Toxicological impact of organic ultrafine particles (UFPs) in human bronchial epithelial BEAS-2B cells at air-liquid interface.

Air pollution has significant health effects worldwide, and airborne particles play a significant role in these effects. Ultrafine particles (UFPs) have an aerodynamic diameter of 0.1 µm or less, can penetrate deep into the respiratory tree, and are more toxic due to their large specific surface area, which should adsorb organic compounds. The aim of this study is to show the toxicological effects of UFPs with high organic content at low dose on BEAS-2B cells through at air-liquid interface (ALI) exposure using a Vitrocell® technology and a miniCAST (Combustion Aerosol Standard) generator. In conjunction with this approach, chemical analysis of particles and gas phase was performed to evaluate the presence of polycyclic aromatic hydrocarbons (PAHs). Chemical analyses confirmed the presence of PAHs in UFPs. With this experimental setup, exposure of the BEAS-2B cells induced neither cytotoxicity nor mitochondrial dysfunction. However, an increase of oxidative stress was observed, as assessed through Nrf2, NQO1, HO-1, CuZnSOD, MnSOD, and Catalase gene expression, together with significant induction of genes related to xenobiotic metabolism CYP1A1 and CYP1B1. Negative regulation of inflammatory genes expression (IL-6 and IL-8) was present three hours after the exposition to the UFPs. Taken together, this experimental approach, using repeatable conditions, should help to clarify the mechanisms by which organic UFPs induce toxicological effects.

Electrocatalytic activity of calcined manganese ferrite solid nanospheres in the oxygen reduction reaction.

In this study, we synthesized MnFe2O4 solid nanospheres (MSN) calcined at different temperatures (200-500 °C) and MSN-based materials mixed with carbon black, for their use as electrocatalysts in the oxygen reduction reaction (ORR) in alkaline medium (0.1 M KOH). It was demonstrated that the calcination temperature of MSN material determined its chemical surface composition and microstructure and it had an important effect on the electrocatalytic properties for ORR, which in turn was reflected in the performance of MSN/CB-based electrocatalysts. The study revealed that the presence of Mn species plays a key role in the ORR activity. Among tested, MSN200/CB and MSN350/CB exhibited the best electrochemical performances together with outstanding stability.

A live porcine model for surgical training in tracheostomy, neck dissection, and total laryngectomy.

OBJECTIVES: Head and neck surgery is associated with a steep learning curve, creating a need for effective training methods. Live animal models can be useful in acquiring the required skills and techniques to perform tracheostomy, neck dissection, and laryngectomy. The aim of this study is to assess the feasibility and usefulness of a porcine model to teach tracheostomy, neck dissection, and laryngectomy, describing the similarities between a swine head and neck surgical model and the human cervical area. METHODS: Twelve surgical training sessions were held with the use of a live porcine model maintained under general anaesthesia; a total of 39 procedures were performed. In each session, one otolaryngology resident per year performed a procedure to acquire the targeted competencies for their respective year of training. Each procedure was time recorded and evaluated based on a modified Objective Structured Assessment of Technical Skills. Linear regression was used to analyse the data and express the results as percentages. RESULTS: Training exercises were performed in shorter times over the study period. A 9% reduction in the time spent was observed. There was a global improvement in the evaluation made by OSATS score of 6% in the first period (2018-2019) and 58% in the second period (2019-2020). CONCLUSION: The porcine model was both manageable and helpful in providing training despite slight anatomical differences between human beings and pigs. However, more studies are necessary to guarantee that the competencies acquired with this type of training are transferable to real-life interventions. LEVEL OF EVIDENCE: Level 5.

Utilidad de etomidato en paciente con síndrome de Cushing con hipertensión arterial e hipopotasemia graves / Usefulness of ethomidate in patients with Cushing syndrome with severe arterial hypertension and hypopotassemia

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PTPL1 and PKCδ contribute to proapoptotic signalling in prostate cancer cells.

