Complete and simultaneous removal of ionic silver and silver nanoparticles by using an ionic liquid supported on a magnetic nanoparticle core.

The global pandemic situation due to COVID-19 has given rise to the massive use of disinfectant products, many of them based on silver atoms. After the use of these products, the silver passes into the aqueous effluents, becoming an emerging contaminant in waters. In this work, a novel procedure for the total and simultaneous removal of ionic and nanomeric silver in aqueous samples is introduced, employing magnetic nanoparticles wrapped with an ionic liquid (Fe3O4@IL) as a removal agent. Experimental variables such as pH, contact time, temperature, as well as pollutant and removal agent doses were studied to achieve the total elimination, exhibiting exceptional conditions for the removal of different concentrations of silvers species in water. The approach achieves 100% removal efficiency for the simultaneous removal of both silver species, goal not achieved previously. Also, 100% removal efficiency is reached for the both species separately, since ionic silver is adsorbed onto the Fe3O4, while nanomeric silver is extracted in the IL. Particularly, for concentrations within the range 50-200 µg L-1, total removal efficiency was reached for a wide range of temperatures and a pH range 7-9, achieved in just 15 min, for all cases. Additionally, the doses of Fe3O4@IL employed to remove all concentrations of silver were 13.7 mg. Characterization of Fe3O4@IL surfaces before and after the process was performed by means of Field Effect Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy. Fe3O4@IL was recycled by employing 100 µL of 1% HNO3 solution, allowing its use for 10 additional silver removal cycles without loss of efficiency. The study of adsorption kinetics and equilibrium isotherms reveal a Freundlich-type adsorption, which suggests affinity between sites in the complex surface of Fe3O4@IL, and Elovich kinetics, indicative of chemisorption onto a heterogeneous surface, while the temperature shows no effect on the results.

A multi-herd study shows that saliva is more than a reflection of serum biomarkers in pigs.

This study evaluates if biomarkers of porcine health status in saliva samples is a mere reflection of serum to detect disease in pigs under field conditions. Four farms from the same commercial company were included to obtain samples from animals with different pathological conditions. A total of 10 healthy animals and 10-15 animals from each farm with clinical symptoms of the disease were sampled for paired saliva and blood during a veterinary clinical visit. The biomarker panel included acute-phase proteins (APPs), C-reactive protein (CRP), haptoglobin (Hp), an inflammatory marker, adenosine deaminase (ADA), the total antioxidant capacity (TAC), the levels of essential trace elements, copper (Cu) and zinc (Zn), and the measurement of the total protein content (TP). After detailed statistical analysis, the results showed that saliva could replace serum for APP measurements since a good agreement has been observed between the concentrations of APPs in both body fluids. For any other biomarker, no agreement between the concentrations quantified in serum and saliva samples was observed visually. However, salivary ADA and TP concentrations were statistically significantly higher in the diseased, whereas the statistical tests with serum concentrations were inconclusive. Furthermore, greater differentiation between healthy and diseased animals could be observed when the distribution of biomarkers was analysed in saliva than in other serum samples. The diagnostic power to discriminate between healthy and diseased pigs is similar in saliva and in serum samples. Preliminary regression models may offer an optimal combination of biomarkers for disease detection in saliva (Hp, CRP, and TAC) and serum (Hp, CRP, and Cu), which demands less labour, sample, and financial cost for saliva determinations. The contradictory results observed for TAC, Cu, and Zn levels between body fluids indicate a need for further studies. To sum up, saliva-based biomarkers instead of serum-based biomarkers could contribute to more efficient detection of diseased animals.

[Endovascular treatment of intracranial venous sinus stenosis in intracranial hypertension: three case reports and a discussion of the literature]. / Tratamiento endovascular de la estenosis de los senos venosos intracraneales en la hipertensión intracraneal: descripción de tres casos y discusión de la bibliografía.

INTRODUCTION: Idiopathic intracranial hypertension is an entity with an incidence of approximately 1.2: 100,000 inhabitants/year. It affects in a greater proportion obese women and women of childbearing age. Headache is the most characteristic symptom, followed by visual disturbances. In recent years, the diagnosis of dural sinus stenosis has increased in cases of intracranial hypertension resistant to conventional treatment. For this reason, the development of endovascular therapy as a therapeutic option in selected patients is booming. CASE REPORTS: We present three cases of intracranial hypertension secondary to dural sinus stenosis, diagnosed and treated in our hospital. Despite the establishment of adequate diuretic treatment and the performance of invasive procedures to bypass the cerebrospinal fluid, they persisted with neurological symptoms and visual deficits. After verifying that they fulfilled the requirements described in the literature, they underwent intracranial stenting, with satisfactory results in all of them, achieving the disappearance of the headache and recovery of visual acuity. CONCLUSION: Stenting of dural sinus stenosis as a cause of intracranial hypertension is an increasingly used technique, which has presented favorable results. Studies are necessary to know its long-term impact.

