RESUMEN

In the chemical industry, formaldehyde is an important bulk chemical. The traditional synthesis of formaldehyde involves an energy intensive oxidation of methanol over a metal oxide catalyst. The selective electrochemical oxidation of methanol is challenging. Herein, we report a catalytic system with an immobilized TEMPO electrode that selectively oxidizes methanol to formaldehyde with high turnover numbers. Upon the addition of various organic and inorganic bases, the activity of the catalyst could be tuned. The highest Faradaic efficiency that was achieved was 97.5 %, the highest turnover number was 17100. Additionally, we found that the rate determining step changed from the step in which the carbonyl specie is created from the methanol-TEMPO adduct to the oxidative regeneration of the TEMPO+ species. Finally, we showed that the system could be applied to the oxidation of other aliphatic alcohols.

RESUMEN

We report a case of livedo reticularis of the lower limbs in a 30-year-old woman scuba diver after a diving session. Consideration of the differential diagnoses, the clinical picture, and the course of the symptoms led to a diagnosis of cutaneous decompression sickness. This accident, which resolved favorably in this scuba diver without any right-to-left shunt, is an alarm signal that calls for her to comply strictly with safety rules before resuming scuba diving, to avoid a more serious accident.

Asunto(s)

RESUMEN

The intensive production of polycyclic aromatic hydrocarbons by anthropogenic activities is a serious environmental problem. Therefore, new bioremediation methods are required to avoid widespread contamination. In this work, Serratia sp. AC-11 strain isolated from a tropical peat was selected for immobilization into chitosan beads, which were employed in the biodegradation of fluoranthene. The sizes of the produced beads were relatively uniform with an average diameter of 3 mm. The material was characterized by SEM and FT-IR, confirming the cells immobilization and the protective barrier formed by the chitosan surrounding the biomass. The immobilized bacteria were able to degrade 56% of fluoranthene (the initial concentration was 100 mg L-1) in just 1 day at twice the degradation rate achieved by free-living cells. Furthermore, the immobilized bacteria showed excellent removal during five reuse cycles, from 76% to 59% of biodegradation. These results showed the potential of this approach for remediation of contaminated sites.

Asunto(s)

RESUMEN

BACKGROUND: 18F-FDG PET/CT predicts cardiovascular disease. To analyze the predictive value of cardiovascular events from inflammation and arterial calcification in patients who underwent an 18F-FDG PET/CT for lung cancer. METHODS: A retrospective study of 274 patients with primary lung neoplasia. We determined: (i) TBR (target-to-background ratio), and (ii) the calcium score, at eight common arterial segments. We took as arteriosclerosis, a TBR ≥1.6 and ≥15 Calcium Score sum. We registered cardiovascular risk factors, comorbidities, histology, stage, treatment, status at the last clinical review, cause of death and cardiovascular event during the follow-up. RESULTS: The territory presenting the greatest uptake of 18F-FDG, was the thoracic aorta with an average of 1.77 (± 0.27 TBR) in the aortic arch, while the greatest degree of calcification was obtained in the abdominal aorta (52% with a Calcium Score ≥ 3). 24% of the patients presented a sum Calcium Score ≥15, and 17% a TBR ≥1.6. Patients with high TBR, (17%), had not a higher frequency of cardiovascular comorbidities beforehand, nor did they in the follow-up. However, those with a sum Calcium Score ≥15 (24%), were older, had more cardiovascular risk factors and ischemic events during follow-up. The calcium score, but not the TBR, predicted the emergence of a cardiovascular event (HR 4.9 IC95% 2.1-9.1, P < 0.05). CONCLUSION: In our cohort, a high Calcium Score was an independent predictor for developing cardiovascular events.

