Complete photocatalytic reduction of CO2 to methane by H2 under solar light irradiation.

Nickel supported on silica-alumina is an efficient and reusable photocatalyst for the reduction of CO2 to methane by H2, reaching selectivity above 95% at CO2 conversion over 90%. Although NiO behaves similarly, it undergoes a gradual deactivation upon reuse. About 26% of the photocatalytic activity of Ni/silica-alumina under solar light derives from the visible light photoresponse.

The impact of TOURISM and seasonality on different types of municipal solid waste (MSW) generation: The case of Ibiza.

Most studies analysing waste generation consider the impact on the resident population; however, in the case of tourist destinations, it is important to differentiate the impact between the local population and tourists. This research separates these two population groups using the stochastic impacts by regression on population, affluence and technology (STIRPAT) model for the case of Ibiza. The results confirm different waste generation patterns in tourist and non-tourist populations depending on the waste type (non-sorted and sorted). Moreover, our analysis found that the amount of waste generated per person decreased over time, demonstrating the growth of circular economy practices in the destination. Furthermore, the STIRPAT model highlights the development of a circular economy, showing a downward trend in the generation of non-sorted waste and a positive trend towards collecting recyclable materials. Finally, the results confirm that waste generation patterns vary by season, population, and waste type. Additionally, for both populations, there is a reduction in per capita non-sorted waste generation (this is more significant for the non-tourist population). In contrast, per capita sorted waste generation has increased for both types of population.

Visible-light photocatalytic conversion of carbon monoxide to methane by nickel(II) oxide.

Solar Fuels: Different n- and p-type semiconductors have been investigated for sustainable solar fuel production. p-Type semiconductors, such as NiO, Fe3 O4 , Co3 O4 , and CuO, are able to reduce carbon monoxide by water or hydrogen to methane. The highest CH4 yield achieved was 17.26 mmol of CH4 per gram of catalyst using NiO in an excess of H2 .

Sunlight Powered Continuous Flow Reverse Water Gas Shift Process Using a Plasmonic Au/TiO2 Nanocatalyst.

The continuous flow reverse water gas shift (rWGS) process was efficiently catalyzed by a plasmonic Au/TiO2 nanocatalyst using sunlight as sole and sustainable energy source. The influence of the catalyst bed thickness on the CO production rate was studied, and three different catalytic regimes were identified as direct plasmon catalysis (DPC), shielded plasmon catalysis (SPC) and unused plasmon catalysis (UPC). The CO2 : H2 ratio was optimized to 4 : 1 and a maximum CO production rate of 7420 mmol ⋅ m-2 ⋅ h-1 was achieved under mild reaction conditions (p=3.5 bar, no external heating, Ee =14.0 kW ⋅ m-2 ), corresponding to an aparent quantum efficiency of 4.15%. The stability of the Au/TiO2 catalyst was studied for 110 h continuous operation, maintaining more than 82% of the initial CO production rate. On/off experiments mimicking discontinuous sunlight powered processing furthermore showed that the Au/TiO2 catalyst was stable for 8 consecutive runs.

185 nm photoreduction of CO2 to methane by water. Influence of the presence of a basic catalyst.

Photolysis of CO(2) at 185 nm using a Hg lamp in the presence of H(2) or H(2)O leads to the formation of CH(4) (after an induction period) and a lesser amount of CO. Using H(2) gas as reducing agent, up to 40% conversion was achieved with almost complete selectivity to methane and energy consumption of 1.55 Gcal/mol. When CO(2) irradiation is carried out in the gas phase in the presence of H(2)O, both reagents can undergo photolysis, and H(2) generation from water is a competing process accompanying the formation of CO and CH(4) (CO(2) conversion 0.67% at 14 h). For the irradiation of CO(2) using H(2)O as reducing agent, basic solids (K(+)-exchanged Y zeolite or hydrotalcites) can increase CO(2) conversion up to 2.21% with total selectivity toward CH(4) and an energy consumption of 4.5 Gcal/mol. This result opens a door in the quest for efficient photocatalysts that could further increase the apparent quantum yield of the process, particularly at longer wavelengths.

Conversion of methane into C1 oxygenates by deep-UV photolysis on solid surfaces: influence of the nature of the solid and optimization of photolysis conditions.

