Basic physical properties and potential application of graphene oxide fibers synthesized from rice husk.

The synthesis method and correlation between compositional, vibrational, and electrical properties in graphene oxide fibers (GOF) are presented and discussed here, as well as a potential application through the development of a heater device based on GOF. The GOF samples were synthesized from rice husk (RH), via a thermal decomposition method, employing an automated pyrolysis system with a controlled nitrogen atmosphere, varying carbonization temperature (TCA) from 773 to 1273 K. The compositional analysis shows peaks in the XPS spectrum associated with C1s and O1s, with presence of hydroxyl and epoxy bridges; the oxide concentration (OC) of samples varied from 0.21 to 0.28, influenced by TCA. The GOF samples exhibit fiber morphology, vibrational characteristics which are typical of graphene oxide multilayers, and electrical behavior that scales with OC. The electrical response shows that OC decreases and increases electrical conductivity at the polycrystalline phase, possibly attributed to the desorption of some oxides and organic compounds. In addition, physical correlations between OC and its vibrational response showed that decreasing OC increases edge defect density and decreases crystal size as a result of thermal decomposition processes. The correlation between OC and physical properties suggests that by controlling the OC in GOF, it was possible to modify vibrational and electrical properties of great interest in fabrication of advanced electronics; consequently, we show a potential application of GOF samples by developing an electrically controlled heater device.

Exploring the capture and desorption of CO2 on graphene oxide foams supported by computational calculations.

In the last decade, the highest levels of greenhouse gases (GHG) in the atmosphere have been recorded, with carbon dioxide (CO2) being one of the GHGs that most concerns mankind due to the rate at which it is generated on the planet. Given its long time of permanence in the atmosphere (between 100 to 150 years); this has deployed research in the scientific field focused on the absorption and desorption of CO2 in the atmosphere. This work presents the study of CO2 adsorption employing materials based on graphene oxide (GO), such as GO foams with different oxidation percentages (3.00%, 5.25%, and 9.00%) in their structure, obtained via an environmentally friendly method. The characterization of CO2 adsorption was carried out in a closed system, within which were placed the GO foams and other CO2 adsorbent materials (zeolite and silica gel). Through a controlled chemical reaction, production of CO2 was conducted to obtain CO2 concentration curves inside the system and calculate from these the efficiency, obtained between 86.28 and 92.20%, yield between 60.10 and 99.50%, and effectiveness of CO2 adsorption of the materials under study. The results obtained suggest that GO foams are a promising material for carbon capture and the future development of a new clean technology, given their highest CO2 adsorption efficiency and yield.

Temperature dependence of electrical conductivity and variable hopping range mechanism on graphene oxide films.

The rapid development of optoelectronic applications for optical-to-electrical conversion has increased the interest in graphene oxide material. Here, graphene oxide films (GOF) were used as source material in an infrared photodetector configuration and the temperature dependence of the electrical conductivity was studied. GOF were prepared by the double-thermal decomposition (DTD) method at 973 K, with a fixed carbonization temperature, in a pyrolysis system, under a controlled nitrogen atmosphere, over quartz substrates. Graphene oxide films were mechanically supported in a photodetector configuration on Bakelite substrates and electrically contacted with copper wires and high-purity silver paint. Morphological images from the GOF's surface were taken employing a scanning electron microscope and observed a homogeneous surface which favored the electrical contacts deposition. Vibrational characteristics were studied employing Raman spectroscopy and determined the typical graphene oxide bands. GOF were used to discuss the effect of temperature on the film's electrical conductivity. Current-voltage (I-V) curves were taken for several temperatures varying from 20 to 300 K and the electrical resistance values were obtained from 142.86 to 2.14 kΩ. The GOF electrical conductivity and bandgap energy (Eg) were calculated, and it was found that when increasing temperature, the electrical conductivity increased from 30.33 to 2023.97 S/m, similar to a semiconductor material, and Eg shows a nonlinear change from 0.33 to 0.12 eV, with the increasing temperature. Conduction mechanism was described mainly by three-dimensional variable range hopping (3D VRH). Additionally, measurements of voltage and electrical resistance, as a function of wavelength were considered, for a spectral range between 1300 and 3000 nm. It was evidenced that as the wavelength becomes longer, a greater number of free electrons are generated, which contributes to the electrical current. The external quantum efficiency (EQE) was determined for this proposed photodetector prototype, obtaining a value of 40%, similar to those reported for commercial semiconductor photodetectors. This study provides a groundwork for further development of graphene oxide films with high conductivity in large-scale preparation.

