UV- and visible-light photocatalysis using Ni-Co bimetallic and monometallic hydrotalcite-like materials for enhanced CO2 methanation in sabatier reaction.

The CO2 catalytic reduction activities of four different Co-modified Ni-based catalysts derived from hydrotalcite-like materials (HTCs) prepared by co-precipitation method were investigated under thermal and photocatalytic conditions. All catalysts were tested from 473 to 723 K at 10 bar (abs). The light intensity for photocatalytic reactions was 2.4 W cm-2. The samples were characterized to determine the effect of morphological and physicochemical properties of mono-bimetallic active phases on their methanation activity. The activity toward CO2 methanation followed the next order: Ni > Co-Ni > Co. For the monometallic Ni catalyst an increase of a 72% was achieved in the photo-catalytic activity under UV and vis light irradiation at temperatures lower by > 100 K than those in a conventional reaction. Co-modified Ni based hydrotalcite catalysts performed with stability and no deactivation for the 16 h studied under visible light for methanation at 523 K due to the presence of basic sites.

Development of High Temperature Water Sorbents Based on Zeolites, Dolomite, Lanthanum Oxide and Coke.

Methanation is gaining attention as it produces green methane from CO2 and H2, through Power-to-Gas technology. This process could be improved by in situ water sorption. The main difficulty for this process intensification is to find effective water sorbents at useful reaction temperatures (275-400 °C). The present work comprises the study of the water sorption capacity of different materials at 25-400 °C. The sorption capacity of the most studied solid sorbents (zeolites 3A & 4A) was compared to other materials such as dolomite, La2O3 and cokes. In trying to improve their stability and sorption capacity at high temperatures, all these materials were modified with alkaline-earth metals (Ba, Ca & Mg). Lanthana-Ba and dolomite sorbents were the most promising materials, reaching water sorption values of 120 and 102 mgH2O/gsorbent, respectively, even at 300 °C, i.e., values 10-times higher than the achieved ones with zeolites 3A or 4A under the same operating conditions. At these high temperatures, around 300 °C, the water sorption process was concluded to be closer to chemisorption than to physisorption.

Graphene-based versus alumina supports on CO2 methanation using lanthanum-promoted nickel catalysts.

The valorization of CO2 as a biofuel, transforming it through methanation as part of the power-to-gas (P2G) process, will allow the reduction of the net emissions of this gas to the atmosphere. Catalysts with 13 wt.% of nickel (Ni) loading incorporated into alumina and graphene derivatives were used, and the effect of the support on the activity was examined at temperatures between 498 and 773 K and 10 bar of pressure. Among the graphene-based catalysts (13Ni/AGO, 13Ni/BGO, 13Ni/rGO, 13Ni-Ol/GO, 13Ni/Ol-GO, and 13Ni/Ol-GO Met), the highest methane yield was found for 13Ni/rGO (78% at 810 K), being the only system comparable to the catalyst supported on alumina 13Ni/Al2O3 (89.5% at 745 K). The incorporation of 14 wt.% of lanthanum (La) into the most promising supports, rGO and alumina, led to nickel-support interactions that enhanced the catalytic activity of 13Ni/Al2O3 (89.5% at lower temperature, 727 K) but was not effective for 13Ni/rGO. The resistance against deactivation by H2S poisoning was also studied for these catalysts, and a fast deactivation was observed. In addition, activity recovery was impossible despite the regeneration treatment carried out over catalysts. The resistance against deactivation by H2S poisoning was also studied for these catalysts, observing that both suffered a rapid/immediate deactivation and which in addition/unfortunately was impossible to solve despite the regeneration treatment carried out over catalysts.

A study of deactivation by H2S and regeneration of a Ni catalyst supported on Al2O3, during methanation of CO2. Effect of the promoters Co, Cr, Fe and Mo.