PTPL1 is a non-receptor protein tyrosine phosphatase involved in apoptosis regulation, although controversial findings have been reported in different cancer types. We report here a proapoptotic role for PTPL1 in PC3 and LNCaP prostate cancer cells, as its absence induces apoptosis resistance upon treatment with different drugs. In PC3 cells, PTPL1 silencing by small interfering RNA influences the expression levels of Bcl-xL and Mcl-1(S) proteins as well as final events in the apoptotic process such as activation of caspases and caspase-mediated cleavage of proteins like Mcl-1 or poly (ADP-ribose) polymerase. We have identified PKCδ as an intermediary of PTPL1-mediated apoptotic signalling and that phosphorylation status of NF-κB and IκBα is influenced by PTPL1 and PKCδ. Furthermore, the loss of PTPL1 and PKCδ expression in poorly differentiated, more aggressive human prostate cancers also indicate that their absence could be related to apoptosis resistance and tumour progression.

Seudoaneurisma peroneo postraumático tardío y embolización intravascular: una alternativa terapéutica / Delayed post-traumatic pseudoaneurysm and endovascular embolisation: a therapeutic alternative

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Adsorption mechanisms of metal cations from water on an oxidized carbon surface.

Adsorption of Cr(III), Mn(II), Cu(II) and Zn(II) on an oxidized activated carbon cloth was studied. Its surface chemistry was characterized by potentiometric titration. This technique revealed the amount of surface oxygen functionalities and their acidity constant distribution. The acidity constant range involved in the metal cation adsorption was obtained from this distribution. Metal cation adsorption increased with higher adsorption temperature due to the increase in the negative surface charge of the oxidized activated carbon. Adsorption was by proton exchange and the number, amount and strength of the surface acid groups involved could be obtained. The proton exchange was by an inner-sphere or outer-sphere surface metal complex formation mechanism. In the case of divalent cation adsorption, the increase in temperature changed the adsorption mechanism from outer-sphere to inner-sphere. However, the adsorption mechanism of Cr(III) was outer-sphere and independent of temperature. Adsorption capacity augmented with the increase in the charge-to-size ratio of the hexa-aquo cations. In addition, the adsorption capacity of divalent cations increased with the rise in stability of the surface metal complex formed.

Batch and column adsorption of herbicide fluroxypyr on different types of activated carbons from water with varied degrees of hardness and alkalinity.

There has been little research into the effects of the water hardness and alkalinity of surface waters on the adsorption of herbicides on activated carbons. The aim of this study was to determine the influence of these water characteristics on fluroxypyr adsorption on different activated carbons. At low fluroxypyr surface concentrations, the amount adsorbed from distilled water was related to the surface hydrophobicity. Surface area of carbons covered by fluroxypyr molecules ranged from 60 to 65%. Variations in fluroxypyr solubility with water hardness and alkalinity showed a salting-in effect. Calcium, magnesium and bicarbonate ions were adsorbed to a varied extent on the activated carbons. The presence of fluroxypyr in solution decreased their adsorption due to a competition effect. K(F) from the Freundlich equation linearly increased with water hardness due to salt-screened electrostatic repulsions between charged fluroxypyr molecules. The amount adsorbed from distilled water was largest at high fluroxypyr solution concentrations, because there was no competition between inorganic ions and fluroxypyr molecules. The column breakthrough volume and the amount adsorbed at breakthrough were smaller in tap versus distilled water. Carbon consumption was lower with activated carbon cloth than with the use of granular activated carbon.

Adsorption and thermal desorption of the herbicide fluroxypyr on activated carbon fibers and cloth at different pH values.

Adsorption of fluroxypyr was studied at pH values between 2 and 10 and at temperatures of 298 and 313 K. Adsorption capacity decreased when the solution pH increased. This was explained by changes in fluroxypyr solubility and in dispersive and electrostatic adsorbent-adsorbate interactions with the increase in pH. The highest adsorption was found at pH 2, when the solubility was the lowest and only dispersive interactions operated. An increase in temperature produced a decrease in adsorption capacity. Thermal desorption of fluroxypyr up to 1073 K left a residue on the carbon surface, which increased with higher adsorption pH. Differential thermogravimetry (DTG) profiles showed two desorption peaks at pH values of 2 and 4 and only one peak at pH values of 7 and 10. The appearance of one or two peaks may be related to the type of adsorbate-adsorbent interactions established during adsorption. The predominance of electrostatic interactions favours the strongly bound or chemisorbed fluroxypyr. One important conclusion is that the highest amounts of fluroxypyr are adsorbed and thermally desorbed when there are only non-electrostatic interactions between fluroxypyr molecules and carbon surface. Activation desorption energy and pre-exponential factor were obtained from the shift in temperature of desorption peaks with higher heating rate.

