To evaluate disease activity statuses' (DAS') impact on systemic lupus erythematosus (SLE) outcomes.
Four DAS were defined: remission off-therapy: SLE Disease Activity Index (SLEDAI)=0, no prednisone ...or immunosuppressive drugs (IS); remission on-therapy: SLEDAI=0, prednisone ≤5 mg/day and/or IS (maintenance); low (L) DAS: SLEDAI ≤4, prednisone ≤7.5 mg/day and/or IS (maintenance); non-optimally controlled: SLEDAI >4 and/or prednisone >7.5 mg/day and/or IS (induction). Antimalarials were allowed in all. Predefined outcomes were mortality, new damage (increase of at least one Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) damage index (SDI) point) and severe new damage (increase of at least 3 SDI points). Univariable and multivariable Cox regression models were performed to define the impact of DAS, as time-dependent variable, on these outcomes.
1350 patients were included, 79 died during follow-up, 606 presented new and 177 severe new damage. In multivariable analyses, remission (on/off-therapy) was associated with a lower risk of new (HR 0.60; 95% CI 0.43 to 0.85), and of severe new damage (HR 0.32; 95% CI 0.15 to 0.68); low disease activity status (LDAS) was associated with a lower risk of new damage (HR 0.66; 95% CI 0.48 to 0.93) compared with non-optimally controlled. No significant effect on mortality was observed.
Remission was associated with a lower risk of new and severe new damage; LDAS with a lower risk of new damage after adjusting for other damage confounders.
Biomass comes from different sources and can be used for different purposes, for electricity generation, for transport fuels, for heating, as well as for the manufacturing of bio-based products. ...Nowadays, the European framework for energy calls for the use of biomass in electricity, heat, and transport (fuels), to reach 20% of all energy use from renewable sources by 2020. Therefore, the use of biomass should roughly have to double. If this is the case, large amounts of biomass will be mobilized and handling problems are expected to grow aligned with the increased use of biomass. Biomass is characterized because it does not flow well, packs easily, it can knit together, it is very dusty, and it is prone to self-heating and self-ignition, among others. If more research is not conducted on the characterization of the behavioral properties of biomasses, the sustainability of supply chains could be then severely affected.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The cleaning (H
2S removal) and upgrading (CO
2/CH
4 ratio adjustment for syngas synthesis) of biogas by pressure swing adsorption (PSA) with thermal desorption using two synthetic molecular sieves ...(5A and 13X) and a natural zeolite (Clinoptilolite) as adsorbent materials have been studied. Prior to use, zeolites were activated according to literature methods and supplier recommendations in order to dispose of adsorbed gases and soluble impurities which may compete with H
2S and CO
2 for the active sites of the zeolites. The behaviours of the zeolites have been compared by using three basic parameters: selectivity, capacity and regenerability. The experimental results indicate that Clinoptilolite is the best material choice because it is simultaneously suitable both for the purification and upgrading of biogas. For a CH
4/CO
2/H
2S biogas molar composition of 59.95/39.95/0.10, the breakthrough capacity of Clinoptilolite at 1
cm/s biogas feeding velocity, 7
bar and 25
°C is 1.39
mgH
2S/g Clinoptilolite, twice the adsorption capacity of the synthetic molecular sieves subjected to study. The high CO
2 adsorption capacity observed (173.9
mg CO
2/g Clinoptilolite) makes the adjusting of CH
4/CO
2 ratio in the biogas possible. Additionally, Clinoptilolite is completely regenerable and stable through several adsorption–desorption cycles which, together with its abundance and low cost, make this process highly attractive from an economical standpoint. Finally, this study demonstrates the importance of the selection of the optimal activation method of natural zeolites in order to offset variable composition and low purity often responsible for poorer separation performance compared to synthetic zeolites.
•A process of optimization is carried out to an evacuated tube solar collector.•The optimization integrates simulated annealing and computational fluid dynamics.•Design of experiments and ...computational fluid dynamics found meaningful parameters.•Optimal geometry and lower cost of the evacuated tube solar collector are obtained.•Comparison of thermal and hydraulic performance of optimal geometries is discussed.