Asunto(s)

RESUMEN

Municipal solid waste management is a challenge for local authorities since mismanagement leads to environmental damage and social discontent. The objective of this study was to assess in an integrated manner the socio-environmental situation of a municipal landfill from México, using a design of mixed methods, which considered a quantitative evaluation of physicochemical and microbiological variables measured in leachates, surface and groundwater samples, soil and air, and a qualitative evaluation by in-depth interviews with the near-by inhabitants about their perception of the impacts of the landfill. The results show that leachates polluted the soil and surface water in a radius of up to 500 m from the landfill, but did not reach the groundwater, while the mean concentrations of PM10, Mn, and Ni measured in air samples at the landfill of 146 µg m-3, 0.12 µg m-3, 0.10 µg m-3, respectively, in the dry season and of Mn and Ni of 0.13 µg m-3 and 0.11 µg m-3, respectively, in the rainy season, surpassed permissible limits. From the residents perspective the landfill pollutes soil, water and air and it contributes to vehicle traffic and noise, promotes harmful fauna and disturbs the esthetic view. Air measurements coincide with social perception and in general, the applied mixed study design helped to assess in an integrated manner the socio-environmental concerns and to give advice to improve the current management of the landfill.

Asunto(s)

RESUMEN

AIM: To perform a scoping review of the existing literature in order to gather the most relevant information in the paediatric dentistry field related to the oral management of children affected by Henoch-Schönlein Purpura and associated Glomerulonephritis (HSPG). MATERIALS AND METHODS: Using scoping review methodology for the screening and selection of valid articles, the steps of this review were the following: first, to pose a research question; second, to identify relevant studies; third, to select and retrieve the studies; fourth, to chart the critical data, and finally, to collate, summarise, and report the results from the included articles. Relevant articles published over a 25-year period, up to July 31, 2017, were identified and retrieved from four Internet databases: PubMed; EMBASE/Ovid; Ebsco/Dentistry & Oral Science Source, and the Cochrane Collaboration Library. RESULTS: By title and abstract screening and after removing duplicates, four articles were finally included in the scoping review. According to the extracted data, the following are the most important clinical issues to be considered: (1) the disease can appear as a consequence of a dental treatment, such as those indicated for oral infectious processes; (2) children with HSPG are highly susceptible to dental caries and apical periodontitis, and (3) in affected children, oral infectious foci must be exhaustively eradicated in order to avoid the dissemination of the infection. CONCLUSIONS: Paediatric Dentists should be aware of HSPG, because the disease can be triggered or worsen subsequent to dental treatment. Adequate treatment of oral active infectious processes, together with an exhaustive oral preventive programme and long-term patient screening, are the best management approaches for children with HSPG.

Asunto(s)

RESUMEN

BACKGROUND: Tetrastarch can cause acute kidney injury (AKI) in humans with sepsis, but less likely to result in tissue edema than lactated Ringer's solution (LRS). OBJECTIVES: Compare effects of volume replacement (VR) with LRS and 6% tetrastarch solution (TS) on extravascular lung water (EVLW) and markers of AKI in hemorrhaged dogs. ANIMALS: Six healthy English Pointer dogs (19.7-35.3 kg). METHODS: Prospective crossover study. Animals underwent anesthesia without hemorrhage (Control). Two weeks later, dogs hemorrhaged under anesthesia on 2 occasions (8-week washout intervals) and randomly received VR with LRS or TS at 3 : 1 or 1 : 1 of shed blood, respectively. Anesthesia was maintained until 4 hour after VR for EVLW measurements derived from transpulmonary thermodilution cardiac output. Neutrophil gelatinase-associated lipocalin (NGAL) and creatinine concentrations in plasma and urine were measured until 72 hour after VR. RESULTS: The EVLW index (mL/kg) was lower at 1 hour after TS (10.0 ± 1.9) in comparison with controls (11.9 ± 3.4, P = 0.04), and at 4 hour after TS (9.7 ± 1.9) in comparison with LRS (11.8 ± 2.7, P = 0.03). Arterial oxygen partial pressure-to-inspired oxygen fraction ratio did not differ among treatments from 0.5 to 4 hour after VR. Urine NGAL/creatinine ratio did not differ among treatments and remained below threshold for AKI (120,000 pg/mg). CONCLUSIONS AND CLINICAL IMPORTANCE: Although TS causes less EVLW accumulation than LRS, neither fluid produced evidence of lung edema (impaired oxygenation). Both fluids appear not to cause AKI when used for VR after hemorrhage in healthy nonseptic dogs.