Energy storage from renewable sources is possible by chemical procedures, power to gas technology being a possible solution for long-term storage. In this work, CO2 methanation from a sulphur containing gas was studied, taking into account deactivation of the catalysts and a regeneration process. In order to improve the sulphur resistance of a standard nickel (13%) catalyst supported on alumina, transition metals like molybdenum (Mo), iron (Fe), cobalt (Co) or chromium (Cr), in different proportions (from 4 to 8 wt%) were added to the catalyst formulation. The catalyst activity, between 573 and 773 K, at 10 bar, increased when transition metals were added except for Mo in the highest proportion. These bimetallic catalysts presented a similar deactivation resistance than the monometallic catalyst when sulphur was present in the feed. Once H2S was removed from the feed, and the catalysts regenerated with oxygen, only the catalyst containing cobalt recovered up to a 13% methane yield.

Multicatalysis Combining 3D-Printed Devices and Magnetic Nanoparticles in One-Pot Reactions: Steps Forward in Compartmentation and Recyclability of Catalysts.

A tricatalytic compartmentalized system that immobilizes metallic species to perform one-pot sequential functionalization is described: a three-dimensional (3D)-printed palladium monolith, ferritic copper(I) magnetic nanoparticles, and a 3D-printed polypropylene capsule-containing copper(II) loaded onto polystyrene-supported 1,5,7-triazabicyclo[4.4.0]dec-5-ene (PS-TBD) allowed the rapid synthesis of diverse substituted 1-([1,1'-biphenyl]-4-yl)-1H-1,2,3-triazoles. The procedure is based on the Chan-Lam azidation/copper alkyne-azide cycloaddition/Suzuki reaction strategy in the solution phase. This catalytic system enabled the efficient assembly of the final compounds in high yields without the need for special additives or intermediate isolation. The monolithic catalyst-containing immobilized palladium species was synthesized by surface chemical modification of a 3D-printed silica monolith using a soluble polyimide resin as a key reagent, thus creating an extremely robust composite. All three immobilized catalysts described here were easily recovered and reused in numerous cycles. This work exemplifies the role of 3D printing in the design and manufacture of devices for compartmented multicatalytic systems to carry out complex one-pot transformations.

Heterogeneous Catalyzed Thermochemical Conversion of Lignin Model Compounds: An Overview.

Thermochemical lignin conversion processes can be described as complex reaction networks involving not only de-polymerization and re-polymerization reactions, but also chemical transformations of the depolymerized mono-, di-, and oligomeric compounds. They typically result in a product mixture consisting of a gaseous, liquid (i.e., mono-, di-, and oligomeric products), and solid phase. Consequently, researchers have developed a common strategy to simplify this issue by replacing lignin with simpler, but still representative, lignin model compounds. This strategy is typically applied to the elucidation of reaction mechanisms and the exploration of novel lignin conversion approaches. In this review, we present a general overview of the latest advances in the principal thermochemical processes applied for the conversion of lignin model compounds using heterogeneous catalysts. This review focuses on the most representative lignin conversion methods, i.e., reductive, oxidative, pyrolytic, and hydrolytic processes. An additional subchapter on the reforming of pyrolysis oil model compounds has also been included. Special attention will be given to those research papers using "green" reactants (i.e., H2 or renewable hydrogen donor molecules in reductive processes or air/O2 in oxidative processes) and solvents, although less environmentally friendly chemicals will be also considered. Moreover, the scope of the review is limited to those most representative lignin model compounds and to those reaction products that are typically targeted in lignin valorization.

[Does continuous veno-venous hemodiafiltration therapy reduce mortality due to acute renal failure as compared to intermittent hemodialysis?]. / Es la hemodiafiltración veno-venosa continua superior a la hemodiálisis intermitente en términos de supervivencia en los enfermos con fracaso renal agudo? Respuesta mediante una revisión sistemática.