In this work, the optimization of a low temperature, water-in-glass, evacuated tubes solar collector is presented. The process of optimization combined the simulated annealing method and a computational fluid dynamics model. The numerical study was carried out in three dimensions, steady-state and laminar regime. A design of experiments study via computational fluid dynamics was carried out with two levels and five parameters, 25, the parameters with significance in the performance of the collector were found from a commercial collector. This collector was used as base case in the process of optimization. In the optimization process, the absorber area was analyzed under three different cases because of the combination of geometrical parameters: length, diameter and number of tubes. Thus, 259 different collector geometries were constructed and modeled. Results from the design of experiments showed that the significant parameters on the thermal performance of the solar collector are: the diameter of the tubes, the absorber area, and the mass flow rate. Results of the optimization process showed that the minimum absorber area for an optimal geometry is 2.49 m2, which is 19.4% lower than the commercial geometry considering the same outlet temperature. The diameter of the tubes increased around 30%, the length of the tubes decreased 40%, the cost of the optimal geometry and the number of evacuated tubes decreased 38.9% and the thermal efficiency increased 26.3%, compared to the commercial geometry. The results of this work can be helpful in further specific applications where the maximum performance and the minimum costs are important, such as: the design of low temperature, water-in-glass, evacuated tubes solar collector networks for heating water in swimming pools, buildings, hospitals and industries.
Macroscopic staining in anatomical samples of the central nervous system is a technique that has been used for decades to achieve better differentiation of multiple gray matter structures, such as ...the cortex, basal ganglia, and cerebellar nuclei. Staining methods are based on using the different components of the brain, mainly the lipids present in the white matter. These techniques have been progressively forgotten while computer renderings are increasing; however, as a primary exposure to surgical anatomy, stained brain specimens are considered a helpful tool. We aim to summarize different staining techniques, their principles, and their current applications for neuroanatomy learning purposes. In total, four gray matter staining protocol descriptions (Mulligan's, Roberts's, Alston's, and Prussian Blue) were performed, as well as Likert scale surveys of second-year medical students about their perceptions of the stained sections. The results showed that the different macroscopic stains for brain tissue are based on lipid and reactant interactions, intending to increase the white matter (WM) and gray matter (GM) contrast. The search also showed that most staining protocols would take 2 days to develop. Efficient preservation options include submerging the sections in formaldehyde solutions, formaldehyde-free solutions, ethanol, or applying plastination techniques. Based on the student's perspective, the stained slices seem to be a valuable alternative to facilitate the study and identification of the basal ganglia and their relationships with the white matter (from 51.2 to 72% based on the Likert scale) compared with the non-stained sections. In conclusion, macroscopic staining of brain tissue continues to be a valuable tool for comprehensively studying the brain. Further research is needed to determine the efficacy of stained specimens as teaching tools.
Simultaneous energy integration and intensification of the hydrotreating process to produce biojet fuel from jatropha curcas.
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•Biojet fuel: promising alternative for sustainable ...development of aviation sector.•Hydrotreating process can be optimized to reduce its energy consumption.•Energy integration and intensification of hydrotreating process are proposed.•A decreasing of 87% in CO2 emissions is obtained.
The sustainable development of aviation sector relies on four strategies, being the use of biojet fuel as the most promising. There are different processes to produce biojet fuel; however, the hydrotreating process is certified by ASTM for its use in commercial and passenger flights. This process has several opportunity areas to decrease energy consumption and environmental impact. In this work, we propose the simultaneous energy integration and intensification of the hydrotreating process to produce biojet fuel from jatropha curcas oil. The released energy by the hydrodeoxygenation reactor is used to perform the energy integration of the process. Moreover, the separation zone of the process is intensified through thermally coupled distillation sequences, which are optimized with a multiobjective stochastic strategy. Results show that it is possible to reduce significantly the energy requirements of the process when energy integration is performed; however, the decreasing in the service costs is accompanied by an increasing in the equipment costs. On the other hand, the intensification of the separation zone does not lead to a decreasing in energy consumption. Therefore, net effect of both strategies on the total annual cost and biojet fuel prices is small, but significant decreasing in CO2 emissions is achieved.