Asunto(s)

RESUMEN

BACKGROUND: Congenital Heart Diseases (CHD) involves a wide range of pathological conditions, such as Pulmonary Atresia with Ventricle Septal Defect (PA/VSD). This disorder leads to the systemic circulation of oxygen-poor blood (cyanosis), with associated features and consequences in the oral cavity. MATERIAL AND METHODS: Using scoping review methodology for screening and article selection, the primary objectives of this paper were as follows: first, to pose a research question; second, to identify relevant studies in order to answer the research question; third, to select and retrieve the studies; fourth, to chart the critical data, and finally, to collate, summarize, and report the results from the most important articles on the dental management of children affected with PA/VSD. Relevant articles (Randomized Controlled Trials [RCT], reviews, observational studies, and clinical case reports) published over a 10-year period were identified and retrieved from four Internet databases: PubMed; Embase/Ovid; Cochrane Library, and Google Scholar. RESULTS: By title and abstract screening and after removing duplicates, 24 articles were finally included in the present scoping review. According to the extracted data, the following are the most important clinical issues to be considered when treating children with PA/VSD in the dental setting: prevalence of dental caries; prevention of dental disease (oral hygiene and diet); bacteremia and infective endocarditis risk, and child behavior control and treatment under general anesthesia. CONCLUSIONS: Pediatric Dentists should bear in mind that early diagnosis and treatment, together a long-term follow-up of children with PA/VSD, continue to be the best approaches for achieving enhanced patient psychological well-being and, in consequence, their good quality of life.

Asunto(s)

RESUMEN

Seasonality is an important aspect associated with population dynamic and structure of tropical insect assemblages. This study evaluated the effects of seasonality on abundance, richness, diversity and composition of an insect group, drosophilids, including species native to the Neotropical region and exotic ones. Three preserved fragments of the northern Atlantic Forest were surveyed, where temperatures are above 20 °C throughout the year and rainfall regimes define two seasons (dry and rainy). As opposed to other studies about arthropods in tropical regions, we observed that abundance of drosophilids was significantly higher in the dry season, possibly due to biological aspects and the colonization strategy adopted by the exotic species in these environments. Contrarily to abundance, we did not observe a seasonal pattern for richness. As for other parts of the Atlantic Forest, the most representative Neotropical species (Drosophila willistoni, D. sturtevanti, D. paulistorum and D. prosaltans) were significantly more abundant in the rainy season. Among the most abundant exotic species, D. malerkotliana, Zaprionus indianus and Scaptodrosophila latifasciaeformis were more importantly represented the dry season, while D. simulans was more abundant in the rainy period. The seasonality patterns exhibited by the most abundant species were compared to findings published in other studies. Our results indicate that exotic species were significantly more abundant in the dry season, while native ones exhibited an opposite pattern.

Asunto(s)

RESUMEN

In this study, semi-arid environments were tested to see if they support insect diversity. This was evaluated through the structure of the composition of assemblies of drosophilids in three conservation units placed in three different ecoregions in the dryland forests, Caatinga. This is a unique biome in northeast Brazil, comprising approximately 10% of the country. Species richness was investigated over 2 years during a prolonged drought, considered the worst affliction the Caatinga ecosystem had experienced in the last 50 years. Alpha diversity indices and the ecological similarity between the samples were calculated to determine how the environments drive the composition of Drosophilidae in such semi-arid places. A total of 7352 specimens were sampled. They were classified into 20 species belonging to four genera: Drosophila, Rhinoleucophenga, Scaptodrosophila, and Zaprionus. Drosophila nebulosa Sturtevant (44.5%) and Drosophila cardini Sturtevant (12.5%) were the most abundant species. The occurrences and abundances of all the species differed greatly between sites. These results and other ecological analyses indicate that although placed in the same biome, there are great variability in the drosophilid species and abundance among the three protected and conserved dryland environments.

Asunto(s)

RESUMEN

The high-altitude wet forests of northeastern Brazil, locally known as "Brejos de Altitude," are enclaves of the Atlantic Forest situated above 500 m, surrounded by dryland vegetation, the Caatinga. The aim of this study was to characterize drosophilid communities in these upland forests, since few ecological studies on drosophilid communities have been conducted in northeastern Brazil. Four sites were investigated in three different times of the year throughout standardized traps. The results reveal the presence of 55 different species in a total of 13,064 specimens collected. The data were evaluated using ecological diversity measurements and compared with those obtained for other environments in the same geographic region. As for species composition, the Bonito upland forest, in a boundary forest location, stood out as having high species richness.