OBJECTIVE: To estimate whether continuous veno-venous hemodiafiltration (CVVHDF) is superior to intermittent hemodialysis (IHD) in terms of survival of adult patients with acute renal failure (ARF) admitted to the Intensive Care Unit. SELECTION OF STUDIES: Controlled clinical trials (CCT) and systematic reviews comparing CWHDF and IHD for managing ARF in adult patients (age > 19 years). Observational and case series were excluded. SEARCH SOURCES: The basic syntax <> was used to search Pub Med and Ovid System databases. A manual search was done by reviewing the references in the corresponding topic of UpToDate. ANALYSIS: Data were extracted by two author and their methodological quality was assessed according to the Cochrane Renal Group recommendations that include the procedure for assigning, blinding, intention to treat analysis, and follow-up. OUTCOMES VARIABLES: All data relating to mortality were extracted, specifying the time of collection, time and circumstances (mortality in the ICU or hospitalization). Values gathered are expressed as mortality rates in both the experimental group (CVVHDF) and the control group (IHD), indicating the absolute risk reduction (ARR) and its 95% confidence interval. OUTCOMES AGGREGATION: Studies meeting clinical and methodological homogeneity criteria were combined with the fix effect model by using the Review Manager tool from Cochrane Collaboration. Methodological heterogeneity was analyzed by using the chi-squared test for n-1 freedom degrees, with an alpha value of 0.05. A sensitivity analysis was done adjusting for methodological quality to confirm the results obtained. RESULTS: Seven clinical trials directly comparing the survival of severe ARF patients in a prospective, randomized, and controlled way were identifiec. Almost all published estudies have quality problems because of being too small to study survival rates, treatment allocation problems and high numbers of loss to follow-up, differences in initial severity levels, or to premature study closure. When combining the results, it was observed that mortality was 64% for IHD and 65% for CVVHDF, with a relative risk of 0.98 (95% CI 0.89-1.07), p = 0.65, with no statistically significant heterogeneity between studies included. When excluding from the analysis the most questionable study due to selection bias, high loss to follow-up (21%), and baseline differences in co-variables influencing the study outcomes, the results are not changed, the observed mortality was 67% for extra-renal intermittent depurative techniques versus 65% for continous ones, with a relative risk of 1.03 (95% CI 0.94-1.14), p = 0.54, again with no statistically significant heterogeneity between studies included. CONCLUSION: CVVHDF does not offer any benefit as compared to IHD in terms of survival and according to available data from the literature. However, continuous techniques bring other potential benefits such as hemodynamic stability, better tolerability of ultrafiltration, and depuration of solutes, which merit a systematic review to estimate and quantify their magnitude, and which would allow for better defining their place in the therapeutic armamentarium available for this high-mortality condition.

Eccema coxsackium en pacientes con dermatitis atópica / Coxsackium eczema in patients with atopic dermatitis

El eccema coxsackium es una dermatosis infecciosa caracterizada por lesiones papulovesiculosas, eccematosas e incluso costrosas de predominio en extremidades, nalgas y región perioral. Suele aparecer en pacientes con afectación cutánea previa, como es el caso de la dermatitis atópica de los niños. El germen causante más frecuentemente aislado es el Coxsackie A6. Está considerado como una forma atípica de la enfermedad mano-pie-boca y es importante un correcto diagnóstico diferencial para evitar tratamientos innecesarios (AU)

Eczema coxsackium is an infectious dermatosis characterized by papulovesicular, ezzematous and even crusty lesions predominantly on the extremities, buttocks and perioral region. It usually appears in patients with previous skin involvement, as in the case of atopic dermatitis in children. The most frequently isolated causative germ is Coxsackie A6. It is considered an atypical form of Hand, Foot and Mouth Disease and a correct differential diagnosis is important to avoid unnecessary treatments. (AU)

Sustainable hydrogen production from bio-oil model compounds (meta-xylene) and mixtures (1-butanol, meta-xylene and furfural).