Spinal osteosarcoma in the paediatric age group: case series and literature review. / Osteosarcoma lumbar en edad pediátrica: reporte de casos y revisión de la literatura.

INTRODUCTION AND OBJECTIVE: Osteosarcoma is the most frequent malignant spinal tumour in the paediatric age group. Diagnosis and early treatment of this pathology is essential for a good prognosis. The aim of this study was to present the results of treatment of paediatric patients with lumbar osteosarcoma and conduct a literature review. MATERIAL AND METHODS: All the patients with lumbar osteosarcoma who were operated between 2012 and 2014 in the same centre were included. Demographic and radiological data (Enneking, WBB and Tomita classification), as well as anatomopathological (Broders classification) variables were analysed. All the patients were treated by surgical resection associated with adjuvant therapies (chemotherapy and radiotherapy); according to consensus with the tumour committee. The average follow-up was 62.53 months (47-70 months). RESULTS: A total of 3 patients were studied, two girls of 9 and 11, with L5 osteosarcoma, and a 15-year-old boy with L4 osteosarcoma. Two of the cases were initially treated as an osteoblastoma, supported by radiological and anatomopathological images. None of the patients had local recurrences or metastases during follow-up. CONCLUSIONS: Due to a lack of long series of cases of osteosarcoma in the mobile spine during childhood, the optimal treatment and prognosis in these patients is uncertain. Block resection improves local control of the disease, without demonstrating improvement in overall survival. Intralesional resection is associated with a higher rate of local recurrence. Oncological treatment is essential in the treatment of this pathology. A correct differential diagnosis of the tumour (osteosarcoma vs. osteoblastoma) is vital for its correct treatment.

Correlation of the Glomerular Filtration Rate Measured With the Use of DTPA-Tc99m in Live Kidney Donors With Equations Based on Creatinine and Cystatin C.

BACKGROUND: Renal donation leads to a risk of developing chronic kidney disease, with an incidence of 0.47%. To evaluate for its presence, formulas based on serum creatinine are used, but up to 80% of these formulas underestimate the glomerular filtration rate (GFR) in donors. The aim of this work was to confirm the highest correlation of the GFR as measured with the use of DTPA-Tc99m with the GFR as estimated by means of the formula based on serum cystatin C (CKD-EPI creatinine-cystatin C) in healthy kidney donors. METHODS: In this observational, analytic, cross-sectional study, the GFR of kidney donors was determined ≥1 year after donation by means of DTPA gammagram and estimation with the use of conventional formulations and with cystatin C. RESULTS: Of 112 donors, 38 (34%) were included, 20 (60%) were female, with an overall average age of 40 years, 36.5 months after donation, and body mass index of 25.5 kg/m2. Correlation with the GFR as measured by means of DTPA gammagram was better with the use of CKD-EPI cystatin C (0.402; P = .020) and CKD-EPI creatinine-cystatin (0.549; P < .001) than the conventional formulas. Linear correlation with serum cystatin C was 0.825 (P < .001; 95% confidence interval, -105.3 to -63.2) for the CKD-EPI cystatin C formula, 0.77 (P < .001; -89.9 to -48.1) for the CKD-EPI creatinine-cystatin formula, and 0.525 (P = .002; -91.1 to -23.2) for DTPA-Tc99m scintigraphy. CONCLUSIONS: There is a strong correlation between estimate the GFR by equations based on cystatin C and the measurement of the GFR by DTPA-Tc99m gammagram.

Cardiac Remodeling in Structure and Function Six Months After Kidney Transplantation.