TITLE: Tratamiento endovascular de la estenosis de los senos venosos intracraneales en la hipertensión intracraneal: descripción de tres casos y discusión de la bibliografía.Introducción. La hipertensión intracraneal idiopática es una entidad con una incidencia anual aproximada de 1,2 por cada 100.000 habitantes. Afecta en mayor proporción a mujeres obesas y en edad fértil. La cefalea es el síntoma más característico, seguido de las alteraciones visuales. En los últimos años, se ha incrementado el diagnóstico de la estenosis de los senos durales en los casos de hipertensión intracraneal resistentes al tratamiento convencional. Por ello, se encuentra en auge el desarrollo de la terapia endovascular como opción terapéutica en pacientes seleccionados. Casos clínicos. Se presentan tres casos de hipertensión intracraneal secundaria a estenosis de los senos durales, diagnosticados y tratados en nuestro hospital. A pesar de la instauración del adecuado tratamiento diurético y de la realización de procedimientos invasivos de derivación del líquido cefalorraquídeo, persistían la clínica neurológica y el déficit visual. Tras comprobar que cumplían los requisitos descritos en la bibliografía, se sometieron a la implantación de stent intracraneal (stenting), con resultado satisfactorio en todos ellos, logrando la desaparición de la cefalea y la recuperación de la agudeza visual. Conclusión. El stenting de la estenosis de los senos durales como causa de hipertensión intracraneal es una técnica cada vez más utilizada que ha presentado resultados favorables. Es necesaria la realización de estudios para conocer su impacto a largo plazo.

Head-space gas chromatography coupled to mass spectrometry for the assessment of the contamination of mayonnaise by yeasts.

Head-space (HS) gas chromatography (GC) coupled to mass spectrometry (MS) is proposed for the assessment of the contamination of mayonnaise as an alternative to plate counting, which is the technique commonly used for evaluating microbial contamination. More specifically, this method was applied in the detection of Candida metapsilosis and Zygosaccharomyces bailii, both of great importance in term of food spoilage since they are resistant to many of the common methods of food preservation. Different chemometric models were investigated using the data obtained by GC-MS (m/z profile, area of the chromatographic peaks and entire chromatographic profile), in order to obtain the highest classification success. The best results were obtained using the chromatographic profile (success rate of 92%). Contaminated samples could also be classified according to the concentration of yeast, obtaining a success rate of 87.5%. Finally, a chemometric model was constructed in an attempt to differentiate between strains.

Trombosis arterial y venosa masiva / Massive Arterial and Venous Thromboses

No disponible

Retroneumoperitoneo por espondilodiscitis fulminante / Retropneumoperitoneum due to fulminant spondylodiscitis

No disponible

Pneumonia in mechanically ventilated patients: no diagnostic and prognostic value of different quantitative tracheal aspirates thresholds.

BACKGROUND: Diagnosis of pneumonia in ventilated patients is challenging due to the lack of specific and definitive clinical symptoms, laboratory data or radiological abnormalities. METHODS: Based on quantitative tracheal aspirate (QTA) results, three groups of patients were compared: <105 cfu/ml, ≥105 cfu/ml and <106 cfu/ml, and ≥106 cfu/ml. We recorded demographic variables, underlying diseases and severity of illness at ICU admission. On the day of pneumonia diagnosis, we registered temperature, leukocyte count, C-reactive protein, Sequential Organ Failure Assessment (SOFA) score, clinical pulmonary infection score (CPIS) and adequacy of empirical antimicrobial therapy. RESULTS: In 231 episodes, clinical presentation, laboratory data, severity of illness, CPIS, the presence of bacteremia and radiological score did not differ among the three groups. ICU and hospital mortalities were also similar in the three groups. Factors independently associated with in-hospital mortality were age, SOFA score and inappropriate antimicrobial therapy. The bacterial burden in the QTA was not included in the model. CONCLUSIONS: Quantification of tracheal aspirate samples may not be necessary in ventilated patients clinically suspected of having nosocomial pneumonia.

Rotura diafragmática traumática. Diagnóstico por imagen / Traumatic diaphragmatic rupture. Diagnostic imaging

No disponible

Insuficiencia hepática aguda grave por virus del herpes simple en un paciente inmunocompetente / Severe acute liver failure due to herpes simplex virus infection in an immunocompetent patient

No disponible

Liquid-phase microextraction with solidification of the organic floating drop for the preconcentration and determination of mercury traces by electrothermal atomic absorption spectrometry.

