Impacts of age and sex on retinal layer thicknesses measured by spectral domain optical coherence tomography with Spectralis

Objective: To examine differences in individual retinal layer thicknesses measured by spectral domain optical coherence tomography (SD-OCT) (Spectralis®) produced with age and according to sex. Design: Cross-sectional, observational study. Methods: The study was conducted in 297 eyes of 297 healthy subjects aged 18 to 87 years. In one randomly selected eye of each participant the volume and mean thicknesses of the different macular layers were measured by SD-OCT using the instrument's macular segmentation software. Main outcome measures: Volume and mean thickness of macular retinal nerve fiber layer (mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), retinal pigmentary epithelium (RPE) and photoreceptor layer (PR). Results: Retinal thickness was reduced by 0.24 μm for every one year of age. Age adjusted linear regression analysis revealed mean GCL, IPL, ONL and PR thickness reductions and a mean OPL thickness increase with age. Women had significantly lower mean GCL, IPL, INL, ONL and PR thicknesses and volumes and a significantly greater mRNFL volume than men. Conclusion: The thickness of most retinal layers varies both with age and according to sex. Longitudinal studies are needed to determine the rate of layer thinning produced with age

Progress on Catalyst Development for the Steam Reforming of Biomass and Waste Plastics Pyrolysis Volatiles: A Review

[EN]n recent decades, the production of H-2 from biomass, waste plastics, and their mixtures has attracted increasing attention in the literature in order to overcome the environmental problems associated with global warming and CO2 emissions caused by conventional H-2 production processes. In this regard, the strategy based on pyrolysis and in-line catalytic reforming allows for obtaining high H-2 production from a wide variety of feedstocks. In addition, it provides several advantages compared to other thermochemical routes such as steam gasification, making it suitable for its further industrial implementation. This review analyzes the fundamental aspects involving the process of pyrolysis-reforming of biomass and waste plastics. However, the optimum design of transition metal based reforming catalysts is the bottleneck in the development of the process and final H-2 production. Accordingly, this review focuses especially on the influence the catalytic materials (support, promoters, and active phase), synthesis methods, and pyrolysis-reforming conditions have on the process performance. The results reported in the literature for the steam reforming of the volatiles derived from biomass, plastic wastes, and biomass/plastics mixtures on different metal based catalysts have been compared and analyzed in terms of H-2 production.This work was carried out with the financial support from Spain's Ministries of Science, Innovation and Universities (Grant RTI2018-101678-B-I00 (MCIU/AEI/FEDER, UE) and Grant RTI2018-098283-J-I00 (MCIU/AEI/FEDER, UE)) and Science and Innovation (Grant PID2019-107357RB-I00 (AEI/FEDER, UE)) and the Basque Government (Grants IT1218-19 and KK-2020/00107). Moreover, this project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 823745

Removal of NO at low concentration from air in urban built environments by activated miscanthus biochar

This work presents an innovative and sustainable approach to remove NO emissions from urban ambient air in confined areas (underground parking areas or tunnels) using low-cost activated carbons obtained from Miscanthus biochar (MSP700) by physical activation (with CO2 or steam) at temperatures ranging from 800 to 900 °C. The NO removal capacity of the activated biochars was evaluated under different conditions (temperature, humidity and oxygen concentration) and compared against a commercial activated carbon. This last material showed a clear dependence on oxygen concentration and temperature, exhibiting a maximum capacity of 72.6% in air at 20 °C, whilst, its capacity notably decreased at higher temperatures, revealing that physical NO adsorption is the limiting step for the commercial sample that presents limited oxygen surface functionalities. In contrast, MSP700-activated biochars reached nearly complete NO removal (99.9%) at all tested temperatures in air ambient. Those MSP700-derived carbons only required low oxygen concentration (4 vol%) in the gas stream to achieve the full NO removal at 20 °C. Moreover, they also showed an excellent performance in the presence of H2O, reaching NO removal higher than 96%. This remarkable activity results from the abundance of basic oxygenated surface groups, which act as active sites for NO/O2 adsorption, along with the presence of a homogeneous microporosity of 6 Å, which enables intimate contact between NO and O2. These features promote the oxidation of NO to NO2, which is further retained over the carbon surface. Therefore, the activated biochars studied here could be considered promising materials for the efficient removal of NO at low concentrations from air at moderate temperatures, thus closely approaching real-life conditions in confined spaces.J. Fermoso gratefully acknowledges the financial support from the Comunidad de Madrid through the Talent Attraction Programme (2018-T1/AMB-10023)

Tuning pyrolysis temperature to improve the in-line steam reforming catalyst activity and stability