BACKGROUND: Cardiovascular disease accounts for 35% to 50% of the causes of mortality in chronic kidney disease. The majority of patients in substitution therapy in Mexico are subdialyzed owing to limited economic resources. This produces more cardiac deterioration than described in the statistics and has a direct impact on the prognosis of kidney transplantation. The aim of this work was to demonstrate and to quantify the improvement in the echocardiographic parameters 6 months after renal transplantation in patients with stable renal function. METHODS: This was an observational, analytic, prospective study of 23 patients with chronic kidney disease who received transplants in 2016 and had a glomerular filtration rate ≥80 mL/min (Chronic Kidney Disease-Epidemiology Collaboration) 6 months after transplantation. RESULTS: Echocardiographic results showed an increase in the left ventricular ejection fraction from 57.17 ± 10.46% to 64.09 ± 9.8%, an increase in the right ventricular ejection fraction from 0.56 ± 0.09% to 0.60 ± 0.08% and a reduction of the pulmonary arterial systolic pressure from 44.57 ± 13.88 mm Hg to 39.74 ± 11.04 mm Hg. There were also decreases in mitral regurgitation from 1.0 to 0.43, tricuspid insufficiency from 1.35 to 0.43, pulmonary insufficiency from 0.48 to 0.04, and aortic insufficiency from 0.35 to 0.04, all of these significant with P < .05. CONCLUSIONS: There was a significant improvement in cardiovascular function in our population 6 months after transplantation, despite the fact that renal transplantation is performed with greater cardiac deterioration than described in patients in other countries.

High expression of interleukine-1 receptor antagonist in rheumatoid arthritis: Association with IL1RN*2/2 genotype.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by inflammation and pro-inflammatory cytokines production. IL-1Ra is an anti-inflammatory cytokine codified by IL1RN gene that blocks IL-1 signalling. A VNTR polymorphism of 86 bp in IL1RN gene has been associated with RA risk and regulation of IL-1Ra expression. In this study, we determined mRNA and protein expression of IL-1Ra in RA patients and control subjects (CS). This study included 85 RA patients classified according to the ACR/EULAR 2010 criteria and 67 CS. Polymerase chain reaction was used to identify IL1RN VNTR polymorphism, the expression of sIL-1Ra (secreted isoform) mRNA was determined by SYBR Green-based real time quantitave-PCR assay, and IL-1Ra soluble levels quantification was evaluated by ELISA test. RA patients had higher soluble levels of IL-1Ra than CS (p < .01), sIL-1Ra mRNA expression was higher in RA patients compared to CS (p < .01). Carriers of IL1RN*2/2 homozygous genotype show increased IL-1Ra soluble levels compared to IL1RN*long/long and IL1RN*2/long genotypes (p < .05) in the CS group, whereas mRNA expression in carriers of IL1RN*2/2 genotype was 1.2 times higher compared to IL1RN*long/long genotypes in the same group. Regarding RA patients, high expression of sIL-1Ra mRNA on carriers of IL1RN*long/long genotype was observed. Nevertheless, in RA patients IL-1Ra soluble levels among genotypes did not show significant differences. High expression of IL-1Ra in RA patients under treatment or not with antirheumatic drugs was detected. Additionally, carriers of IL1RN*2/2 genotype had higher IL-1Ra expression than carriers of other genotypes.

[Anterior knee pain in knee arthroplasty with or without a patellar component]. / Dolor anterior de rodilla en pacientes operados de artroplastía de rodilla con o sin remplazo del componente patelar.

INTRODUCTION: The appearance of patellofemoral pain after a knee arthroplasty, particularly in rheumatic diseases, resulted in the incorporation of the substitution of the patellar component in all designs. The replacement of the patella became a standard part of knee arthroplasty, but the controversy over whether to restore it or not continues among orthopedists that perform knee arthroplasties. OBJECTIVE: To analyze the incidence of anterior knee pain in patients who underwent primary knee arthroplasty with or without replacement of the patellar component. MATERIAL AND METHODS: Observational, retrospective, descriptive and transversal study from January 2011 to December 2013. RESULTS: A total of 54 patients were included, 12 men (with an average age of 63 years) and 42 women (with an average age of 71 years), totaling 64 knees that were surgically intervened. CONCLUSION: This study found no significant difference in anterior knee pain and in the function of the patellofemoral joint and the knee in the groups of patients who were tested with the different scales.

La aparición de dolor patelofemoral postoperatorio en la artroplastía de rodilla, sobre todo en pacientes reumáticos, resultó en la incorporación de la sustitución del componente patelar en la mayoría de los diseños. Esta se convirtió en una parte estándar de la artroplastía total de rodilla; la controversia sobre si restituir o no el componente patelar continúa siendo debatida por los cirujanos ortopedistas que realizan artroplastías de rodilla.