Kinetics of diuron and amitrole adsorption from aqueous solution on activated carbons.

A study was conducted on the adsorption kinetics of diuron and amitrole from aqueous solutions on activated carbons of different particle sizes and on an activated carbon fiber. Different kinetic models were applied to the experimental results obtained. A pseudo-second-order rate equation fitted the adsorption kinetics data better than a pseudo-first-order rate equation. Amitrole showed faster adsorption kinetics compared with diuron because of the smaller size of the former herbicide, despite its lower driving force for adsorption. Both reaction rate constants increased when the particle size decreased. The activated carbon fiber and the activated carbon of smallest particle size (0.03 mm) showed similar adsorption kinetics. The intraparticle diffusion rate constant increased with higher initial concentration of herbicides in solution and with lower particle size of the adsorbent. This is because the rise in initial concentration increased the amount adsorbed at equilibrium, and the reduction in particle size increased the number of collisions between adsorbate and adsorbent particles. Demineralization of the activated carbon with particle size of 0.5mm had practically no effect on the adsorption kinetics.

Inter- and intra-primary-particle structure of monolithic carbon aerogels obtained with varying solvents.

Different carbon aerogels were obtained by carbonization of organic aerogels prepared from the polymerization of resorcinol and formaldehyde using potassium carbonate as catalyst. Various solvents were added to the initial mixture to study their effects on the inter- and intra-primary-particle structure of the carbon aerogels. To carry out this study, various techniques were used, including high-resolution transmission and scanning electron microscopy, mercury porosimetry, mechanical tests, N2 and CO2 adsorption at -196 and 0 degrees C, respectively, and immersion calorimetry into benzene. Variation of the solvent used produced changes in the gelation time of the organic aerogels, which gave rise to variations in the inter- and intra-primary-particle structure of the carbon aerogels obtained. The monolith density of the carbon aerogels ranged from 0.37 to 0.87 g/cm3. Samples with a density higher than 0.61 g/cm3 had micropores and mesopores but no macropores. Macro- and mesoporosity had a monomodal pore size distribution. The elastic modulus showed a scaling relationship with density. In all samples studied, which had a mean micropore width of 0.62-1.06 nm, the surface area obtained by enthalpy of immersion into benzene yielded a realistic value of their total surface area.

Adsorption of benzene, toluene, and xylenes on monolithic carbon aerogels from dry air flows.

Monolithic carbon aerogels were obtained by carbonization of organic aerogels prepared by polymerization of resorcinol and formaldehyde under different conditions. Some carbon aerogels obtained were further CO2-activated. Samples were characterized by gas adsorption, scanning electron microscopy, high-resolution transmission electron microscopy, and mechanical tests. Benzene, toluene and xylenes were adsorbed from dry air by using carbon bed columns, obtaining the breakthrough curves. There was no correlation between the amount adsorbed at the breakthrough point and the volume of micropores narrower than 0.7 nm. Conversely, a good linear relationship between the amount adsorbed at the breakthrough point and the total micropore volume up to a mean micropore width of around 1.05 nm was found. In addition, the height of the mass transfer zone decreased with the mean width of the total micropores up to a value of around 1.05-1.10 nm. One of the best adsorbents obtained showed the lowest height of the mass transfer zone and one of the highest amounts adsorbed at the breakthrough point, either per mass or volume unit. However, it had a lower elastic modulus and compressive strength than other monolithic carbon aerogels, although its compressive strength (3 MPa) was still high enough to use it in carbon bed columns. The sample with the best mechanical properties was a poorer adsorbent. Regeneration of the exhausted adsorbents allowed the recovery of the hydrocarbons adsorbed without any appreciable loss of adsorption capacity of the carbon bed.