A procedure for the determination of traces of mercury by liquid-phase microextraction based on solidification of a floating organic droplet for separation and electrothermal atomic absorption spectrometry for final measurement has been developed. For this purpose, 50 microL of pre-heated (50 degrees C) undecanoic acid (UA), are added to 25 mL of aqueous sample solution at pH 5. The mixture, maintained at 50 degrees C, is stirred for 10 min using a high stirring rate in order to fragment the UA drop into droplets, thus favoring the extraction process. Next, the vial is immersed in an ice bath, which results in the solidification of the UA drop that is easily separated. Injection into the atomizer is carried out after gentle heating. The pyrolytic atomizers are coated with electrolytically reduced palladium that acts as an effective chemical modifier for more than 500 firings. Under the optimized conditions, the detection limit was 70 ng L(-1) mercury with an enrichment factor of 430. The relative standard deviation of the measurements was in the 2.1-3.5% range. Recovery studies applied to the determination of mercuric ions in bottled and tap water samples were in the 92-104% range.

Liquid chromatography-electrothermal atomic absorption spectrometry for the separation and preconcentration of molybdenum in milk and infant formulas.

Two procedures for the electrothermal atomic absorption spectrometric determination of molybdenum in milk and infant formulas using slurried samples are described. For powdered milk samples, 10% (m/v) slurries were prepared in a medium containing 25 and 75% (v/v) concentrated hydrogen peroxide and hydrofluoric acid, respectively, and introduced directly into the furnace. Palladium (200 microg mL(-1)) was used as the modifier and calibration was carried out using aqueous standards prepared in the same medium. The detection limit was 0.02 microg g(-1) for powdered milk samples suspended at 10% (m/v) (equivalent to 2 microg L(-1)). The relative standard deviation (R.S.D.) for five measurements was 1.9%, the characteristic mass being 25 pg. For liquid milk samples, a procedure was proposed based on preconcentration and removal of the matrix, using ionic exchange (Amberlite IRA 743) and elution of molybdenum with 5% (m/v) NaOH. In this case, a 30-fold improvement in the calibration slope was achieved, leading to a detection limit of 0.04 microg L(-1) for liquid samples diluted to 10%. The R.S.D. was 3.5%. Using a size-based separation procedure, it was found that molybdenum is present in its inorganic form or associated to low molecular weight substances in cow milk, while in breast milk it is associated to proteins. The reliability of the procedure was checked by comparing the results obtained with those found using a previous mineralization stage and by analyzing three certified reference materials, namely, BCR 063R (skim milk powder), NBS 1549 (non-fat milk powder) and NBS 8435 (whole milk powder).

Thickness dependence of structural relaxation in spin-cast, glassy polymer thin films.

The isothermal structural relaxation of glassy, spin-cast polymer thin films has been investigated. Specifically, the thickness h of freshly cast poly(methyl methacrylate) thin films was measured over time using spectroscopic ellipsometry. The spin-cast films exhibit a gradual decrease in thickness, which is attributed to structural relaxation of the glass combined with simultaneous solvent loss. In all cases, h was found to be greater than the equilibrium thickness h(infinity) , which is obtained by cooling slowly from the melt. It is observed that both the rate of the volume relaxation and the fractional departure from h(infinity) (referred to as delta(0) ) increase with increasing film thickness. In the limit of very thin films, the initial h is close to h(infinity) , and delta(0) is small, whereas in thick films (>500 nm) , a plateau value of delta(0) of 0.16 is observed, which is close to the volume fraction of the solvent at the vitrification point. This dependence of delta(0) on thickness is observed regardless of the substrate, polymer molecular weight, or angular velocity during spin casting. Enhanced mobility near film surfaces could be leading to greater relaxation in thinner films prior to, and immediately after, the vitrification of the polymer during the deposition process.

Purge-and-trap capillary gas chromatography with atomic emission detection for volatile halogenated organic compounds determination in waters and beverages.