Electrical conductivity of oxidized-graphenic nanoplatelets obtained from bamboo: effect of the oxygen content.

The large-scale production of graphene and reduced-graphene oxide (rGO) requires low-cost and eco-friendly synthesis methods. We employed a new, simple, cost-effective pyrolytic method to synthetize oxidized-graphenic nanoplatelets (OGNP) using bamboo pyroligneous acid (BPA) as a source. Thorough analyses via high-resolution transmission electron microscopy and electron energy-loss spectroscopy provides a complete structural and chemical description at the local scale of these samples. In particular, we found that at the highest carbonization temperature the OGNP-BPA are mainly in a sp(2) bonding configuration (sp(2) fraction of 87%). To determine the electrical properties of single nanoplatelets, these were contacted by Pt nanowires deposited through focused-ion-beam-induced deposition techniques. Increased conductivity by two orders of magnitude is observed as oxygen content decreases from 17% to 5%, reaching a value of 2.3 × 10(3) S m(-1) at the lowest oxygen content. Temperature-dependent conductivity reveals a semiconductor transport behavior, described by the Mott three-dimensional variable range hopping mechanism. From the localization length, we estimate a band-gap value of 0.22(2) eV for an oxygen content of 5%. This investigation demonstrates the great potential of the OGNP-BPA for technological applications, given that their structural and electrical behavior is similar to the highly reduced rGO sheets obtained by more sophisticated conventional synthesis methods.

Wastewater treatment and biodiesel production by Scenedesmus obliquus in a two-stage cultivation process.

The microalga Scenedesmus obliquus was cultured in two cultivation stages: (1) in batch with real wastewater; (2) maintaining the stationary phase with different conditions of CO2, light and salinity according to a factorial design in order to improve the lipid content. The presence of the three factors increased lipid content from 35.8% to 49% at the end of the second stage; CO2 presence presented the highest direct effect increasing lipid content followed by light presence and salt presence. The ω-3 fatty acids content increased with CO2 and light presence acting in isolation, nevertheless, when both factors acted together the interaction effect was negative. The ω-3 eicosapentaenoic acid content of the oil from S. obliquus slightly exceeded the 1% maximum to be used as biodiesel source (EU normative). Therefore, it is suggested the blend with other oils or the selective extraction of the ω-3 fatty acids from S. obliquus oil.

Influence of light presence and biomass concentration on nutrient kinetic removal from urban wastewater by Scenedesmus obliquus.

This work was aimed at studying the effect of light-darkness and high-low biomass concentrations in the feasibility of removing nitrogen and phosphorus from urban treated wastewater by the microalga Scenedesmus obliquus. Laboratory experiments were conducted in batch, where microalgae were cultured under different initial biomass concentrations (150 and 1500mgSSl(-1)) and light conditions (dark or illuminated). Nutrient uptake was more dependent on internal nutrient content of the biomass than on light presence or biomass concentration. When a maximum nitrogen or phosphorus content in the biomass was reached (around 8% and 2%, respectively), the removal of that nutrient was almost stopped. Biomass concentration affected more than light presence on the nutrient removal rate, increasing significantly with its increase. Light was only required to remove nutrients when the maximum nutrient storage capacity of the cells was reached and further growth was therefore needed. Residence times to maintain a stable biomass concentration, avoiding the washout of the reactor, were much higher than those needed to remove the nutrients from the wastewater. This ability to remove nutrients in the absence of light could lead to new configurations of reactors aimed to wastewater treatment.

Armas eléctricas: ¿qué sabemos? ¿qué ignoramos? / Electronic control devices: what is known? what is unknown?