The synthesis of lactic acid by alkaline hydrothermal conversion of glycerol at high glycerol concentrations under autogenous pressure is described. Temperature (250−290 °C), NaOH/glycerol molar ...ratio (1.1−1.75), glycerol concentration (2.5−3.5 M), and reaction time (30−250 min) have been the variables studied with temperature and NaOH/glycerol molar ratio having the major influence. An 84.5% lactic acid (as sodium lactate) yield is obtained at 280 °C and 90 min with a 2.5 M glycerol concentration and a 1.1 NaOH/glycerol molar ratio. The same yield is obtained starting from crude glycerol from biodiesel production as raw material. Sodium acrylate, oxalate and formate, and sodium carbonate have been identified as the main byproducts with carbonate being the major one. Several conversion routes based on the experimental results are proposed. A process for lactic acid separation based on electrodialysis is outlined.
This work reports the electrochemical properties of graphene supercapacitors that employ flexible graphene electrodes (FGEs) coated by V2O5 (VOx) or carbon nanotubes (CNTs)/VOx layers. According to ...scanning electron microscopy images, the morphology of VOx consists in micro-ribbons with lengths of 20–45 μm and widths from 5 to 12 μm. The CNTs form interconnected long fibers, which were functionalized with carboxylic groups for producing defects. We demonstrated that the gel electrolyte used for the supercapacitors produces V4+-oxygen vacancies (VO) defects. Both, the CNTs and V4+-VO defects act as redox centers, which delay the current discharge in the supercapacitors. The presence of the carboxylic groups, defects in CNTs, defects in VOx, and oxidation states (V4+ and V5+), were confirmed by the UV–Vis, XPS, and FTIR techniques. The electrochemical characterization of the supercapacitors indicated that the devices made with FGEs coated by VOx or CNTs/VOx layers produced constant voltages of 0.14 V and 0.38 V during 535 and 593 min, respectively. The increase of voltage is explained by the increase of surface area and by the extra redox centers (defects) introduced by the CNTs. The results indicated that the CNTs/VOx layer increases the voltage and discharge times of the graphene supercapacitors, which can be of interest for the development of graphene systems with high charge storage capabilities.
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•Flexible Supercapacitors (SCs) were made with graphene electrodes.•The SCs with CNTs and V4+-VO defects in their electrodes had prolonged discharge times.•A maximum constant voltage discharge of 0.38 V was observed for 10 h.
: Family dementia caregivers often suffer from an immense toll of grief while caring for their loved ones. We sought to identify the clinical relationship between grief, depression and mindfulness ...and identify neural predictors of symptomatology and improvement.
: Twenty three family dementia caregivers were assessed at baseline for grief, mindfulness and depression, of which 17 underwent functional magnetic resonance imaging (fMRI). During fMRI, caregivers were shown faces of either their dementia-stricken relative or that of a stranger, paired with grief-related or neutral words. In nine subjects, post fMRI scans were also obtained after 4 weeks of either guided imagery or relaxation. Robust regression was used to predict changes in symptoms with longitudinal brain activation (BA) changes as the dependent variable.
: Grief and depression symptoms were correlated (
= 0.50,
= 0.01), and both were negatively correlated with mindfulness (
= -0.70,
= 0.0002;
= -0.52,
= 0.01). Relative to viewing strangers, caregivers showed pictures of their loved ones (picture factor) exhibited increased activation in the dorsal anterior cingulate gyrus and precuneus. Improvement in grief but not mindfulness or depression was predicted by increased relative BA in the precuneus and anterior cingulate (different subregions from baseline). Viewing grief-related vs. neutral words elicited activity in the medial prefrontal cortex and precuneus.
: Caregiver grief, depression and mindfulness are interrelated but have at least partially nonoverlapping neural mechanisms. Picture and word stimuli related to caregiver grief evoked brain activity in regions previously identified with bereavement grief. These activation foci might be useful as biomarkers of treatment response.
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