A method for the simultaneous determination of 10 volatile halogenated organic compounds (VHOCs), including four trihalomethanes (THMs), in waters and beverages was developed. The analytes were stripped from the aqueous sample by a flow of helium, preconcentrated in a capillary trap and thermally desorbed using a purge-and-trap (PT) system. This was followed by capillary gas chromatography with microwave-induced plasma atomic emission spectrometry (GC-AED). For element-specific detection, three wavelengths were monitored, corresponding to chlorine (479 nm), bromine (478 nm) and iodine (193 nm). Each chromatographic run took 21 min, including the purge time. After careful choice of the experimental conditions, the performance of the system was evaluated. Calibration curves were obtained by plotting peak area versus concentration and the correlation coefficients for linear calibration were at least 0.9987. Detection limits, calculated for 5 ml sample volume, ranged from 0.05 microg l(-1) for chloroform to 0.5 microg l(-1) for tetrachloromethane. The method was successfully applied to the quantitative analysis of water samples of different origin and also of several beer and juice samples. The tap water samples analyzed contain variable concentrations of the four trihalomethanes, ranging from 1.0 to 66.5 microg l(-1), depending of the compound. Whereas chloroform, bromodichloromethane and bromoform were found in some of the juice samples, only chloroform was detected in the beer samples. The method is reliable and can be used for routine monitoring in water and beverages.

Stability of arsenobetaine levels in manufactured baby foods.

The stability of arsenobetaine in baby foods under different experimental conditions is evaluated. Total arsenic was analyzed by electrothermal atomic absorption spectrometry, and the speciation of arsenicals was carried out by coupling liquid chromatography to hydride generation-atomic absorption spectrometry. The highest arsenic levels in the analyzed baby foods corresponded to those containing plaice (2 to 3 microg/g). The speciation data indicated that arsenobetaine, a nontoxic species, was the only arsenical present in the baby foods analyzed at levels between 0.2 and 3 microg/g. Two different procedures for extracting arsenicals from baby foods, involving a water-methanol-chloroform mixture and enzymatic hydrolysis, were tested, and similar results were obtained. Furthermore, the arsenobetaine levels remained unchanged when the baby foods were stored for different times or when the samples were freeze-dried, thus confirming the stability of arsenobetaine and the nonappearance of other arsenic species by interconversion. The reliability of the procedure was checked by analyzing a certified reference material.

Determination of pesticides in waters by capillary gas chromatography with atomic emission detection.

Capillary gas chromatography with atomic emission detection (GC-AED) was successfully used to separate and quantify 14 pesticides (organochlorines, organophosphorus compounds and pyrethrins) in water samples after liquid-liquid extraction with ethyl acetate. Monitoring the emission lines for elements such as chlorine, bromine and sulfur ensures nearly specific chromatograms for these elements, and markedly increases selectivity. Calibration curves were obtained by plotting peak area versus concentration and the correlation coefficients relating to linearity were at least 0.999. Each chromatographic separation takes 21 min and, since two injections are necessary, it requires approximately 1 h to analyze one sample. The method shows a precision of 4.3-8.2% (RSD), depending on the compound. The application of liquid-liquid extraction with ethyl acetate led to recoveries from spiked samples ranging from 76 to 113%. The sensitivity and linearity for the elements chlorine, sulfur, nitrogen and phosphorus were checked under the optimized conditions at their customary emission wavelength. The sensitivity and linearity for these compounds decreased in the order (atom and emission wavelength) Cl (479 nm)>S (181 nm)>P (178 nm)>N (174 nm). A study of the GC-AED system's response to chlorine concentration in eight pesticide molecules was performed and a linear relationship was found with a correlation coefficient of 0.987.

On-line filtration system for determining total chromium and chromium in the soluble fraction of industrial effluents by flow injection flame atomic absorption spectrometry.

Two manifolds were assessed for the purpose of determining both the total chromium content and that present as a soluble form in industrial effluents by flow injection flame atomic absorption spectrometry (FI-FAAS). To determine the chromium content in the soluble fraction the samples were used without additional treatment, a 0.45 microm filter being included in the FI system. To determine the total chromium content, the samples were acidified with nitric acid 20% (v/v) and heated for 30 s in a microwave oven (temperatures of about 70 degrees C were reached). The problem posed by the very different concentration range in which total and soluble chromium are present was overcome by using programmed flow rate methodology and by only partially emptying the sample loop. A personal computer controlled both the rotation speed of a peristaltic pump and the volume of sample injected into the system, thus obtaining the dispersion degree required. Using the manifold proposed, the chromium content in the soluble fraction can be determined in the 0.5-20 microg mL(-1) range using a 10 microg mL(-1) single standard for calibration. To determine the total chromium content, a calibration line in the 20-200 microg mL(-1) range was obtained using a single 50 microg mL(-1) chromium standard solution. The reliability of the semi-automatic devices was verified by comparing the results obtained with those found by treating the samples and using both FAAS in a conventional way and a spectrophotometric method using diphenylcarbazide at the 95% confidence level (ANOVA test). The proposed procedures showed a RSD lower than +/-3%.