Las armas eléctricas se introdujeron como una alternativa a las armas de fuego en la policía, aunque también están siendo utilizadas fuera del marco de la ley. Mediante las descargas eléctricas que producen, se inmoviliza a la víctima como consecuencia de una contracción muscular tetánica dolorosa. La utilización de estas armas es controvertida, ya que se les han atribuido algunas muertes en custodia en Estados Unidos. Revisamos la literatura médica sobre este tema y concluimos que algunas veces pueden ser letales, y que es necesario analizar factores de riesgo potencial asociados para confirmar o descartar una verdadera relación causa-efecto en estos casos (AU)

Conducted energy devices are used as a non-lethal weapons by law enforcement personal internationally to subdue potentially violent or combative subjects. The victim is immobilized as a result of painful tetanic contraction of the muscles. However, controversy exists about these weapons, because they have been implicated in some deaths in custody in the United States. We review medical literature related on this topic and conclude that they are not always non lethal and that all potential associated factors must be analyzed to be able to confirm or disprove a true causal relationship (AU)

Photobiotreatment model (PhBT): a kinetic model for microalgae biomass growth and nutrient removal in wastewater.

This article proposes a kinetic model for wastewater photobiotreatment with microalgae (the PhBT model). The PhBT model for nutrient uptake, coupled with the Verhulst growth model, is a simple and useful tool to describe batch experiments of nutrient removal by microalgae. The model has been validated with experiments of Chlorella vulgaris (C. vulgaris) grown in wastewater and different synthetic media. The model provided information about nitrogen and phosphorus limitation and their luxury uptake during the test. Productivity observed in synthetic medium (0.17 g SS L(-1) d(-1)) was similar to that obtained in nutrient enriched wastewater (0.15 g SS L(-1) d(-1)). Biomass productivity of this alga in wastewater and the efficient nutrient removal suggested that C. vulgaris could be cultured in wastewater for biomass production while nutrients are reduced from this stream.

Photobiotreatment: influence of nitrogen and phosphorus ratio in wastewater on growth kinetics of Scenedesmus obliquus.

Nitrogen and phosphorus concentration in the effluent of a wastewater treatment plant can vary significantly, which could affect the growth kinetic and chemical composition of microalgae when cultivated in this medium. The aim of this work was to study the rate of growth, nutrient removal and carbon dioxide biofixation as well as biomass composition of Scenedesmus obliquus (S. obliquus) when it is cultivated in wastewater at different nitrogen and phosphorus ratio, from 1:1 to 35:1. A more homogeneous method for calculating productivities in batch reactors was proposed. The proper N:P ratio for achieving optimum batch biomass productivity ranged between 9 and 13 (263 and 322 mg L(-1) d(-1) respectively). This was also the ratio range for achieving a total N and P removal. Above and below this range (9-13) the maximum biomass concentration changed, instead of the specific growth rate.The maximum carbon dioxide biofixation rate was achieved at N:P ratio between 13 and 22 (553 and 557 mg CO2 L(-1) d(-1) respectively). Lipid and crude protein content, both depend on the aging culture, reaching the maximum lipid content (34%) at the lowest N:P (1:1) and the maximum crude protein content (34.2%) at the highest N:P (35:1).

Efficacy of low-dose tylvalosin for the control of clostridiosis in broilers and its effect on productive parameters.

The study was carried out under field conditions in a commercial farm, and 1,440 as-hatched Ross-308 broilers were included. Broilers were randomly distributed into 24 experimental 4-m(2) pens (60 broilers/pen). Pens were randomized to the 3 treatment groups: a) tylvalosin 10 mg/kg of live BW during 2 d, b) positive control (tylosin during 2 d), and c) negative control (no treatment). The drugs were provided in the water supply. Mortality, individual BW, and feed intake were assessed. Clostridium presence was assessed in fecal and cecal samples, coccidian oocyst counts were assessed in fecal samples, and bacterial diversity was assessed in ileal content. Live BW at 42 d old was significantly better in the tylvalosin group than in tylosin and no-treatment groups, with tylvalosin-treated broilers reaching 80 to 100 g higher final live weight. Average daily gain results mirrored BW findings. The improvement of feed conversion rate with tylvalosin amounted to 0.13 and to 0.10 versus tylosin and no-treatment, respectively, with mortality being similar in all groups. Significantly reduced sulfite-reducing Clostridium and Clostridium perfringens counts in tylvalosin and tylosin groups versus the no-treatment group were observed in cecum content samples. In conclusion, according to the present study results, tylvalosin, at doses substantially lower than registered for poultry in Europe, has proven effective in controlling the colonization of the cecum by Clostridium ssp. in broilers, improving some productive performances.

Performance of a flat panel reactor in the continuous culture of microalgae in urban wastewater: prediction from a batch experiment.