Deep-UV photolysis (either 165 or 185 nm) of surface hydroxy groups leads to homolytic O-H bond-cleavage with the generation of oxyl radicals that can initiate the room-temperature radical-chain methane activation. Whilst in the absence of oxygen, radical coupling reactions to give low-molecular-weight alkanes are observed in the gas phase, the presence of some oxygen quenches these radicals and increases the selectivity towards C1 oxygenates (methanol, formaldehyde, and formic acid species). The nature of the solid influences the efficiency of the photochemical process and the distribution between products in the gas and solid phases. Using Beta-, delaminated ITQ2 and ITQ6, and medium-pore ZSM5 zeolites, mesoporous MCM41 silicates, and non-porous TiO(2), we observed that confinement and porosity increased the proportion of C1 oxygenates adsorbed onto the solid and reduced the contribution of the gas-phase products. In addition, the presence of aluminum in the zeolite framework, which is responsible for the generation of acid sites, increased overoxidation of methanol and methoxy groups into formaldehyde and formic acids. For a given amount of methane and unchanged photolysis conditions, the conversion increased with the amount of the solid used as photocatalyst. In this way, methane conversions of up to 7% were achieved for the 185 nm photolysis of methane for 1 h with a 76 MJ mol(-1) energy consumption.

Sunlight-Powered Reverse Water Gas Shift Reaction Catalysed by Plasmonic Au/TiO2 Nanocatalysts: Effects of Au Particle Size on the Activity and Selectivity.

This study reports the low temperature and low pressure conversion (up to 160 °C, p = 3.5 bar) of CO2 and H2 to CO using plasmonic Au/TiO2 nanocatalysts and mildly concentrated artificial sunlight as the sole energy source (up to 13.9 kW·m-2 = 13.9 suns). To distinguish between photothermal and non-thermal contributors, we investigated the impact of the Au nanoparticle size and light intensity on the activity and selectivity of the catalyst. A comparative study between P25 TiO2-supported Au nanocatalysts of a size of 6 nm and 16 nm displayed a 15 times higher activity for the smaller particles, which can only partially be attributed to the higher Au surface area. Other factors that may play a role are e.g., the electronic contact between Au and TiO2 and the ratio between plasmonic absorption and scattering. Both catalysts displayed ≥84% selectivity for CO (side product is CH4). Furthermore, we demonstrated that the catalytic activity of Au/TiO2 increases exponentially with increasing light intensity, which indicated the presence of a photothermal contributor. In dark, however, both Au/TiO2 catalysts solely produced CH4 at the same catalyst bed temperature (160 °C). We propose that the difference in selectivity is caused by the promotion of CO desorption through charge transfer of plasmon generated charges (as a non-thermal contributor).

Selective, room-temperature transformation of methane to C1 oxygenates by deep UV photolysis over zeolites.

Methane can directly be transformed into liquid C(1) oxygenated products with selectivities above 95% at 13% conversion by deep UV photocatalysis, in the presence of H(2)O and air. Pure silica zeolites, and more specifically, beta zeolite with a large number of internal silanol groups is active and selective, while amorphous silica with no micropores is much less efficient. Irradiation produces the homolytic cleavage of surface hydroxyl groups, leading to silyloxyl radicals that will generate methyl radicals from methane. The selectivity arises from the occurrence of the reaction in a confined space restricting the mobility of the radical intermediates that will be mostly attached to the solid surface. Energy consumption of the process is in the order of 7.2 Gcal × mol(-1) that compares very favorably with the energy required for transforming methane to synthesis gas (15.96 Gcal × mol(-1)).

Measuring risks and vulnerability of tourism to the COVID-19 crisis in the context of extreme uncertainty: The case of the Balearic Islands.

The COVID-19 crisis is dramatically affecting the world economy and, particularly, the tourism sector. In the context of extreme uncertainty, the use of probabilistic forecasting models is especially suitable. We use Monte Carlo simulations to evaluate the outcomes of four possible tourism demand recovery scenarios in the Balearic Islands, which are further used to measure the risks and vulnerability of Balearic economy to the COVID-19 crisis. Our results show that fear of contagion and loss of income in tourism emitting countries will result in a maximum 89% drop in arrivals in the Balearic Islands in 2020.Given that most tourism-related occupations are not highly skilled and are characterized by lower salaries, there are greater risks of loss of welfare, especially for women, who are a major share of the tourism labour force.The model shows important differences among minimum, average and maximum estimates for tourism sector production in 2021, reflecting considerable uncertainty regarding the speed of the sector's recovery. The results serve as a basis to prepare a range of policies to reduce destination vulnerability under different crisis outcomes.