Asunto(s)

RESUMEN

The discharge of sewage and industrial effluents containing high concentrations of pollutants in water bodies increases eutrophication. Cyanobacteria, some of the organisms whose growth is promoted by high nutrient concentrations, are resistant and produce several types of toxins, known as cyanotoxins, highly harmful to human beings. Current water treatment systems for the public water supply are not efficient in degradation of toxins. Advanced oxidation processes (AOP) have been tested for the removal of cyanotoxins, and the results have been positive. This study examines the application of photoelectrooxidation in the degradation of cyanotoxins (microcystins). The performance of the oxidative processes involved was evaluated separately: Photocatalysis, Electrolysis and Photoelectrooxidation. Results showed that the electrical current and UV radiation were directly associated with toxin degradation. The PEO system is efficient in removing cyanotoxins, and the reduction rate reached 99%. The final concentration of toxin was less than 1 µg/L of microcystin in the treated solution.

Asunto(s)

RESUMEN

Municipal water disinfection systems in some areas are not always able to meet water consumer needs, such as ensuring distributed water quality, because household water management can be a contributing factor in water re-contamination. This fact is related to the storage options that are common in places where water is scarce or is distributed over limited time periods. The aim of this study is to assess the removal capacity of a multiple-barrier water disinfection device for protozoa, bacteria, and viruses. Water samples were taken from households in Mexico City and spiked with a known amount of protozoa (Giardia cyst, Cryptosporidium oocyst), bacteria (Escherichia coli), and viruses (rotavirus, adenovirus, F-specific ribonucleic acid (FRNA) coliphage). Each inoculated sample was processed through a multiple-barrier device. The efficiency of the multiple-barrier device to remove E. coli was close to 100%, and more than 87% of Cryptosporidium oocysts and more than 98% of Giardia cysts were removed. Close to 100% of coliphages were removed, 99.6% of the adenovirus was removed, and the rotavirus was almost totally removed. An effect of site by zone was detected; this observation is important because the water characteristics could indicate the efficiency of the multiple-barrier disinfection device.

Asunto(s)

RESUMEN

Candida tropicalis is an emerging virulent species. The aim of this study is to determine the biofilm-forming ability of 29 strains of C. tropicalis isolated from inpatients, and to examine its relation with other virulence factors such as cellular surface hydrophobicity (CSH), immediate (15 min, IA) and late (24 h, LA) plastic adherence and filamentation ability. The study was performed in parallel using two incubation temperatures - 37 and 22 °C - to determine the effect of growth temperature variations on these pathogenic attributes of C. tropicalis. Biofilm formation (BF) was measured by optical density (OD) and by XTT reduction (XTT); Slime index (SI), which includes growth as a correction factor in BF, was calculated in both methods. All strains were hydrophobic and adherent - at 15 min and 24 h - at both temperatures, with higher values for 22 °C; the adhered basal yeast layer appears to be necessary to achieve subsequent development of biofilm. Filamentation ability varied from 76.2% of strains at 37 °C to 26.6% at 22 °C. All C. tropicalis strains were biofilm producers, with similar results obtained using OD determination and XTT measurement to evaluation methods; SI is useful when good growth is not presented. BF at 37 °C was similar at 24 h and 96 h incubation; conversely, at 22 °C, the highest number of biofilm-producing strains was detected at 96 h. CSH is an important pathogenic factor which is involved in adherence, is influenced by the filamentation of yeast, and plays a critical role in BF.

Asunto(s)

RESUMEN

Myiasis is the term used to describe infestations, both obligatory and accidental, in vertebrate animals and humans by dipteral larvae. The oral cavity is rarely affected by this infestation and the circumstances which can lead to oral myiasis include persistent mouth opening together with poor hygiene, or facial traumatism. We present a case of oral myiasis by larvae of Lucilia sericata, a species present in the Iberian Peninsula, in a hospitalized patient with surgical problems.