A laboratory-scale flat panel photobioreactor was operated for the continuous growth of Scenedesmus obliquus and consequent removal of nutrients in wastewater. This study develops a simple model by which biomass values in continuous operation can be predicted from kinetic growth parameters obtained from a shorter batch experiment. Based on this study, biomass concentrations and productivities in continuous operation can be successfully predicted as a function of the specific hydraulic retention time (HRT) assumed. Considerable biomass production and nutrient uptake from wastewater were achieved in the experiment. Optimum operating conditions for the reactor depend on the particular objective: the maximization of biomass production and carbon dioxide biofixation involves a HRT of 2 µ(-1) (specific growth rate), whereas efficient nutrient removal involves a HRT as close as possible to µ(-1) (as long as discharges comply fully with the parameters set); alternatively biomass intended for biodiesel or biogas production would involve a HRT > 2 µ(-1).

Síndromes neurológicos asociados al uso de medicamentos. Frecuencia y caracterización / Neurological syndromes associated with drug use. Frequency and characterisation

Introducción: La necesidad de una asistencia sanitaria segura en la que los cuidados y tratamientos no supongan daños diferentes a los derivados de la enfermedad de base, ha motivado este estudio. Nuestro objetivo ha sido determinar la frecuencia y describir los síndromes neurológicos atribuibles a fármacos, su evitabilidad y los niveles asistenciales implicados. Métodos: Estudio observacional. Cohorte prospectiva de todos los sujetos derivados desde atención primaria y especializada, en el período de diciembre de 2008 a enero de 2010, por síntomas neurológicos atribuibles a fármacos y enfermos neurológicos conocidos con clínica distinta o agravada de la enfermedad de base causada por fármacos. Las notificaciones quedaron reflejadas en un cuestionario. Se realizaron distribuciones de frecuencias, medidas de tendencia central, pruebas de la 2 o Fisher y pruebas no paramétricas correspondientes. Resultados: La prevalencia de efectos adversos neurológicos respecto a la muestra total fue 0,586%. De los 105 pacientes seleccionados, los principales efectos adversos fueron: 25,7% síndrome rígido-acinético; 18,1% discinético; 11,4% síntomas neuropsiquiátricos, y 10,5% síndrome confusional. Los grupos farmacológicos más registrados fueron, en orden decreciente: antiepilépticos, dopaminérgicos, antidepresivos, neurolépticos, antivertiginosos y procinéticos. Describimos la población más susceptible y las asociaciones estadísticamente significativas entre la presencia de determinados grupos farmacológicos y síndromes neurológicos concretos.Conclusiones: La baja prevalencia detectada puede deberse al diseño del estudio, aunque los efectos adversos neurológicos suponen el 2,84% de los ingresos en una unidad de neurología.Conocer la epidemiología permitirá identificar los abordajes más seguros, aplicarlos correctamente a la población de mayor riesgo y reducir necesidades asistenciales y recursos médicos (AU)

Introduction: The need for safe health care, in which the care and treatment of the patient does not cause any injuries in addition to those already arising from their baseline disease, hasled to the present study. Our objective has been to determine the frequency and describe the neurological syndromes attributable to drugs, their preventability and the levels of medical care involved. Methods: Observational study. Cohort of subjects referred from Primary and Specialized Care between December 2008 and January 2010 due to neurological symptoms attributable to drugs, and previously known neurology patients who began to have symptoms other than those of the baseline disease, also caused by drugs. The notifications were recorded in a questionnaire. Frequency distributions, central tendency measurements, X2 or Fisher tests and non-parametric tests were performed. Results: The prevalence of adverse neurological events was 0.586% of the total sample. Of the 105 patients selected, the most frequent adverse events were: 25.7%, akinetic-rigid syndrome, 18.1%, dyskinetic syndrome, 11.4% neuro-psychiatric symptoms, and 10.5% confusional syndrome. The most commonly recorded pharmacological groups were, in decreasing order: anti-epileptic, dopaminergic, antidepressant, neuroleptic, antivertiginous and prokinetic drugs. We describe the most susceptible population and the statistically significant relationships between the presence of certain pharmacological groups and neurological syndromes. Conclusions: The low prevalence detected may be due to the study design, although adverse neurological events accounted for 2.84% of the admissions to a Neurology Unit. Understanding the epidemiology should help to identify the safest approaches, apply them correctly to the population at a higher risk, and reduce healthcare needs and consumption of medical resources (AU)

Neurological syndromes associated with drug use. Frequency and characterisation.