Genetic mutations in a Spanish population with chronic pancreatitis.

BACKGROUND/AIMS: Mutations in the PRSS1 and the SPINK1 genes have variably been associated with alcohol-related, idiopathic and hereditary chronic pancreatitis (CP). The aim of this study was to determine for the first time the significance of PRSS1, SPINK1 mutations and genetic variants of AAT in a group of Spanish patients with CP. METHODS: 104 consecutive patients with CP were included, as well as 84 healthy control subjects. The R122H and N29I mutations in the PRSS1 gene, the N34S mutation in the SPINK1 gene and PiS and PiZ mutations in the AAT gene were analyzed by RFLP-PCR methods. RESULTS: No R122H mutation was found in the PRSS1 gene, and N29I mutation was detected in 7.7% of CP patients. A N29I mutation was observed in 3.9% of patients with alcohol-related pancreatitis (ACP). A total of 5.8% of CP patients were identified with the N34S mutation. Genotype MS, SS and MZ were detected in 18.3, 3.8 and 1.3% of CP patients, respectively. CONCLUSION: The percentage of N29I mutations in ACP patients was higher than that reported in other studies, while the percentage of N34S and AAT mutations in ACP and idiopathic CP patients was similar.

Sunlight-Fueled, Low-Temperature Ru-Catalyzed Conversion of CO2 and H2 to CH4 with a High Photon-to-Methane Efficiency.

Methane, which has a high energy storage density and is safely stored and transported in our existing infrastructure, can be produced through conversion of the undesired energy carrier H2 with CO2. Methane production with standard transition-metal catalysts requires high-temperature activation (300-500 °C). Alternatively, semiconductor metal oxide photocatalysts can be used, but they require high-intensity UV light. Here, we report a Ru metal catalyst that facilitates methanation below 250 °C using sunlight as an energy source. Although at low solar intensity (1 sun) the activity of the Ru catalyst is mainly attributed to thermal effects, we identified a large nonthermal contribution at slightly elevated intensities (5.7 and 8.5 sun) resulting in a high photon-to-methane efficiency of up to 55% over the whole solar spectrum. We attribute the excellent sunlight-harvesting ability of the catalyst and the high photon-to-methane efficiency to its UV-vis-NIR plasmonic absorption. Our highly efficient conversion of H2 to methane is a promising technology to simultaneously accelerate the energy transition and reduce CO2 emissions.

Dietary phytosterols modulate T-helper immune response but do not induce apparent anti-inflammatory effects in a mouse model of acute, aseptic inflammation.

Although most studies have focused on the cholesterol-lowering activity of phytosterols, other biological actions have been ascribed to these plant sterol compounds, one of which is a potential immune modulatory effect. To gain insight into this issue, we used a mouse model of acute, aseptic inflammation induced by a single subcutaneous turpentine injection. Hypercholesterolemic apolipoprotein E-deficient (apoE(-/-)) mice, fed with or without a 2% phytosterol supplement, were treated with turpentine or saline and euthanized 48 h later. No differences were observed in spleen lymphocyte subsets between phytosterol- and control-fed apoE(-/-) mice. However, cultured spleen lymphocytes of apoE(-/-) mice fed with phytosterols and treated with turpentine showed increased IL-2 and IFN-gamma secretion (T-helper type1, Th1 lymphocyte cytokines) compared with turpentine-treated, control-fed animals. In contrast, there was no change in Th2 cytokines IL-4 and IL-10. Phytosterols also inhibit intestinal cholesterol absorption in wild-type C57BL/6J mice but, in this case, without decreasing plasma cholesterol. Spleen lymphocytes of turpentine-treated C57BL/6J mice fed with phytosterols also showed increased IL-2 production, but IFN-gamma, IL-4 and IL-10 production was unchanged. The Th1/Th2 ratio was significantly increased both in phytosterol-fed apoE(-/-) and C57BL/6J mice. We conclude that phytosterols modulate the T-helper immune response in vivo, in part independently of their hypocholesterolemic effect in a setting of acute, aseptic inflammation. Further study of phytosterol effects on immune-based diseases characterized by an exacerbated Th2 response is thus of interest.

Platelet-activating factor acetylhydrolase is mainly associated with electronegative low-density lipoprotein subfraction.