In the present work m-xylene and an equimolecular mixture of m-xylene, 1-butanol and furfural, all of them bio-oil model compounds, were studied in steam reforming (SR) conditions. Three different nickel catalysts, which showed to be active in 1-butanol SR (Ni/Al2O3, Ni/CeO2-Al2O3 and Ni/La2O3-Al2O3), were tested and compared with thermodynamic equilibrium values. Tests were carried out at temperatures from 800 to 600°C at atmospheric pressure with a steam to carbon ratio (S/C) of 5.0. Despite the different bio-oils fed, the amount of moles going through the catalytic bed was kept constant in order to obtain comparable results. After their use, catalysts were characterized by different techniques and those values were correlated with the activity results. All catalysts were deactivated during the SR of the mixture, mainly by coking. The highest hydrogen yields were obtained with Ni/Al2O3 and Ni/CeO2-Al2O3 catalysts in the SR of m-xylene and SR of the mixture, respectively.

Adenosine induces a calcium-dependent glomerular contraction.

Glomeruli isolated from rat kidney cortex were incubated with adenosine in the presence or absence of verapamil and calcium and their change in cross-sectional area was recorded. Adenosine induced a 10% decrease in glomerular cross-sectional area. This decrease was blocked by verapamil or a calcium-free medium. The results suggest that the effect of adenosine in the kidney could be due to glomerular constriction, and that this constriction depends on the entry of calcium into glomerular cells.

Atrial natriuretic peptide inhibits glomerular contraction induced by angiotensin II and platelet activating factor.

Isolated rat glomeruli were incubated with angiotensin II, PAF and atrial natriuretic peptide (ANP). Angiotensin II and PAF produced a significant glomerular contraction as evidenced by the decrease in glomerular cross-sectional area. The addition of ANP abolished this effect. These results suggest that ANP could modulate glomerular filtration rate, not only by inducing changes in intrarenal hemodynamics, but also by preventing the effect of some hormones on the filtration surface and subsequently on the ultrafiltration coefficient.

Factors affecting beta 2-microglobulin plasma concentration during hemodialysis.

We studied ten patients on hemodialysis (HD) treated in sequence with cuprophan (CU), ethylenevinylalcohol (EVAL), polyacrylonitrile (A-69) and polysulphone (PSP) membrane dialyzers. beta 2-microglobulin (beta 2m) was measured by radioimmunoassay in plasma and dialysate samples. Plasma concentrations were corrected for changes in extracellular volume (ECV). We also studied adsorption in vitro by incubating the above membranes with I-125-labelled beta 2m. There were no changes in beta 2m plasma concentration after HD with CU dialyzers, but a significant decrease was observed with the other membranes tested. Filtration of beta 2m across the dialyzer was absent with CU and minimal with EVAL. However, large amounts were recovered from dialysate with the high-permeability dialyzers, AN-69 and PSP. In vitro studies showed that maximal adsorption capacity was obtained with AN-69 (13%) compared to 9% with CU, 4% with EVAL and 7% with PSP. In summary, beta 2m clearance with PSP is achieved through greater removal of this protein by mass transport across the membrane. The mechanism by which beta 2m is removed from blood during AN-69 dialysis seems to include both adsorption to and filtration by the membrane itself.

[Validation of a new questionnaire to evaluate the quality of life in patients after myocardial infarction]. / Validación de un nuevo cuestionario para evaluar la calidad de vida en pacientes postinfarto.

Quality of life is an important measurement in chronic diseases and especially in patients after myocardial infarction. We designed and structured a new Questionnaire of Quality of Life for Spanish speaking patients from the existing English questionnaires. The new Questionnaire of Velasco-Del Barrio has a total of 44 items, grouped in 9 subscales: health, sleep and rest, emotional behaviour, concerns to the future, mobility, social relations alertness behaviour, communication, and work and leisure time. The questionnaire has been validated taking as a gold standard, the Quality of Life Questionnaire for Myocardial Infarction (QLMI-Q) of Oldridge. The reliability and the reproducibility have also been studied. The validity of the Velasco-Del Barrio Questionnaire was high (r = 0.81), as its reproducibility (0.75) and reliability (0.90). We assume that the usefulness of the new Questionnaire is at least, similar to that of the Oldridge's one, and that it can be recommended in postinfarction patients, even though it can be more advantageous in patients of Spanish speaking cultures.