INTRODUCTION: The need for safe health care, in which the care and treatment of the patient does not cause any injuries in addition to those already arising from their baseline disease, has led to the present study. Our objective has been to determine the frequency and describe the neurological syndromes attributable to drugs, their preventability and the levels of medical care involved. METHODS: Observational study. Cohort of subjects referred from Primary and Specialized Care between December 2008 and January 2010 due to neurological symptoms attributable to drugs, and previously known neurology patients who began to have symptoms other than those of the baseline disease, also caused by drugs. The notifications were recorded in a questionnaire. Frequency distributions, central tendency measurements, X(2) or Fisher tests and non-parametric tests were performed. RESULTS: The prevalence of adverse neurological events was 0.586% of the total sample. Of the 105 patients selected, the most frequent adverse events were: 25.7%, akinetic-rigid syndrome, 18.1%, dyskinetic syndrome, 11.4% neuro-psychiatric symptoms, and 10.5% confusional syndrome. The most commonly recorded pharmacological groups were, in decreasing order: anti-epileptic, dopaminergic, antidepressant, neuroleptic, antivertiginous and prokinetic drugs. We describe the most susceptible population and the statistically significant relationships between the presence of certain pharmacological groups and neurological syndromes. CONCLUSIONS: The low prevalence detected may be due to the study design, although adverse neurological events accounted for 2.84% of the admissions to a Neurology Unit. Understanding the epidemiology should help to identify the safest approaches, apply them correctly to the population at a higher risk, and reduce healthcare needs and consumption of medical resources.

Effect of nitrogen and phosphorus concentration on their removal kinetic in treated urban wastewater by Chlorella vulgaris.

This study evaluates the feasibility of removing nutrients by the microalgae Chlorella vulgaris, using urban wastewater as culture medium, namely the effluent subjected to secondary biological treatment in a wastewater treatment plant (WWTP). For this, laboratory experiments were performed in batch cultures to study the effect of initial nitrogen and phosphorus concentrations on growth and reduction of nutrient performance of C. vulgaris. The microalga was cultivated in enriched wastewater containing different phosphorus (1.3-143.5 mg x L(-1) P.PO4(3-)), ammonium (5.8-226.8 mg x L(-1) N-NH4+) and nitrate (1.5-198.3 mg x L(-1) N-NO3-) concentrations. The nutrient removal and growth kinetics have been studied: maximum productivity of 0.95 g SS x L(-1) x day(-1), minimum yield factor for cells on substrate (Y) of 11.51 g cells x g nitrogen(-1) and 0.04 g cells x g phosphorus(-1) were observed. The results suggested that C. vulgaris has a high potential to reduce nutrients in secondary WWTP effluents.

El peso metabólicamente activo: entre la ley de Kleiber y la segunda ley de la termodinámica / Metabolically active weight: between Kleiber's law and the second law of thermodinamics

Al plantear que los seres vivos utilizan la energía que disipan para generar su propia estructura, el Principio de Margalef relaciona la capacidad metabólica con la generación de masa corporal. El estudio de la Tasa Metabólica Basal (TMB) y el peso corporal, pueden ayudar a observar la relación propuesta. La capacidad de disipar energía contribuye a generar una creciente estructura, a la vez que declina con el tiempo. En ese marco, la precisión del concepto de peso metabólicamente activo es fundamental. La dinámica de la relación entre estas dos variables, puede colaborar en la comprensión de ciertos aspectos fundamentales de los seres vivos. Y la adecuada definición del peso metabólicamente activo puede influir sobre aspectos clínicos de esta relación.

In arguing that living things use their dissipated energy to generate their own structure, the Margalef principle relates metabolic capacity to body mass. By studying the Basal Metabolic Rate (BMR) and body weight we can observe the proposed relationship. The ability to dissipate energy contributes to a growing structure and declines over time. In this context, the accuracy of the concept of metabolically active weight is fundamental. The dynamics of the relationship between these two variables may contribute to an understanding of fundamental aspects of living organisms. In addition, a proper definition of the metabolically active weight may influence the clinical aspects of this relationships.