RESUMEN

A correlation between mucosal colonization by Candida albicans and the subsequent development of invasive respiratory infection has been previously described. The aim of this study was to evaluate different enzymatic activities in vitro and to determine the capacity to form biofilms by 17 C. albicans isolates from bronchial aspirates of mechanically ventilated patients hospitalized in intensive care units. All the C. albicans clinical isolates tested were biofilm producers and displayed detectable levels of proteinase and hemolytic activities, although phospholipase activity was not detected in one strain. The correlation noted among the virulence factors studied suggests that the presence of more than one concurrent factor could facilitate the spread of infection.

Asunto(s)

RESUMEN

Objetivo: Analizar la supervivencia a largo plazo y el resultado funcional de un modelo de prótesis de rodilla no cementada. Material y método: Realizamos un estudio prospectivo observacional de pacientes operados entre los años 1989 y 1996 con el modelo Low Contact Stress Mobile-Bearing Total Knee Replacement(R) (Depuy, Warsaw, IN, EE. UU.). Las variables estudiadas fueron edad, sexo, tiempo de seguimiento, puntuación del Knee Society Score (KSS), supervivencia del implante y motivos de la revisión. Un total de 96 artroplastias de 127 completaron el seguimiento. La media de edad fue de 79 años. La media de seguimiento fue de 14,5 años. Once prótesis se reintervinieron (6 por aflojamiento aséptico de implantes y 5 por problemas de componentes móviles). Se obtuvieron curvas de supervivencia al considerado el tiempo de seguimiento, el tiempo desde la cirugía primaria hasta la reintervención y el episodio «recambio por aflojamiento de componente metálico» y «necesidad de reintervención». Resultados: Las curvas de supervivencia arrojaron una supervivencia del 96,45% a los 9 años y del 92,78% a los 12 años, y se consideró la «necesidad de reintervención» como punto final. Al considerar la necesidad de recambio de componentes metálicos, la supervivencia a los 14 años y medio fue del 93,75%. La puntuación media del KSS funcional fue de 89,2. Conclusión: En nuestra experiencia y con el modelo protésico utilizado, las prótesis totales de rodilla no cementadas proporcionan un resultado clínico y funcional excelente, valorado por el KSS, y una supervivencia del 93,75% a los 14 años y medio al considerar la supervivencia del implante metálico (AU)

Purpose: To analyze the long term survivorship and functional results of a model of uncemented knee prosthesis. Materials and methods: We carried out a prospective observational study of patients implanted between 1989 and 1996 with the Low Contact Stress Mobile-Bearing Total Knee Replacement (Depuy, Warsaw, IN, EEUU). Variables studied included: age, gender, follow-up, Knee Society Score, implant survivorship and reasons for revision. A total of 96 arthroplasties out of 127 reached the end of follow-up Mean age was 79 years. Mean follow-up was 14 years. Eleven prostheses were revised (6 following aseptic loosening and 5 because of problems with the mobile bearings). Survivorship curves were obtained considering length of follow-up, time elapsed between the primary and the revision surgery and the “revision following loosening of a metal component” and “need for revision” events. Results: When "need for revision" was considered as the endpoint, survivorship curves revealed a survivorship rate of 96.45% at 9 years and 92.78% at 12 years. When the endpoint was the "need to revise metal components" 14.5-year survivorship was 93.75%. Mean Knee Society Score was 89.2 points. Conclusion: The use of the uncemented LCS knee has resulted in excellent clinical and functional results as measured by the Knee Society Score, as well as 93.75% survivorship at 14 years and a half, considering the survivorship of the metal implant (AU)

Asunto(s)

RESUMEN

Secretion of hydrolytic enzymes is considered a virulence factor in Candida spp. Extracellular enzymatic activities in 29 clinical isolates of Candida tropicalis were analyzed by plate assays. C. tropicalis, similar to Candida albicans, showed elevated hemolytic and esterase activities. However, unlike C. albicans, low aspartyl protease and very low phospholipase activities were detected in C. tropicalis isolates.