Removal of diuron and amitrole from water under static and dynamic conditions using activated carbons in form of fibers, cloth, and grains.

This study investigated the removal of the herbicides diuron and amitrole from water under static and dynamic conditions using different activated carbons in the form of fibers, cloth, and grains. In all cases, there was much greater adsorption of diuron than of amitrole due to the lower solubility, greater hydrophobicity, and larger dipolar moment of the former. The activated carbon cloth was the best adsorbent for diuron under dynamic conditions because it had the largest mesopore volume, water-accessible pore volume, and surface area. However, the best adsorbent for amitrole under dynamic conditions was the granular activated carbon due to its higher surface basicity. Comparisons using the best adsorbent for each herbicide showed that diuron was removed by the activated carbon more efficiently compared with amitrole under both dynamic and static conditions.

Effect of surface chemistry, solution pH, and ionic strength on the removal of herbicides diuron and amitrole from water by an activated carbon fiber.

A study was conducted on the effects of carbon surface chemistry, solution pH, and ionic strength on the removal of diuron and amitrole from aqueous solutions by adsorption on an as-received and oxidized activated carbon fiber. Results obtained were explained by the surface characteristics of the adsorbents and the characteristics of the herbicide molecules. Under the experimental conditions used, diuron uptake was much higher than that of amitrole, despite its larger molecular dimensions, due to the lesser water solubility, greater hydrophobicity, and larger dipolar moment of diuron compared with amitrole. Uptake variations associated with differences in carbon surface oxidation, solution pH, and ionic strength were explained by corresponding changes in electrostatic, hydrophobic, and van der Waals interactions.

Oral beclomethasone dipropionate for the treatment of gastrointestinal acute graft-versus-host disease (GVHD).

Acute graft-versus-host disease (aGVHD) remains one of the most severe complications after allogeneic transplantation; in particular, the presence of gut involvement has been related to increased mortality and poorer response. The use of systemic steroids remains the standard for first-line treatment despite its severe secondary effects. Beclomethasone dipropionate (BDP) is a topically active corticosteroid with low absorption, thereby avoiding many of the deleterious side effects associated with systemic steroids. In the present study we analyzed the efficacy of BDP in a series of 26 patients who were diagnosed with grade 1 and 2 gastrointestinal aGVHD. Twenty patients (77%) responded to BDP treatment, 17 (65.5%) reached complete remission (CR), and 3 (11.5%) showed partial response. Among those patients who reached CR, 5 relapsed, although 1 of them reached second CR after a second course of BDP; therefore, 13 (50%) of the 26 patients did not require systemic steroids to treat gastrointestinal aGVHD. CR rates in those showing gastrointestinal symptoms were 68% for patients with persistent nausea, 50% for those with vomiting, and 54% for those with diarrhea (P=.2). No patient included in the study developed any symptom related to adrenal axis suppression. Thirteen patients (50%) developed >or=1 infectious episode during the first 100 days after transplantation. Transplant-related mortality was 0% at 100 days, and overall transplant-related mortality was 30%, with only 2 patients dying due to infectious complications. Therefore, our study shows that monotherapy with oral BDP is an effective initial therapeutic approach for mild to moderate intestinal GVHD, which avoids complications related to systemic steroids.

Molybdenum carbide formation in molybdenum-doped organic and carbon aerogels.

A Mo-doped organic aerogel and its corresponding carbonized derivative at 1000 degrees C were obtained. Both samples were treated in a H(2)/Ar flow. After this treatment, a mixture of Mo(VI) and Mo(2)C was detected in both samples. The results obtained indicate that the presence of H(2) in the gas flow is necessary to obtain the carbide phase, due to the formation of CH(4) or even CH(x)() species that reduce and carburize the molybdenum oxide phase. Carburization of the Mo-doped organic aerogel yielded better results compared with carburization of the Mo-doped carbon aerogel.