestatic dose of protoporphyrin IX was infused, the taurocholate-induced bile flow and secretion of lecithin and cholesterol were significantly reduced. 3. Biliary output of phospholipid species other than lecithin did not counterbalance the protoporphyrin IX-induced reduction in biliary lecithin secretion. Biliary outputs of both total phospholipid and lecithin were inhibited by protoporphyrin IX to similar extents. 4. Protoporphyrin IX alone had no effect on the biliary release of 5'-nucleotidase, whereas when it was given with taurocholate, it increased the bile acid-induced biliary output of this enzyme markedly. 5. In summary, these results indicate that protoporphyrin IX impairs the biliary secretion of phospholipids and cholesterol but not that of bile acid. The release of canalicular membrane constituents other than lipids was also modified by protoporphyrin IX.

Effect of protoporphyrin IX on ursodeoxycholate-induced hypercholeresis in the rat.

1. It is known that the perfusion of rat livers with solutions containing protoporphyrin IX induces a decrease in bile flow which is not due to inhibition of bile acid secretion but rather to decreased electrolyte transport into bile. By contrast, ursodeoxycholate induces hypercholeresis, partly due to a marked stimulation of biliary bicarbonate secretion. The aim of the present work was to investigate the effect of protoporphyrin IX on ursodeoxycholate-induced choleresis in anesthetized male Wistar rats. 2. Protoporphyrin IX infusion at rates of 10, 20 and 40 micrograms min-1 100 g-1 body weight into the jugular vein induced a dose-dependent inhibitory effect on bile flow as well as on bile acid and electrolyte secretion. The lowest infused rate only induced slight and non-significant changes in spontaneous bile formation and functional variables such as glycaemia, packed cell volume, blood pH, PCO2, PO2 and bicarbonate concentration, and in hepatic carbonic anhydrase activity. It was thus considered as a subtoxic dose. 3. Sodium taurocholate was infused (0.5 mumol min-1 100 g-1 body weight) over the second hour of the lowest dose of protoporphyrin IX infusion. In these rats, no significant changes in bile flow or bile acid and electrolyte secretion were observed as compared with animals receiving sodium taurocholate plus saline solution. 4. Bile acid secretion induced by ursodeoxycholate infusion (1 mumol min-1 100 g-1 body weight) was similar both in rats receiving ursodeoxycholate plus saline solution and in animals infused with this bile acid over the second hour of the lowest dose of protoporphyrin IX infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Drenaje al vacio reutilizable. / Reusable vaccuum drainage

Se describe un drenaje al vacio confeccionado con elementos reutilizables, como alternativa a los de tipo comercial de costo relativamente alto. Se describen su funcionamiento y sus indicaciones y se enfatiza su bajo costo y su efectividad

Costo de la atencion a personas mordidas por perros en Ciudad Juarez, Mexico. / The cost of medical care for persons bitten by dogs in Ciudad Juarez, Mexico

La incidencia de rabia humana en Ciudad Juarez, Chihuahua, llevo a efectuar un estudio del costo del tratamiento de las personas que acudieron al Centro Antirrabico de esa ciudad por haber tenido contacto o haber sido mordidas por un animal que se sospechaba rabioso