Asunto(s)

RESUMEN

Introducción. La historia clínica y la exploración física son fundamentales para el enfoque diagnóstico de la prótesis de rodilla dolorosa. A la hora de planificar una estrategia diagnóstica es útil diferenciar entre problemas extraarticulares e intraarticulares.Diagnóstico y conclusiones. La radiología simple es la primera prueba complementaria a considerar, aportando en la mayoría de los casos información suficiente para establecer un diagnóstico. La tomografía axial computarizada será de utilidad para la valoración de áreas de osteólisis y alteracionesrotacionales de los componentes. La ecografía tiene utilidad en el estudio de las partes blandas periarticulares. Estudios recientes destacan el valor de la resonancia magnética nuclear para la valoración de la prótesis dolorosa. Desde el punto de vista analítico, la velocidad de sedimentación globular y la proteína C reactiva, pese a su baja especificidad, pueden ser de utilidad en el diagnóstico de laartroplastia total de rodilla infectada, especialmente si contamos con niveles seriados. Los estudios de Medicina Nuclear presentan una alta sensibilidad, aunque su especificidad es escasa. El uso de estudios isotópicos combinados (tecnecio e indio) puede ayudarnos al diagnóstico diferencial del aflojamiento protésico

Introduction. Clinical history and physical examination are essential factors for the diagnosis of the painful knee prosthesis. It is useful to make a distinction between extra andintra-articular problems before setting about planning for a diagnostic strategy. Diagnosis and conclusions. Plain films should be seen as the first supplementary imaging studies to be performed sincein most cases they contribute enough information to makea diagnosis. Computed axial tomography will be usefulto evaluate osteolytic areas and rotational alterations of the components. Ultrasound is useful for the analysis of periarticular soft tissues. Recent studies have emphasized the value of MRI for the assessment of the painful knee prosthesis. From the analytical viewpoint, the ESR and C-reactive protein, in spite of their low specificity, could be valuable tools in the diagnosis of infected total knee replacement, especiallyso if serial levels are available. Nuclear medicinestudies are highly sensitive, but their specificity is low. The use of combined isotope studies (technetium and indium) might help us with the differential diagnosis of prosthetic loosening

Asunto(s)

RESUMEN

Introducción. La historia clínica y la exploración física son fundamentales para el enfoque diagnóstico de la prótesis de rodilla dolorosa. A la hora de planificar una estrategia diagnóstica es útil diferenciar entre problemas extraarticulares e intraarticulares.Diagnóstico y conclusiones. La radiología simple es la primera prueba complementaria a considerar, aportando en la mayoría de los casos información suficiente para establecer un diagnóstico. La tomografía axial computarizada será de utilidad para la valoración de áreas de osteólisis y alteraciones rotacionales de los componentes. La ecografía tiene utilidad en el estudio de las partes blandas periarticulares. Estudiosrecientes destacan el valor de la resonanciamagnética nuclear para la valoración de la prótesis dolorosa. Desde el punto de vista analítico, la velocidad de sedimentación globular y la proteína C reactiva, pese a su baja especificidad, pueden ser de utilidad en el diagnóstico de la artroplastia total de rodilla infectada, especialmente si contamoscon niveles seriados. Los estudios de Medicina Nuclearpresentan una alta sensibilidad, aunque su especificidades escasa. El uso de estudios isotópicos combinados(tecnecio e indio) puede ayudarnos al diagnóstico diferencial del aflojamiento protésico

Introduction. Clinical history and physical examination are essential factors for the diagnosis of the painful knee prosthesis. It is useful to make a distinction between extra and intra-articular problems before setting about planning for a diagnostic strategy.Diagnosis and conclusions. Plain films should be seen asthe first supplementary imaging studies to be performed since in most cases they contribute enough information to make a diagnosis. Computed axial tomography will be useful to evaluate osteolytic areas and rotational alterations of the components. Ultrasound is useful for the analysis of periarticular soft tissues. Recent studies have emphasized the value of MRI for the assessment of the painful knee prosthesis.From the analytical viewpoint, the ESR and C-reactiveprotein, in spite of their low specificity, could be valuable tools in the diagnosis of infected total knee replacement, especially so if serial levels are available. Nuclear medicine studies are highly sensitive, but their specificity is low. Theuse of combined isotope studies (technetium and indium)might help us with the differential diagnosis of prosthetic loosening

Asunto(s)