BACKGROUND: Electronegative LDL [LDL(-)], a modified subfraction of LDL present in plasma, induces the release of interleukin-8 and monocyte chemotactic protein-1 from cultured endothelial cells. METHODS AND RESULTS: We demonstrate that platelet-activating factor acetylhydrolase (PAF-AH) is mainly associated with LDL(-). LDL(-) had 5-fold higher PAF-AH activity than the nonelectronegative LDL subfraction [LDL(+)] in both normolipemic and familial hypercholesterolemic subjects. Western blot analysis after SDS-PAGE confirmed these results, because a single band of 44 kDa corresponding to PAF-AH appeared in LDL(-) but not in LDL(+). Nondenaturing polyacrylamide gradient gel electrophoresis demonstrated that PAF-AH was bound to LDL(-) regardless of LDL size. In accordance with the above findings, nonesterified fatty acids, a cleavage product of PAF-AH, were increased in LDL(-) compared with LDL(+). CONCLUSIONS: The high PAF-AH activity observed in LDL(-) could be related to the proinflammatory activity of these lipoproteins toward cultured endothelial cells.

[Determination and utilisation of the plasmatic concentration of homocysteine in clinical practice]. / Determinación y utilización de la concentración plasmática de homocisteína en la práctica clínica.

Homocysteine is a methionine-derived amino acid and its metabolism depends on B12, B6 and B2 vitamins and folic acid. The total homocysteine plasmatic concentration can be measured in most laboratories by means of enzymeimmunoassays. Hyperhomocysteinemia may be caused by genetic defects of the enzymes involved in its metabolism, nutritional deficiencies or absorption deficiencies of the vitamin cofactors of these enzymes, chronic diseases or administration of some drugs. An increase in the total plasmatic concentration of homocysteine represents a sensitive marker of folate and cobalamin deficiencies as well as an independent risk factor of cardiovascular disease. Furthermore, total plasmatic concentrations of homocysteine are related to the development of congenital malformations, pregnancy complications, psychiatric diseases and to cognitive impairment in the elderly. Therefore, the measurement of the concentration of homocysteine has a notable clinical interest, which may increase in future if it is confirmed that the association with these disorders is causal and that they can be prevented by treating hyperhomocysteinemia.

Phenytoin treatment reduces atherosclerosis in mice through mechanisms independent of plasma HDL-cholesterol concentration.

Phenytoin (PHT) increases high density lipoprotein cholesterol (HDL-C) and reduces coronary artery disease mortality in humans. We report the results of PHT treatment on atherosclerosis susceptibility and lipid profile in four different types of mouse: control C57BL/6 mice and cholesteryl ester transfer protein transgenic mice as models of fatty streak, and LDL receptor-deficient mice and apolipoprotein E-deficient mice as models of mature atherosclerosis. Each mouse type was fed an appropriate diet to induce atherosclerosis and prevent liver toxicity. PHT treatment demonstrated a protective effect in all models. Reduction in aortic atherosclerotic area by PHT treatment was more evident in early atherosclerosis (2.3-fold) than in mature atherosclerosis (decreases of 40 and 23%, respectively, but only in mice in the upper 50% percentile of plasma PHT concentration). Atherosclerosis prevention was not concomitant with a consistent increase in HDL-C or any other protective change in the lipid profile. Different analyses of potential antiatherogenic HDL functions did not provide additional information. Microarray liver gene expression analyses identified a potential atheroprotective mechanism characterized by decreased expression of syndecan-4, RhoA2, double LIM protein-1, zeta-chain-associated protein kinase-70 and interleukin 6 receptor-alpha. However, to demonstrate that these changes are part of a PHT-antiatherogenic effect, they will need to be found also in arteries, maintained at protein level and proved to be causal rather than reactive.

Impulsive and compulsive behaviors in Parkinson's disease: a one-year follow-up study.