This study analyzes the two-step process of biomass pyrolysis and in-line steam reforming for the production of H2. In order to evaluate the effect of the volatile composition on the commercial Ni/Al2O3 catalyst performance and stability, biomass pyrolysis step was conducted at different temperatures (500–800 °C). The analysis of the deactivated catalysts has also allowed identifying the main bio-oil compounds responsible for catalyst decay (coke precursors). Pyrolysis temperature allows modifying the composition of the volatile stream that is subsequently reformed at 600 °C. An increase in pyrolysis temperature to 800 °C improves considerably the production of both H2 and gaseous stream at the initial reaction stages, reaching values of 12.95 wt% and 2.23 Nm3 kg−1, respectively. Catalyst stability is also considerably improved when pyrolysis temperature is increased due to the lower bio-oil yield and its different composition at high temperatures. Coke was the main cause of catalyst deactivation. Besides, the nature of the coke deposited is influenced by the composition of the pyrolysis volatiles, with encapsulating coke being formed by the adsorption and subsequent condensation of all hydrocarbons (oxygenated and non-oxygenated ones) preferably at low temperatures, whereas filamentous coke is formed when the concentrations of CO and light hydrocarbons in the volatile stream are increased at 800 °C.This work was carried out with the financial support of the grants RTI2018–101678-B-I00, RTI2018–098283-J-I00 and PID2019–107357RB-I00 funded by MCIN/AEI/ 10.13039/501100011033 and “ERDF, a way of making Europe”, and the grant IT1645–22 funded by the Basque Government. Moreover, this project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 823745

Role of temperature in the biomass steam pyrolysis in a conical spouted bed reactor

[EN] The steam pyrolysis of pinewood sawdust has been conducted in a bench scale plant provided with a conical spouted bed reactor (CSBR). This process is of uttermost relevance for the in-line valorisation of pyrolysis volatiles, specifically for their catalytic steam reforming for hydrogen production. The influence of temperature on the product yields has been analyzed in the 500-800 degrees C range. A detailed analysis of the volatile stream (condensable and non-condensable components) has been carried out by chromatographic techniques, and the char samples have been characterized by ultimate and proximate analyses, N-2 adsorption-desorption, and Scanning Electron Microscopy. A high bio-oil yield was obtained at 500 degrees C (75.4 wt%), which is evidence of the suitable features of the conical spouted bed reactor for this process. As temperature was increased, higher gas and lower liquid and char yields were obtained. Steam was fully inert at low pyrolysis temperatures (500-600 degrees C), and only had a little influence at 700 degrees C due to the low gas residence time in the conical spouted bed reactor. At 800 degrees C, the reaction mechanism was controlled by gasification reactions. The composition of the liquid fraction was considerably influenced by pyrolysis temperature, with a less oxygenated stream as temperature was increased. Thus, phenolic compounds accounted for the major fraction at low pyrolysis temperatures, whereas hydrocarbons prevailed at 800 degrees C. The char obtained in the whole temperature range can be further used as active carbon or energy source.This work was carried out with the financial support from Spain's ministries of Science, Innovation and Universities (RTI2018-101678-B-I0 0 (MCIU/AEI/FEDER, UE) and RTI2018-098283-J-I0 0 (MCIU/AEI/FEDER, UE) ) and Science and Innovation (PID2019-107357RB-I0 0 (AEI/FEDER, UE) ) and the Basque Government (IT1218-19 and KK-2020/00107) . Moreover, this project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 823745

Normative database for separate inner retinal layers thickness using spectral domain optical coherence tomography in Caucasian population

Purpose: Develop the first normative database of the thickness of every inner retinal layer in the macular area in a healthy, Caucasian population between 18 to 87 years old, using Spectralis Optical Coherence Tomography (OCT). Methods: On this transversal, observational study, 300 patients between 18 to 87 years old and without an ophthalmological condition were recruited. Macular OCT scans were performed on all patients (Spectralis OCT, Heidelberg Engineering). An axial length measurement, and keratometry were performed using an optical biometer. The volume and thickness of the different macular sectors of the inner retinal layers (retinal nerve fiber layer (RNFL), ganglion cells layer (CGL) and inner plexiform layer (IPL)) were analyzed with the Spectralis OCT segmentation software. An eye was randomly selected for each patient. Results: 297 patients (179 females and 118 males) were included in the study. The mean age was 56.07 years (range: 40.50-72). The multivariate analysis showed a positive correlation between the RNFL thickness and the axial length (p < 0.001). The mean central retinal thickness was 278.2 Mm (range: 266-291), the mean central RNFL thickness was 12.61 Mm (range: 11-14), the mean central CGL thickness was 17.63 Mm (range: 14-21) and the mean central IPL thickness was 22.02 Mm (range: 20-25). The multivariate analysis showed a negative correlation between age and CGL thickness and inner IPL thickness (p< 0.001). Conclusion: This study provides a normative database of the volume of each of the inner retinal layers on a Caucasian population