Impulsive and compulsive behaviors (ICBs) have been reported to occur frequently in Parkinson's disease (PD) and include impulse control disorders (ICDs), punding and dopamine dysregulation syndrome (SSD). We report on the outcomes of 25 PD patients who developed ICBs. Information was collected on changes in parkinsonian and psychiatric medication follow-up (median=12.1 months). At time 1, only 18 patients (72%) were taking dopamine agonists (DA). At time 2, fifteen patients (83.33%) either discontinued or decreased their DA treatment. Of these patients, thirteen (86.67%) reported experiencing full or partial remission of their ICBs symptoms. When analyzing separately the 11 patients with punding, these symptoms remained unchanged in 9 patients (81.82%) independently of changes in dopaminergic drugs. In conclusion, the current study suggests that there are clear similarities, but also important differences, between punding and ICDs over time. Pathological gambling, binge or compulsive eating, pathological hypersexuality and compulsive shopping in PD were robustly associated with the use of DA but the relationship between dopaminergic medications and punding is less clear. It is important to determine if other treatment strategies may be effective for punding in PD.

Visible-light hydrogen generation using as photocatalysts layered titanates incorporating in the intergallery space ruthenium tris(bipyridyl) and methyl viologen.

A series of layered titanates containing in the interlayer space tris(2,2'-bipyridyl)ruthenium(II) [Ru(bpy)(3)(2+)] or methyl viologen (MV(2+)) or both has been prepared and characterized by elemental analyses, XRD, and optical and vibrational spectroscopy. Incorporation of Ru(bpy)(3)(2+) and MV(2+) is confirmed by the increase of the distance between the titanate layers. The presence of Ru(bpy)(3)(2+) in the material is also revealed in optical spectroscopy where the ligand to metal charge transfer band appearing at λ(max) 460 nm is observed. Also incorporation of MV(2+) leads to the observation of the charge transfer complex band with the titanate host from 350 to 650 nm. These solids are active for the photocatalytic hydrogen generation from water when colloidal platinum as catalyst and EDTA as sacrificial electron donor are present in the solution. The maximum efficiency was obtained for a solid consisting of layered titanate containing a 10.2 wt.% loading of Ru(bpy)(3)(2+) incorporated in the titanate layers and MV(2+) and Pt nanoparticles in the aqueous solution. This heterogeneous system produced about one-half the hydrogen generated for the conventional homogeneous system where all the components [Ru(bpy)(3)(2+), MV(2+), Pt, and EDTA] are in solution, with the advantage that it can be used as film or recovered by filtration from the aqueous medium.

Standardized peptidome profiling of human serum for the detection of pancreatic cancer.

OBJECTIVE: To establish new biomarkers for accurate diagnosis of pancreatic cancer (PC) using a standardized serum peptidome profiling and compare the results with those from the tumor marker, CA 19-9. METHODS: Serum samples from 102 patients (55 with chronic pancreatitis and 47 with PC) and 56 healthy controls were collected and analyzed following a protocol that was rigorously designed to prevent preanalytical variation. Serum peptides were extracted using immobilized copper ion chromatography on a robotic platform. Mass spectra were acquired by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry on an Autoflex II spectrometer (Bruker Daltonics, Bremen, Germany). Statistical analysis was performed using the Clinprotools 2.2 software (Bruker Daltonics) and the SPSS 15.0 software (SPSS Inc, Chicago, Ill). RESULTS: Standardized peptidome profiling showed a median coefficient of variation of 11.6% calculated using all the extracted peptides and negligible influence of sex and age on peptidome profiles. The diagnostic sensitivity was 89.9%, and the diagnostic specificity was 92.7%, using 2 serum features and CA 19-9 serum concentration. Healthy controls were differentiated from patients with PC and chronic pancreatitis, with the use of 3 features of the peptidome (diagnostic sensitivity, 98.2%; diagnostic specificity, 97.1%). CONCLUSIONS: Standardized serum peptidome profiling could be a useful tool to improve biochemical diagnosis of PC in combination with the classic tumor marker, CA 19-9.

Photochemistry of gold nanoparticles functionalized with an iron(II) terpyridine complex. An integrated visible light photocatalyst for hydrogen generation.

Gold nanoparticles functionalized with iron(II) terpyridine complexes undergo upon laser flash excitation long-lived charge separation in both conventional organic solvents and ionic liquids. The nature of the transient species depends on the laser excitation wavelength, 308 (Fe(tpyR)(2)(3+) and Au-) or 532 nm (solvated e-). No transients in the microsecond timescale are observed in acetonitrile upon excitation of gold nanoparticles lacking iron(ii) terpyridine complexes. The photogeneration of long-lived transients upon irradiation of these functional gold nanoparticles has been applied to develop an integrated (light harvester plus catalyst) visible-light photocatalysts for H2 generation from water that does not need methyl viologen as an electron relay.